WO2023193254A1 - 解码方法、编码方法、解码器以及编码器 - Google Patents

解码方法、编码方法、解码器以及编码器 Download PDF

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WO2023193254A1
WO2023193254A1 PCT/CN2022/085898 CN2022085898W WO2023193254A1 WO 2023193254 A1 WO2023193254 A1 WO 2023193254A1 CN 2022085898 W CN2022085898 W CN 2022085898W WO 2023193254 A1 WO2023193254 A1 WO 2023193254A1
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mip
mode
current block
optimal
block
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French (fr)
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谢志煌
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Guangdong Oppo Mobile Telecommunications Corp Ltd
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Guangdong Oppo Mobile Telecommunications Corp Ltd
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Priority to PCT/CN2022/085898 priority Critical patent/WO2023193254A1/zh
Priority to JP2024558335A priority patent/JP2025511315A/ja
Priority to EP22936192.8A priority patent/EP4507295A4/en
Priority to CN202280094572.3A priority patent/CN119032562A/zh
Publication of WO2023193254A1 publication Critical patent/WO2023193254A1/zh
Priority to US18/898,188 priority patent/US20250024027A1/en
Priority to MX2024012272A priority patent/MX2024012272A/es
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
    • H04N19/103—Selection of coding mode or of prediction mode
    • H04N19/109—Selection of coding mode or of prediction mode among a plurality of temporal predictive coding modes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
    • H04N19/103—Selection of coding mode or of prediction mode
    • H04N19/11—Selection of coding mode or of prediction mode among a plurality of spatial predictive coding modes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
    • H04N19/103—Selection of coding mode or of prediction mode
    • H04N19/105—Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/134—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or criterion affecting or controlling the adaptive coding
    • H04N19/146—Data rate or code amount at the encoder output
    • H04N19/147—Data rate or code amount at the encoder output according to rate distortion criteria
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/169—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding
    • H04N19/17—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being an image region, e.g. an object
    • H04N19/176—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being an image region, e.g. an object the region being a block, e.g. a macroblock
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/189—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the adaptation method, adaptation tool or adaptation type used for the adaptive coding
    • H04N19/196—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the adaptation method, adaptation tool or adaptation type used for the adaptive coding being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/50—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding
    • H04N19/593—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding involving spatial prediction techniques
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/60—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using transform coding
    • H04N19/61—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using transform coding in combination with predictive coding

Definitions

  • the embodiments of the present application relate to the technical field of image and video encoding and decoding, and more specifically, to a decoding method, an encoding method, a decoder, and an encoder.
  • Digital video compression technology mainly compresses huge digital image and video data to facilitate transmission and storage.
  • Digital video compression standards can implement video decompression technology, there is still a need to pursue better digital video decompression technology to Improving compression efficiency.
  • Embodiments of the present application provide a decoding method, encoding method, decoder and encoder, which can improve compression efficiency.
  • this application provides a decoding method, including:
  • the distortion cost of the multiple MIP modes includes the distortion cost obtained by using the multiple MIP modes to predict samples in the template area adjacent to the current block;
  • a reconstructed block of the current block is obtained.
  • this application provides an encoding method, including:
  • the distortion cost of the multiple MIP modes includes the distortion cost obtained by using the multiple MIP modes to predict samples in the template area adjacent to the current block;
  • this application provides a decoder, including:
  • the parsing unit is used to parse the code stream to obtain the residual block of the current block in the current sequence
  • Prediction unit used for:
  • the distortion cost of the multiple MIP modes includes the distortion cost obtained by using the multiple MIP modes to predict samples in the template area adjacent to the current block;
  • a reconstruction unit configured to obtain a reconstruction block of the current block based on the residual block of the current block and the prediction block of the current block.
  • this application provides an encoder, including:
  • Prediction unit used for:
  • the distortion cost of the multiple MIP modes includes the distortion cost obtained by using the multiple MIP modes to predict samples in the template area adjacent to the current block;
  • a residual unit configured to obtain a residual block of the current block based on the prediction block of the current block and the original block of the current block;
  • a coding unit used to code the residual block of the current block to obtain the code stream of the current sequence.
  • this application provides a decoder, including:
  • a processor adapted to implement computer instructions
  • Computer-readable storage medium stores computer instructions, and the computer instructions are suitable for the processor to load and execute the decoding method in the above-mentioned first aspect or its various implementations.
  • processors there are one or more processors and one or more memories.
  • the computer-readable storage medium may be integrated with the processor, or the computer-readable storage medium may be provided separately from the processor.
  • this application provides an encoder, including:
  • a processor adapted to implement computer instructions
  • the computer-readable storage medium stores computer instructions, and the computer instructions are suitable for the processor to load and execute the encoding method in the above-mentioned second aspect or its respective implementations.
  • processors there are one or more processors and one or more memories.
  • the computer-readable storage medium may be integrated with the processor, or the computer-readable storage medium may be provided separately from the processor.
  • the present application provides a computer-readable storage medium that stores computer instructions.
  • the computer instructions When the computer instructions are read and executed by a processor of a computer device, the computer device performs the above-mentioned first aspect.
  • the present application provides a code stream, which code stream relates to the code stream in the above-mentioned first aspect or the code stream involved in the above-mentioned second aspect.
  • the decoder determines the intra prediction mode of the current block, it determines the optimal MIP mode for predicting the current block based on the distortion costs of multiple MIP modes, and determines the optimal MIP mode based on the optimal MIP mode.
  • the intra prediction mode of the current block is equivalent to preventing the decoder from obtaining the MIP mode by parsing the code stream. Compared with the traditional MIP technology, it can effectively reduce the bit overhead at the coding unit level, thereby improving decompression. efficiency.
  • Figure 1 is a schematic block diagram of a coding framework provided by an embodiment of the present application.
  • FIG. 2 is a schematic diagram of the MIP mode provided by the embodiment of the present application.
  • FIG. 3 is a schematic diagram of a template used by TIMD provided by an embodiment of the present application.
  • Figure 4 is a schematic block diagram of a decoding framework provided by an embodiment of the present application.
  • Figure 5 is a schematic flowchart of a decoding method provided by an embodiment of the present application.
  • Figure 6 is a schematic flow chart of the encoding method provided by the embodiment of the present application.
  • Figure 7 is a schematic block diagram of a decoder provided by an embodiment of the present application.
  • Figure 8 is a schematic block diagram of an encoder provided by an embodiment of the present application.
  • Figure 9 is a schematic block diagram of an electronic device provided by an embodiment of the present application.
  • the solutions provided by the embodiments of this application can be applied to the field of digital video coding technology, including but not limited to: image coding and decoding, video coding and decoding, hardware video coding and decoding, dedicated circuit video coding and decoding, and real-time video coding and decoding. field.
  • the solution provided by the embodiments of the present application can be combined with the Audio Video Coding Standard (AVS), the second generation AVS standard (AVS2) or the third generation AVS standard (AVS3).
  • AVS Audio Video Coding Standard
  • VVC Very Video Coding
  • the solution provided by the embodiment of the present application can be used to perform lossy compression on images (lossy compression), or can also be used to perform lossless compression on images (lossless compression).
  • the lossless compression can be visually lossless compression (visually lossless compression) or mathematically lossless compression (mathematically lossless compression).
  • Video coding and decoding standards all adopt block-based hybrid coding framework.
  • Each frame in the video is divided into square largest coding units (LCU largest coding unit) or coding tree units (CTU Coding Tree Unit) of the same size (such as 128x128, 64x64, etc.).
  • Each maximum coding unit or coding tree unit can be divided into rectangular coding units (CU coding units) according to rules.
  • Coding units may also be divided into prediction units (PU prediction unit), transformation units (TU transform unit), etc.
  • the hybrid coding framework includes prediction, transform, quantization, entropy coding, in loop filter and other modules.
  • the prediction module includes intra prediction and inter prediction.
  • Inter-frame prediction includes motion estimation (motion estimation) and motion compensation (motion compensation).
  • Intra-frame prediction only refers to the information of the same frame image and predicts the pixel information within the current divided block. Since there is a strong similarity between adjacent frames in the video, the inter-frame prediction method is used in video coding and decoding technology to eliminate the temporal redundancy between adjacent frames, thereby improving coding efficiency.
  • Inter-frame prediction can refer to image information of different frames and use motion estimation to search for motion vector information that best matches the current divided block. The transformation converts the predicted image blocks into the frequency domain and redistributes the energy. Combined with quantization, it can remove information that is insensitive to the human eye and is used to eliminate visual redundancy.
  • Entropy coding can eliminate character redundancy based on the current context model and the probability information of the binary code stream.
  • the encoder can first read a black-and-white image or color image from the original video sequence, and then encode the black-and-white image or color image.
  • the black-and-white image may include pixels of the brightness component
  • the color image may include pixels of the chrominance component.
  • the color image may also include pixels with a brightness component.
  • the color format of the original video sequence can be luminance-chrominance (YCbCr, YUV) format or red-green-blue (Red-Green-Blue, RGB) format, etc.
  • the encoder reads a black-and-white image or a color image, it divides it into blocks respectively, and uses intra-frame prediction or inter-frame prediction for the current block to generate a predicted block of the current block.
  • the prediction block is subtracted from the original block of the current block. block to obtain a residual block, transform and quantize the residual block to obtain a quantized coefficient matrix, entropy encode the quantized coefficient matrix and output it to the code stream.
  • the decoder uses intra prediction or inter prediction for the current block to generate a prediction block of the current block.
  • the decoder parses the code stream to obtain the quantization coefficient matrix, performs inverse quantization and inverse transformation on the quantization coefficient matrix to obtain the residual block, and adds the prediction block and the residual block to obtain the reconstruction block.
  • Reconstruction blocks can be used to compose a reconstructed image, and the decoder performs loop filtering on the reconstructed image based on images or blocks to obtain a decoded image.
  • the current block can be the current coding unit (CU) or the current prediction unit (PU), etc.
  • the encoding end also requires similar operations as the decoding end to obtain the decoded image.
  • the decoded image can be used as a reference frame for inter-frame prediction for subsequent frames.
  • the block division information determined by the encoding end, mode information or parameter information such as prediction, transformation, quantization, entropy coding, loop filtering, etc., need to be output to the code stream if necessary.
  • the decoding end determines the same block division information as the encoding end through parsing and analyzing based on existing information, prediction, transformation, quantization, entropy coding, loop filtering and other mode information or parameter information, thereby ensuring the decoded image and decoding obtained by the encoding end
  • the decoded image obtained at both ends is the same.
  • the decoded image obtained at the encoding end is usually also called a reconstructed image.
  • the current block can be divided into prediction units during prediction, and the current block can be divided into transformation units during transformation.
  • the divisions between prediction units and transformation units can be the same or different.
  • the above is only the basic process of the video codec under the block-based hybrid coding framework. With the development of technology, some modules of the framework or some steps of the process may be optimized. This application is applicable to this block-based hybrid coding.
  • Figure 1 is a schematic block diagram of a coding framework 100 provided by an embodiment of the present application.
  • the coding framework 100 may include an intra prediction unit 180, an inter prediction unit 170, a residual unit 110, a transformation and quantization unit 120, an entropy coding unit 130, an inverse transformation and inverse quantization unit 140, and a loop. filter unit 150.
  • the encoding framework 100 may also include a decoded image buffer unit 160. This coding framework 100 may also be called a hybrid framework coding mode.
  • the intra prediction unit 180 or the inter prediction unit 170 may predict the image block to be encoded to output the prediction block.
  • the residual unit 110 may calculate a residual block, that is, a difference value between the prediction block and the image block to be encoded, based on the prediction block and the image block to be encoded.
  • the transformation and quantization unit 120 is used to perform operations such as transformation and quantization on the residual block to remove information that is insensitive to the human eye, thereby eliminating visual redundancy.
  • the residual block before transformation and quantization by the transformation and quantization unit 120 may be called a time domain residual block
  • the time domain residual block after transformation and quantization by the transformation and quantization unit 120 may be called a frequency residual block. or frequency domain residual block.
  • the entropy encoding unit 130 may output a code stream based on the transform quantization coefficient. For example, the entropy encoding unit 130 may eliminate character redundancy according to the target context model and probability information of the binary code stream. For example, the entropy coding unit 130 may be used for context-based adaptive binary arithmetic entropy coding (CABAC). The entropy encoding unit 130 may also be called a header information encoding unit.
  • CABAC context-based adaptive binary arithmetic entropy coding
  • the image block to be encoded can also be called an original image block or a target image block, and a prediction block can also be called a predicted image block or image prediction block, and can also be called a prediction signal or prediction information.
  • the reconstruction block may also be called a reconstructed image block or an image reconstruction block, and may also be called a reconstructed signal or reconstructed information.
  • the image block to be encoded may also be called an encoding block or a coded image block, and for the decoding end, the image block to be encoded may also be called a decoding block or a decoded image block.
  • the image block to be encoded may be a CTU or a CU.
  • the encoding framework 100 calculates the residual between the prediction block and the image block to be encoded to obtain the residual block, and then transmits the residual block to the decoder through processes such as transformation and quantization.
  • the decoder receives and parses the code stream, it obtains the residual block through steps such as inverse transformation and inverse quantization.
  • the prediction block predicted by the decoder is superimposed on the residual block to obtain the reconstructed block.
  • the inverse transform and inverse quantization unit 140, the loop filter unit 150 and the decoded image buffer unit 160 in the encoding framework 100 may be used to form a decoder.
  • the intra prediction unit 180 or the inter prediction unit 170 can predict the image block to be encoded based on the existing reconstructed block, thereby ensuring that the encoding end and the decoding end have consistent understanding of the reference frame.
  • the encoder can replicate the decoder's processing loop and thus produce the same predictions as the decoder.
  • the quantized transform coefficients are inversely transformed and inversely quantized by the inverse transform and inverse quantization unit 140 to copy the approximate residual block at the decoding side.
  • the approximate residual block After the approximate residual block is added to the prediction block, it can pass through the loop filtering unit 150 to smoothly filter out block effects and other effects caused by block-based processing and quantization.
  • the image blocks output by the loop filter unit 150 may be stored in the decoded image buffer unit 160 for use in prediction of subsequent images.
  • Figure 1 is only an example of the present application and should not be understood as a limitation of the present application.
  • the loop filtering unit 150 in the coding framework 100 may include a deblocking filter (DBF) and sample adaptive compensation filtering (SAO).
  • DBF deblocking filter
  • SAO sample adaptive compensation filtering
  • the encoding framework 100 may adopt a neural network-based loop filtering algorithm to improve video compression efficiency.
  • the coding framework 100 may be a video coding hybrid framework based on a deep learning neural network.
  • a model based on a convolutional neural network can be used to calculate the result of filtering the pixels based on the deblocking filter and sample adaptive compensation filtering.
  • the network structures of the loop filter unit 150 on the luminance component and the chrominance component may be the same or different. Considering that the brightness component contains more visual information, the brightness component can also be used to guide the filtering of the chroma component to improve the reconstruction quality of the chroma component.
  • intra-frame prediction only refers to the information of the same frame image and predicts pixel information within the image block to be encoded to eliminate spatial redundancy;
  • the frame used for intra-frame prediction can be an I frame.
  • the image block to be encoded can refer to the upper left image block, the upper image block and the left image block as reference information to predict the image block to be encoded, and the image block to be encoded The block is used as reference information for the next image block, so that the entire image can be predicted.
  • the input digital video is in color format, such as YUV 4:2:0 format, then every 4 pixels of each image frame of the digital video consists of 4 Y components and 2 UV components.
  • the encoding framework can components (i.e. luma blocks) and UV components (i.e. chrominance blocks) are encoded separately.
  • the decoding end can also perform corresponding decoding according to the format.
  • the process involved in the MIP mode can be divided into three main steps, which are the down-sampling process, the matrix multiplication process and the up-sampling process.
  • the spatially adjacent reconstructed samples are first downsampled through the downsampling process, and then the downsampled sample sequence is used as the input vector of the matrix multiplication process, that is, the output vector of the downsampling process is used as the input of the matrix multiplication process.
  • vector multiply the preset matrix and add the offset vector, and output the calculated sample vector; finally, use the output vector of the matrix multiplication process as the input vector of the upsampling process, and obtain the final result through upsampling. prediction block.
  • FIG. 2 is a schematic diagram of the MIP mode provided by the embodiment of the present application.
  • the MIP mode obtains the upper-adjacent down-sampled reconstructed sample vector bdry top by averaging the reconstructed samples adjacent to the top of the current coding unit, and obtains the left-adjacent down-sampled vector bdry top by averaging the reconstructed samples adjacent to the left.
  • Sampling reconstructed sample vector bdry left After obtaining bdry top and bdry left , use them as the input vector bdry red of the matrix multiplication process.
  • the sample can be obtained through the top row vector bdry top red , bdry left , A k ⁇ bdry red +b k based on bdry red Vector, where A k is a preset matrix, b k is a preset bias vector, and k is the index of the MIP mode.
  • a k is a preset matrix
  • b k is a preset bias vector
  • k is the index of the MIP mode.
  • MIP in order to predict a block with width W and height H, MIP requires H reconstructed pixels in the left column of the current block and W reconstructed pixels in the upper row of the current block as input.
  • MIP generates prediction blocks in the following three steps: reference pixel averaging (Averaging), matrix multiplication (Matrix Vector Multiplication) and interpolation (Interpolation).
  • the core of MIP is matrix multiplication, which can be thought of as a process of generating prediction blocks using input pixels (reference pixels) in a matrix multiplication manner.
  • MIP provides a variety of matrices. Different prediction methods can be reflected in different matrices. Using different matrices for the same input pixel will yield different results.
  • reference pixel averaging and interpolation is a design that compromises performance and complexity. For larger blocks, an effect similar to downsampling can be achieved by reference pixel averaging, allowing the input to be adapted to a smaller matrix, while interpolation achieves an upsampling effect. In this way, there is no need to provide MIP matrices for blocks of each size, but only matrices of one or several specific sizes. As the demand for compression performance increases and hardware capabilities improve, more complex MIPs may appear in the next generation of standards.
  • the MIP mode can be simplified from the neural network.
  • the matrix used can be obtained based on training. Therefore, the MIP mode has strong generalization ability and prediction effects that traditional prediction models cannot achieve.
  • the MIP mode can be a model obtained through multiple simplifications of hardware and software complexity for an intra-frame prediction model based on a neural network. Based on a large number of training samples, multiple prediction modes represent a variety of models and parameters, which can compare Good coverage of natural sequences of textures.
  • MIP is somewhat similar to planar mode, but obviously MIP is more complex and more flexible than planar mode.
  • the number of MIP modes may be different. For example, for a coding unit of 4x4 size, the MIP mode has 16 prediction modes; for a coding unit of 8x8 with width equal to 4 or height equal to 4, the MIP mode has 8 prediction modes; for coding units of other sizes, the MIP mode has 6 prediction modes.
  • MIP mode has a transpose function. For prediction modes that conform to the current size, MIP mode can try transposition calculations on the encoder side. Therefore, MIP mode not only requires a flag bit to indicate whether the current coding unit uses MIP mode, but also, if the current coding unit uses MIP mode, an additional transposed flag bit needs to be transmitted to the decoder.
  • the transposed flag bit of MIP is binarized by fixed-length encoding (Fixed Length, FL), and the length is 1.
  • the mode index of MIP is binarized by truncated binary encoding (Truncated Binary, TB).
  • the codec also uses the operation to derive the prediction mode to save the overhead of the transmission mode index.
  • the TIMD prediction mode can be understood as two main parts. First, the cost information of each prediction mode is calculated according to the template. The prediction mode corresponding to the minimum cost and the second-lowest cost will be selected. The prediction mode corresponding to the minimum cost is recorded as prediction mode 1. The prediction mode corresponding to the small cost is recorded as prediction mode 2; if the ratio of the next smallest cost value (costMode2) to the minimum cost value (costMode1) meets the preset conditions, such as costMode2 ⁇ 2*costMode1, then prediction mode 1 and prediction mode 2. Each corresponding prediction block can be weighted and fused according to the corresponding weights of prediction mode 1 and prediction mode 2 to obtain the final prediction block.
  • the corresponding weights of prediction mode 1 and prediction mode 2 are determined in the following manner:
  • weight1 costMode2/(costMode1+costMode2)
  • weight2 1-weight1
  • weight1 is the weight of the prediction block corresponding to prediction mode 1
  • weight2 is the weight of the prediction block corresponding to prediction mode 2.
  • weighted fusion between prediction blocks will not be performed, and the prediction block corresponding to prediction mode 1 will be the prediction block of TIMD.
  • the TIMD prediction mode selects the planar mode to perform intra prediction on the current block. That is, no unweighted fusion is performed. Same as the DIMD prediction mode, the TIMD prediction mode needs to transmit a flag bit to the decoder to indicate whether the current coding unit uses the TIMD prediction mode.
  • the process of the encoder or decoder calculating the cost information of each prediction mode is mainly: performing intra mode prediction on the samples in the template area based on the reconstructed samples adjacent to the upper or left side of the template area.
  • the prediction process is the same as the original intra prediction.
  • the modes are the same; for example, when DC mode is used to perform intra mode prediction on samples in the template area, the mean value of the entire coding unit is calculated; and when angle prediction mode is used to perform intra mode prediction on samples in the template area, the corresponding mode is selected according to the mode.
  • interpolation filter and interpolate prediction samples according to rules At this time, based on the predicted samples and reconstructed samples in the template area, the distortion between the predicted samples and reconstructed samples in the area can be calculated, which is the cost information of the current prediction mode.
  • FIG. 3 is a schematic diagram of a template used by TIMD provided by an embodiment of the present application.
  • the codec can be based on a coding unit with a width equal to 2(M+L1)+1 and a height equal to 2(N+L2)+1
  • Select the reconstructed samples in the reference template (Reference of template) of the current block to predict the samples in the template area of the current block.
  • the TIMD prediction mode selects the planar mode to perform intra prediction on the current block.
  • the available adjacent reconstruction samples may be samples adjacent to the left and upper sides of the current CU in Figure 3, that is, there are no available reconstruction samples in the diagonally filled area. That is to say, if there are no available reconstruction samples in the diagonal padding area, the TIMD prediction mode selects the planar mode to perform intra prediction on the current block.
  • the left and upper sides of the current block can theoretically obtain reconstruction values, that is, the template of the current block contains available adjacent reconstruction samples.
  • the decoder can use a certain intra prediction mode to predict on the template, and compare the prediction value and the reconstructed value to obtain the cost of the intra prediction mode on the template.
  • a certain intra prediction mode to predict on the template, and compare the prediction value and the reconstructed value to obtain the cost of the intra prediction mode on the template.
  • the reconstructed samples in the template are correlated with the pixels in the current block. Therefore, the performance of a prediction mode on the template can be used to estimate the performance of this prediction mode on the current block. .
  • TIMD predicts some candidate intra prediction modes on the template, obtains the cost of the candidate intra prediction mode on the template, and replaces the one or two intra prediction modes with the lowest cost as the intra prediction value of the current block. If the template cost difference between the two intra prediction modes is not large, the compression performance can be improved by weighting the prediction values of the two intra prediction modes.
  • the weights of the predicted values of the two prediction modes are related to the above-mentioned costs. For example, the weights are inversely proportional to the costs.
  • TIMD uses the prediction effect of the intra prediction mode on the template to screen the intra prediction mode, and can weight the two intra prediction modes according to the cost on the template.
  • the advantage of TIMD is that if the TIMD mode is selected for the current block, there is no need to indicate which intra prediction mode is used in the code stream. Instead, the decoder itself derives it through the above process, which saves overhead to a certain extent.
  • Figure 4 is a schematic block diagram of the decoding framework 200 provided by the embodiment of the present application.
  • the decoding framework 200 may include an entropy decoding unit 210, an inverse transform and inverse quantization unit 220, a residual unit 230, an intra prediction unit 240, an inter prediction unit 250, a loop filtering unit 260, and a decoded image buffer. Unit 270.
  • the entropy decoding unit 210 After the entropy decoding unit 210 receives and parses the code stream, it obtains the prediction block and the frequency domain residual block. For the frequency domain residual block, the inverse transform and inverse quantization unit 220 performs steps such as inverse transformation and inverse quantization to obtain the time domain residual block. Difference block, the residual unit 230 superposes the prediction block predicted by the intra prediction unit 240 or the inter prediction unit 250 to the time domain residual block after inverse transformation and inverse quantization by the inverse transformation and inverse quantization unit 220, we can obtain Rebuild block. For example, the intra prediction unit 240 or the inter prediction unit 250 may obtain the prediction block by decoding the header information of the code stream.
  • Figure 5 is a schematic flow chart of the decoding method 300 provided by the embodiment of the present application. It should be understood that the decoding method 300 can be performed by a decoder. For example, it is applied to the decoding framework 200 shown in FIG. 4 . For the convenience of description, the following takes the decoder as an example.
  • the decoding method 300 may include some or all of the following:
  • the decoder parses the code stream to obtain the residual block of the current block in the current sequence
  • the decoder determines the optimal MIP mode for predicting the current block based on the distortion costs of multiple matrix-based intra prediction MIP modes
  • the distortion cost of the multiple MIP modes includes the distortion cost obtained by using the multiple MIP modes to predict samples in the template area adjacent to the current block;
  • the decoder determines the intra prediction mode of the current block based on the optimal MIP mode
  • S340 The decoder predicts the current block based on the intra prediction mode of the current block to obtain a prediction block of the current block;
  • the decoder obtains a reconstructed block of the current block based on the residual block of the current block and the prediction block of the current block.
  • this application may also combine S320 and S330 (that is, the decoder determines the optimal MIP mode based on the distortion costs of the multiple MIP modes and determines the current block based on the optimal MIP mode).
  • the process of intra prediction mode is referred to as the template matching MIP (Template Matching MIP, TMMIP) technology or the MIP prediction mode derivation method based on template matching; that is to say, after the decoder obtains the residual block of the current block, The intra prediction mode of the current block can be determined based on TMMIP technology, and then the current block can be predicted based on the intra prediction mode of the current block to obtain the prediction block of the current block; finally, the decoder can be based on the residual block of the current block and The predicted block of the current block is used to obtain the reconstructed block of the current block.
  • TMMIP Temporal Matching MIP
  • the decoder determines the intra prediction mode of the current block, it determines the optimal MIP mode for predicting the current block based on the distortion costs of multiple MIP modes, and determines the optimal MIP mode based on the optimal MIP mode.
  • the intra prediction mode of the current block is equivalent to preventing the decoder from obtaining the MIP mode by parsing the code stream. Compared with the traditional MIP technology, it can effectively reduce the bit overhead at the coding unit level, thereby improving decompression. efficiency.
  • MIP is a simplified technology based on neural network technology. It is quite different from traditional interpolation filter prediction technology. For some special textures, although MIP prediction is better than traditional intra-frame prediction mode, its larger logo Overhead is a flaw of MIP technology.
  • this application uses the decoder to independently determine the optimal MIP mode for predicting the current block and determines the intra prediction mode of the current block based on the optimal MIP mode, which can save up to 5 or 6 bits of overhead. It can effectively reduce the bit overhead at the coding unit level, thereby improving decompression efficiency.
  • the solution provided by this application can solve the shortcomings of traditional MIP technology, that is, reduce the bit overhead at the image block level, thereby improving decompression efficiency.
  • the distortion cost involved in the decoder in this application is different from the rate distortion cost (RDcost) involved in the encoder.
  • the rate distortion cost is used by the encoding end to determine a certain intraframe among multiple intraframe prediction technologies.
  • the rate distortion cost can be the cost value obtained by comparing the distorted image and the original image. Since the decoder cannot obtain the original image, the distortion cost involved in the decoder can be the difference between the reconstructed sample and the predicted sample.
  • the distortion cost such as the Sum of Absolute Transformed Difference (SATD) cost between reconstructed samples and predicted samples, or other costs that can be used to calculate the difference between reconstructed samples and predicted samples.
  • SATD Sum of Absolute Transformed Difference
  • the S320 may include:
  • the decoder parses the code stream of the current sequence to obtain a first identifier; if the first identifier is used to identify that the optimal MIP mode is allowed to be used to predict image blocks in the current sequence, the decoder based on the The distortion costs of multiple MIP modes are determined to determine the optimal MIP mode.
  • the value of the first identifier is a first numerical value, it is used to identify that the optimal MIP mode is allowed to be used to predict the image block in the current sequence; if the value of the first identifier is If the value is the second numerical value, it is used to identify that the optimal MIP mode is not allowed to be used to predict the image blocks in the current sequence.
  • the first value is 1 and the second value is 0. In another implementation, the first value is 0 and the second value is 1.
  • the first numerical value and the second numerical value can also be other numerical values, which are not limited in this application.
  • the first flag is true, it is used to identify that the optimal MIP mode is allowed to be used to predict the image block in the current sequence; if the first flag is false, it is used to identify The optimal MIP mode is not allowed to be used for prediction of image blocks in the current sequence.
  • the decoder parses the block-level identifier. If the current block adopts the intra prediction mode, it parses or obtains the first identifier. If the first identifier is true, the decoder uses the block-level identifier based on the multiple MIP modes. The distortion cost determines the optimal MIP mode.
  • the first flag is recorded as sps_timd_enable_flag.
  • the decoder parses or obtains sps_timd_enable_flag. If the sps_timd_enable_flag is true, the decoder determines the optimal MIP based on the distortion costs of the multiple MIP modes. model.
  • the first identifier is a sequence-level identifier.
  • the first identifier is used to identify that the optimal MIP mode is allowed to be used to predict the image blocks in the current sequence, and may also be replaced by a description with similar or identical meanings.
  • the first identifier is used to identify that the optimal MIP mode is allowed to be used to predict image blocks in the current sequence, and may be replaced by any of the following:
  • the first identifier is used to identify that the TMMIP technology is allowed to be used to determine the intra prediction mode of the image block in the current sequence.
  • the first identifier is used to identify that the TMMIP technology is allowed to be used to perform intra prediction of the image block in the current sequence.
  • the first identifier is used to identify that the image blocks in the current sequence are allowed to use the TMMIP technology, and the first identifier is used to identify that the image blocks in the current sequence are allowed to be predicted using the MIP mode determined based on the multiple MIP modes.
  • the permission flag bits of other technologies can also be used to indirectly indicate whether the current sequence is allowed to use the TMMIP technology.
  • TIMD technology when the first identifier is used to indicate that the current sequence is allowed to use TIMD technology, it means that the current sequence is also allowed to use TMMIP technology; or in other words, the first identifier is used to indicate that the current sequence is allowed to use TIMD. technology, it means that the current sequence allows the use of TIMD technology and TMMIP technology at the same time; to further save bit overhead.
  • the decoder parses the code stream to obtain the second identifier; if If the second identifier is used to identify that the optimal MIP mode is allowed to be used to predict the current block, the decoder determines the optimal MIP mode based on the distortion costs of the multiple MIP modes.
  • the decoder parses the block-level identifier. If the current block adopts intra prediction mode, the decoder parses or obtains the first identifier. If the first identifier is true, the decoder parses or obtains the second identifier. , if the second flag is true, the decoder determines the optimal MIP mode based on the distortion costs of the multiple MIP modes.
  • the third value of the second identifier is used to identify that the optimal MIP mode is allowed to be used to predict the current block; if the fourth value of the second identifier is used to identify The current block is not allowed to be predicted using the optimal MIP mode.
  • the third value is 1 and the fourth value is 0.
  • the third value is 0 and the fourth value is 1.
  • the third numerical value and the fourth numerical value can also be other numerical values, which are not specifically limited in this application.
  • the second identifier For example, if the second identifier is true, it is used to identify that the optimal MIP mode is allowed to be used to predict the current block; if the second identifier is false, it is used to identify that the use of the optimal MIP mode is not allowed.
  • the optimal MIP mode predicts the current block.
  • the decoder parses or obtains sps_timd_enable_flag. If the sps_timd_enable_flag is true, the decoder can parse or obtain cu_timd_enable_flag. If the If cu_timd_enable_flag is true, the decoder determines the optimal MIP mode based on the distortion costs of the multiple MIP modes.
  • the second identification is a block-level identification or a coding unit-level identification.
  • the second identifier is used to identify that the optimal MIP mode is allowed to be used to predict the current block, and may also be replaced by a description with a similar or identical meaning.
  • the second identification is used to identify that the optimal MIP mode is allowed to be used to predict the current block, and may be replaced by any of the following: the second identification Used to identify that the TMMIP technology is allowed to be used to determine the intra prediction mode of the current block, the second identification is used to identify that the TMMIP technology is allowed to be used to perform intra prediction on the current block, the second identification is used to identify that the current block is allowed to be in The image block uses the TMMIP technology, and the second identifier is used to identify that the current block is allowed to be predicted using the MIP mode determined based on the plurality of MIP modes.
  • whether the current block is allowed to use the TMMIP technology can also be indirectly indicated through the permission flag bits of other technologies.
  • TIMD technology when the second identifier is used to indicate that the current block is allowed to use TIMD technology, it means that the current block is also allowed to use TMMIP technology; or in other words, the second identifier is used to indicate that the current block is allowed to use TIMD. technology, it means that the current block allows the use of TIMD technology and TMMIP technology at the same time; to further save bit overhead.
  • the decoding end when the decoding end parses the second identifier, it can parse the second identifier before parsing the residual block of the current block, or it can parse the second identifier after parsing the residual block of the current block.
  • This application provides This is not specifically limited.
  • the method 300 may further include:
  • the decoder determines the arrangement order of the multiple MIP modes based on the distortion cost of the MIP mode; the decoder determines the encoding method used by the optimal MIP mode based on the arrangement order of the multiple MIP modes; the decoder determines the encoding method used by the optimal MIP mode based on the arrangement order.
  • the encoding method used by the optimal MIP mode decodes the code stream of the current sequence to obtain the index of the optimal MIP mode.
  • the decoder determines the optimal MIP mode for predicting the current block based on the distortion costs of multiple MIP modes, it needs to calculate the distortion cost of each MIP mode in the multiple MIP modes, and calculate the distortion cost according to The distortion cost of each MIP mode ranks the multiple MIP modes, and the MIP mode with the smallest cost is the optimal prediction result.
  • the index of the MIP mode is usually binarized using truncated binary.
  • This encoding method is closer to equal probability encoding, that is, it divides all prediction modes into two segments, and one segment is Represented by N codewords, the other is represented by N+1 codewords.
  • the decoder may first calculate the distortion of each MIP mode in the multiple MIP modes. cost, and sorts the multiple MIP modes according to the distortion cost of each MIP mode.
  • the decoder can choose to use a more flexible variable length encoding method and an equal probability encoding method based on the sorting of the multiple MIP modes.
  • the decoder can choose to use a more flexible variable length encoding method and an equal probability encoding method based on the sorting of the multiple MIP modes.
  • by flexibly setting the encoding method of the MIP mode it is helpful to save the bit overhead of the index of the MIP mode.
  • the codeword length of the encoding method used by the first n MIP modes in the arrangement sequence is smaller than the codeword length of the encoding mode used by the MIP mode after the nth MIP mode in the arrangement sequence; and/ Or, the first n MIP patterns use variable length encoding and the MIP patterns after the nth MIP pattern use truncated binary encoding.
  • N can be any value greater than or equal to 1.
  • the arrangement order is the order obtained by the decoder arranging the multiple MIP modes in order from small to large distortion costs, and the codewords of the encoding methods used by the first n MIP modes in the arrangement order are The length is less than the codeword length of the encoding method used by the MIP mode after the n-th MIP mode in the arrangement sequence; and/or, the first n MIP modes use variable-length encoding and the n-th MIP mode after the MIP mode uses truncated binary encoding.
  • the codewords of the encoding method used by the first n MIP modes in the arrangement order are The length is designed to be less than the codeword length of the encoding method used by the MIP mode after the nth MIP mode in the arrangement sequence; and/or, the encoding method used by the first n MIP modes is designed as a variable length encoding method and The coding method used in the MIP mode after the nth MIP mode is designed as a truncated binary coding method; equivalently, the MIP mode used by the encoder with a high probability uses a shorter codeword length or a variable length coding method, which can save MIP modes The bit overhead of the index improves the decompression performance.
  • the S330 may include:
  • the decoder determines the optimal MIP mode as the intra prediction mode of the current block.
  • the decoder determines the optimal MIP mode, it directly performs intra prediction on the current block based on the optimal MIP mode to obtain a prediction block of the current block.
  • the S330 may include:
  • the decoder predicts the current block based on the optimal MIP mode to obtain a first prediction block; the decoder derives a TIMD mode based on the intra mode of the template to predict the current block and obtains a second prediction block; the decoder Based on the distortion cost of the first prediction block and the distortion cost of the second prediction block, the prediction mode with the smallest distortion cost among the optimal MIP mode and the TIMD mode is determined as the intra-frame of the current block. Prediction mode.
  • the optimal intra prediction mode among the optimal MIP mode and the TIMD mode is determined as the intra prediction mode of the current block.
  • the decoder can directly perform intra-frame processing on the current block based on the optimal MIP mode. Predict to obtain the predicted block of the current block. If the optimal prediction mode in the optimal MIP mode and the TIMD mode is the TIMD mode, the decoder can directly obtain the current prediction mode based on the optimal prediction mode and the suboptimal prediction mode obtained in the TIMD mode. Block prediction block.
  • the distortion cost of the optimal prediction mode requires a prediction block fusion operation; that is, the decoder can first perform intra prediction on the current block according to the optimal prediction mode to obtain the optimal prediction block; secondly, the current block can be obtained based on the suboptimal prediction mode. Perform intra-frame prediction to obtain the suboptimal prediction block; then use the ratio between the distortion cost of the optimal prediction mode and the distortion cost of the suboptimal prediction mode to calculate the weight value belonging to the optimal prediction block and the weight of the suboptimal prediction block.
  • the optimal prediction block and the suboptimal prediction block are weighted and fused to obtain the prediction block of the current block.
  • the optimal prediction mode or suboptimal prediction mode is planar mode or DC mode, or the distortion cost of the suboptimal prediction mode is greater than twice the distortion cost of the optimal prediction mode, then there is no need to perform a prediction block fusion operation, that is, Only the optimal prediction block obtained based on the optimal prediction mode can be directly used as the prediction block of the current block.
  • the S320 may include:
  • the decoder predicts the samples in the template area based on the third identifier and the multiple MIP modes, and obtains the distortion cost of the multiple MIP modes in each state of the third identifier; the third identifier The input vector and the output vector used to identify whether to transpose the MIP mode; the decoder determines the optimal MIP mode based on the distortion cost of the multiple MIP modes in each state of the third identification.
  • MIP has more bit overhead than other intra prediction tools. It not only requires a flag bit to indicate whether to use MIP technology, but also needs a flag bit to indicate whether to use transposition. MIP, the last and most expensive part, requires the use of truncated binary encoding to represent the prediction mode of MIP. MIP is a simplified technology based on neural network technology. It is quite different from traditional interpolation filter prediction technology. For some special textures, although MIP prediction is better than traditional intra-frame prediction mode, its larger logo Overhead is a flaw of MIP technology.
  • this application considers the transposition function of the MIP mode by traversing each state of the third identifier, which can save the cost of one MIP transposition identifier, thereby improving the solution. Compression efficiency.
  • the decoder traverses each state of the third identifier and the multiple MIP modes, determines the distortion cost of the multiple MIP modes in each state of the third identifier, and determines the distortion cost of the multiple MIP modes based on the third identifier.
  • the distortion cost of the multiple MIP modes in each state of the three identifiers is determined to determine the optimal MIP mode; or, the decoder traverses each state of the third identifier and the multiple MIP modes to determine the
  • the optimal MIP mode is determined based on the distortion cost of the multiple MIP modes in each state of the third identifier, and based on the distortion costs of the multiple MIP modes in each state of the third identifier. That is to say, the decoding end may first traverse the multiple MIP modes, or may first traverse the state of the third identifier.
  • the value of the third identifier is a fifth numerical value, it is used to identify the input vector and output vector of the transposed MIP mode; if the value of the third identifier is a sixth numerical value, then it is used to identify the input vector and output vector of the transposed MIP mode. Identifies the input and output vectors of the non-transposed MIP mode.
  • each state of the third identifier can also be replaced by each value of the third identifier.
  • the fifth value is 1 and the sixth value is 0.
  • the fifth value is 0 and the sixth value is 1.
  • the fifth numerical value and the sixth numerical value can also be other numerical values, which are not limited in this application.
  • the third identifier is true, it is used to identify the input vector and the output vector of the transposed MIP mode; if the third identifier is false, it is used to identify the input vector and the output vector of the non-transposed MIP mode. Output vector. At this time, whether the third identifier is true or false is a state of the third identifier.
  • the third identification is a sequence level identification, a block level identification or a coding unit level identification.
  • the third identification may also be called transposition information, transposition identification, or MIP transposition identification bit.
  • the third identifier is used to identify whether to transpose the input vector and the output vector of the MIP mode, and can also be replaced with a description with similar or identical meaning.
  • the third identifier is used to identify whether the input and output of the MIP mode need to be transposed, and the third identifier is used to identify whether the input vector and the output vector of the MIP mode are transposed. vector, and the third identifier is used to indicate whether to transpose.
  • the S320 may include:
  • the decoder determines the optimal MIP mode based on the distortion costs of the multiple MIP modes.
  • the preset size may include a size whose width is the preset width and whose height is the preset height. That is to say, if the width of the current block is the preset width and the height is the preset height, the decoder determines the optimal MIP mode based on the distortion costs of the multiple MIP modes.
  • the preset size can be realized by pre-saving corresponding codes, tables or other methods that can be used to indicate relevant information in the device (for example, including a decoder and an encoder).
  • This application is concerned with its specific implementation.
  • the method is not limited.
  • the preset size may refer to the size defined in the agreement.
  • the "protocol" may refer to a standard protocol in the field of coding and decoding technology, which may include, for example, VCC or ECM protocols and other related protocols.
  • the decoder may also use other methods to determine whether to determine the optimal MIP mode based on the distortion costs of the multiple MIP modes based on the preset size, which is not specified in this application. limited.
  • the decoder may determine whether to determine the optimal MIP mode based on the distortion costs of the plurality of MIP modes based solely on the width or height of the current block. In one implementation, if the width of the current block is the preset width or the height is the preset height, the decoder determines the optimal MIP mode based on the distortion costs of the multiple MIP modes. For another example, the decoder may determine whether to determine the optimal MIP mode based on the distortion costs of the multiple MIP modes by comparing the size of the current block with the preset size. In one implementation, if the size of the current block is larger or smaller than a preset size, the decoder determines the optimal MIP mode based on the distortion costs of the multiple MIP modes.
  • the decoder determines the optimal MIP mode based on distortion costs of the multiple MIP modes. In another implementation, if the height of the current block is greater than or less than a preset height, the decoder determines the optimal MIP mode based on distortion costs of the multiple MIP modes.
  • the S320 may include:
  • the decoder determines the optimal MIP mode based on the distortion costs of the multiple MIP modes.
  • the decoder based on the multiple MIP modes
  • the distortion cost is determined by determining the optimal MIP mode. That is to say, only when the image frame in which the current block is located is an I frame, the decoder determines whether to determine the optimal value based on the distortion costs of the multiple MIP modes based on the size of the current block. MIP mode.
  • the S320 may include:
  • the decoder determines the optimal MIP mode based on the distortion costs of the multiple MIP modes.
  • the decoder may directly determine the optimal MIP mode based on the distortion costs of the multiple MIP modes. That is to say, when the image frame in which the current block is located is a B frame, regardless of the size of the current block, the decoder can directly determine the optimal MIP based on the distortion costs of the multiple MIP modes. model.
  • the method 300 may further include:
  • the decoder obtains the MIP mode used by the adjacent block adjacent to the current block; the decoder determines the MIP mode used by the adjacent block as the multiple MIP modes.
  • the adjacent block may be an image block adjacent to at least one of the upper side, the left side, the lower left, the upper right, and the upper left of the current block.
  • the decoder may determine image blocks acquired in the order of upper, left, lower left, upper right, and upper left of the current block as the adjacent blocks.
  • the plurality of MIP modes can be used to construct an available MIP mode or an available MIP mode list that the decoder determines is used to predict the current block, so that the decoder passes the template area in the available MIP mode or available MIP mode list.
  • the optimal MIP mode is determined by predicting the samples within the model.
  • the method 300 may further include:
  • the decoder performs reconstruction sample filling on the adjacent reference area outside the template area to obtain the reference rows and reference columns of the template area; the decoder uses the reference rows and the reference columns as input, and uses the multiple
  • the MIP mode predicts the samples in the template area respectively to obtain multiple prediction blocks corresponding to the multiple MIP modes; the decoder determines the multiple prediction blocks based on the multiple prediction blocks and the reconstruction block in the template area. Distortion costs of multiple MIP modes.
  • the decoder fills in the reference reconstruction samples required for template prediction
  • the width of the area in the reference area adjacent to the upper side of the template area is equal to the width of the template area
  • the height of the area in the reference area adjacent to the left side of the template area is equal to the width of the template area. is equal to the width of the template area; if the width of the area in the reference area adjacent to the upper side of the template area is greater than the width of the template area, the decoder can The area adjacent to the upper side of the area is subjected to downsampling or dimensionality reduction processing to obtain the reference row. If the height of the area in the reference area adjacent to the left side of the template area can be greater than the width of the template area, the decoder can determine the area in the reference area adjacent to the left side of the template area. The region is subjected to downsampling or dimensionality reduction processing to obtain the reference column.
  • the template area may be a template area used in the TIMD mode mentioned above, and the reference area may be a reference template (Reference of template) used in the TIMD mode.
  • the decoder will The composed reference area is filled with reconstructed samples, and the filled reference area is downsampled or dimensionally reduced to obtain the reference rows and reference columns, and then the MIP pattern is constructed based on the reference rows and reference columns. input vector.
  • the decoder obtains the reference row and the reference column
  • the reference row and the reference column are used as input
  • the multiple MIP modes are used to predict the samples in the template area, respectively.
  • Multiple prediction blocks corresponding to the multiple MIP modes are obtained; that is to say, the decoder, based on the reconstructed samples in the reference template of the current block, traverses the multiple MIP modes to estimate the template area of the current block. Make predictions on the samples within.
  • the decoder uses the reference row, the reference column, the index of the current traversal MIP mode, and the third identifier mentioned above as inputs to obtain the prediction corresponding to the current traversal MIP mode.
  • the reference row and the reference column are used to construct the input vector of the current traversal MIP mode; the index of the current traversal MIP mode is used to determine the matrix and/or offset vector of the current traversal MIP mode;
  • the third identifier is used to identify whether to transpose the input vector and the output vector of the MIP mode; for example, if the third identifier is used to identify the input vector and the output vector of the MIP mode not to be transposed, then the reference columns are spliced after the reference line to form the input vector of the current traversal MIP mode; if the third identifier is used to identify the input vector and output vector of the transposed MIP mode, then the reference line is spliced to the reference line.
  • the decoder transposes the output of the current traversal MIP mode to obtain the prediction block of the template area.
  • the decoder can based on the distortion cost between the multiple prediction blocks and the reconstructed samples in the template area, according to The minimum distortion cost principle selects the MIP mode with the smallest cost and determines it as the optimal MIP mode in the current block's template matching-based MIP mode.
  • the decoder when the decoder uses the multiple MIP modes to predict samples in the template area, it first downsamples the reference row and the reference column to obtain the input vector; and then uses the The input vector is used as input, and the samples in the template area are predicted by traversing the multiple MIP modes to obtain the output vectors of the multiple MIP modes; finally, the output vectors of the multiple MIP modes are Upsample to obtain prediction blocks corresponding to the multiple MIP modes.
  • the reference row and the reference column satisfy the input conditions of the multiple MIP modes. If the reference row and the reference column do not meet the input conditions of the multiple MIP modes, the reference row and/or the reference column can be processed first as input that meets the input conditions of the multiple MIP modes. samples, and then determine the input vectors of the plurality of MIP modes based on the input samples that satisfy the input conditions of the plurality of MIP modes. For example, taking the input condition as a specified number of input samples, if the reference row and the reference column do not meet the number of input samples in the MIP mode, the decoder can modify the reference row and/or the reference column.
  • the reference column is dimensionally reduced to a specified number of input samples by methods such as Haar-downsampling, and the input vectors of the multiple MIP modes are determined based on the specified number of input samples after dimensionality reduction.
  • the S320 may include:
  • the decoder determines the optimal MIP pattern based on the sum of absolute transform differences SATD of the plurality of MIP patterns on the template region.
  • the distortion costs of the multiple MIP modes are designed to be the multiple MIP modes.
  • SATD compared with directly calculating the rate distortion cost of the multiple MIP modes, can not only determine the optimal MIP mode based on the distortion cost of the multiple MIP modes on the template area, but also simplify the process. Describes the computational complexity of the distortion cost of multiple MIP modes, thereby improving the decompression performance of the decoder.
  • the reconstructed samples in the reference area are filled, that is, the reference reconstructed samples required for predicting the samples in the template area (such as the template shown in FIG. 3).
  • the width and height of the reference area do not need to exceed the width and height of the template area. If the reference area is filled with samples that exceed the width and height of the template area, downsampling or other methods need to be used to reduce the dimension to meet the MIP input dimension requirements.
  • the decoder uses the reference reconstructed samples in the reference area, the indexes of the multiple MIP modes, and the MIP transposition flag bits as inputs to predict the samples in the template area to obtain the multiple MIP modes. corresponding prediction block.
  • the reference reconstruction samples in the reference area need to meet MIP input conditions, such as Haar-downsampling, etc. to reduce the dimension to a specified number of input samples.
  • the indexes of the multiple MIP modes are used to determine the matrix index of the MIP technology, and then obtain the MIP prediction matrix coefficients.
  • the MIP transposition flag bit is used to identify whether input and output need to be transposed.
  • the decoding method according to the embodiment of the present application is described in detail from the perspective of the decoder above.
  • the encoding method according to the embodiment of the present application is described in detail from the perspective of the encoder with reference to FIG. 8 .
  • Figure 6 is a schematic flow chart of the encoding method 400 provided by the embodiment of the present application. It should be understood that the encoding method 400 may be performed by an encoder. For example, it is applied to the coding framework 100 shown in FIG. 1 . For ease of description, the following uses an encoder as an example.
  • the encoding method 400 may include:
  • the distortion cost of the multiple MIP modes includes the distortion cost obtained by using the multiple MIP modes to predict samples in the template area adjacent to the current block;
  • S430 Predict the current block based on the intra prediction mode of the current block to obtain a prediction block of the current block;
  • S450 Encode the residual block of the current block to obtain the code stream of the current sequence.
  • the S410 may include:
  • the optimal MIP mode is determined based on the distortion costs of the multiple MIP modes
  • the S450 may include:
  • the S420 may include:
  • the optimal prediction mode based on the optimal MIP mode
  • the optimal prediction mode as the intra prediction mode of the current block
  • the S450 may include:
  • the second identifier is used to identify that the optimal MIP mode is allowed to be used to predict the current block; If the first rate distortion cost is greater than the minimum value of the at least one rate distortion cost, the second identification is used to identify that the optimal MIP mode is not allowed to be used to predict the current block.
  • the S420 may include:
  • the optimal MIP mode is determined as the optimal prediction mode.
  • the S420 may include:
  • the template-based intra mode derivation TIMD mode predicts the current block to obtain the second prediction block
  • the prediction mode with the smallest distortion cost among the optimal MIP mode and the TIMD mode is determined as the optimal prediction mode.
  • the S450 may include:
  • the code stream is obtained by encoding the residual block of the current block and encoding the index of the optimal MIP mode based on the encoding method used in the optimal MIP mode.
  • the codeword length of the encoding method used by the first n MIP modes in the arrangement sequence is smaller than the codeword length of the encoding mode used by the MIP mode after the nth MIP mode in the arrangement sequence; and/ Or, the first n MIP patterns use variable length encoding and the MIP patterns after the nth MIP pattern use truncated binary encoding.
  • the S410 may include:
  • the optimal MIP mode is determined based on the distortion costs of the multiple MIP modes in each state of the third identifier.
  • the S410 may include:
  • the optimal MIP mode is determined based on the distortion costs of the multiple MIP modes.
  • the S410 may include:
  • the optimal MIP mode is determined based on the distortion costs of the multiple MIP modes.
  • the S410 may include:
  • the optimal MIP mode is determined based on the distortion costs of the multiple MIP modes.
  • the method 400 may further include:
  • the MIP modes used by the adjacent blocks are determined as the multiple MIP modes.
  • the method 400 may further include:
  • Distortion costs for the plurality of MIP modes are determined based on the plurality of prediction blocks and reconstruction blocks within the template region.
  • the multiple MIP modes when using the multiple MIP modes to predict samples in the template area, first down-sample the reference row and the reference column to obtain an input vector; and then use the input
  • the vector is the input
  • the samples in the template area are predicted by traversing the multiple MIP modes to obtain the output vectors of the multiple MIP modes; finally, the output vectors of the multiple MIP modes are upsampled. , obtain prediction blocks corresponding to the multiple MIP modes.
  • the S410 may include:
  • the optimal MIP pattern is determined based on the sum SATD of absolute transformation differences of the plurality of MIP patterns on the template region.
  • the encoding method can be understood as the reverse process of the decoding method. Therefore, for the specific solution of the encoding method 400, please refer to the relevant content of the decoding method 300. For the convenience of description, this application will not repeat it again.
  • the encoder or decoder can directly determine the optimal MIP mode used to predict the current block as the intra prediction mode of the current block.
  • the encoder traverses the prediction mode. If the current block is in intra mode, the encoder obtains the sequence-level allowable flag bit, which is used to indicate whether the current sequence is allowed to use the MIP mode derivation technology based on template matching, which can be in the form of sps_tmmip_enable_flag. If the allowed flag bits of tmmip are all true, it means that the current encoder allows the use of TMMIP technology.
  • the encoder process can be implemented as the following process:
  • step 1
  • step 2 If sps_tmmip_enable_flag is true, the encoder tries TMMIP technology, that is, performs step 2; if sps_tmmip_enable_flag is false, the encoder does not try TMMIP technology, that is, skips step 2 and proceeds to step 3 directly.
  • the encoder fills the adjacent rows and columns outside the template region with reconstructed samples.
  • the filling process is the same as the filling method in the original intra prediction process. For example, the encoder can traverse and fill from the lower left corner to the upper right corner. If all reconstructed samples are available, all available reconstructed samples will be filled in sequence; if all reconstructed samples are available If it is not available, all the reconstructed samples will be filled with the mean value; if some reconstructed samples are available, the available reconstructed samples will be filled in first. For the remaining unavailable reconstructed samples, the encoder can traverse according to the above order from the lower left corner to the upper right corner until the first available reconstruction sample appears. After a sample is reconstructed, previously unavailable locations are filled with the first available reconstructed sample.
  • the encoder takes the reconstructed samples outside the filled template area as input, and uses the allowable MIP mode to predict the samples within the template area.
  • MIP patterns are allowed to be used for a 4x4 block size.
  • the allowed MIP patterns are 8.
  • the allowed MIP pattern for other size blocks is 6.
  • blocks of any size can use the MIP transpose function, and the prediction mode of TMMIP mentioned above is the same as the MIP technology.
  • the specific prediction calculation process includes: the encoder first performs Haar down-sampling on the reconstructed samples. For example, the encoder determines the down-sampling step size based on the block size. Then, the encoder adjusts the splicing order of the reconstructed samples after downsampling on the upper side and the reconstructed samples after downsampling on the left based on the information about whether to transpose or not; if transposition is not required, the reconstructed samples after downsampling on the left are spliced on top After the reconstructed sample after side downsampling, the obtained vector is used as input.
  • the encoder obtains the MIP matrix coefficients based on the traversed prediction mode as an index, and calculates the output vector with the input. Finally, the encoder upsamples the output vector according to the number of output vectors and the current template size. If upsampling is not required, the vectors are filled in the horizontal direction and output as the template prediction block. If upsampling is required, the horizontal direction is upsampled first. Then downsample in the vertical direction, upsample to the same size as the template, and then output it as a prediction block in the template area.
  • the encoder calculates the distortion cost based on the prediction block of the template area obtained by traversing each MIP mode and the reconstructed samples in the template area, and records the distortion cost value under the prediction mode and transposition information. After traversing all allowed prediction modes and transposition information, according to the principle of minimum cost, the optimal MIP mode and its corresponding transposition information are selected as the optimal prediction mode for the current block in TMMIP mode.
  • the encoder samples the reconstructed samples adjacent to the upper and left sides of the current block as appropriate and splices them according to the transposition information as the input vector, and uses the MIP mode as the index Read the matrix coefficients in the current mode, and then obtain the output vector by calculating the input vector and matrix coefficients.
  • the encoder can perform output transposition according to the transposition information, and upsample the output vector according to the size of the current block and the number of samples of the output vector, and obtain an output with the same size as the current block as the prediction block of the current block. Based on this, the encoder obtains the rate distortion cost of the current block and records it as cost1.
  • the encoder continues to traverse other intra prediction techniques and calculates the corresponding rate-distortion cost as cost2...costN.
  • the current block uses TMMIP technology, and the encoder sets the TMMIP usage flag of the current block to true and writes it into the code stream; if cost1 is not the minimum rate distortion cost, the current block uses other intra-frame techniques. Prediction technology, the encoder sets the TMMIP usage flag position of the current block and writes it into the code stream. It should be understood that information such as identification bits or indexes of other intra prediction technologies are transmitted according to definition and will not be elaborated here;
  • the encoder determines the residual block of the current block based on the prediction block of the current block and the original block of the current block, and performs operations such as transformation and quantization, entropy coding, and loop filtering on the residual block of the current block. It should be understood that the specific process can be found in the relevant content above, and to avoid repetition, it will not be described again here.
  • the decoder parses the block-level type flag bit. If it is intra-frame mode, it parses or obtains the sequence-level allowable flag bit, which is used to indicate whether the current sequence is allowed to use the MIP mode export technology based on template matching, which can be in the form of sps_tmmip_enable_flag. If the allowed flag bits of tmmip are all true, it means that the current decoder allows the use of TMMIP technology.
  • the decoder process can be implemented as the following process:
  • step 1
  • the decoder parses the TMMIP usage flag of the current block. Otherwise, the current decoding process does not need to decode the block-level TMMIP usage flag.
  • the block-level TMMIP usage flag defaults to No. If the TMMIP usage flag of the current block is true, perform step 2; otherwise, perform step 3.
  • the decoder fills the adjacent rows and columns outside the template region with reconstructed samples.
  • the filling process is the same as the filling method in the original intra prediction process. For example, the decoder can traverse and fill from the lower left corner to the upper right corner. If all reconstructed samples are available, all available reconstructed samples will be filled in sequence; if all reconstructed samples are available If it is not available, all the reconstructed samples will be filled with the mean; if some of the reconstructed samples are available, the available reconstructed samples will be filled in first. For the remaining unavailable reconstructed samples, the decoder can traverse according to the above order from the lower left corner to the upper right corner until the first available reconstruction sample appears. After a sample is reconstructed, previously unavailable locations are filled with the first available reconstructed sample.
  • the decoder takes the reconstructed samples outside the filled template area as input, and uses the allowed MIP mode to predict the samples in the template area.
  • MIP patterns are allowed to be used for a 4x4 block size.
  • the allowed MIP patterns are 8.
  • the allowed MIP pattern for other size blocks is 6.
  • blocks of any size can use the MIP transpose function, and the prediction mode of TMMIP mentioned above is the same as the MIP technology.
  • the specific prediction calculation process includes: the decoder first performs Haar down-sampling on the reconstructed samples. For example, the decoder determines the down-sampling step size based on the block size. Then, the decoder adjusts the splicing order of the reconstructed samples after downsampling on the upper side and the reconstructed samples after downsampling on the left based on the information about whether to transpose or not; if transposition is not required, the reconstructed samples after downsampling on the left are spliced on top After the reconstructed sample after side downsampling, the obtained vector is used as input.
  • the decoder obtains the MIP matrix coefficients based on the traversed prediction mode as an index, and calculates the output vector with the input. Finally, the decoder upsamples the output vector according to the number of output vectors and the current template size. If upsampling is not required, the vectors are filled in the horizontal direction and output as the template prediction block. If upsampling is required, the horizontal direction is upsampled first. Then downsample in the vertical direction, upsample to the same size as the template, and then output it as a prediction block in the template area.
  • the decoder calculates the distortion cost based on the prediction block of the template area obtained by traversing each MIP mode and the reconstructed samples in the template area, and records the distortion cost value under the prediction mode and transposition information. After traversing all allowed prediction modes and transposition information, according to the principle of minimum cost, the optimal MIP mode and its corresponding transposition information are selected as the optimal prediction mode for the current block in TMMIP mode.
  • the decoder samples the reconstructed samples adjacent to the upper and left sides of the current block as appropriate and splices them according to the transposition information as the input vector, and uses the MIP mode as the index Read the matrix coefficients in the current mode, and then obtain the output vector by calculating the input vector and matrix coefficients.
  • the decoder can perform output transposition according to the transposition information, and upsample the output vector according to the size of the current block and the number of samples of the output vector, and obtain an output with the same size as the current block as the prediction block of the current block.
  • the decoder continues to parse information such as usage flags or indexes of other intra prediction technologies, and obtains the final prediction block of the current block based on the parsed information.
  • the decoder parses the code stream and obtains the frequency domain residual block of the current block (also called frequency domain residual information), and performs inverse quantization and inverse transformation on the frequency domain residual block of the current block to obtain the residual block of the current block (also known as the temporal residual block or temporal residual information); the decoder then superimposes the prediction block of the current block and the residual block of the current block to obtain a reconstructed sample block.
  • frequency domain residual information also called frequency domain residual information
  • temporal residual block or temporal residual information also known as the temporal residual block or temporal residual information
  • the reconstructed image can be used as video output or as a reference for subsequent decoding.
  • the size of the template area used by the encoder or decoder in the TMMIP technology can be predefined according to the size of the current block.
  • the width of the upper area adjacent to the current block in the template area is the width of the current block, and its height is the height of two rows of samples; the left side of the template area adjacent to the left side of the current block
  • the height of the region is the height of the current block, and its width is the width of two rows of samples.
  • it can also be implemented as template areas of other sizes, and this application does not specifically limit this.
  • the encoder or decoder can determine the optimal prediction mode as the current The intra prediction mode of the block. That is to say, the encoder or decoder can predict image blocks based on TMMIP technology and TIMD technology. For example, under the condition that TIMD technology is allowed to be used, TMMIP technology and TIMD technology only need one usage identification bit at the sequence level and block level to identify whether to use TIMD or TMMIP technology.
  • the template areas of TIMD technology and TMMIP technology can be set the same, that is, the distortion cost area for calculating the template area is the same, and the two technologies can be merged together for comparison.
  • TIMD derives traditional intra prediction modes while TMMIP technology derives MIP modes and their corresponding transposed information.
  • the encoder traverses the prediction mode. If the current block is in intra mode, it obtains the allowed use flag of TIMD. This flag is a sequence-level flag, indicating that the current encoder allows the use of TIMD technology, which can be in the form of sps_TIMD_enable_flag.
  • the encoder process can be implemented as the following process:
  • step 1
  • the encoder tries the TIMD prediction method, that is, performs step 2; if the allowed use flag of TIMD is false, the encoder does not try the TIMD prediction method, that is, skips step 2 directly. Perform step 3.
  • the encoder fills the adjacent rows and columns outside the template region with reconstructed samples.
  • the filling process is the same as the filling method in the original intra prediction process. For example, the encoder can traverse and fill from the lower left corner to the upper right corner. If all reconstructed samples are available, all available reconstructed samples will be filled in sequence; if all reconstructed samples are available If it is not available, all the reconstructed samples will be filled with the mean value; if some of the reconstructed samples are available, the available reconstructed samples will be filled in first. For the remaining unavailable reconstructed samples, the encoder can traverse according to the above order from the lower left corner to the upper right corner until the first available reconstruction sample appears. After a sample is reconstructed, previously unavailable locations are filled with the first available reconstructed sample.
  • the encoder takes the reconstructed samples outside the filled template area as input, and uses the allowable MIP mode to predict the samples within the template area.
  • MIP patterns are allowed to be used for a 4x4 block size.
  • the allowed MIP patterns are 8.
  • the allowed MIP pattern for other size blocks is 6.
  • blocks of any size can use the MIP transpose function, and the prediction mode of TMMIP mentioned above is the same as the MIP technology.
  • the specific prediction calculation process includes: the encoder first performs Haar down-sampling on the reconstructed samples. For example, the encoder determines the down-sampling step size based on the block size. Then, the encoder adjusts the splicing order of the reconstructed samples after downsampling on the upper side and the reconstructed samples after downsampling on the left based on the information about whether to transpose or not; if transposition is not required, the reconstructed samples after downsampling on the left are spliced on top After the reconstructed sample after side downsampling, the obtained vector is used as input.
  • the encoder obtains the MIP matrix coefficients based on the traversed prediction mode as an index, and calculates the output vector with the input. Finally, the encoder upsamples the output vector according to the number of output vectors and the current template size. If upsampling is not required, the vectors are filled in the horizontal direction and output as the template prediction block. If upsampling is required, the horizontal direction is upsampled first. Then downsample in the vertical direction, upsample to the same size as the template, and then output it as a prediction block in the template area.
  • the encoder also needs to try the template matching calculation process of TIMD, that is, the encoder can obtain different interpolation filters based on different prediction mode indexes to interpolate the reference samples to obtain prediction samples within the template.
  • the encoder calculates the distortion cost based on the prediction block of the template area obtained by traversing each MIP mode and the reconstructed samples in the template area, and records the distortion cost under the prediction mode and transposition information.
  • the encoder also needs to traverse all intra prediction modes allowed by TIMD, calculate the prediction blocks within the template, calculate the distortion cost with the reconstructed samples within the template, and record the distortion cost in each prediction mode. After the encoder traverses all allowed MIP modes and transposed information and traverses the prediction modes allowed by TIMD, it can select the optimal prediction mode based on the principle of minimum distortion cost.
  • the MIP mode and its The corresponding transposition information is used as the optimal prediction mode of the current block; if the distortion cost of the TIMD mode is the smallest, the TIMD mode is used as the optimal prediction mode of the current block, and the optimal intra prediction mode derived by the TIMD technology is recorded and recorded. Distortion cost, while recording the suboptimal prediction mode derived by TIMD technology and its distortion cost.
  • the encoder will sample the reconstructed samples adjacent to the upper and left sides of the current block according to the optimal MIP mode and transposition information as appropriate, and transform them according to the situation.
  • the position information is spliced as an input vector, and the matrix coefficients in the current mode are read according to the MIP mode as an index.
  • the output vector is obtained by calculating the input vector and matrix coefficients.
  • the encoder can perform output transposition according to the transposition information, and upsample the output vector according to the size of the current block and the number of samples of the output vector, and obtain an output with the same size as the current block as the prediction block of the current block. Based on this, the encoder obtains the rate distortion cost of the current block and records it as cost1.
  • the optimal prediction mode obtained by the encoder is the TIMD mode. If neither the optimal prediction mode nor the suboptimal prediction mode is the mean (DC) mode or the flat (PLANAR) mode, and the distortion cost of the suboptimal prediction mode is less than twice the distortion cost of the optimal prediction mode, the encoder needs to predict the block Fusion operation. First, the encoder obtains the interpolation filter coefficients according to the optimal prediction mode, performs interpolation filtering on the upper and left adjacent reconstructed samples to obtain prediction samples at all positions in the current block, which are recorded as the optimal prediction block; secondly, the encoder performs interpolation filtering according to the suboptimal prediction mode.
  • the prediction mode obtains the interpolation filter coefficients, and performs interpolation filtering on the upper and left adjacent reconstructed samples to obtain prediction samples at all positions in the current block, which are recorded as suboptimal prediction blocks.
  • the encoder uses the ratio between the optimal prediction mode cost value and the suboptimal prediction mode cost value to calculate the weight value belonging to the optimal prediction block and the weight value of the suboptimal prediction block.
  • the encoder performs a weighted fusion of the optimal prediction block and the suboptimal prediction block to obtain the prediction block of the current block as output.
  • the encoder does not need to perform prediction blocks In the fusion operation, only the optimal prediction block obtained by interpolation filtering the upper and left adjacent reconstructed samples using the optimal prediction mode is used as the prediction block of the current block. Based on this, the encoder obtains the rate distortion cost of the current block, recorded as cost1.
  • the encoder continues to traverse other intra prediction techniques and calculates the corresponding rate distortion cost, which is recorded as cost2...costN;
  • the encoder is allowed to use TIMD technology in the current block, set the TIMD usage flag of the current block to true and write it into the code stream. It should be noted that in this embodiment, the encoder is allowed to use TIMD technology in the current block, which can be understood as the encoder is allowed to use TIMD technology or allows TMMIP technology in the current block. The specific use of TIMD technology or TMMIP technology can be determined based on the cost information. Sure. If cost1 is not the minimum rate distortion cost, the encoder uses other intra-frame prediction techniques in the current block, sets the TIMD usage flag position of the current block false and writes it into the code stream. It should be understood that information such as identification bits or indexes of other intra prediction technologies are transmitted according to definition and will not be elaborated here.
  • the encoder determines the residual block of the current block based on the prediction block of the current block and the original block of the current block, and performs operations such as transformation and quantization, entropy coding, and loop filtering on the residual block of the current block. It should be understood that the specific process can be found in the relevant content above, and to avoid repetition, it will not be described again here.
  • the decoder parses the block-level type flag bit. If it is intra-frame mode, it parses or obtains the TIMD allowed use flag bit. This flag bit is a sequence-level flag bit, indicating that the current decoder allows the use of TIMD technology.
  • the decoder process can be implemented as the following process:
  • step 1
  • the decoder parses the TIMD use flag of the current block. Otherwise, the current decoding process does not need to decode the block-level TIMD use flag, and the block-level TIMD use flag defaults to No. If the TIMD usage flag of the current block is true, perform step 2; otherwise, perform step 3.
  • the decoder fills the adjacent rows and columns outside the template region with reconstructed samples.
  • the filling process is the same as the filling method in the original intra prediction process. For example, the decoder can traverse and fill from the lower left corner to the upper right corner. If all reconstructed samples are available, all available reconstructed samples will be filled in sequence; if all reconstructed samples are available If it is not available, all the reconstructed samples will be filled with the mean; if some of the reconstructed samples are available, the available reconstructed samples will be filled in first. For the remaining unavailable reconstructed samples, the decoder can traverse according to the above order from the lower left corner to the upper right corner until the first available reconstruction sample appears. After a sample is reconstructed, previously unavailable locations are filled with the first available reconstructed sample.
  • the decoder takes the reconstructed samples outside the filled template area as input, and uses the allowed MIP mode to predict the samples in the template area.
  • MIP patterns are allowed to be used for a 4x4 block size.
  • the allowed MIP patterns are 8.
  • the allowed MIP pattern for other size blocks is 6.
  • blocks of any size can use the MIP transpose function, and the prediction mode of TMMIP mentioned above is the same as the MIP technology.
  • the specific prediction calculation process includes: the decoder first performs Haar down-sampling on the reconstructed samples. For example, the decoder determines the down-sampling step size based on the block size. Then, the decoder adjusts the splicing order of the reconstructed samples after downsampling on the upper side and the reconstructed samples after downsampling on the left based on the information about whether to transpose or not; if transposition is not required, the reconstructed samples after downsampling on the left are spliced on top After the reconstructed sample after side downsampling, the obtained vector is used as input.
  • the decoder obtains the MIP matrix coefficients based on the traversed prediction mode as an index, and calculates the output vector with the input. Finally, the decoder upsamples the output vector according to the number of output vectors and the current template size. If upsampling is not required, the vectors are filled in the horizontal direction and output as the template prediction block. If upsampling is required, the horizontal direction is upsampled first. Then downsample in the vertical direction, upsample to the same size as the template, and then output it as a prediction block in the template area.
  • the decoder also needs to try the template matching calculation process of TIMD, that is, the decoder obtains different interpolation filters based on different prediction mode indexes to interpolate the reference samples to obtain prediction samples within the template.
  • the decoder calculates the distortion cost based on the prediction block of the template area obtained by traversing each MIP mode and the reconstructed samples in the template area, and records the distortion cost value under the prediction mode and transposition information.
  • the decoder also needs to traverse all intra prediction modes allowed by TIMD, calculate the prediction blocks within the template, calculate the distortion cost with the reconstructed samples in the template, and record the distortion cost in each prediction mode. After the decoder traverses all allowed MIP modes and transposed information and traverses the prediction modes allowed by TIMD, it can select the optimal prediction mode based on the principle of minimum distortion cost.
  • the MIP mode and its The corresponding transposition information is used as the optimal prediction mode of the current block; if the distortion cost of the TIMD mode is the smallest, the TIMD mode is used as the optimal prediction mode of the current block, and the optimal intra prediction mode derived by the TIMD technology is recorded and recorded. Distortion cost, while recording the suboptimal prediction mode derived by TIMD technology and its distortion cost.
  • the decoder will sample the reconstructed samples adjacent to the upper and left sides of the current block according to the optimal MIP mode and transposition information as appropriate, and transform them according to the situation.
  • the position information is spliced as an input vector, and the matrix coefficients in the current mode are read according to the MIP mode as an index.
  • the output vector is obtained by calculating the input vector and matrix coefficients.
  • the decoder can perform output transposition according to the transposition information, and upsample the output vector according to the size of the current block and the number of samples of the output vector, and obtain an output with the same size as the current block as the prediction block of the current block. Based on this, the decoder obtains the rate distortion cost of the current block and records it as cost1.
  • the optimal prediction mode obtained by the decoder is the TIMD mode. If neither the optimal prediction mode nor the suboptimal prediction mode is the mean (DC) mode or the flat (PLANAR) mode, and the distortion cost of the suboptimal prediction mode is less than twice the distortion cost of the optimal prediction mode, the decoder needs to predict the block Fusion operation. First, the decoder obtains the interpolation filter coefficients according to the optimal prediction mode, and performs interpolation filtering on the upper and left adjacent reconstructed samples to obtain prediction samples at all positions in the current block, which are recorded as the optimal prediction block; secondly, the decoder performs interpolation filtering according to the suboptimal prediction mode.
  • the prediction mode obtains the interpolation filter coefficients, and performs interpolation filtering on the upper and left adjacent reconstructed samples to obtain prediction samples at all positions in the current block, which are recorded as suboptimal prediction blocks.
  • the decoder uses the ratio between the optimal prediction mode cost value and the suboptimal prediction mode cost value to calculate the weight value belonging to the optimal prediction block and the weight value of the suboptimal prediction block.
  • the decoder performs a weighted fusion of the optimal prediction block and the suboptimal prediction block to obtain the prediction block of the current block as output.
  • the decoder does not need to perform prediction blocks In the fusion operation, only the optimal prediction block obtained by interpolation filtering the upper and left adjacent reconstructed samples using the optimal prediction mode is used as the prediction block of the current block. Based on this, the decoder obtains the rate distortion cost of the current block, recorded as cost1.
  • the decoder continues to parse information such as usage flags or indexes of other intra prediction technologies, and obtains the final prediction block of the current block based on the parsed information.
  • the decoder parses the code stream and obtains the frequency domain residual block of the current block (also called frequency domain residual information), and performs inverse quantization and inverse transformation on the frequency domain residual block of the current block to obtain the residual block of the current block (also known as the temporal residual block or temporal residual information); the decoder then superimposes the prediction block of the current block and the residual block of the current block to obtain a reconstructed sample block.
  • frequency domain residual information also called frequency domain residual information
  • temporal residual block or temporal residual information also known as the temporal residual block or temporal residual information
  • the reconstructed image can be used as video output or as a reference for subsequent decoding.
  • the calculation process of the weight value of the weighted fusion of TIMD prediction blocks can be referred to the content described above in the introduction to TIMD technology. To avoid duplication, it will not be described again here.
  • the size of the template area used by the encoder or decoder in the TMMIP technology can be predefined based on the size of the current block. For example, if the MIP mode is the optimal prediction mode or the suboptimal prediction mode, you can also try a weighted fusion operation; in addition, the definition of the template area in the TMMIP technology can be consistent with the definition of the template area in the TIMD technology, or it can be different.
  • the width of the current block is less than or equal to 8
  • the height of the upper area adjacent to the current block in the template area is the height of two rows of samples, otherwise the height is the height of four rows of samples; similarly, if the height of the current block is less than If equal to 8, then the width of the left area in the template area adjacent to the left side of the current block is two columns of sample height, otherwise the width is four columns of sample height.
  • the size of the sequence numbers of the above-mentioned processes does not mean the order of execution.
  • the execution order of each process should be determined by its functions and internal logic, and should not be used in this application.
  • the execution of the examples does not constitute any limitations.
  • Figure 7 is a schematic block diagram of the decoder 500 according to the embodiment of the present application.
  • the decoder 500 may include:
  • the parsing unit 510 is used to parse the code stream to obtain the residual block of the current block in the current sequence
  • Prediction unit 520 used for:
  • the distortion cost of the multiple MIP modes includes the distortion cost obtained by using the multiple MIP modes to predict samples in the template area adjacent to the current block;
  • the reconstruction unit 530 is configured to obtain a reconstruction block of the current block based on the residual block of the current block and the prediction block of the current block.
  • the prediction unit 520 is specifically used to:
  • the optimal MIP mode is determined based on the distortion costs of the multiple MIP modes.
  • the prediction unit 520 is specifically used to:
  • the first identifier is used to identify that the optimal MIP mode is allowed to be used to predict the image blocks in the current sequence, then parse the code stream to obtain the second identifier;
  • the optimal MIP mode is determined based on the distortion costs of the multiple MIP modes.
  • the parsing unit 510 is also used to:
  • the code stream of the current sequence is decoded based on the encoding method used in the optimal MIP mode to obtain the index of the optimal MIP mode.
  • the codeword length of the encoding method used by the first n MIP modes in the arrangement sequence is smaller than the codeword length of the encoding mode used by the MIP mode after the nth MIP mode in the arrangement sequence; and/ Or, the first n MIP patterns use variable length encoding and the MIP patterns after the nth MIP pattern use truncated binary encoding.
  • the prediction unit 520 is specifically used to:
  • the optimal MIP mode is determined as the intra prediction mode of the current block.
  • the prediction unit 520 is specifically used to:
  • the template-based intra mode derivation TIMD mode predicts the current block to obtain the second prediction block
  • the prediction mode with the smallest distortion cost among the optimal MIP mode and the TIMD mode is determined as the intra-frame of the current block. Prediction mode.
  • the prediction unit 520 is specifically used to:
  • the optimal MIP mode is determined based on the distortion costs of the multiple MIP modes in each state of the third identifier.
  • the prediction unit 520 is specifically used to:
  • the optimal MIP mode is determined based on the distortion costs of the multiple MIP modes.
  • the prediction unit 520 is specifically used to:
  • the optimal MIP mode is determined based on the distortion costs of the multiple MIP modes.
  • the prediction unit 520 is specifically used to:
  • the optimal MIP mode is determined based on the distortion costs of the multiple MIP modes.
  • the prediction unit 520 before determining the optimal MIP mode for predicting the current block based on the distortion costs of multiple matrix-based intra prediction MIP modes, the prediction unit 520 is also used to:
  • the MIP modes used by the adjacent blocks are determined as the multiple MIP modes.
  • the prediction unit 520 before determining the optimal MIP mode for predicting the current block based on the distortion costs of multiple matrix-based intra prediction MIP modes, the prediction unit 520 is also used to:
  • Distortion costs for the plurality of MIP modes are determined based on the plurality of prediction blocks and reconstruction blocks within the template region.
  • the prediction unit 520 is specifically used to:
  • the output vectors of the multiple MIP modes are upsampled to obtain prediction blocks corresponding to the multiple MIP modes.
  • the prediction unit 520 is specifically used to:
  • the optimal MIP pattern is determined based on the sum SATD of absolute transformation differences of the plurality of MIP patterns on the template region.
  • Figure 8 is a schematic block diagram of the encoder 600 according to the embodiment of the present application.
  • the encoder 600 may include:
  • Prediction unit 610 used for:
  • the distortion cost of the multiple MIP modes includes the distortion cost obtained by using the multiple MIP modes to predict samples in the template area adjacent to the current block;
  • Residual unit 620 configured to obtain a residual block of the current block based on the prediction block of the current block and the original block of the current block;
  • the encoding unit 630 is used to encode the residual block of the current block to obtain the code stream of the current sequence.
  • the prediction unit 610 is specifically used to:
  • the optimal MIP mode is determined based on the distortion costs of the multiple MIP modes
  • the encoding unit 630 is specifically used for:
  • the prediction unit 610 is specifically used to:
  • the optimal prediction mode based on the optimal MIP mode
  • the optimal prediction mode as the intra prediction mode of the current block
  • the encoding unit 630 is specifically used for:
  • the second identifier is used to identify that the optimal MIP mode is allowed to be used to predict the current block; If the first rate distortion cost is greater than the minimum value of the at least one rate distortion cost, the second identification is used to identify that the optimal MIP mode is not allowed to be used to predict the current block.
  • the prediction unit 610 is specifically used to:
  • the optimal MIP mode is determined as the optimal prediction mode.
  • the prediction unit 610 is specifically used to:
  • the template-based intra mode derivation TIMD mode predicts the current block to obtain the second prediction block
  • the prediction mode with the smallest distortion cost among the optimal MIP mode and the TIMD mode is determined as the optimal prediction mode.
  • the encoding unit 630 is specifically used to:
  • the code stream is obtained by encoding the residual block of the current block and encoding the index of the optimal MIP mode based on the encoding method used in the optimal MIP mode.
  • the codeword length of the encoding method used by the first n MIP modes in the arrangement sequence is smaller than the codeword length of the encoding mode used by the MIP mode after the nth MIP mode in the arrangement sequence; and/ Or, the first n MIP patterns use variable length encoding and the MIP patterns after the nth MIP pattern use truncated binary encoding.
  • the prediction unit 610 is specifically used to:
  • the optimal MIP mode is determined as the intra prediction mode of the current block.
  • the prediction unit 610 is specifically used to:
  • the optimal MIP mode is determined based on the distortion costs of the multiple MIP modes in each state of the third identifier.
  • the prediction unit 610 is specifically used to:
  • the optimal MIP mode is determined based on the distortion costs of the multiple MIP modes.
  • the prediction unit 610 is specifically used to:
  • the optimal MIP mode is determined based on the distortion costs of the multiple MIP modes.
  • the prediction unit 610 is specifically used to:
  • the optimal MIP mode is determined based on the distortion costs of the multiple MIP modes.
  • the prediction unit 610 before determining the optimal MIP mode for predicting the current block in the current sequence based on the distortion cost of multiple matrix-based intra prediction MIP modes, the prediction unit 610 is also used to:
  • the MIP modes used by the adjacent blocks are determined as the multiple MIP modes.
  • the prediction unit 610 before determining the optimal MIP mode for predicting the current block in the current sequence based on the distortion cost of multiple matrix-based intra prediction MIP modes, the prediction unit 610 is also used to:
  • Distortion costs for the plurality of MIP modes are determined based on the plurality of prediction blocks and reconstruction blocks within the template region.
  • the prediction unit 610 is specifically used to:
  • the output vectors of the multiple MIP modes are upsampled to obtain prediction blocks corresponding to the multiple MIP modes.
  • the prediction unit 610 is specifically used to:
  • the optimal MIP pattern is determined based on the sum SATD of absolute transformation differences of the plurality of MIP patterns on the template region.
  • the device embodiments and the method embodiments may correspond to each other, and similar descriptions may refer to the method embodiments. To avoid repetition, they will not be repeated here.
  • the decoder 500 shown in Figure 7 may correspond to the corresponding subject in performing the method 300 of the embodiment of the present application, and the foregoing and other operations and/or functions of each unit in the decoder 500 are respectively to implement the method 300, etc.
  • the encoder 600 shown in Figure 8 may correspond to the corresponding subject in performing the method 400 of the embodiment of the present application, that is, the foregoing and other operations and/or functions of each unit in the encoder 600 are respectively in order to implement the method 400, etc. Corresponding processes in each method.
  • each unit in the decoder 500 or encoder 600 involved in the embodiment of the present application can be separately or entirely combined into one or several other units to form, or some of the units (some) can also be disassembled. It is divided into multiple units with smaller functions, which can achieve the same operation without affecting the realization of the technical effects of the embodiments of the present application.
  • the above units are divided based on logical functions. In practical applications, the function of one unit can also be realized by multiple units, or the functions of multiple units can be realized by one unit. In other embodiments of the present application, the decoder 500 or the encoder 600 may also include other units. In practical applications, these functions may also be implemented with the assistance of other units, and may be implemented by multiple units in cooperation.
  • a general-purpose computing device including a general-purpose computer including processing elements and storage elements such as a central processing unit (CPU), a random access storage medium (RAM), a read-only storage medium (ROM), etc.
  • Run a computer program capable of executing each step involved in the corresponding method to construct the decoder 500 or encoder 600 involved in the embodiment of the present application, and implement the encoding method or decoding method of the embodiment of the present application.
  • the computer program can be recorded on, for example, a computer-readable storage medium, loaded into an electronic device through the computer-readable storage medium, and run therein to implement the corresponding methods of the embodiments of the present application.
  • the units mentioned above can be implemented in the form of hardware, can also be implemented in the form of instructions in the form of software, or can be implemented in the form of a combination of software and hardware.
  • each step of the method embodiments in the embodiments of the present application can be completed by integrated logic circuits of hardware in the processor and/or instructions in the form of software.
  • the steps of the methods disclosed in conjunction with the embodiments of the present application can be directly embodied in hardware.
  • the execution of the decoding processor is completed, or the execution is completed using a combination of hardware and software in the decoding processor.
  • the software can be located in a mature storage medium in this field such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, register, etc.
  • the storage medium is located in the memory, and the processor reads the information in the memory and completes the steps in the above method embodiment in combination with its hardware.
  • FIG. 9 is a schematic structural diagram of an electronic device 700 provided by an embodiment of the present application.
  • the electronic device 700 at least includes a processor 710 and a computer-readable storage medium 720 .
  • the processor 710 and the computer-readable storage medium 720 may be connected through a bus or other means.
  • the computer-readable storage medium 720 is used to store a computer program 721
  • the computer program 721 includes computer instructions
  • the processor 710 is used to execute the computer instructions stored in the computer-readable storage medium 720.
  • the processor 710 is the computing core and the control core of the electronic device 700. It is suitable for implementing one or more computer instructions. Specifically, it is suitable for loading and executing one or more computer instructions to implement the corresponding method flow or corresponding functions.
  • the processor 710 may also be called a central processing unit (Central Processing Unit, CPU).
  • the processor 710 may include, but is not limited to: a general-purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field programmable gate array (Field Programmable Gate Array, FPGA) Or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.
  • DSP Digital Signal Processor
  • ASIC Application Specific Integrated Circuit
  • FPGA Field Programmable Gate Array
  • the computer-readable storage medium 720 can be a high-speed RAM memory, or a non-volatile memory (Non-Volatile Memory), such as at least one disk memory; optionally, it can also be at least one located far away from the aforementioned processor 710 Computer-readable storage media.
  • the computer-readable storage medium 720 includes, but is not limited to: volatile memory and/or non-volatile memory.
  • non-volatile memory can be read-only memory (Read-Only Memory, ROM), programmable read-only memory (Programmable ROM, PROM), erasable programmable read-only memory (Erasable PROM, EPROM), electrically removable memory.
  • Volatile memory may be Random Access Memory (RAM), which is used as an external cache.
  • RAM Random Access Memory
  • SRAM static random access memory
  • DRAM dynamic random access memory
  • DRAM synchronous dynamic random access memory
  • DDR SDRAM double data rate synchronous dynamic random access memory
  • Enhanced SDRAM, ESDRAM enhanced synchronous dynamic random access memory
  • SLDRAM synchronous link dynamic random access memory
  • Direct Rambus RAM Direct Rambus RAM
  • the electronic device 700 may be the encoder or coding framework involved in the embodiment of the present application; the computer-readable storage medium 720 stores the first computer instructions; the computer-readable instructions are loaded and executed by the processor 710
  • the first computer instructions stored in the storage medium 720 are used to implement the corresponding steps in the encoding method provided by the embodiment of the present application; in other words, the first computer instructions in the computer-readable storage medium 720 are loaded by the processor 710 and execute the corresponding steps, To avoid repetition, they will not be repeated here.
  • the electronic device 700 may be the decoder or decoding framework involved in the embodiment of the present application; the computer-readable storage medium 720 stores second computer instructions; the computer-readable instructions are loaded and executed by the processor 710 The second computer instructions stored in the storage medium 720 are used to implement the corresponding steps in the decoding method provided by the embodiment of the present application; in other words, the second computer instructions in the computer-readable storage medium 720 are loaded by the processor 710 and execute the corresponding steps, To avoid repetition, they will not be repeated here.
  • embodiments of the present application also provide a coding and decoding system, including the above-mentioned encoder and decoder.
  • embodiments of the present application also provide a computer-readable storage medium (Memory).
  • the computer-readable storage medium is a memory device in the electronic device 700 and is used to store programs and data.
  • computer-readable storage medium 720 may include a built-in storage medium in the electronic device 700 , and of course may also include an extended storage medium supported by the electronic device 700 .
  • the computer-readable storage medium provides storage space that stores the operating system of the electronic device 700 .
  • one or more computer instructions suitable for being loaded and executed by the processor 710 are also stored in the storage space. These computer instructions may be one or more computer programs 721 (including program codes).
  • a computer program product or computer program is provided, the computer program product or computer program including computer instructions stored in a computer-readable storage medium.
  • the data processing device 700 can be a computer.
  • the processor 710 reads the computer instructions from the computer-readable storage medium 720.
  • the processor 710 executes the computer instructions, so that the computer executes the encoding method provided in the above various optional ways. or decoding method.
  • the computer program product includes one or more computer instructions.
  • the computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable device.
  • the computer instructions may be stored in or transmitted from one computer-readable storage medium to another, e.g., the computer instructions may be transmitted from a website, computer, server, or data center to Transmission to another website, computer, server or data center via wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) methods.
  • wired such as coaxial cable, optical fiber, digital subscriber line (DSL)
  • wireless such as infrared, wireless, microwave, etc.

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Abstract

本申请实施例提供了一种解码方法、编码方法、解码器以及编码器。所述解码方法包括：解析码流获取当前序列中当前块的残差块；基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测所述当前块的最优MIP模式；其中，所述多个MIP模式的失真代价包括利用所述多个MIP模式对与所述当前块相邻的模板区域内的样本进行预测得到的失真代价；基于所述最优MIP模式，确定所述当前块的帧内预测模式；基于所述当前块的帧内预测模式对所述当前块进行预测，得到所述当前块的预测块；基于所述当前块的残差块和所述当前块的预测块，得到所述当前块的重建块。本申请的方案能够提高解压缩效率。

Description

解码方法、编码方法、解码器以及编码器 技术领域
本申请实施例涉及图像视频编解码技术领域，并且更具体地，涉及解码方法、编码方法、解码器以及编码器。
背景技术
数字视频压缩技术主要是将庞大的数字影像视频数据进行压缩，以便于传输以及存储等。随着互联网视频的激增以及人们对视频清晰度的要求越来越高，尽管已有的数字视频压缩标准能够实现视频的解压缩技术，但目前仍然需要追求更好的数字视频解压缩技术，以在提升压缩效率。
发明内容
本申请实施例提供了一种解码方法、编码方法、解码器以及编码器，能够提升压缩效率。
第一方面，本申请提供了一种解码方法，包括：
解析码流获取当前序列中当前块的残差块；
基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测所述当前块的最优MIP模式；
其中，所述多个MIP模式的失真代价包括利用所述多个MIP模式对与所述当前块相邻的模板区域内的样本进行预测得到的失真代价；
基于所述最优MIP模式，确定所述当前块的帧内预测模式；
基于所述当前块的帧内预测模式对所述当前块进行预测，得到所述当前块的预测块；
基于所述当前块的残差块和所述当前块的预测块，得到所述当前块的重建块。
第二方面，本申请提供了一种编码方法，包括：
基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测当前序列中的当前块的最优MIP模式；
其中，所述多个MIP模式的失真代价包括利用所述多个MIP模式对与所述当前块相邻的模板区域内的样本进行预测得到的失真代价；
基于所述最优MIP模式，确定所述当前块的帧内预测模式；
基于所述当前块的帧内预测模式对所述当前块进行预测，得到所述当前块的预测块；
基于所述当前块的预测块和所述当前块的原始块，得到所述当前块的残差块；
对所述当前块的残差块进行编码，得到所述当前序列的码流。
第三方面，本申请提供了一种解码器，包括：
解析单元，用于解析码流获取当前序列中当前块的残差块；
预测单元，用于：
基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测所述当前块的最优MIP模式；
其中，所述多个MIP模式的失真代价包括利用所述多个MIP模式对与所述当前块相邻的模板区域内的样本进行预测得到的失真代价；
基于所述最优MIP模式，确定所述当前块的帧内预测模式；
基于所述当前块的帧内预测模式对所述当前块进行预测，得到所述当前块的预测块；
重建单元，用于基于所述当前块的残差块和所述当前块的预测块，得到所述当前块的重建块。
第四方面，本申请提供了一种编码器，包括：
预测单元，用于：
基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测当前序列中的当前块的最优MIP模式；
其中，所述多个MIP模式的失真代价包括利用所述多个MIP模式对与所述当前块相邻的模板区域内的样本进行预测得到的失真代价；
基于所述最优MIP模式，确定所述当前块的帧内预测模式；
基于所述当前块的帧内预测模式对所述当前块进行预测，得到所述当前块的预测块；
残差单元，用于基于所述当前块的预测块和所述当前块的原始块，得到所述当前块的残差块；
编码单元，用于对所述当前块的残差块进行编码，得到所述当前序列的码流。
第五方面，本申请提供了一种解码器，包括：
处理器，适于实现计算机指令；以及，
计算机可读存储介质，计算机可读存储介质存储有计算机指令，计算机指令适于由处理器加载并执 行上述第一方面或其各实现方式中的解码方法。
在一种实现方式中，该处理器为一个或多个，该存储器为一个或多个。
在一种实现方式中，该计算机可读存储介质可以与该处理器集成在一起，或者该计算机可读存储介质与处理器分离设置。
第六方面，本申请提供了一种编码器，包括：
处理器，适于实现计算机指令；以及，
计算机可读存储介质，计算机可读存储介质存储有计算机指令，计算机指令适于由处理器加载并执行上述第二方面或其各实现方式中的编码方法。
在一种实现方式中，该处理器为一个或多个，该存储器为一个或多个。
在一种实现方式中，该计算机可读存储介质可以与该处理器集成在一起，或者该计算机可读存储介质与处理器分离设置。
第七方面，本申请提供了一种计算机可读存储介质，该计算机可读存储介质存储有计算机指令，该计算机指令被计算机设备的处理器读取并执行时，使得计算机设备执行上述第一方面涉及的解码方法或上述第二方面涉及的编码方法。
第八方面，本申请提供了一种码流，该码流上述第一方面中涉及所述的码流或上述第二方面中涉及的码流。
基于以上技术方案，解码器在确定当前块的帧内预测模式时，基于多个MIP模式的失真代价确定用于预测所述当前块的最优MIP模式，并基于所述最优MIP模式确定所述当前块的帧内预测模式；相当于，有利于避免解码器通过解析码流获取所述MIP模式，与传统的MIP技术相比，能够有效减少编码单元级的比特开销，进而能够提高解压缩效率。
附图说明
图1是本申请实施例提供的编码框架的示意性框图。
图2是本申请实施例提供的MIP模式的示意图。
图3是本申请实施例提供的TIMD使用的模板的示意图。
图4是本申请实施例提供的解码框架的示意性框图。
图5是本申请实施例提供的解码方法的示意性流程图。
图6是本申请实施例提供的编码方法的示意性流程图。
图7是本申请实施例提供的解码器的示意性框图。
图8是本申请实施例提供的编码器的示意性框图。
图9是本申请实施例提供的电子设备的示意性框图。
具体实施方式
下面将结合附图，对本申请实施例中的技术方案进行描述。
本申请实施例提供的方案可应用于数字视频编码技术领域，例如，包括但不限于：图像编解码领域、视频编解码领域、硬件视频编解码领域、专用电路视频编解码领域以及实时视频编解码领域。此外，本申请实施例提供的方案可结合至音视频编码标准(Audio Video coding Standard，AVS)、第二代AVS标准(AVS2)或第三代AVS标准(AVS3)。例如，包括但不限于：H.264/音视频编码(Audio Video coding，AVC)标准、H.265/高效视频编码(High Efficiency Video Coding，HEVC)标准以及H.266/多功能视频编码(Versatile Video Coding，VVC)标准。另外，本申请实施例提供的方案可以用于对图像进行有损压缩(lossy compression)，也可以用于对图像进行无损压缩(lossless compression)。其中该无损压缩可以是视觉无损压缩(visually lossless compression)，也可以是数学无损压缩(mathematically lossless compression)。
视频编解码标准都采用基于块的混合编码框架。视频中的每一帧被分割成相同大小(如128x128，64x64等)的正方形的最大编码单元(LCU largest coding unit)或编码树单元(CTU Coding Tree Unit)。每个最大编码单元或编码树单元可根据规则划分成矩形的编码单元(CU coding unit)。编码单元可能还会划分为预测单元(PU prediction unit)，变换单元(TU transform unit)等。混合编码框架包括预测(prediction)、变换(transform)、量化(quantization)、熵编码(entropy coding)、环路滤波(in loop filter)等模块。预测模块包括帧内预测(intra prediction)和帧间预测(inter prediction)。帧间预测包括运动估计(motion estimation)和运动补偿(motion compensation)。由于视频的一个帧中的相邻像素之间存在很强的相关性，在视频编解码技术中使用帧内预测的方法消除相邻像素之间的空间冗余。帧内预测只参考同一帧图像的信息，预测当前划分块内的像素信息。由于视频中的相邻帧之间存在着很强的相似性，在 视频编解码技术中使用帧间预测方法消除相邻帧之间的时间冗余，从而提高编码效率。帧间预测可以参考不同帧的图像信息，利用运动估计搜索最匹配当前划分块的运动矢量信息。变换将预测后的图像块转换到频率域，能量重新分布，结合量化可以将人眼不敏感的信息去除，用于消除视觉冗余。熵编码可以根据当前上下文模型以及二进制码流的概率信息消除字符冗余。
在数字视频编码过程中，编码器可以先从原始视频序列中读取一幅黑白图像或彩色图像，然后针对黑白图像或彩色图像进行编码。其中，黑白图像可以包括亮度分量的像素，彩色图像可以包括色度分量的像素。可选的，彩色图像还可以包括亮度分量的像素。原始视频序列的颜色格式可以是亮度色度(YCbCr，YUV)格式或红绿蓝(Red-Green-Blue，RGB)格式等。具体地，编码器读取一幅黑白图像或彩色图像之后，分别将其划分成块，并对当前块使用帧内预测或帧间预测产生当前块的预测块，当前块的原始块减去预测块得到残差块，对残差块进行变换、量化得到量化系数矩阵，对量化系数矩阵进行熵编码输出到码流中。在数字视频解码过程中，解码端对当前块使用帧内预测或帧间预测产生当前块的预测块。此外，解码端解析码流得到量化系数矩阵，对量化系数矩阵进行反量化、反变换得到残差块，将预测块和残差块相加得到重建块。重建块可用于组成重建图像，解码端基于图像或基于块对重建图像进行环路滤波得到解码图像。
当前块(current block)可以是当前编码单元(CU)或当前预测单元(PU)等。
需要说明的是，编码端同样需要和解码端类似的操作获得解码图像。解码图像可以为后续的帧作为帧间预测的参考帧。编码端确定的块划分信息，预测、变换、量化、熵编码、环路滤波等模式信息或者参数信息，如果有必要需要在输出到码流中。解码端通过解析及根据已有信息进行分析确定与编码端相同的块划分信息，预测、变换、量化、熵编码、环路滤波等模式信息或者参数信息，从而保证编码端获得的解码图像和解码端获得的解码图像相同。编码端获得的解码图像通常也叫做重建图像。在预测时可以将当前块划分成预测单元，在变换时可以将当前块划分成变换单元，预测单元和变换单元的划分可以相同也可以不同。当然，上述仅是基于块的混合编码框架下的视频编解码器的基本流程，随着技术的发展，框架的一些模块或流程的一些步骤可能会被优化，本申请适用于该基于块的混合编码框架下的视频编解码器的基本流程。
为了便于理解，先对本申请提供的编码框架进行简单介绍。
图1是本申请实施例提供的编码框架100的示意性框图。
如图1所示，该编码框架100可包括帧内预测单元180、帧间预测单元170、残差单元110、变换与量化单元120、熵编码单元130、反变换与反量化单元140、以及环路滤波单元150。可选的，该编码框架100还可包括解码图像缓冲单元160。该编码框架100也可称为混合框架编码模式。
其中，帧内预测单元180或帧间预测单元170可对待编码图像块进行预测，以输出预测块。残差单元110可基于预测块与待编码图像块计算残差块，即预测块和待编码图像块的差值。变换与量化单元120用于对残差块执行变换与量化等操作，以去除人眼不敏感的信息，进而消除视觉冗余。可选的，经过变换与量化单元120变换与量化之前的残差块可称为时域残差块，经过变换与量化单元120变换与量化之后的时域残差块可称为频率残差块或频域残差块。熵编码单元130接收到变换与量化单元120输出的变换量化系数后，可基于该变换量化系数输出码流。例如，熵编码单元130可根据目标上下文模型以及二进制码流的概率信息消除字符冗余。例如，熵编码单元130可以用于基于上下文的自适应二进制算术熵编码(CABAC)。熵编码单元130也可称为头信息编码单元。可选的，在本申请中，该待编码图像块也可称为原始图像块或目标图像块，预测块也可称为预测图像块或图像预测块，还可以称为预测信号或预测信息，重建块也可称为重建图像块或图像重建块，还可以称为重建信号或重建信息。此外，针对编码端，该待编码图像块也可称为编码块或编码图像块，针对解码端，该待编码图像块也可称为解码块或解码图像块。该待编码图像块可以是CTU或CU。
编码框架100将预测块与待编码图像块计算残差得到残差块经由变换与量化等过程，将残差块传输到解码端。相应的，解码端接收并解析码流后，经过反变换与反量化等步骤得到残差块，将解码端预测得到的预测块叠加残差块后得到重建块。
需要说明的是，编码框架100中的反变换与反量化单元140、环路滤波单元150以及解码图像缓冲单元160可用于形成一个解码器。相当于，帧内预测单元180或帧间预测单元170可基于已有的重建块对待编码图像块进行预测，进而能够保证编码端和解码端的对参考帧的理解一致。换言之，编码器可复制解码器的处理环路，进而可与解码端产生相同的预测。具体而言，量化的变换系数通过反变换与反量化单元140反变换与反量化来复制解码端的近似残差块。该近似残差块加上预测块后可经过环路滤波单元150，以平滑滤除由于基于块处理和量化产生的块效应等影响。环路滤波单元150输出的图像块可存储在解码图像缓存单元160中，以便用于后续图像的预测。
应理解，图1仅为本申请的示例，不应理解为对本申请的限制。
例如，该编码框架100中的环路滤波单元150可包括去块滤波器(DBF)和样点自适应补偿滤波(SAO)。DBF的作用是去块效应，SAO的作用是去振铃效应。在本申请的其他实施例中，该编码框架100可采用基于神经网络的环路滤波算法，以提高视频的压缩效率。或者说，该编码框架100可以是基于深度学习的神经网络的视频编码混合框架。在一种实现中，可以在去块滤波器和样点自适应补偿滤波基础上，采用基于卷积神经网络的模型计算对像素滤波后的结果。环路滤波单元150在亮度分量和色度分量上的网络结构可以相同，也可以有所不同。考虑到亮度分量包含更多的视觉信息，还可以采用亮度分量指导色度分量的滤波，以提升色度分量的重建质量。
下面对帧内预测的相关内容进行说明。
对于帧内预测，帧内预测只参考同一帧图像的信息，预测待编码图像块内的像素信息，用于消除空间冗余；帧内预测所使用的帧可以为I帧。例如，可根据从左至右、从上到下的编码顺序，待编码图像块可以参考左上方图像块，上方图像块以及左侧图像块作为参考信息来预测待编码图像块，而待编码图像块又作为下一个图像块的参考信息，如此，可对整幅图像进行预测。若输入的数字视频为彩色格式，例如YUV 4:2:0格式，则该数字视频的每一图像帧的每4个像素点由4个Y分量和2个UV分量组成，编码框架可对Y分量(即亮度块)和UV分量(即色度块)分别进行编码。类似的，解码端也可根据格式进行相应的解码。
下面对本申请涉及的其他帧内预测模式进行介绍：
(1)、基于矩阵的帧内预测(Matrix based Intra Prediction，MIP)模式。
MIP模式涉及的流程可以分为三个主要步骤，其分别是下采样过程、矩阵相乘过程以及上采样过程。具体来说，首先通过下采样过程下采样空间相邻重建样本，然后，将得到下采样后的样本序列作为矩阵相乘过程的输入向量，即将下采样过程的输出向量作为矩阵相乘过程的输入向量，与预先设定好的矩阵相乘并加上偏置向量，并输出计算之后的样本向量；最后，将矩阵相乘过程的输出向量作为上采样过程的输入向量，通过上采样得到最终的预测块。
图2是本申请实施例提供的MIP模式的示意图。
如图2所示，MIP模式在下采样过程中通过平均当前编码单元上边相邻的重建样本后得到上相邻下采样重建样本向量bdry top，通过平均左相邻的重建样本后得到左相邻下采样重建样本向量bdry left。得到bdry top和bdry left后，将其作为矩阵相乘过程的输入向量bdry red，具体地，可通基于bdry red的顶行向量bdry top red、bdry left、A k·bdry red+b k得到样本向量，其中A k为预先设定好的矩阵，b k为预先设定好的偏置向量，k为MIP模式的索引。得到样本向量后通过线性插值对其进行上采样，以得到与实际编码单元样本数相符的预测样本块。
换言之，为了对一个宽度为W高度为H的块进行预测，MIP需要当前块左侧一列的H个重建像素和当前块上侧一行的W个重建像素作为输入。MIP按如下3个步骤生成预测块：参考像素平均(Averaging)，矩阵乘法(Matrix Vector Multiplication)和插值(Interpolation)。其中MIP的核心是矩阵乘法，其可以认为是用一种矩阵乘法的方式用输入像素(参考像素)生成预测块的过程。MIP提供了多种矩阵，预测方式的不同可以体现在矩阵的不同上，相同的输入像素使用不同的矩阵会得到不同的结果。而参考像素平均和插值的过程是一种性能和复杂度折中的设计。对于尺寸较大的块，可以通过参考像素平均来实现一种近似于降采样的效果，使输入能适配到比较小的矩阵，而插值则实现一种上采样的效果。这样就不需要对每一种尺寸的块都提供MIP的矩阵，而是只提供一种或几种特定的尺寸的矩阵即可。随着对压缩性能的需求的提高，以及硬件能力的提高，下一代的标准中也许会出现复杂度更高的MIP。
对于MIP模式而言，MIP模式可以由神经网络简化而来，例如其采用的矩阵可以是基于训练得到，因此，MIP模式拥有较强的泛化能力和传统预测模式达不到的预测效果。MIP模式可以是对一个基于神经网络的帧内预测模型经过多次硬件和软件复杂度简化而得到的模型，在大量训练样本的基础上，多种预测模式代表着多种模型和参数，能够较好的覆盖自然序列的纹理情况。
MIP有些类似于平面模式，但显然MIP比平面模式更复杂，灵活性也更强。
需要说明的是，对于不同块尺寸的编码单元，MIP模式的个数可以有所不同。示例性地，对于4x4大小的编码单元，MIP模式有16种预测模式；对于8x8、宽等于4或高等于4的编码单元，MIP模式有8种预测模式；其他尺寸的编码单元，MIP模式有6种预测模式。同时，MIP模式有一个转置功能，对于符合当前尺寸的预测模式，MIP模式在编码器侧可以尝试转置计算。因此，MIP模式不仅需要一个标志位来表示当前编码单元是否使用MIP模式，同时，若当前编码单元使用MIP模式，则额外还需要传输一个转置标志位到解码器。
MIP的转置标志位由定长编码方式(Fixed Length，FL)进行二值化，长度为1。而MIP的模式索引由截断二进制编码方式(Truncated Binary，TB)进行二值化。
(2)、基于模板的帧内模式导出(Template based Intra Mode Derivation，TIMD)预测模式。
对于TIMD预测模式，编解码器同样的利用操作导出预测模式的方式来节省传输模式索引的开销。TIMD预测模式主要可以理解成两个主要部分，首先根据模板计算各预测模式的代价信息，最小代价及次小代价对应的预测模式将被选中，最小代价对应的预测模式记为预测模式1，次小代价对应的预测模式记为预测模式2；若次小代价的数值(costMode2)与最小代价的数值(costMode1)比例满足预设条件，如costMode2<2*costMode1，则将预测模式1与预测模式2各对应的预测块可按照预测模式1与预测模式2各对应的权重进行加权融合，进而得到最终的预测块。
示例性地，预测模式1与预测模式2各对应的权重根据以下方式确定：
weight1＝costMode2/(costMode1+costMode2)；
weight2＝1-weight1；
其中，weight1即为预测模式1对应预测块的加权权重，weight2即为预测模式2对应预测块的加权权重。但若次小代价的数值costMode2与最小代价的数值costMode1比例不满足预设条件，则不做预测块之间的加权融合，预测模式1对应预测块即为TIMD的预测块。
需要说明的是，若采用TIMD预测模式对当前块进行帧内预测时，若当前块的重建样本模板中不包含可用相邻重建样本，则TIMD预测模式选择平面模式对当前块进行帧内预测，即不进行不加权融合。与DIMD预测模式相同，TIMD预测模式需要传输一个标志位到解码器，以表示当前编码单元是否使用TIMD预测模式。
编码器或解码器计算各预测模式的代价信息过程主要为：根据与模板区域的上侧或左侧相邻重建样本对模板区域内的样本进行帧内模式预测，预测过程与原有帧内预测模式相同；例如利用DC模式对模板区域内的样本进行帧内模式预测时，计算整个编码单元的均值；再如利用角度预测模式对模板区域内的样本进行帧内模式预测时，根据模式选择对应的插值滤波器并根据规则插值出预测样本。此时，可根据模板区域内的预测样本和重建样本，计算该区域预测样本与重建样本之间的失真，即为当前预测模式的代价信息。
图3是本申请实施例提供的TIMD使用的模板的示意图。
如图3所示，若当前块为宽等于M且高等于N的编码单元，编解码器可以基于宽等于2(M+L1)+1且高等于2(N+L2)+1的编码单元中选择当前块的参考模板(Reference of template)内的重建样本对当前块的模板区域内的样本进行预测。当然，若当前块的模板区域中不包含可用相邻重建样本，则TIMD预测模式选择平面模式对当前块进行帧内预测。例如，所述可用相邻重建样本可以是图3中与当前CU的左侧和上侧相邻的样本，即斜线填充区域中没有可用重建样本。也即是说，若斜线填充区域中没有可用重建样本，则TIMD预测模式选择平面模式对当前块进行帧内预测。
需要说明的是，除了边界情况，在编解码当前块时，当前块的左侧和上侧理论上是可以得到重建值的，即当前块的模板中包含可用相邻重建样本。具体实现中，解码器可以使用某一个帧内预测模式在模板上进行预测，并且将预测值和重建值进行比较，以得到该帧内预测模式在模板上的代价。比如SAD，SATD，SSE等。由于模板和当前块是相邻的，因此，模板内的重建样本和当前块内的像素具有相关性，因此，可以用一个预测模式在模板上的表现来估计这个预测模式在当前块上的表现。TIMD将一些候选的帧内预测模式在模板上进行预测，得到候选的帧内预测模式在模板上的代价，取代价最低的一个或2个帧内预测模式作为当前块的帧内预测值。如果2个帧内预测模式在模板上的代价差距不大，将2个帧内预测模式的预测值进行加权平均可以得到压缩性能的提升。可选的，2个预测模式的预测值的权重跟上述的代价有关，例如权重跟代价成反比。
总结来说，TIMD利用帧内预测模式在模板上的预测效果来筛选帧内预测模式，而且可以将2个帧内预测模式根据模板上的代价进行加权。TIMD的好处在于如果当前块选择了TIMD模式，则码流中不需要再去指示具体使用了哪种帧内预测模式，而是由解码器自己通过上述流程导出，一定程度上节省了开销。
图4是本申请实施例提供的解码框架200的示意性框图。
如图4所示，该解码框架200可包括熵解码单元210、反变换反量化单元220、残差单元230、帧内预测单元240、帧间预测单元250、环路滤波单元260、解码图像缓存单元270。
熵解码单元210接收并解析码流后，以获取预测块和频域残差块，针对频域残差块，通过反变换反量化单元220进行反变换与反量化等步骤，可获取时域残差块，残差单元230将帧内预测单元240或帧间预测单元250预测得到的预测块叠加至经过通过反变换反量化单元220进行反变换与反量化之后的时域残差块，可得到重建块。例如，帧内预测单元240或帧间预测单元250可通过解码码流的头信息，获取预测块。
图5是本申请实施例提供的解码方法300的示意性流程图。应理解，该解码方法300可由解码器执 行。例如应用于图4所示的解码框架200。为便于描述，下面以解码器为例进行说明。
如图5所示，所述解码方法300可包括以下中的部分或全部：
S310，解码器解析码流获取当前序列中当前块的残差块；
S320，解码器基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测所述当前块的最优MIP模式；
其中，所述多个MIP模式的失真代价包括利用所述多个MIP模式对与所述当前块相邻的模板区域内的样本进行预测得到的失真代价；
S330，解码器基于所述最优MIP模式，确定所述当前块的帧内预测模式；
S340，解码器基于所述当前块的帧内预测模式对所述当前块进行预测，得到所述当前块的预测块；
S350，解码器基于所述当前块的残差块和所述当前块的预测块，得到所述当前块的重建块。
示例性地，本申请也可将所述S320和所述S330(即解码器基于所述多个MIP模式的失真代价确定所述最优MIP模式并基于所述最优MIP模式确定所述当前块的帧内预测模式的过程)简称为模板匹配的MIP(Template Matching MIP，TMMIP)技术或基于模板匹配的MIP预测模式导出方法；也即是说，解码器在获取当前块的残差块后，可以基于TMMIP技术确定当前块的帧内预测模式，再基于当前块的帧内预测模式对当前块进行预测，得到当前块的预测块；最后，解码器可基于所述当前块的残差块和所述当前块的预测块，得到所述当前块的重建块。
本实施例中，解码器在确定当前块的帧内预测模式时，基于多个MIP模式的失真代价确定用于预测所述当前块的最优MIP模式，并基于所述最优MIP模式确定所述当前块的帧内预测模式；相当于，有利于避免解码器通过解析码流获取所述MIP模式，与传统的MIP技术相比，能够有效减少编码单元级的比特开销，进而能够提高解压缩效率。
换言之，对于传统的MIP技术，其比特开销相比于其他帧内预测工具要多一些，其不仅需要一个标识位去表示是否使用MIP技术，还需要一个标识位去表示是否转置使用MIP，最后也是最大开销部分，它需要使用截断二进制编码去表示MIP的预测模式。MIP是基于神经网络技术简化而来的技术，与传统插值滤波预测技术有较大的不同，对于一些特殊的纹理，虽然MIP预测比传统帧内预测模式的效果更好，但其较大的标识开销是MIP技术的缺陷，以4x4大小的编码单元为例，共有16个预测样本，但其比特开销包括1个MIP使用标识，1个MIP转置标识和5或6位的截断二进制标识。有鉴于此，本申请利用解码器自主确定用于预测当前块的最优MIP模式并基于最优MIP模式确定当前块的帧内预测模式的方式，能够节省最多5或6个比特位的开销，能够有效减少编码单元级的比特开销，进而能够提高解压缩效率。
简言之，本申请提供的方案能够解决传统MIP技术的缺陷，即减少图像块级的比特开销，进而提高解压缩效率。
下面结合表1的测试结果对本申请提供的方案的有益效果进行说明。
表1
Figure PCTCN2022085898-appb-000001
如表1所示，从测试结果中可以看到，本申请提供的方案对于人工智能(AI)的所有序列类别均有性能上的提升，以4K序列(即类别A1)的提升最为明显，平均有0.05％的比特率节省。其中，比约加德增量比特率(
Figure PCTCN2022085898-appb-000002
delta bit rate，BD-rate)为负代表基于本申请提供的方案相对于ECM2.0的测试结果的性能提升。值得注意的是，ECM2.0集成的TIMD预测模式在ECM1.0的基础上有着较高的复杂度，同时仅有0.4％的性能增益。本申请在不增加解码器复杂度的情况下，能够带来不错的性能增益，特别是对于4K序列。此外，由于服务器负载原因，即使编解码时间略有波动，理论上解码时间基本不会增加。
值得注意的是，本申请中的解码器涉及的失真代价不同于编码器涉及的率失真代价(RDcost)，率失真代价为编码端用于在多种帧内预测技术中确定某一种帧内预测技术时使用的失真代价，率失真代价可以是失真图像和原始图像比较得到的代价值，由于解码器并不能获取原始图像，因此，解码器涉及的失真代价可以是重建样本和预测样本之间的失真代价，例如重建样本和预测样本之间的绝对变换差的和 (Sum of Absolute Transformed Difference，SATD)代价或其他可用于计算重建样本和预测样本之间的差异的代价。
在一些实施例中，所述S320可包括：
解码器解析所述当前序列的码流获取第一标识；若所述第一标识用于标识允许使用所述最优MIP模式对所述当前序列中的图像块进行预测，则解码器基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
示例性地，若所述第一标识的取值为第一数值，则用于标识允许使用所述最优MIP模式对所述当前序列中的图像块进行预测；若所述第一标识的取值为第二数值，则用于标识不允许使用所述最优MIP模式对所述当前序列中的图像块进行预测。在一种实现方式中，所述第一数值为1且所述第二数值为0，在另一种实现方式中，所述第一数值为0且所述第二数值为1。当然，所述第一数值和所述第二数值也可为其他数值，本申请对此不作限定。
示例性地，若所述第一标识为真，则用于标识允许使用所述最优MIP模式对所述当前序列中的图像块进行预测；若所述第一标识为假，则用于标识不允许使用所述最优MIP模式对所述当前序列中的图像块进行预测。
示例性地，解码器解析块级标识，若当前块采用帧内预测模式，则解析或获取所述第一标识，若所述第一标识为真，则解码器基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
示例性地，所述第一标识记为sps_timd_enable_flag，此时，解码器解析或获取sps_timd_enable_flag，若所述sps_timd_enable_flag为真，则解码器基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
示例性地，所述第一标识为序列级标识。
需要说明的是，所述第一标识用于标识允许使用所述最优MIP模式对所述当前序列中的图像块进行预测，也可替换为具有类似或相同含义的描述。例如，在其他可替代实施例中，所述第一标识用于标识允许使用所述最优MIP模式对所述当前序列中的图像块进行预测，也可替换为以下中的任一项：所述第一标识用于标识允许使用TMMIP技术确定当前序列中的图像块的帧内预测模式，所述第一标识用于标识允许使用TMMIP技术对当前序列中的图像块进行帧内预测，所述第一标识用于标识允许所述当前序列中的图像块使用TMMIP技术，所述第一标识用于标识允许使用基于所述多个MIP模式确定的MIP模式对当前序列中的图像块进行预测。
此外，在其他可替代实施例中，将TMMIP技术结合至其他技术时，也可通过其他技术的允许标志位来间接指示当前序列是否允许使用TMMIP技术。例如，以TIMD技术为例，所述第一标识用于指示当前序列允许使用TIMD技术时，则说明当前序列也允许使用TMMIP技术；或者说，所述第一标识用于指示当前序列允许使用TIMD技术时，则说明当前序列允许同时使用TIMD技术和TMMIP技术；以进一步节省比特开销。
在一些实施例中，若所述第一标识用于标识允许使用所述最优MIP模式对所述当前序列中的图像块进行预测，则解码器解析所述码流获取第二标识；若所述第二标识用于标识允许使用所述最优MIP模式对所述当前块进行预测，则解码器基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
示例性地，解码器解析块级标识，若当前块采用帧内预测模式，则解析或获取所述第一标识，若所述第一标识为真，则解码器解析或获取所述第二标识，若所述第二标识为真，则解码器基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
示例性地，若所述第二标识的第三数值，则用于标识允许使用所述最优MIP模式对所述当前块进行预测；若所述第二标识的第四数值，则用于标识不允许使用所述最优MIP模式对所述当前块进行预测。在一种实现方式中，所述第三数值为1且所述第四数值为0，在另一种实现方式中，所述第三数值为0且所述第四数值为1。当然，所述第三数值和所述第四数值也可为其他数值，本申请对此不作具体限定。
示例性地，若所述第二标识为真，则用于标识允许使用所述最优MIP模式对所述当前块进行预测；若所述第二标识为假，则用于标识不允许使用所述最优MIP模式对所述当前块进行预测。
示例性地，所述第一标识记为sps_timd_enable_flag，所述第二标识记为cu_timd_enable_flag，此时，解码器解析或获取sps_timd_enable_flag，若所述sps_timd_enable_flag为真，则解码器可以解析或获取cu_timd_enable_flag，若所述cu_timd_enable_flag为真，则解码器基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
示例性地，所述第二标识为块级标识或编码单元级标识。
需要说明的是，所述第二标识用于标识允许使用所述最优MIP模式对所述当前块进行预测，也可替换为具有类似或相同含义的描述。例如，在其他可替代实施例中，所述第二标识用于标识允许使用所 述最优MIP模式对所述当前块进行预测，也可替换为以下中的任一项：所述第二标识用于标识允许使用TMMIP技术确定当前块的帧内预测模式，所述第二标识用于标识允许使用TMMIP技术对当前块进行帧内预测，所述第二标识用于标识允许所述当前块中的图像块使用TMMIP技术，所述第二标识用于标识允许使用基于所述多个MIP模式确定的MIP模式对当前块进行预测。
此外，在其他可替代实施例中，将TMMIP技术结合至其他技术时，也可通过其他技术的允许标志位来间接指示当前块是否允许使用TMMIP技术。例如，以TIMD技术为例，所述第二标识用于指示当前块允许使用TIMD技术时，则说明当前块也允许使用TMMIP技术；或者说，所述第二标识用于指示当前块允许使用TIMD技术时，则说明当前块允许同时使用TIMD技术和TMMIP技术；以进一步节省比特开销。
另外，解码端解析所述第二标识时，可以在解析当前块的残差块之前解析所述第二标识，也可以在解析当前块的残差块之后解析所述第二标识，本申请对此不作具体限定。
在一些实施例中，所述方法300还可包括：
解码器基于所述MIP模式的失真代价，确定所述多个MIP模式的排列顺序；解码器基于所述多个MIP模式的排列顺序，确定所述最优MIP模式使用的编码方式；解码器基于最优MIP模式使用的编码方式对所述当前序列的码流进行解码，得到最优MIP模式的索引。
示例性地，解码器基于多个MIP模式的失真代价，确定用于预测所述当前块的最优MIP模式之前，需要计算所述多个MIP模式中的每一个MIP模式的失真代价，并根据每一个MIP模式的失真代价对所述多个MIP模式进行排序，代价最小的MIP模式即为最优预测结果。
需要说明的是，对于传统的MIP技术，对MIP模式的索引通常选择截断二进制的方式进行二值化，这种编码方式比较接近等概率编码，即其将所有的预测模式分成两段，一段用N个码字表示，另一个由N+1个码字进行表示。有鉴于此，本申请中，解码器基于多个MIP模式的失真代价确定用于预测所述当前块的最优MIP模式之前，可以先计算所述多个MIP模式中的每一个MIP模式的失真代价，并根据每一个MIP模式的失真代价对所述多个MIP模式进行排序，最终，解码器可基于所述多个MIP模式的排序选择使用更灵活的变长编码方式，与等概率编码方式相比，通过灵活设置MIP模式的编码方式，有利于节省所述MIP模式的索引的比特开销。
在一些实施例中，所述排列顺序中前n个MIP模式使用的编码方式的码字长度小于所述排列顺序中第n个MIP模式之后的MIP模式使用的编码方式的码字长度；和/或，所述前n个MIP模式使用变长编码方式且所述第n个MIP模式之后的MIP模式使用截断二进制编码方式。
示例性地，N可以是大于或等于1的任意数值。
示例性地，所述排列顺序为解码器按照失真代价有小到大的顺序对所述多个MIP模式进行排列得到的顺序，所述排列顺序中前n个MIP模式使用的编码方式的码字长度小于所述排列顺序中第n个MIP模式之后的MIP模式使用的编码方式的码字长度；和/或，所述前n个MIP模式使用变长编码方式且所述第n个MIP模式之后的MIP模式使用截断二进制编码方式。
本实施例中，由于MIP模式的失真代价越小，编码器使用其对当前块进行帧内预测的概率越大，因此，将所述排列顺序中前n个MIP模式使用的编码方式的码字长度设计为小于所述排列顺序中第n个MIP模式之后的MIP模式使用的编码方式的码字长度；和/或，将所述前n个MIP模式使用的编码方式设计为变长编码方式且将所述第n个MIP模式之后的MIP模式使用的编码方式设计为截断二进制编码方式；相当于，编码器大概率使用的MIP模式使用较短码字长度或变长编码方式，能够节省MIP模式的索引的比特开销，提升解压缩性能。
在一些实施例中，所述S330可包括：
解码器将所述最优MIP模式确定为所述当前块的帧内预测模式。
示例性地，解码器确定所述最优MIP模式后，直接基于所述最优MIP模式对所述当前块进行帧内预测，得到所述当前块的预测块。
在一些实施例中，所述S330可包括：
解码器基于所述最优MIP模式对所述当前块进行预测，得到第一预测块；解码器基于模板的帧内模式导出TIMD模式对所述当前块进行预测，得到第二预测块；解码器基于所述第一预测块的失真代价和所述第二预测块的失真代价，将所述最优MIP模式和所述TIMD模式中失真代价最小的预测模式，确定为所述当前块的帧内预测模式。
示例性地，解码器确定所述最优MIP模式后，在所述最优MIP模式和所述TIMD模式中，将最优的帧内预测模式确定为所述当前块的帧内预测模式。
示例性地，若所述最优MIP模式和所述TIMD模式中的最优预测模式为所述最优MIP模式，则解码器可直接基于所述最优MIP模式对所述当前块进行帧内预测，得到所述当前块的预测块。若所述最 优MIP模式和所述TIMD模式中的最优预测模式为所述TIMD模式，则解码器可直接基于所述TIMD模式得到的最优预测模式和次优预测模式，得到所述当前块的预测块。例如，若所述最优预测模式与次优预测模式都不是直流模式(也可称为均值模式)或者平面模式(也可称为平坦模式)，且次优预测模式的失真代价小于两倍的最优预测模式的失真代价，则需要进行预测块融合操作；即解码器可以先根据最优预测模式对当前块进行帧内预测，以获取最优预测块；其次根据次优预测模式对当前块进行帧内预测，以获取次优预测块；再利用最优预测模式的失真代价与次优预测模式的失真代价之间的比例计算得到属于最优预测块的权重值与次优预测块的权重值；最后将最优预测块与次优预测块进行加权融合得到当前块的预测块。再如，若最优预测模式或次优预测模式为平面模式或直流模式，或者次优预测模式的失真代价大于两倍的最优预测模式的失真代价，则不需要进行预测块融合操作，即仅可以将基于最优预测模式得到的最优预测块直接作为当前块的预测块。
在一些实施例中，所述S320可包括：
解码器基于第三标识和所述多个MIP模式对所述模板区域内的样本进行预测，得到所述第三标识的每一个状态下所述多个MIP模式的失真代价；所述第三标识的用于标识是否转置MIP模式的输入向量和输出向量；解码器基于所述第三标识的每一个状态下所述多个MIP模式的失真代价，确定所述最优MIP模式。
如前所述，对于传统的MIP技术，其比特开销相比于其他帧内预测工具要多一些，其不仅需要一个标识位去表示是否使用MIP技术，还需要一个标识位去表示是否转置使用MIP，最后也是最大开销部分，它需要使用截断二进制编码去表示MIP的预测模式。MIP是基于神经网络技术简化而来的技术，与传统插值滤波预测技术有较大的不同，对于一些特殊的纹理，虽然MIP预测比传统帧内预测模式的效果更好，但其较大的标识开销是MIP技术的缺陷，以4x4大小的编码单元为例，共有16个预测样本，但其比特开销包括1个MIP使用标识，1个MIP转置标识和5或6位的截断二进制标识。有鉴于此，本申请在确定最优MIP模式时，通过遍历所述第三标识的每一个状态，考虑了MIP模式的转置功能，能够节省1个MIP转置标识的开销，进而能够提高解压缩效率。
示例性地，解码器遍历所述第三标识的每一个状态和所述多个MIP模式，确定所述第三标识的每一个状态下所述多个MIP模式的失真代价，并基于所述第三标识的每一个状态下所述多个MIP模式的失真代价，确定所述最优MIP模式；或者，解码器遍历所述第三标识的每一个状态和所述多个MIP模式，确定所述多个MIP模式在所述第三标识的每一个状态下的失真代价，并基于所述多个MIP模式在所述第三标识的每一个状态下的失真代价，确定所述最优MIP模式。也即是说，解码端可以先遍历所述多个MIP模式，也可以先遍历所述第三标识的状态。
示例性地，若所述第三标识的取值为第五数值，则用于标识转置MIP模式的输入向量和输出向量；若所述第三标识的取值为第六数值，则用于标识不转置MIP模式的输入向量和输出向量。此时，所述第三标识的每一个状态也可替换为所述第三标识的每一个取值。在一种实现方式中，所述第五数值为1且所述第六数值为0，在另一种实现方式中，所述第五数值为0且所述第六数值为1。当然，所述第五数值和所述第六数值也可为其他数值，本申请对此不作限定。
示例性地，若所述第三标识为真，则用于标识转置MIP模式的输入向量和输出向量；若所述第三标识为假，则用于标识不转置MIP模式的输入向量和输出向量。此时，所述第三标识为真或为假均为所述第三标识的一个状态。
示例性地，所述第三标识为序列级标识、块级标识或编码单元级标识。
示例性地，所述第三标识也可称为转置信息、转置标识、或MIP转置标识位。
需要说明的是，所述第三标识用于标识是否转置MIP模式的输入向量和输出向量，也可替换为具有类似或相同含义的描述。例如，在其他可替代实施例中，所述第三标识用于标识是否需要转置MIP模式的输入和输出，所述第三标识用于标识MIP模式的输入向量和输出向量是否为转置后的向量，所述第三标识用于表示是否转置。
在一些实施例中，所述S320可包括：
若所述当前块的尺寸为预设尺寸，则解码器基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
示例性地，所述预设尺寸可以包括宽度为预设宽度且高度为预设高度的尺寸。也即是说，若所述当前块的宽度为预设宽度且高度为预设高度，则解码器基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
示例性地，所述预设尺寸可以通过在设备(例如，包括解码器和编码器)中预先保存相应的代码、表格或其他可用于指示相关信息的方式来实现，本申请对于其具体的实现方式不做限定。比如，预设尺寸可以是指协议中定义的尺寸。可选地，所述"协议"可以指编解码技术领域的标准协议，例如可以包括 VCC或ECM协议等相关协议。
当然，在其他可替代实施例中，解码器也可以通过其他方式，基于所述预设尺寸确定是否基于所述多个MIP模式的失真代价确定所述最优MIP模式，本申请对此不作具体限定。
例如，解码器可以仅基于所述当前块的宽度或高度，确定是否基于所述多个MIP模式的失真代价确定所述最优MIP模式。在一种实现方式中，若所述当前块的宽度为预设宽度或高度为预设高度，则解码器基于所述多个MIP模式的失真代价，确定所述最优MIP模式。再如，解码器可以通过比较所述当前块的尺寸和所述预设尺寸，确定是否基于所述多个MIP模式的失真代价确定所述最优MIP模式。在一种实现方式中，若所述当前块的尺寸大于或小于预设尺寸，则解码器基于所述多个MIP模式的失真代价，确定所述最优MIP模式。在另一种实现方式中，若所述当前块的宽度大于或小于预设宽度，则解码器基于所述多个MIP模式的失真代价，确定所述最优MIP模式。在另一种实现方式中，若所述当前块的高度大于或小于预设高度，则所述解码器基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
在一些实施例中，所述S320可包括：
若所述当前块所在的图像帧为I帧、且所述当前块的尺寸为所述预设尺寸，则解码器基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
示例性地，若所述当前块所在的图像帧为I帧、所述当前块的宽度为预设宽度、且所述当前块的高度为预设高度，则解码器基于所述多个MIP模式的失真代价，确定所述最优MIP模式。也即是说，只有在所述当前块所在的图像帧为I帧的情况下，解码器才基于所述当前块的尺寸，确定是否基于所述多个MIP模式的失真代价确定所述最优MIP模式。
在一些实施例中，所述S320可包括：
若所述当前块所在的图像帧为B帧，则解码器基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
示例性地，若所述当前块所在的图像帧为B帧，则解码器可以直接基于所述多个MIP模式的失真代价，确定所述最优MIP模式。也即是说，在所述当前块所在的图像帧为B帧的情况下，不管当前块的尺寸为多少，解码器都可以直接基于所述多个MIP模式的失真代价确定所述最优MIP模式。
在一些实施例中，所述S320可之前，所述方法300还可包括：
解码器获取与所述当前块相邻的相邻块使用的MIP模式；解码器将所述相邻块使用的MIP模式，确定为所述多个MIP模式。
示例性地，所述相邻块可以是与所述当前块的上侧、左侧、左下、右上及左上中的至少一项相邻的图像块。例如，解码器可按照所述当前块的上侧、左侧、左下、右上及左上的顺序获取的图像块确定为所述相邻块。可选的，所述多个MIP模式可用于构建解码器确定用于预测当前块的可用MIP模式或可用MIP模式列表，以便解码器在所述可用MIP模式或可用MIP模式列表中通过对模板区域内的样本进行预测的方式确定所述最优MIP模式。
在一些实施例中，所述S320可之前，所述方法300还可包括：
解码器对所述模板区域外部相邻的参考区域进行重建样本填充，得到所述模板区域的参考行和参考列；解码器以所述参考行和所述参考列为输入，利用所述多个MIP模式分别对所述模板区域内的样本进行预测，得到所述多个MIP模式对应的多个预测块；解码器基于所述多个预测块和所述模板区域内的重建块，确定所述多个MIP模式的失真代价。
示例性地，解码器填充模板预测所需要的参考重建样本，
示例性地，所述参考区域中与所述模板区域的上侧相邻的区域的宽度等于所述模板区域的宽度，所述参考区域中与所述模板区域的左侧相邻的区域的高度等于所述模板区域的宽度；若所述参考区域中与所述模板区域的上侧相邻的区域的宽度大于所述模板区域的宽度，则解码器可以对所述参考区域中与所述模板区域的上侧相邻的区域进行下采样或降维处理，以得到所述参考行。若所述参考区域中与所述模板区域的左侧相邻的区域的高度可大于所述模板区域的宽度，则解码器可以对所述参考区域中与所述模板区域的左侧相邻的区域进行下采样或降维处理，以得到所述参考列。
示例性地，所述模板区域可以是上文涉及的TIMD模式中使用的模板(template)区域，所述参考区域可以是所述TIMD模式中使用的参考模板(Reference of template)。例如，结合图3来说，若当前块为宽等于M且高等于N的编码单元，解码器对宽等于2(M+L1)+1且高等于2(N+L2)+1的编码单元组成的参考区域进行重建样本的充填，并对填充后的参考区域进行降采样或降维处理，得到所述参考行和所述参考列，进而基于所述参考行和所述参考列构建MIP模式的输入向量。
示例性地，解码器获取所述参考行和所述参考列后，以所述参考行和所述参考列为输入，利用所述多个MIP模式分别对所述模板区域内的样本进行预测，得到所述多个MIP模式对应的多个预测块；也 即是说，所述解码器基于当前块的参考模板内的重建样本，通过遍历所述多个MIP模式的方式对当前块的模板区域内的样本进行预测。以当前遍历MIP模式为例，解码器以所述参考行、所述参考列、所述当前遍历MIP模式的索引、上文涉及的第三标识为输入，得到所述当前遍历MIP模式对应的预测块；其中，所述参考行和所述参考列用于构建所述当前遍历MIP模式的输入向量；所述当前遍历MIP模式的索引用于确定当前遍历MIP模式的矩阵和/或偏置向量；所述第三标识用于标识是否转置MIP模式的输入向量和输出向量；例如，若所述第三标识用于标识不转置MIP模式的输入向量和输出向量，则将所述参考列拼接在所述参考行之后，以形成所述当前遍历MIP模式的输入向量；若所述第三标识用于标识转置MIP模式的输入向量和输出向量，则将所述参考行拼接在所述参考列之后，以形成所述当前遍历MIP模式的输入向量。相应的，若所述第三标识用于标识转置MIP模式的输入向量和输出向量，解码器对所述当前遍历MIP模式的输出进行转置，以得到所述模板区域的预测块。解码器遍历所述多个MIP模式的方式获取所述多个MIP模式对应的多个预测块后，可以基于所述多个预测块和所述模板区域内的重建样本之间的失真代价，根据失真代价最小原则选出代价最小的MIP模式，并将其确定为当前块基于模板匹配的MIP模式下最优MIP模式。
在一些实施例中，解码器利用所述多个MIP模式分别对所述模板区域内的样本进行预测时，先对所述参考行和所述参考列进行下采样，得到输入向量；再以所述输入向量为输入，通过遍历所述多个MIP模式的方式对所述模板区域内的样本进行预测，得到所述多个MIP模式的输出向量；最后对所述多个MIP模式的输出向量进行上采样，得到所述多个MIP模式对应的预测块。
示例性地，所述参考行和所述参考列满足所述多个MIP模式的输入条件。若所述参考行和所述参考列不满足所述多个MIP模式的输入条件，可以先将所述参考行和/或所述参考列处理为满足所述多个MIP模式的输入条件的输入样本，然后基于满足所述多个MIP模式的输入条件的输入样本，确定所述多个MIP模式的输入向量。例如，以所述输入条件为指定个数的输入样本为例，若所述参考行和所述参考列不满足MIP模式的输入样本个数时，解码器可对所述参考行和/或所述参考列进行哈尔下采样(Haar-downsampling)等方式降维到指定个数的输入样本，并基于降维后的指定个数的输入样本确定所述多个MIP模式的输入向量。
在一些实施例中，所述S320可包括：
解码器基于所述多个MIP模式在所述模板区域上的绝对变换差的和SATD，确定所述最优MIP模式。
本实施例中，解码器基于所述多个MIP模式在所述模板区域上的失真代价确定所述最优MIP模式时，将所述多个MIP模式的失真代价设计为所述多个MIP模式的SATD，与直接计算所述多个MIP模式的率失真代价相比，不仅能够实现基于所述多个MIP模式在所述模板区域上的失真代价确定所述最优MIP模式，还能够简化所述多个MIP模式的失真代价的计算复杂度，进而能够解码器的提升解压缩性能。
综上所述，解码器基于模板匹配的MIP模式导出方法主要思路可分为以下几个部分：
首先，填充参考区域(例如图3所示的参考模板)内的重建样本，即用于对模板区域(如图3所述的模板)内的样本进行预测时所需要的参考重建样本。可选的，所述参考区域的宽高不需要超出模板区域的宽高。若所述参考区域填充了超出模板区域的宽高的样本，则需要使用下采样或其他方式降维达到MIP输入维度的要求。
然后，解码器以所述参考区域内的参考重建样本、所述多个MIP模式的索引、MIP转置标识位作为输入，对所述模板区域内的样本进行预测，得到所述多个MIP模式对应的预测块。可选的，所述参考区域内的参考重建样本需要满足MIP输入条件，如哈尔下采样(Haar-downsampling)等降维到指定个数的输入样本。所述多个MIP模式的索引用于确定MIP技术的矩阵索引，进而获取MIP预测矩阵系数。MIP转置标识位用于标识是否需要转置输入和输出。
最后，对于所述多个MIP模式对应的预测块而言，可以遍历所有MIP模式与MIP转置与否的组合情况，得到每一个MIP模式及MIP转置标识位的每一个状态下的模板区域的预测样本，并计算模板区域内预测样本与重建样本之间的失真并记录其代价信息；最后，根据失真最小原则选出代价最小的MIP模式及其对应的MIP转置信息，即为当前块基于模板匹配的MIP预测导出模式下最优MIP模式。
值得注意的是，本申请涉及的部分计算可以用查找表和移位的方式代替，虽然查找表的方式在结果上可能会与直接做除法有一定误差，但有利于硬件实现和控制编解码成本。例如，关于失真代价的计算或确定最优MIP模式中涉及到的计算。
上文中从解码器的角度详细描述了根据本申请实施例的解码方法，下面将结合图8，从编码器的角度描述根据本申请实施例的编码方法。
图6是本申请实施例提供的编码方法400的示意性流程图。应理解，该编码方法400可由编码器执 行。例如应用于图1所示的编码框架100。为便于描述，下面以编码器为例进行说明。
如图6所示，所述编码方法400可包括：
S410，基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测当前序列中的当前块的最优MIP模式；
其中，所述多个MIP模式的失真代价包括利用所述多个MIP模式对与所述当前块相邻的模板区域内的样本进行预测得到的失真代价；
S420，基于所述最优MIP模式，确定所述当前块的帧内预测模式；
S430，基于所述当前块的帧内预测模式对所述当前块进行预测，得到所述当前块的预测块；
S440，基于所述当前块的预测块和所述当前块的原始块，得到所述当前块的残差块；
S450，对所述当前块的残差块进行编码，得到所述当前序列的码流。
在一些实施例中，所述S410可包括：
获取第一标识；
若所述第一标识用于标识允许使用所述最优MIP模式对所述当前序列中的图像块进行预测，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式；
其中，所述S450可包括：
对所述当前块的残差块和所述第一标识进行编码，得到所述码流。
在一些实施例中，所述S420可包括：
若所述第一标识用于标识允许使用所述最优MIP模式对所述当前序列中的图像块进行预测，则基于所述最优MIP模式确定最优预测模式；
基于所述最优预测模式对所述当前块进行预测，得到第一率失真代价；
基于至少一个帧内预测模式对所述当前块进行预测，得到至少一个率失真代价；
若所述第一率失真代价小于或等于所述至少一个率失真代价中的最小值，则将所述最优预测模式，确定为所述当前块的帧内预测模式；
其中，所述S450可包括：
对所述当前块的残差块、所述第一标识和第二标识进行编码，得到所述码流；
其中，若所述第一率失真代价小于或等于所述至少一个率失真代价中的最小值，则所述第二标识用于标识允许使用所述最优MIP模式对所述当前块进行预测；若所述第一率失真代价大于所述至少一个率失真代价中的最小值，则所述第二标识用于标识不允许使用所述最优MIP模式对所述当前块进行预测。
在一些实施例中，所述S420可包括：
将所述最优MIP模式确定为所述最优预测模式。
在一些实施例中，所述S420可包括：
基于所述最优MIP模式对所述当前块进行预测，得到第一预测块；
基于模板的帧内模式导出TIMD模式对所述当前块进行预测，得到第二预测块；
基于所述第一预测块的失真代价和所述第二预测块的失真代价，将所述最优MIP模式和所述TIMD模式中失真代价最小的预测模式，确定为所述最优预测模式。
在一些实施例中，所述S450可包括：
基于所述MIP模式的失真代价，确定所述多个MIP模式的排列顺序；
基于所述多个MIP模式的排列顺序，确定所述最优MIP模式使用的编码方式；
对所述当前块的残差块进行编码以及基于最优MIP模式使用的编码方式对所述最优MIP模式的索引进行编码，得到所述码流。
在一些实施例中，所述排列顺序中前n个MIP模式使用的编码方式的码字长度小于所述排列顺序中第n个MIP模式之后的MIP模式使用的编码方式的码字长度；和/或，所述前n个MIP模式使用变长编码方式且所述第n个MIP模式之后的MIP模式使用截断二进制编码方式。
在一些实施例中，所述S410可包括：
基于第三标识和所述多个MIP模式对所述模板区域内的样本进行预测，得到所述第三标识的每一个状态下所述多个MIP模式的失真代价；所述第三标识的用于标识是否转置MIP模式的输入向量和输出向量；
基于所述第三标识的每一个状态下所述多个MIP模式的失真代价，确定所述最优MIP模式。
在一些实施例中，所述S410可包括：
若所述当前块的尺寸为预设尺寸，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
在一些实施例中，所述S410可包括：
若所述当前块所在的图像帧为I帧、且所述当前块的尺寸为所述预设尺寸，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
在一些实施例中，所述S410可包括：
若所述当前块所在的图像帧为B帧，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
在一些实施例中，所述S410之前，所述方法400还可包括：
获取与所述当前块相邻的相邻块使用的MIP模式；
将所述相邻块使用的MIP模式，确定为所述多个MIP模式。
在一些实施例中，所述S410之前，所述方法400还可包括：
对所述模板区域外部相邻的参考区域进行重建样本填充，得到所述模板区域的参考行和参考列；
以所述参考行和所述参考列为输入，利用所述多个MIP模式分别对所述模板区域内的样本进行预测，得到所述多个MIP模式对应的多个预测块；
基于所述多个预测块和所述模板区域内的重建块，确定所述多个MIP模式的失真代价。
在一些实施例中，利用所述多个MIP模式分别对所述模板区域内的样本进行预测时，先对所述参考行和所述参考列进行下采样，得到输入向量；再以所述输入向量为输入，通过遍历所述多个MIP模式的方式对所述模板区域内的样本进行预测，得到所述多个MIP模式的输出向量；最后对所述多个MIP模式的输出向量进行上采样，得到所述多个MIP模式对应的预测块。
在一些实施例中，所述S410可包括：
基于所述多个MIP模式在所述模板区域上的绝对变换差的和SATD，确定所述最优MIP模式。
应当理解，编码方法可以理解为解码方法的逆过程，因此，所述编码方法400的具体方案可参见解码方法300的相关内容，为便于描述，本申请对此不再赘述。
下面结合具体实施例对本申请的方案进行说明。
实施例1：
本实施例中，编码器或解码器可直接将用于预测当前块的最优MIP模式确定为当前块的帧内预测模式。
编码器遍历预测模式，若当前块为帧内模式，则编码器获取序列级允许使用标志位，用于表示是否允许当前序列使用基于模板匹配的MIP模式导出技术，其可以如sps_tmmip_enable_flag的形式。若tmmip的允许使用标志位均为真，则表示当前编码器允许使用TMMIP技术。
示例性地，编码器的流程可实现为以下过程：
步骤1：
若sps_tmmip_enable_flag为真，则编码器尝试TMMIP技术，即执行步骤2；若sps_tmmip_enable_flag为假，则编码器不尝试TMMIP技术，即跳过步骤2直接执行步骤3。
步骤2：
首先，编码器对模板区域外部相邻的行和列进行重建样本填充。填充过程与原始帧内预测过程所填充的方法相同，例如，编码器可以自左下角往右上角进行遍历填充，若所有重建样本均可以用，则依次全部填充可用重建样本；若所有重建样本均不可用，则全部填充均值；若部分重建样本可用，则先填充可用重建样本，对于其余不可用重建样本，编码器可以根据上述自左下角往右上角的顺序进行遍历，直至出现第一个可用重建样本后，用第一个可用重建样本对先前不可用位置进行填充。
其次，编码器以填充完毕的模板区域外侧重建样本作为输入，利用可允许使用的MIP模式对模板区域内的样本进行预测。
示例性地，对于4x4大小的块，可允许使用的MIP模式为16个。对于宽或高为4，或8x8大小的块，可允许使用的MIP模式为8个。其他尺寸的块可允许使用的MIP模式为6个。此外，任意尺寸的块都可以使用MIP转置功能，上述TMMIP的预测模式与MIP技术相同。
示例性地，具体预测计算过程包括：编码器先对重建样本进行哈尔下采样，例如编码器根据块尺寸决定下采样步长。接着，编码器根据转置与否的信息调整上侧下采样后的重建样本与左侧下采样后的重建样本拼接顺序；若不需要转置则将左侧下采样后的重建样本拼接在上侧下采样后的重建样本之后，将得到的向量作为输入，若需要转置则将上侧下采样后的重建样本拼接在左侧下采样后的重建样本之后，将得到的向量作为输入。然后，编码器根据遍历的预测模式作为索引获取MIP矩阵系数，与输入计算得到输出向量。最后，编码器根据输出向量个数与当前模板尺寸情况，对输出向量进行上采样，若不需要上采样则向量以水平方向依次填充作为模板预测块输出，若需要上采样则先上采样水平方向再下采样垂直方向，上采样至与模板尺寸相同后作为模板区域的预测块进行输出。
接着，编码器基于通过遍历每个MIP模式得到的模板区域的预测块与模板区域内重建样本，计算 失真代价，并记录该预测模式与转置信息下的失真代价值。遍历所有允许的预测模式与转置信息后，根据代价最小原则，选择出最优的MIP模式以及其对应的转置信息，作为当前块在TMMIP模式下最优的预测模式。
最后，编码器根据得到的最优MIP模式和转置信息，对当前块上侧和左侧相邻的重建样本视情况下采样并根据转置信息进行拼接作为输入向量，并根据MIP模式作为索引读取当前模式下的矩阵系数，然后，通过输入向量与矩阵系数的计算得到输出向量。编码器可根据转置信息进行输出转置，并根据当前块的尺寸和输出向量的样本数对输出向量进行上采样，得到与当前块相同尺寸的输出作为当前块的预测块。基于此，编码器得到当前块的率失真代价，将其记为cost1。
步骤3：
编码器继续遍历其他帧内预测技术并计算对应的率失真代价记为cost2…costN。
步骤4：
若cost1为所有率失真代价中最小，则当前块采用TMMIP技术，编码器将当前块的TMMIP使用标志位置真并写进码流；若cost1不为最小率失真代价，则当前块采用其他帧内预测技术，编码器将当前块的TMMIP使用标志位置假并写进码流。应当理解，其他帧内预测技术的标识位或索引等信息根据定义传输，此处不详细阐述；
步骤5：
编码器基于当前块的预测块和当前块的原始块确定当前块的残差块，并对当前块的残差块进行变换和量化，熵编码以及环路滤波等操作。应当理解，其具体过程可参见上文相关内容，为避免重复，此处不再赘述。
下面对本实施例中解码器的相关方案进行说明。
解码器解析块级类型标志位，若为帧内模式，则解析或获取序列级允许使用标志位，用于表示是否允许当前序列使用基于模板匹配的MIP模式导出技术，其可以如sps_tmmip_enable_flag的形式。若tmmip的允许使用标志位均为真，则表示当前解码器允许使用TMMIP技术。
示例性地，解码器的流程可实现为以下过程：
步骤1：
若sps_tmmip_enable_flag为真，则解码器解析当前块的TMMIP使用标志位，否则，当前解码过程不需要解码块级的TMMIP使用标志位，块级的TMMIP使用标志位默认为否。若当前块的TMMIP使用标志位为真，则执行步骤2；否则，执行步骤3。
步骤2：
首先，解码器对模板区域外部相邻的行和列进行重建样本填充。填充过程与原始帧内预测过程所填充的方法相同，例如，解码器可以自左下角往右上角进行遍历填充，若所有重建样本均可以用，则依次全部填充可用重建样本；若所有重建样本均不可用，则全部填充均值；若部分重建样本可用，则先填充可用重建样本，对于其余不可用重建样本，解码器可以根据上述自左下角往右上角的顺序进行遍历，直至出现第一个可用重建样本后，用第一个可用重建样本对先前不可用位置进行填充。
其次，解码器以填充完毕的模板区域外侧重建样本作为输入，利用可允许使用的MIP模式对模板区域内的样本进行预测。
示例性地，对于4x4大小的块，可允许使用的MIP模式为16个。对于宽或高为4，或8x8大小的块，可允许使用的MIP模式为8个。其他尺寸的块可允许使用的MIP模式为6个。此外，任意尺寸的块都可以使用MIP转置功能，上述TMMIP的预测模式与MIP技术相同。
示例性地，具体预测计算过程包括：解码器先对重建样本进行哈尔下采样，例如解码器根据块尺寸决定下采样步长。接着，解码器根据转置与否的信息调整上侧下采样后的重建样本与左侧下采样后的重建样本拼接顺序；若不需要转置则将左侧下采样后的重建样本拼接在上侧下采样后的重建样本之后，将得到的向量作为输入，若需要转置则将上侧下采样后的重建样本拼接在左侧下采样后的重建样本之后，将得到的向量作为输入。然后，解码器根据遍历的预测模式作为索引获取MIP矩阵系数，与输入计算得到输出向量。最后，解码器根据输出向量个数与当前模板尺寸情况，对输出向量进行上采样，若不需要上采样则向量以水平方向依次填充作为模板预测块输出，若需要上采样则先上采样水平方向再下采样垂直方向，上采样至与模板尺寸相同后作为模板区域的预测块进行输出。
接着，解码器基于通过遍历每个MIP模式得到的模板区域的预测块与模板区域内重建样本，计算失真代价，并记录该预测模式与转置信息下的失真代价值。遍历所有允许的预测模式与转置信息后，根据代价最小原则，选择出最优的MIP模式以及其对应的转置信息，作为当前块在TMMIP模式下最优的预测模式。
最后，解码器根据得到的最优MIP模式和转置信息，对当前块上侧和左侧相邻的重建样本视情况 下采样并根据转置信息进行拼接作为输入向量，并根据MIP模式作为索引读取当前模式下的矩阵系数，然后，通过输入向量与矩阵系数的计算得到输出向量。解码器可根据转置信息进行输出转置，并根据当前块的尺寸和输出向量的样本数对输出向量进行上采样，得到与当前块相同尺寸的输出作为当前块的预测块。
步骤3：
解码器继续解析其他帧内预测技术的使用标识位或索引等信息，并根据解析到的信息求得当前块的最终预测块。
步骤4：
解码器解析码流并获取当前块的频域残差块(也称为频域残差信息)，并对当前块的频域残差块进行反量化及反变换得到当前块的残差块(也称为时域残差块或时域残差信息)；然后解码器将当前块的预测块与当前块的残差块叠加得到重建样本块。
步骤5：
若当前图像中所有重建样本块经由环路滤波等技术后，得到最终的重建图像。
可选的，重建图像可以作为视频输出，也可以作为后面解码参考。
本实施例中，编码器或解码器在TMMIP技术中用到的模板区域的大小可以根据当前块的尺寸大小预先定义。例如，所述模板区域中与当前块相邻的上侧区域的宽为当前块的宽大小，且其高为两行样本高度；所述模板区域中与当前块的左侧相邻的左侧区域的高为当前块的高度，其其宽为两行样本的宽度。当然，在其他可替代实施例中，也可以实现为其他尺寸的模板区域，本申请对此不作具体限定。
实施例2：
本实施例中，在基于模板匹配的MIP模式导出技术(即TMMIP技术)导出的最优MIP模式和基于TIMD技术导出的预测模式中，编码器或解码器可将最优的预测模式确定为当前块的帧内预测模式。也即是说，编码器或解码器可基于TMMIP技术和TIMD技术对图像块进行预测。例如，在TIMD技术允许使用的条件下，TMMIP技术与TIMD技术在序列级以及块级均仅需要一个使用标识位来标识是否使用TIMD或TMMIP技术。如图3所示，TIMD技术与TMMIP技术的模板区域可以设定相同，即计算模板区域的失真代价区域相同，则两个技术可以融合一起做比较。TIMD导出传统帧内预测模式而TMMIP技术导出MIP模式及其对应的转置信息。
编码器遍历预测模式，若当前块为帧内模式，则获取TIMD的允许使用标志位，该标志位为序列级标志位，表示当前编码器允许使用TIMD技术，可以如sps_TIMD_enable_flag的形式。
示例性地，编码器的流程可实现为以下过程：
步骤1：
若TIMD的允许使用标志位为真，则编码器尝试TIMD的预测方法，即执行步骤2；若TIMD的允许使用标志位为假，则编码器不尝试TIMD的预测方法，即跳过步骤2直接执行步骤3。
步骤3：
首先，编码器对模板区域外部相邻的行和列进行重建样本填充。填充过程与原始帧内预测过程所填充的方法相同，例如，编码器可以自左下角往右上角进行遍历填充，若所有重建样本均可以用，则依次全部填充可用重建样本；若所有重建样本均不可用，则全部填充均值；若部分重建样本可用，则先填充可用重建样本，对于其余不可用重建样本，编码器可以根据上述自左下角往右上角的顺序进行遍历，直至出现第一个可用重建样本后，用第一个可用重建样本对先前不可用位置进行填充。
其次，编码器以填充完毕的模板区域外侧重建样本作为输入，利用可允许使用的MIP模式对模板区域内的样本进行预测。
示例性地，对于4x4大小的块，可允许使用的MIP模式为16个。对于宽或高为4，或8x8大小的块，可允许使用的MIP模式为8个。其他尺寸的块可允许使用的MIP模式为6个。此外，任意尺寸的块都可以使用MIP转置功能，上述TMMIP的预测模式与MIP技术相同。
示例性地，具体预测计算过程包括：编码器先对重建样本进行哈尔下采样，例如编码器根据块尺寸决定下采样步长。接着，编码器根据转置与否的信息调整上侧下采样后的重建样本与左侧下采样后的重建样本拼接顺序；若不需要转置则将左侧下采样后的重建样本拼接在上侧下采样后的重建样本之后，将得到的向量作为输入，若需要转置则将上侧下采样后的重建样本拼接在左侧下采样后的重建样本之后，将得到的向量作为输入。然后，编码器根据遍历的预测模式作为索引获取MIP矩阵系数，与输入计算得到输出向量。最后，编码器根据输出向量个数与当前模板尺寸情况，对输出向量进行上采样，若不需要上采样则向量以水平方向依次填充作为模板预测块输出，若需要上采样则先上采样水平方向再下采样垂直方向，上采样至与模板尺寸相同后作为模板区域的预测块进行输出。
此外，编码器还需要尝试TIMD的模板匹配计算过程，即编码器可根据不同的预测模式索引获取 不同的插值滤波器对参考样本进行插值得到模板内的预测样本。
接着，编码器基于通过遍历每个MIP模式得到的模板区域的预测块与模板区域内重建样本，计算失真代价，并记录该预测模式与转置信息下的失真代价。此外，编码器还需要遍历所有TIMD允许的帧内预测模式，计算得到模板内的预测块并与模板内重建样本计算失真代价，并记录各预测模式下的失真代价。编码器遍历所有允许的MIP模式与转置信息并遍历TIMD允许的预测模式后，可根据失真代价最小原则，选择出最优的预测模式，若MIP模式的失真代价最小，则将MIP模式及其对应的转置信息作为当前块的最优预测模式；若TIMD模式的失真代价最小，则将TIMD模式作为当前块的最优预测模式，记录由TIMD技术导出的最优帧内预测模式并记录其失真代价，同时记录由TIMD技术导出的次优预测模式与其失真代价。
最后，若编码器得到的最优预测模式为MIP模式，则编码器根据得到的最优MIP模式和转置信息，对当前块上侧和左侧相邻的重建样本视情况下采样并根据转置信息进行拼接作为输入向量，并根据MIP模式作为索引读取当前模式下的矩阵系数，然后，通过输入向量与矩阵系数的计算得到输出向量。编码器可根据转置信息进行输出转置，并根据当前块的尺寸和输出向量的样本数对输出向量进行上采样，得到与当前块相同尺寸的输出作为当前块的预测块。基于此，编码器得到当前块的率失真代价，将其记为cost1。
否则，编码器得到的最优预测模式为TIMD模式。若最优预测模式与次优预测模式都不是均值(DC)模式或者平坦(PLANAR)模式，且次优预测模式的失真代价小于两倍的最优预测模式失真代价，则编码器需要进行预测块融合操作。首先，编码器根据最优预测模式获取插值滤波系数，对上侧和左侧相邻重建样本进行插值滤波得到当前块内所有位置的预测样本，记为最优预测块；其次编码器根据次优预测模式获取插值滤波系数，对上侧和左侧相邻重建样本进行插值滤波得到当前块内所有位置的预测样本，记为次优预测块。接着，编码器利用最优预测模式代价值与次优预测模式代价值之间的比例计算得到属于最优预测块的权重值与次优预测块的权重值。最后，编码器将最优预测块与次优预测块进行加权融合得到当前块的预测块作为输出。若最优预测模式或次优预测模式为均值模式(DC)或平坦模式(PLANAR)，或者次优预测模式的代价值大于两倍的最优预测模式代价值，则编码器不需要进行预测块融合操作，仅用最优预测模式对上侧和左侧相邻重建样本进行插值滤波得到的最优预测块作为当前块的预测块。基于此，编码器得到当前块的率失真代价，记为cost1。
步骤3：
编码器继续遍历其他帧内预测技术并计算对应的率失真代价记为cost2…costN；
步骤4：
若cost1为所有率失真代价中最小，则编码器在当前块允许采用TIMD技术，将当前块的TIMD使用标志位置真并写进码流。需要说明的是，本实施例中，编码器在当前块允许采用TIMD技术可以理解为编码器在当前块允许采用TIMD技术或允许TMMIP技术，具体使用TIMD技术还是使用TMMIP技术，可以根据代价信息进行确定。若cost1不为最小率失真代价，则编码器在当前块采用其他帧内预测技术，将当前块的TIMD使用标志位置假并写进码流。应当理解，其他帧内预测技术的标识位或索引等信息根据定义传输，此处不详细阐述。
编码器基于当前块的预测块和当前块的原始块确定当前块的残差块，并对当前块的残差块进行变换和量化，熵编码以及环路滤波等操作。应当理解，其具体过程可参见上文相关内容，为避免重复，此处不再赘述。
下面对本实施例中解码器的相关方案进行说明。
解码器解析块级类型标志位，若为帧内模式，则解析或获取TIMD允许使用标志位，该标志位为序列级标志位，表示当前解码器允许使用TIMD技术。
示例性地，解码器的流程可实现为以下过程：
步骤1：
若TIMD的允许使用标志位均为真，则解码器解析当前块的TIMD使用标志位，否则，当前解码过程不需要解码块级的TIMD使用标志位，块级的TIMD使用标志位默认为否。若当前块的TIMD使用标志位为真，则执行步骤2；否则，执行步骤3。
步骤2：
首先，解码器对模板区域外部相邻的行和列进行重建样本填充。填充过程与原始帧内预测过程所填充的方法相同，例如，解码器可以自左下角往右上角进行遍历填充，若所有重建样本均可以用，则依次全部填充可用重建样本；若所有重建样本均不可用，则全部填充均值；若部分重建样本可用，则先填充可用重建样本，对于其余不可用重建样本，解码器可以根据上述自左下角往右上角的顺序进行遍历，直至出现第一个可用重建样本后，用第一个可用重建样本对先前不可用位置进行填充。
其次，解码器以填充完毕的模板区域外侧重建样本作为输入，利用可允许使用的MIP模式对模板区域内的样本进行预测。
示例性地，对于4x4大小的块，可允许使用的MIP模式为16个。对于宽或高为4，或8x8大小的块，可允许使用的MIP模式为8个。其他尺寸的块可允许使用的MIP模式为6个。此外，任意尺寸的块都可以使用MIP转置功能，上述TMMIP的预测模式与MIP技术相同。
示例性地，具体预测计算过程包括：解码器先对重建样本进行哈尔下采样，例如解码器根据块尺寸决定下采样步长。接着，解码器根据转置与否的信息调整上侧下采样后的重建样本与左侧下采样后的重建样本拼接顺序；若不需要转置则将左侧下采样后的重建样本拼接在上侧下采样后的重建样本之后，将得到的向量作为输入，若需要转置则将上侧下采样后的重建样本拼接在左侧下采样后的重建样本之后，将得到的向量作为输入。然后，解码器根据遍历的预测模式作为索引获取MIP矩阵系数，与输入计算得到输出向量。最后，解码器根据输出向量个数与当前模板尺寸情况，对输出向量进行上采样，若不需要上采样则向量以水平方向依次填充作为模板预测块输出，若需要上采样则先上采样水平方向再下采样垂直方向，上采样至与模板尺寸相同后作为模板区域的预测块进行输出。
此外，解码器还需要尝试TIMD的模板匹配计算过程，即解码器根据不同的预测模式索引获取不同的插值滤波器对参考样本进行插值得到模板内的预测样本。
接着，解码器基于通过遍历每个MIP模式得到的模板区域的预测块与模板区域内重建样本，计算失真代价，并记录该预测模式与转置信息下的失真代价值。此外，解码器还需要遍历所有TIMD允许的帧内预测模式，计算得到模板内的预测块并与模板内重建样本计算失真代价，并记录各预测模式下的失真代价。解码器遍历所有允许的MIP模式与转置信息并遍历TIMD允许的预测模式后，可根据失真代价最小原则，选择出最优的预测模式，若MIP模式的失真代价最小，则将MIP模式及其对应的转置信息作为当前块的最优预测模式；若TIMD模式的失真代价最小，则将TIMD模式作为当前块的最优预测模式，记录由TIMD技术导出的最优帧内预测模式并记录其失真代价，同时记录由TIMD技术导出的次优预测模式与其失真代价。
最后，若解码器得到的最优预测模式为MIP模式，则解码器根据得到的最优MIP模式和转置信息，对当前块上侧和左侧相邻的重建样本视情况下采样并根据转置信息进行拼接作为输入向量，并根据MIP模式作为索引读取当前模式下的矩阵系数，然后，通过输入向量与矩阵系数的计算得到输出向量。解码器可根据转置信息进行输出转置，并根据当前块的尺寸和输出向量的样本数对输出向量进行上采样，得到与当前块相同尺寸的输出作为当前块的预测块。基于此，解码器得到当前块的率失真代价，将其记为cost1。
否则，解码器得到的最优预测模式为TIMD模式。若最优预测模式与次优预测模式都不是均值(DC)模式或者平坦(PLANAR)模式，且次优预测模式的失真代价小于两倍的最优预测模式失真代价，则解码器需要进行预测块融合操作。首先，解码器根据最优预测模式获取插值滤波系数，对上侧和左侧相邻重建样本进行插值滤波得到当前块内所有位置的预测样本，记为最优预测块；其次解码器根据次优预测模式获取插值滤波系数，对上侧和左侧相邻重建样本进行插值滤波得到当前块内所有位置的预测样本，记为次优预测块。接着，解码器利用最优预测模式代价值与次优预测模式代价值之间的比例计算得到属于最优预测块的权重值与次优预测块的权重值。最后，解码器将最优预测块与次优预测块进行加权融合得到当前块的预测块作为输出。若最优预测模式或次优预测模式为均值模式(DC)或平坦模式(PLANAR)，或者次优预测模式的代价值大于两倍的最优预测模式代价值，则解码器不需要进行预测块融合操作，仅用最优预测模式对上侧和左侧相邻重建样本进行插值滤波得到的最优预测块作为当前块的预测块。基于此，解码器得到当前块的率失真代价，记为cost1。
步骤3：
解码器继续解析其他帧内预测技术的使用标识位或索引等信息，并根据解析到的信息求得当前块的最终预测块。
步骤4：
解码器解析码流并获取当前块的频域残差块(也称为频域残差信息)，并对当前块的频域残差块进行反量化及反变换得到当前块的残差块(也称为时域残差块或时域残差信息)；然后解码器将当前块的预测块与当前块的残差块叠加得到重建样本块。
步骤5：
若当前图像中所有重建样本块经由环路滤波等技术后，得到最终的重建图像。
可选的，重建图像可以作为视频输出，也可以作为后面解码参考。
本实施例中，TIMD预测块加权融合的权重值计算过程可参见上文中对TIMD技术介绍所描述的内容，为避免重复，此处不再赘述。此外，编码器或解码器在TMMIP技术中用到的模板区域的大小可以 根据当前块的尺寸大小预先定义。例如，若MIP模式为最优预测模式或次优预测模式，也可以尝试加权融合操作；另外，TMMIP技术中关于模板区域的定义可以与TIMD技术中关于模板区域的定义一致，也可以不同。例如，若当前块的宽小于等于8，则所述模板区域中与当前块相邻的上侧区域的高度为两行样本高度，否则高度为四行样本高度；同理，若当前块高小于等于8，则所述模板区域中与当前块的左侧相邻的左侧区域的宽度为两列样本高度，否则宽度为四列样本高度。
以上结合附图详细描述了本申请的优选实施方式，但是，本申请并不限于上述实施方式中的具体细节，在本申请的技术构思范围内，可以对本申请的技术方案进行多种简单变型，这些简单变型均属于本申请的保护范围。例如，在上述具体实施方式中所描述的各个具体技术特征，在不矛盾的情况下，可以通过任何合适的方式进行组合，为了避免不必要的重复，本申请对各种可能的组合方式不再另行说明。又例如，本申请的各种不同的实施方式之间也可以进行任意组合，只要其不违背本申请的思想，其同样应当视为本申请所公开的内容。还应理解，在本申请的各种方法实施例中，上述各过程的序号的大小并不意味着执行顺序的先后，各过程的执行顺序应以其功能和内在逻辑确定，而不应对本申请实施例的实施过程构成任何限定。
上文详细描述了本申请的方法实施例，下文结合图7至图9，详细描述本申请的装置实施例。
图7是本申请实施例的解码器500的示意性框图。
如图7所示，所述解码器500可包括：
解析单元510，用于解析码流获取当前序列中当前块的残差块；
预测单元520，用于：
基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测所述当前块的最优MIP模式；
其中，所述多个MIP模式的失真代价包括利用所述多个MIP模式对与所述当前块相邻的模板区域内的样本进行预测得到的失真代价；
基于所述最优MIP模式，确定所述当前块的帧内预测模式；
基于所述当前块的帧内预测模式对所述当前块进行预测，得到所述当前块的预测块；
重建单元530，用于基于所述当前块的残差块和所述当前块的预测块，得到所述当前块的重建块。
在一些实施例中，所述预测单元520具体用于：
解析所述当前序列的码流获取第一标识；
若所述第一标识用于标识允许使用所述最优MIP模式对所述当前序列中的图像块进行预测，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
在一些实施例中，所述预测单元520具体用于：
若所述第一标识用于标识允许使用所述最优MIP模式对所述当前序列中的图像块进行预测，则解析所述码流获取第二标识；
若所述第二标识用于标识允许使用所述最优MIP模式对所述当前块进行预测，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
在一些实施例中，所述解析单元510还用于：
基于所述MIP模式的失真代价，确定所述多个MIP模式的排列顺序；
基于所述多个MIP模式的排列顺序，确定所述最优MIP模式使用的编码方式；
基于最优MIP模式使用的编码方式对所述当前序列的码流进行解码，得到最优MIP模式的索引。
在一些实施例中，所述排列顺序中前n个MIP模式使用的编码方式的码字长度小于所述排列顺序中第n个MIP模式之后的MIP模式使用的编码方式的码字长度；和/或，所述前n个MIP模式使用变长编码方式且所述第n个MIP模式之后的MIP模式使用截断二进制编码方式。
在一些实施例中，所述预测单元520具体用于：
将所述最优MIP模式确定为所述当前块的帧内预测模式。
在一些实施例中，所述预测单元520具体用于：
基于所述最优MIP模式对所述当前块进行预测，得到第一预测块；
基于模板的帧内模式导出TIMD模式对所述当前块进行预测，得到第二预测块；
基于所述第一预测块的失真代价和所述第二预测块的失真代价，将所述最优MIP模式和所述TIMD模式中失真代价最小的预测模式，确定为所述当前块的帧内预测模式。
在一些实施例中，所述预测单元520具体用于：
基于第三标识和所述多个MIP模式对所述模板区域内的样本进行预测，得到所述第三标识的每一个状态下所述多个MIP模式的失真代价；所述第三标识的用于标识是否转置MIP模式的输入向量和输出向量；
基于所述第三标识的每一个状态下所述多个MIP模式的失真代价，确定所述最优MIP模式。
在一些实施例中，所述预测单元520具体用于：
若所述当前块的尺寸为预设尺寸，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
在一些实施例中，所述预测单元520具体用于：
若所述当前块所在的图像帧为I帧、且所述当前块的尺寸为所述预设尺寸，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
在一些实施例中，所述预测单元520具体用于：
若所述当前块所在的图像帧为B帧，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
在一些实施例中，所述预测单元520基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测所述当前块的最优MIP模式之前，还用于：
获取与所述当前块相邻的相邻块使用的MIP模式；
将所述相邻块使用的MIP模式，确定为所述多个MIP模式。
在一些实施例中，所述预测单元520基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测所述当前块的最优MIP模式之前，还用于：
对所述模板区域外部相邻的参考区域进行重建样本填充，得到所述模板区域的参考行和参考列；
以所述参考行和所述参考列为输入，利用所述多个MIP模式分别对所述模板区域内的样本进行预测，得到所述多个MIP模式对应的多个预测块；
基于所述多个预测块和所述模板区域内的重建块，确定所述多个MIP模式的失真代价。
在一些实施例中，所述预测单元520具体用于：
对所述参考行和所述参考列进行下采样，得到输入向量；
以所述输入向量为输入，通过遍历所述多个MIP模式的方式对所述模板区域内的样本进行预测，得到所述多个MIP模式的输出向量；
对所述多个MIP模式的输出向量进行上采样，得到所述多个MIP模式对应的预测块。
在一些实施例中，所述预测单元520具体用于：
基于所述多个MIP模式在所述模板区域上的绝对变换差的和SATD，确定所述最优MIP模式。
图8是本申请实施例的编码器600的示意性框图。
如图8所示，所述编码器600可包括：
预测单元610，用于：
基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测当前序列中的当前块的最优MIP模式；
其中，所述多个MIP模式的失真代价包括利用所述多个MIP模式对与所述当前块相邻的模板区域内的样本进行预测得到的失真代价；
基于所述最优MIP模式，确定所述当前块的帧内预测模式；
基于所述当前块的帧内预测模式对所述当前块进行预测，得到所述当前块的预测块；
残差单元620，用于基于所述当前块的预测块和所述当前块的原始块，得到所述当前块的残差块；
编码单元630，用于对所述当前块的残差块进行编码，得到所述当前序列的码流。
在一些实施例中，所述预测单元610具体用于：
获取第一标识；
若所述第一标识用于标识允许使用所述最优MIP模式对所述当前序列中的图像块进行预测，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式；
其中，所述编码单元630具体用于：
对所述当前块的残差块和所述第一标识进行编码，得到所述码流。
在一些实施例中，所述预测单元610具体用于：
若所述第一标识用于标识允许使用所述最优MIP模式对所述当前序列中的图像块进行预测，则基于所述最优MIP模式确定最优预测模式；
基于所述最优预测模式对所述当前块进行预测，得到第一率失真代价；
基于至少一个帧内预测模式对所述当前块进行预测，得到至少一个率失真代价；
若所述第一率失真代价小于或等于所述至少一个率失真代价中的最小值，则将所述最优预测模式，确定为所述当前块的帧内预测模式；
其中，所述编码单元630具体用于：
对所述当前块的残差块、所述第一标识和第二标识进行编码，得到所述码流；
其中，若所述第一率失真代价小于或等于所述至少一个率失真代价中的最小值，则所述第二标识用 于标识允许使用所述最优MIP模式对所述当前块进行预测；若所述第一率失真代价大于所述至少一个率失真代价中的最小值，则所述第二标识用于标识不允许使用所述最优MIP模式对所述当前块进行预测。
在一些实施例中，所述预测单元610具体用于：
将所述最优MIP模式确定为所述最优预测模式。
在一些实施例中，所述预测单元610具体用于：
基于所述最优MIP模式对所述当前块进行预测，得到第一预测块；
基于模板的帧内模式导出TIMD模式对所述当前块进行预测，得到第二预测块；
基于所述第一预测块的失真代价和所述第二预测块的失真代价，将所述最优MIP模式和所述TIMD模式中失真代价最小的预测模式，确定为所述最优预测模式。
在一些实施例中，所述编码单元630具体用于：
基于所述MIP模式的失真代价，确定所述多个MIP模式的排列顺序；
基于所述多个MIP模式的排列顺序，确定所述最优MIP模式使用的编码方式；
对所述当前块的残差块进行编码以及基于最优MIP模式使用的编码方式对所述最优MIP模式的索引进行编码，得到所述码流。
在一些实施例中，所述排列顺序中前n个MIP模式使用的编码方式的码字长度小于所述排列顺序中第n个MIP模式之后的MIP模式使用的编码方式的码字长度；和/或，所述前n个MIP模式使用变长编码方式且所述第n个MIP模式之后的MIP模式使用截断二进制编码方式。
在一些实施例中，所述预测单元610具体用于：
将所述最优MIP模式确定为所述当前块的帧内预测模式。
在一些实施例中，所述预测单元610具体用于：
基于第三标识和所述多个MIP模式对所述模板区域内的样本进行预测，得到所述第三标识的每一个状态下所述多个MIP模式的失真代价；所述第三标识的用于标识是否转置MIP模式的输入向量和输出向量；
基于所述第三标识的每一个状态下所述多个MIP模式的失真代价，确定所述最优MIP模式。
在一些实施例中，所述预测单元610具体用于：
若所述当前块的尺寸为预设尺寸，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
在一些实施例中，所述预测单元610具体用于：
若所述当前块所在的图像帧为I帧、且所述当前块的尺寸为所述预设尺寸，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
在一些实施例中，所述预测单元610具体用于：
若所述当前块所在的图像帧为B帧，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
在一些实施例中，所述预测单元610基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测当前序列中的当前块的最优MIP模式之前，还用于：
获取与所述当前块相邻的相邻块使用的MIP模式；
将所述相邻块使用的MIP模式，确定为所述多个MIP模式。
在一些实施例中，所述预测单元610基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测当前序列中的当前块的最优MIP模式之前，还用于：
对所述模板区域外部相邻的参考区域进行重建样本填充，得到所述模板区域的参考行和参考列；
以所述参考行和所述参考列为输入，利用所述多个MIP模式分别对所述模板区域内的样本进行预测，得到所述多个MIP模式对应的多个预测块；
基于所述多个预测块和所述模板区域内的重建块，确定所述多个MIP模式的失真代价。
在一些实施例中，所述预测单元610具体用于：
对所述参考行和所述参考列进行下采样，得到输入向量；
以所述输入向量为输入，通过遍历所述多个MIP模式的方式对所述模板区域内的样本进行预测，得到所述多个MIP模式的输出向量；
对所述多个MIP模式的输出向量进行上采样，得到所述多个MIP模式对应的预测块。
在一些实施例中，所述预测单元610具体用于：
基于所述多个MIP模式在所述模板区域上的绝对变换差的和SATD，确定所述最优MIP模式。
应理解，装置实施例与方法实施例可以相互对应，类似的描述可以参照方法实施例。为避免重复，此处不再赘述。具体地，图7所示的解码器500可以对应于执行本申请实施例的方法300中的相应主体， 并且解码器500中的各个单元的前述和其它操作和/或功能分别为了实现方法300等各个方法中的相应流程。类似的，图8所示的编码器600可以对应于执行本申请实施例的方法400中的相应主体，即编码器600中的各个单元的前述和其它操作和/或功能分别为了实现方法400等各个方法中的相应流程。
还应当理解，本申请实施例涉及的解码器500或编码器600中的各个单元可以分别或全部合并为一个或若干个另外的单元来构成，或者其中的某个(些)单元还可以再拆分为功能上更小的多个单元来构成，这可以实现同样的操作，而不影响本申请的实施例的技术效果的实现。上述单元是基于逻辑功能划分的，在实际应用中，一个单元的功能也可以由多个单元来实现，或者多个单元的功能由一个单元实现。在本申请的其它实施例中，该解码器500或编码器600也可以包括其它单元，在实际应用中，这些功能也可以由其它单元协助实现，并且可以由多个单元协作实现。根据本申请的另一个实施例，可以通过在包括例如中央处理单元(CPU)、随机存取存储介质(RAM)、只读存储介质(ROM)等处理元件和存储元件的通用计算机的通用计算设备上运行能够执行相应方法所涉及的各步骤的计算机程序(包括程序代码)，来构造本申请实施例涉及的解码器500或编码器600，以及来实现本申请实施例的编码方法或解码方法。计算机程序可以记载于例如计算机可读存储介质上，并通过计算机可读存储介质装载于电子设备中，并在其中运行，来实现本申请实施例的相应方法。
换言之，上文涉及的单元可以通过硬件形式实现，也可以通过软件形式的指令实现，还可以通过软硬件结合的形式实现。具体地，本申请实施例中的方法实施例的各步骤可以通过处理器中的硬件的集成逻辑电路和/或软件形式的指令完成，结合本申请实施例公开的方法的步骤可以直接体现为硬件译码处理器执行完成，或者用译码处理器中的硬件及软件组合执行完成。可选地，软件可以位于随机存储器，闪存、只读存储器、可编程只读存储器、电可擦写可编程存储器、寄存器等本领域的成熟的存储介质中。该存储介质位于存储器，处理器读取存储器中的信息，结合其硬件完成上述方法实施例中的步骤。
图9是本申请实施例提供的电子设备700的示意结构图。
如图9所示，该电子设备700至少包括处理器710以及计算机可读存储介质720。其中，处理器710以及计算机可读存储介质720可通过总线或者其它方式连接。计算机可读存储介质720用于存储计算机程序721，计算机程序721包括计算机指令，处理器710用于执行计算机可读存储介质720存储的计算机指令。处理器710是电子设备700的计算核心以及控制核心，其适于实现一条或多条计算机指令，具体适于加载并执行一条或多条计算机指令从而实现相应方法流程或相应功能。
作为示例，处理器710也可称为中央处理器(Central Processing Unit，CPU)。处理器710可以包括但不限于：通用处理器、数字信号处理器(Digital Signal Processor，DSP)、专用集成电路(Application Specific Integrated Circuit，ASIC)、现场可编程门阵列(Field Programmable Gate Array，FPGA)或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件等等。
作为示例，计算机可读存储介质720可以是高速RAM存储器，也可以是非不稳定的存储器(Non-VolatileMemory)，例如至少一个磁盘存储器；可选的，还可以是至少一个位于远离前述处理器710的计算机可读存储介质。具体而言，计算机可读存储介质720包括但不限于：易失性存储器和/或非易失性存储器。其中，非易失性存储器可以是只读存储器(Read-Only Memory，ROM)、可编程只读存储器(Programmable ROM，PROM)、可擦除可编程只读存储器(Erasable PROM，EPROM)、电可擦除可编程只读存储器(Electrically EPROM，EEPROM)或闪存。易失性存储器可以是随机存取存储器(Random Access Memory，RAM)，其用作外部高速缓存。通过示例性但不是限制性说明，许多形式的RAM可用，例如静态随机存取存储器(Static RAM，SRAM)、动态随机存取存储器(Dynamic RAM，DRAM)、同步动态随机存取存储器(Synchronous DRAM，SDRAM)、双倍数据速率同步动态随机存取存储器(Double Data Rate SDRAM，DDR SDRAM)、增强型同步动态随机存取存储器(Enhanced SDRAM，ESDRAM)、同步连接动态随机存取存储器(synch link DRAM，SLDRAM)和直接内存总线随机存取存储器(Direct Rambus RAM，DR RAM)。
在一种实现方式中，该电子设备700可以是本申请实施例涉及的编码器或编码框架；该计算机可读存储介质720中存储有第一计算机指令；由处理器710加载并执行计算机可读存储介质720中存放的第一计算机指令，以实现本申请实施例提供的编码方法中的相应步骤；换言之，计算机可读存储介质720中的第一计算机指令由处理器710加载并执行相应步骤，为避免重复，此处不再赘述。
在一种实现方式中，该电子设备700可以是本申请实施例涉及的解码器或解码框架；该计算机可读存储介质720中存储有第二计算机指令；由处理器710加载并执行计算机可读存储介质720中存放的第二计算机指令，以实现本申请实施例提供的解码方法中的相应步骤；换言之，计算机可读存储介质720中的第二计算机指令由处理器710加载并执行相应步骤，为避免重复，此处不再赘述。
根据本申请的另一方面，本申请实施例还提供了一种编解码系统，包括上文涉及的编码器和解码器。
根据本申请的另一方面，本申请实施例还提供了一种计算机可读存储介质(Memory)，计算机可 读存储介质是电子设备700中的记忆设备，用于存放程序和数据。例如，计算机可读存储介质720。可以理解的是，此处的计算机可读存储介质720既可以包括电子设备700中的内置存储介质，当然也可以包括电子设备700所支持的扩展存储介质。计算机可读存储介质提供存储空间，该存储空间存储了电子设备700的操作系统。并且，在该存储空间中还存放了适于被处理器710加载并执行的一条或多条的计算机指令，这些计算机指令可以是一个或多个的计算机程序721(包括程序代码)。
根据本申请的另一方面，提供了一种计算机程序产品或计算机程序，该计算机程序产品或计算机程序包括计算机指令，该计算机指令存储在计算机可读存储介质中。例如，计算机程序721。此时，数据处理设备700可以是计算机，处理器710从计算机可读存储介质720读取该计算机指令，处理器710执行该计算机指令，使得该计算机执行上述各种可选方式中提供的编码方法或解码方法。
换言之，当使用软件实现时，可以全部或部分地以计算机程序产品的形式实现。该计算机程序产品包括一个或多个计算机指令。在计算机上加载和执行该计算机程序指令时，全部或部分地运行本申请实施例的流程或实现本申请实施例的功能。该计算机可以是通用计算机、专用计算机、计算机网络、或者其他可编程装置。该计算机指令可以存储在计算机可读存储介质中，或者从一个计算机可读存储介质向另一个计算机可读存储介质进行传输，例如，该计算机指令可以从一个网站站点、计算机、服务器或数据中心通过有线(例如同轴电缆、光纤、数字用户线(digital subscriber line，DSL))或无线(例如红外、无线、微波等)方式向另一个网站站点、计算机、服务器或数据中心进行传输。
本领域普通技术人员可以意识到，结合本文中所公开的实施例描述的各示例的单元以及流程步骤，能够以电子硬件、或者计算机软件和电子硬件的结合来实现。这些功能究竟以硬件还是软件方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本申请的范围。
最后需要说明的是，以上内容，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应以所述权利要求的保护范围为准。

Claims (36)

  1. 一种解码方法，其特征在于，所述方法适用于解码器，所述方法包括：
    解析码流获取当前序列中当前块的残差块；
    基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测所述当前块的最优MIP模式；
    其中，所述多个MIP模式的失真代价包括利用所述多个MIP模式对与所述当前块相邻的模板区域内的样本进行预测得到的失真代价；
    基于所述最优MIP模式，确定所述当前块的帧内预测模式；
    基于所述当前块的帧内预测模式对所述当前块进行预测，得到所述当前块的预测块；
    基于所述当前块的残差块和所述当前块的预测块，得到所述当前块的重建块。
  2. 根据权利要求1所述的方法，其特征在于，所述基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测所述当前块的最优MIP模式，包括：
    解析所述当前序列的码流获取第一标识；
    若所述第一标识用于标识允许使用所述最优MIP模式对所述当前序列中的图像块进行预测，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
  3. 根据权利要求2所述的方法，其特征在于，所述若所述第一标识用于标识允许使用所述最优MIP模式对所述当前序列中的图像块进行预测，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式，包括：
    若所述第一标识用于标识允许使用所述最优MIP模式对所述当前序列中的图像块进行预测，则解析所述码流获取第二标识；
    若所述第二标识用于标识允许使用所述最优MIP模式对所述当前块进行预测，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
  4. 根据权利要求1所述的方法，其特征在于，所述方法还包括：
    基于所述MIP模式的失真代价，确定所述多个MIP模式的排列顺序；
    基于所述多个MIP模式的排列顺序，确定所述最优MIP模式使用的编码方式；
    基于最优MIP模式使用的编码方式对所述当前序列的码流进行解码，得到最优MIP模式的索引。
  5. 根据权利要求4所述的方法，其特征在于，所述排列顺序中前n个MIP模式使用的编码方式的码字长度小于所述排列顺序中第n个MIP模式之后的MIP模式使用的编码方式的码字长度；和/或，所述前n个MIP模式使用变长编码方式且所述第n个MIP模式之后的MIP模式使用截断二进制编码方式。
  6. 根据权利要求1至5中任一项所述的方法，其特征在于，所述基于所述最优MIP模式，确定所述当前块的帧内预测模式，包括：
    将所述最优MIP模式确定为所述当前块的帧内预测模式。
  7. 根据权利要求1至5中任一项所述的方法，其特征在于，所述基于所述最优MIP模式，确定所述当前块的帧内预测模式，包括：
    基于所述最优MIP模式对所述当前块进行预测，得到第一预测块；
    基于模板的帧内模式导出TIMD模式对所述当前块进行预测，得到第二预测块；
    基于所述第一预测块的失真代价和所述第二预测块的失真代价，将所述最优MIP模式和所述TIMD模式中失真代价最小的预测模式，确定为所述当前块的帧内预测模式。
  8. 根据权利要求1至7中任一项所述的方法，其特征在于，所述基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测所述当前块的最优MIP模式，包括：
    基于第三标识和所述多个MIP模式对所述模板区域内的样本进行预测，得到所述第三标识的每一个状态下所述多个MIP模式的失真代价；所述第三标识的用于标识是否转置MIP模式的输入向量和输出向量；
    基于所述第三标识的每一个状态下所述多个MIP模式的失真代价，确定所述最优MIP模式。
  9. 根据权利要求1至8中任一项所述的方法，其特征在于，所述基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测所述当前块的最优MIP模式，包括：
    若所述当前块的尺寸为预设尺寸，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
  10. 根据权利要求9所述的方法，其特征在于，所述若所述当前块的尺寸为预设尺寸，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式，包括：
    若所述当前块所在的图像帧为I帧、且所述当前块的尺寸为所述预设尺寸，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
  11. 根据权利要求1至8中任一项所述的方法，其特征在于，所述基于多个基于矩阵的帧内预测 MIP模式的失真代价，确定用于预测所述当前块的最优MIP模式，包括：
    若所述当前块所在的图像帧为B帧，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
  12. 根据权利要求1至11中任一项所述的方法，其特征在于，所述基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测所述当前块的最优MIP模式之前，所述方法还包括：
    获取与所述当前块相邻的相邻块使用的MIP模式；
    将所述相邻块使用的MIP模式，确定为所述多个MIP模式。
  13. 根据权利要求1至12中任一项所述的方法，其特征在于，所述基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测所述当前块的最优MIP模式之前，所述方法还包括：
    对所述模板区域外部相邻的参考区域进行重建样本填充，得到所述模板区域的参考行和参考列；
    以所述参考行和所述参考列为输入，利用所述多个MIP模式分别对所述模板区域内的样本进行预测，得到所述多个MIP模式对应的多个预测块；
    基于所述多个预测块和所述模板区域内的重建块，确定所述多个MIP模式的失真代价。
  14. 根据权利要求13所述的方法，其特征在于，所述以所述参考行和所述参考列为输入，利用所述多个MIP模式分别对所述模板区域内的样本进行预测，得到所述多个MIP模式对应的多个预测块，包括：
    对所述参考行和所述参考列进行下采样，得到输入向量；
    以所述输入向量为输入，通过遍历所述多个MIP模式的方式对所述模板区域内的样本进行预测，得到所述多个MIP模式的输出向量；
    对所述多个MIP模式的输出向量进行上采样，得到所述多个MIP模式对应的预测块。
  15. 根据权利要求1至14中任一项所述的方法，其特征在于，所述基于多个矩阵的帧内预测MIP模式在模板区域上的失真代价，确定所述多个MIP模式中的最优MIP模式，包括：
    基于所述多个MIP模式在所述模板区域上的绝对变换差的和SATD，确定所述最优MIP模式。
  16. 一种编码方法，其特征在于，所述方法适用于编码器，所述方法包括：
    基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测当前序列中的当前块的最优MIP模式；
    其中，所述多个MIP模式的失真代价包括利用所述多个MIP模式对与所述当前块相邻的模板区域内的样本进行预测得到的失真代价；
    基于所述最优MIP模式，确定所述当前块的帧内预测模式；
    基于所述当前块的帧内预测模式对所述当前块进行预测，得到所述当前块的预测块；
    基于所述当前块的预测块和所述当前块的原始块，得到所述当前块的残差块；
    对所述当前块的残差块进行编码，得到所述当前序列的码流。
  17. 根据权利要求16所述的方法，其特征在于，所述基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测当前序列中的当前块的最优MIP模式，包括：
    获取第一标识；
    若所述第一标识用于标识允许使用所述最优MIP模式对所述当前序列中的图像块进行预测，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式；
    其中，所述对所述当前块的残差块进行编码，得到所述当前序列的码流，包括：
    对所述当前块的残差块和所述第一标识进行编码，得到所述码流。
  18. 根据权利要求17所述的方法，其特征在于，所述基于所述最优MIP模式，确定所述当前块的帧内预测模式，包括：
    若所述第一标识用于标识允许使用所述最优MIP模式对所述当前序列中的图像块进行预测，则基于所述最优MIP模式确定最优预测模式；
    基于所述最优预测模式对所述当前块进行预测，得到第一率失真代价；
    基于至少一个帧内预测模式对所述当前块进行预测，得到至少一个率失真代价；
    若所述第一率失真代价小于或等于所述至少一个率失真代价中的最小值，则将所述最优预测模式，确定为所述当前块的帧内预测模式；
    其中，所述对所述当前块的残差块和所述第一标识进行编码，得到所述码流，包括：
    对所述当前块的残差块、所述第一标识和第二标识进行编码，得到所述码流；
    其中，若所述第一率失真代价小于或等于所述至少一个率失真代价中的最小值，则所述第二标识用于标识允许使用所述最优MIP模式对所述当前块进行预测；若所述第一率失真代价大于所述至少一个率失真代价中的最小值，则所述第二标识用于标识不允许使用所述最优MIP模式对所述当前块进行预 测。
  19. 根据权利要求18所述的方法，其特征在于，所述基于所述最优MIP模式确定最优预测模式，包括：
    将所述最优MIP模式确定为所述最优预测模式。
  20. 根据权利要求18所述的方法，其特征在于，所述基于所述最优MIP模式确定最优预测模式，包括：
    基于所述最优MIP模式对所述当前块进行预测，得到第一预测块；
    基于模板的帧内模式导出TIMD模式对所述当前块进行预测，得到第二预测块；
    基于所述第一预测块的失真代价和所述第二预测块的失真代价，将所述最优MIP模式和所述TIMD模式中失真代价最小的预测模式，确定为所述最优预测模式。
  21. 根据权利要求16所述的方法，其特征在于，所述对所述当前块的残差块进行编码，得到所述当前序列的码流，包括：
    基于所述MIP模式的失真代价，确定所述多个MIP模式的排列顺序；
    基于所述多个MIP模式的排列顺序，确定所述最优MIP模式使用的编码方式；
    对所述当前块的残差块进行编码以及基于最优MIP模式使用的编码方式对所述最优MIP模式的索引进行编码，得到所述码流。
  22. 根据权利要求21所述的方法，其特征在于，所述排列顺序中前n个MIP模式使用的编码方式的码字长度小于所述排列顺序中第n个MIP模式之后的MIP模式使用的编码方式的码字长度；和/或，所述前n个MIP模式使用变长编码方式且所述第n个MIP模式之后的MIP模式使用截断二进制编码方式。
  23. 根据权利要求16至22中任一项所述的方法，其特征在于，所述基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测当前序列中的当前块的最优MIP模式，包括：
    基于第三标识和所述多个MIP模式对所述模板区域内的样本进行预测，得到所述第三标识的每一个状态下所述多个MIP模式的失真代价；所述第三标识的用于标识是否转置MIP模式的输入向量和输出向量；
    基于所述第三标识的每一个状态下所述多个MIP模式的失真代价，确定所述最优MIP模式。
  24. 根据权利要求16至23中任一项所述的方法，其特征在于，所述基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测当前序列中的当前块的最优MIP模式，包括：
    若所述当前块的尺寸为预设尺寸，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
  25. 根据权利要求24所述的方法，其特征在于，所述若所述当前块的尺寸为预设尺寸，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式，包括：
    若所述当前块所在的图像帧为I帧、且所述当前块的尺寸为所述预设尺寸，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
  26. 根据权利要求16至23中任一项所述的方法，其特征在于，所述基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测当前序列中的当前块的最优MIP模式，包括：
    若所述当前块所在的图像帧为B帧，则基于所述多个MIP模式的失真代价，确定所述最优MIP模式。
  27. 根据权利要求16至26中任一项所述的方法，其特征在于，所述基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测当前序列中的当前块的最优MIP模式之前，所述方法还包括：
    获取与所述当前块相邻的相邻块使用的MIP模式；
    将所述相邻块使用的MIP模式，确定为所述多个MIP模式。
  28. 根据权利要求16至27中任一项所述的方法，其特征在于，所述基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测当前序列中的当前块的最优MIP模式之前，所述方法还包括：
    对所述模板区域外部相邻的参考区域进行重建样本填充，得到所述模板区域的参考行和参考列；
    以所述参考行和所述参考列为输入，利用所述多个MIP模式分别对所述模板区域内的样本进行预测，得到所述多个MIP模式对应的多个预测块；
    基于所述多个预测块和所述模板区域内的重建块，确定所述多个MIP模式的失真代价。
  29. 根据权利要求28所述的方法，其特征在于，所述以所述参考行和所述参考列为输入，利用所述多个MIP模式分别对所述模板区域内的样本进行预测，得到所述多个MIP模式对应的多个预测块，包括：
    对所述参考行和所述参考列进行下采样，得到输入向量；
    以所述输入向量为输入，通过遍历所述多个MIP模式的方式对所述模板区域内的样本进行预测， 得到所述多个MIP模式的输出向量；
    对所述多个MIP模式的输出向量进行上采样，得到所述多个MIP模式对应的预测块。
  30. 根据权利要求16至29中任一项所述的方法，其特征在于，所述基于多个矩阵的帧内预测MIP模式在模板区域上的失真代价，确定所述多个MIP模式中的最优MIP模式，包括：
    基于所述多个MIP模式在所述模板区域上的绝对变换差的和SATD，确定所述最优MIP模式。
  31. 一种解码器，其特征在于，包括：
    解析单元，用于解析码流获取当前序列中当前块的残差块；
    预测单元，用于：
    基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测所述当前块的最优MIP模式；
    其中，所述多个MIP模式的失真代价包括利用所述多个MIP模式对与所述当前块相邻的模板区域内的样本进行预测得到的失真代价；
    基于所述最优MIP模式，确定所述当前块的帧内预测模式；
    基于所述当前块的帧内预测模式对所述当前块进行预测，得到所述当前块的预测块；
    重建单元，用于基于所述当前块的残差块和所述当前块的预测块，得到所述当前块的重建块。
  32. 一种编码器，其特征在于，包括：
    预测单元，用于：
    基于多个基于矩阵的帧内预测MIP模式的失真代价，确定用于预测当前序列中的当前块的最优MIP模式；
    其中，所述多个MIP模式的失真代价包括利用所述多个MIP模式对与所述当前块相邻的模板区域内的样本进行预测得到的失真代价；
    基于所述最优MIP模式，确定所述当前块的帧内预测模式；
    基于所述当前块的帧内预测模式对所述当前块进行预测，得到所述当前块的预测块；
    残差单元，用于基于所述当前块的预测块和所述当前块的原始块，得到所述当前块的残差块；
    编码单元，用于对所述当前块的残差块进行编码，得到所述当前序列的码流。
  33. 一种电子设备，其特征在于，包括：
    处理器，适于执行计算机程序；
    计算机可读存储介质，所述计算机可读存储介质中存储有计算机程序，所述计算机程序被所述处理器执行时，实现如权利要求1至15中任一项所述的方法或如权利要求16至30中任一项所述的方法。
  34. 一种计算机可读存储介质，其特征在于，用于存储计算机程序，所述计算机程序使得计算机执行如权利要求1至15中任一项所述的方法或如权利要求16至30中任一项所述的方法。
  35. 一种计算机程序产品，包括计算机程序/指令，其特征在于，所述计算机程序/指令被处理器执行时实现如权利要求1至15中任一项所述的方法或如权利要求16至30中任一项所述的方法。
  36. 一种码流，其特征在于，所述码流如权利要求1至15中任一项所述的方法中的码流或如权利要求16至30中任一项所述的方法生成的码流。
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