JPH09182017A - Video editing equipment - Google Patents

Abstract

(57) An object of the present invention is to provide a moving image editing apparatus capable of easily and inexpensively editing moving image data compressed by a compression method using inter-frame prediction. A decoder 141 decodes moving image data of a first format that has been digitally compressed and encoded by using inter-frame prediction, and video data of a second format obtained by the decoder 141 is displayed as a third image for display. Convert to video data of the format. Next, the video data of the third format is digitally compression-encoded in the fourth format without interframe prediction,
It is held in the secondary storage device 13. Then, by using the display video data of the fourth format held in the secondary storage device 13 for the subsequent editing, editing in frame units of the digital compression-coded moving image data is easily and inexpensively performed. be able to.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving image editing apparatus for fetching and editing, for example, digitally compressed and encoded moving image data, and more particularly to an MPEG (Moving P
When moving image data compressed by a compression method using inter-frame prediction such as image Experts Group 2 is captured and edited, the moving image data is first decoded and then, for example, JPEG (Joint Point Group) is used.
graphic coding Experts G
The present invention relates to a moving image editing apparatus that makes it possible to easily and inexpensively edit in frame units by re-compressing in frame units by using, for example.

[0002]

2. Description of the Related Art In recent years, with the development of computer technology, various so-called multimedia-compatible personal computers have been developed. In addition, many of these types of personal computers have made it possible to handle moving image data, but recently, it is not only possible to play this moving image data, but it is also possible to easily edit the captured moving image data. There is a strong demand to build a system at low cost.

In the conventional moving image editing system, since an analog image is used and a high bandwidth is required, a very expensive recording device is required. Also,
Even in digital processing, high-performance calculation was required.

On the other hand, with the recent development of a large-capacity storage device, improvement of data compression technology, and higher performance of microprocessors and the like, digital moving image data can be displayed on a personal computer as described above. It was However, when editing moving image data, there is a problem that editing is difficult because the difference due to correlation between frames is transmitted depending on the compression method.

[0005]

As described above, when moving image data compressed by a compression method using inter-frame prediction, such as MPEG2, is edited, differences due to correlation between frames are sequentially transmitted. In order to
There is a problem that editing is difficult in a system constructed relatively inexpensively with a personal computer or the like.

The present invention has been made in view of the above circumstances, and moving image data compressed by a compression method using inter-frame prediction can be easily edited only by adding a simple structure. An object of the present invention is to provide a moving image editing apparatus that can be constructed at low cost.

[0007]

According to the present invention, in a moving picture editing apparatus for editing moving picture data, a CPU and a video decoder for decoding moving picture data of a first format which is digitally compressed and encoded by using inter-frame prediction. And conversion means for causing the CPU to convert the video data of the second format obtained by the decoding of the video decoder into video data of the third format for display, and the CPU by the conversion of the conversion means. A compression means for digitally compression-encoding the obtained video data of the third format in the fourth format without interframe prediction, and a display video digitally compression-encoded in the fourth format by the compression means. A secondary storage device for holding data, and a fourth format stored in the secondary storage device. And performing video editing using the display video data.

According to the present invention, when moving image data (first format) digitally encoded by a compression method using inter-frame prediction such as MPEG2 is fetched and edited, the compression is performed. Video data such as YUV (luminance / color) data (second video data)
Format) and further converts this video data into video data for display (third format) such as RGB data. Then, the video data for display is digitally compressed and encoded by a compression method such as JPEG without using inter-frame prediction (fourth format), and the video data for display compressed in this frame unit is secondary-coded. Store in a storage device.

In subsequent editing, the video data for display, which is stored in the secondary storage device and compressed in frame units, is used for editing, so that the correlation with the preceding and following frames is taken into consideration. It is possible to easily and inexpensively edit moving images in frame units without having to perform any advanced calculations.

At this time, it is desirable that the display video data to be edited can be transferred from, for example, the system memory to the image memory, and the edited result is displayed on the screen in real time to be presented to the user.

Further, not only is video data (first format) digitally compressed and coded by a compression method using inter-frame prediction taken in and edited, but also video, for example, recorded by a video camera or recorded from a television or the like. When editing a moving image, if the YUV data (second format) is taken in and the above-described editing process is performed, digital high-quality editing without deterioration of image quality is achieved.
It can be realized easily and cheaply. Moreover, cost reduction can be achieved by executing data compression and decompression by an application program.

[0012]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the system configuration of a personal computer according to this embodiment.
This system corresponds to, for example, a desktop type personal computer and the like, and as shown in the figure, a system bus 10, a CPU 11, a system memory 12, a secondary storage device 13, a moving image reproducing device (moving image recording device) 14, a display. It has a controller 15, a video memory (VRAM) 16, and a work memory 17,
The moving picture data compressed and encoded by the MPEG2 is decoded into the digital YUB data by the MPEG decoder 141 of the moving picture reproducing apparatus 14 and taken in.

In this embodiment, moving image data encoded by MPEG2, that is, moving image data compressed and encoded by using inter-frame prediction is taken in and edited, and the encoding format of this moving image data is JPEG.
Is converted to a frame-based compression coding format that does not use interframe prediction, and editing as an intermediate work is performed on the moving image data coded by JPEG to obtain the final editing result. MPEG
It shall be encoded by 2 and output.

The JPEG encoding of the moving image data is executed by the application program executed by the CPU 11. The MPEG2 encoding of the moving image data is processed by the MPEG encoder 141 of the moving image recording device 14.

MPEG will now be described with reference to FIGS.
An outline of encoding and decoding according to is explained. FIG.
It is a conceptual diagram for demonstrating the structure of the moving image data encoded by MPEG2.

In MPEG2, the coded image data is created based on the preceding and following screen data, so that the information cannot be completed with only one screen. GOP (G
group of pictures) as a unit to enable random access. The sequence header is used to find the random access. That is, in the MPEG2 bit stream, entry points for each GOP are prepared at various places (FIG. 2A).

In MPEG, in order to enable bidirectional prediction of forward prediction from past reproduced images and backward prediction from future reproduced images, I picture and P are added to each screen data in the GOP. Three types of picture and B picture are defined (FIG. 2 (b)).

(1) I-picture An I-picture is a picture coded from only the information of the picture and is generated without using inter-frame prediction. Moreover, at least one I picture is required in the GOP.

(2) P picture P picture is generated by performing prediction (forward prediction) from I picture or P picture.

(3) B picture A B picture is generated by bidirectional prediction. Further, subtypes such as forward prediction and backward prediction are added to this B picture.

MPEG2 moving image data having such a data structure is decoded by the procedure shown in FIG. 3 and output as video. That is, screen data and a screen type are input as digital moving image data, the screen data is inversely quantized, and inverse DCT (Discrete Cosin) is performed.
e Transform: Discrete Cosine Transform) operation is performed, and the image is combined with the image of either the forward prediction memory or the backward prediction memory according to the input image type and output.

On the other hand, when a video image is input, this image data is encoded by the procedure shown in FIG.
That is, the input image data is quantized after the difference between it and the image in either the forward prediction memory or the backward prediction memory is acquired by encoding control, and the acquired difference is subjected to DCT operation. Output as digital image data together with the screen type. Note that this image data is subjected to inverse quantization, inverse DCT, and synthesis to restore the original image in order to obtain the difference of the image data to be input next, and then is restored to the forward prediction memory or backward prediction memory. Stored in one of the memories.

Next, the outline of encoding and decoding by JPEG will be described with reference to FIG. When the image data is input, in JPEG, encoding is performed according to the procedure shown in FIG. That is, first, the input image is
Divide into blocks of × 8 pixels, and DC
T operation is performed, and the obtained DCT coefficient is calculated as DC (Dire
ct Current: DC component and AC (Alte
It is quantized independently of the rnate Current (AC) component. At this time, the luminance signal quantization table and the color difference signal quantization table are referred to.

Then, entropy coding is performed according to the Huffman code table and the result is output. on the other hand,
Decoding is almost as shown in FIG. 5 (a) as shown in FIG. 5 (b).
The procedure is reverse to the procedure shown in. That is, the Huffman coding table and the quantization table are extracted from the coded (compressed) data, subjected to entropy decoding, then dequantized, and subjected to the inverse DCT operation together with the separately decoded DC coefficient to form an image. Decrypt.

Next, each unit of the system shown in FIG. 1 will be described. The CPU 11 controls the operation of the entire system, and executes the operating system and application programs to be executed, which are stored in the system memory 12.

The moving picture reproducing apparatus (moving picture recording apparatus) 14 is composed of M
The moving picture data encoded by PEG2 is decoded by the MPEG decoder 141 to obtain the YUV video data 14a.
Is output. The display controller 15 converts the RGB data held in the video memory (VRAM) 16 into C
Output to RT display. The display controller 15 also includes a work memory 17, and the work memory 17 stores one frame of YUB video data. Furthermore, this display controller 15
Has a YUV-RGB conversion circuit for converting the YUB video data stored in the work memory 17 into RGB video data, and a bit block transfer circuit for performing high-speed data transfer between the video memory (VRAM) 16 and the work memory 17. .

The secondary storage device 13 includes the CPU 11
The moving image data compressed and encoded in the JPEG format is stored. Here, with reference to FIG.
The operation procedure when converting the compression method of moving image data to the PEG format will be described.

The moving picture data digitally compressed and encoded in the MPEG format is transferred to the MPEG decoder 1 of the moving picture reproducing apparatus 14.
The display controller 1 decodes the YUV video data obtained by this decoding by the reference numeral 41.
5 ((1) in FIG. 6). Y from the MPEG decoder 141 to the display controller 15 in this case
The video bus 14a is used to transfer the UV video data, and the system bus 10 is not used. Therefore,
This YUV video data transfer can be performed at high speed.

On the other hand, the display controller 15 receiving the YUV video data stores the YUV video data in the work memory 17, converts the stored YUV video data into RGB video data, and transfers the RGB video data to the video memory (VRAM) 16. ((2) in FIG. 6).

The RGB video data transferred to the video memory (VRAM) 16 is transferred to the system memory 12 via the system bus 10 by the CPU 11 ((3) in FIG. 6) and is digitally recorded on the system memory 12 by JPEG. After the compression coding, the secondary storage device 1
3 ((4) in FIG. 6).

As a result, the moving image data which has been digitally compressed and encoded by using the inter-frame prediction is converted into the digital compression-encoding format of each frame which does not use the inter-frame prediction.

Next, referring to FIG. 7, an operation procedure for editing moving image data will be described. The editing of the moving image data is executed by the CPU 11 executing the application program stored in the system memory 12.

First, the CPU 11 transfers the data of the frame to be edited from the secondary storage device 13 to the system memory 1.
It is read out to 2 ((1) in FIG. 7). Here, the CPU 11
Decodes the data digitally encoded by JPEG on the system memory 12, and the RGB video data obtained by this decoding is transferred via the system bus 12 to the video memory (VRA) of the display controller 15.
M) 16 is transferred ((2) in FIG. 7).

At this time, the display controller 15
Is the R transferred to the video memory (VRAM) 16.
The GB video data is displayed on the CRT display, and the user edits the displayed image.

Then, the CPU 11 edits the RGB video data on the system memory 12 in accordance with the editing performed by the user at this time. At this time, the CPU
11 transfers the edited RGB video data to the video memory (VRAM) 16 to cause the display controller 15 to display the CRT display, and presents the edited result to the user in real time.

When the editing of this frame is completed, the RGB video data on the system memory 12 is digitally compressed and encoded by JPEG again,
The data is stored in the secondary storage device 13 ((3) in FIG. 7).

As a result, frame-by-frame editing can be performed easily and inexpensively without considering the correlation between preceding and following frames. Next, an operation procedure when converting the compression method of moving image data from the JPEG format to the MPEG format will be described with reference to FIG.

When the end of the editing work is instructed, the CPU 1
1 reads out the JPEG format data stored in the secondary storage device 13 to the system memory 12 ((1) in FIG. 8). Next, the CPU 11 decodes the JPEG format data into YUV video data, and further decodes the decoded YUV video data into MPE of the video recording device 14.
The data is transferred to the G encoder 141 ((2) in FIG. 8). Then, the MPEG encoder 141 performs digital compression coding using interframe prediction according to MPEG2. The edited moving image data digitally compressed and encoded by the MPEG2 is recorded by the moving image recording device 14.

That is, according to the moving picture editing apparatus of the present embodiment, the moving picture data compression-coded by the frame correlation is temporarily converted into the compression format on a frame-by-frame basis, while displaying each frame. The editing work can be easily realized even by a relatively inexpensive personal computer or the like.

If not only digitally compressed and encoded moving image data but also, for example, a moving image recorded by a video camera or a moving image recorded from a TV set is taken in as YUV data and edited, the image quality of digital image is improved. Editing without deterioration can be realized easily and inexpensively.

[0041]

As described above in detail, according to the present invention, MPEG (Moving Picture Exp) is used.
erts Group) 2 or the like, when capturing and editing moving image data compressed by a compression method using inter-frame prediction, the moving image data is decompressed once, and then, for example, JPEG (Joint Photographic).
By re-compressing in frame units using a coding experts group) or the like, editing in frame units can be performed easily and at low cost.

In addition to taking in and editing moving picture data that has been digitally compressed and coded by a compression method using inter-frame prediction, for example, when editing a moving picture recorded by a video camera or a moving picture recorded from a television, If the YUV data is fetched and the above-mentioned editing processing is performed, it is possible to easily and inexpensively perform digital high-quality editing without deterioration of image quality.

[Brief description of the drawings]

FIG. 1 is a diagram showing a system configuration of a personal computer according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram for explaining the structure of moving image data encoded by MPEG2.

FIG. 3 is a diagram for explaining an operation procedure of MPEG2 decoding.

FIG. 4 is a diagram for explaining an operation procedure of MPEG2 encoding.

FIG. 5 is a diagram for explaining an operation procedure of MPEG2 encoding and decoding.

FIG. 6 is a diagram for explaining an operation procedure when converting the compression method of moving image data from the MPEG format of the present embodiment to the JPEG format.

FIG. 7 is a diagram for explaining an operation procedure when editing moving image data according to the present embodiment.

FIG. 8 is a diagram for explaining an operation procedure when converting a compression method of moving image data from JPEG format to MPEG format according to the present embodiment.

[Explanation of symbols]

10 ... System bus, 11 ... CPU, 12 ... System memory, 13 ... Secondary storage device, 14 ... Movie reproducing device (movie recording device), 15 ... Display controller, 16 ...
Video memory (VRAM), 17 ... Work memory.

Claims (8)

[Claims] 1. A moving image editing apparatus for editing moving image data, comprising: a CPU, and a first digital compression coded using inter-frame prediction.
A video decoder which decodes moving image data of the format, and a conversion unit which causes the CPU to convert the video data of the second format obtained by the decoding of the video decoder into the video data of the third format for display, The third obtained by the conversion of the conversion means to the CPU
Compression means for digitally compressing and coding video data of the above format into a fourth format which does not use inter-frame prediction, and holding the video data for display digitally compressed and coded in the fourth format by this compression means. A moving image editing apparatus comprising: a secondary storage device, wherein a moving image is edited using the display video data of the fourth format held in the secondary storage device. 2. A decoding means for causing the CPU to decode the display video data of the fourth format, and a display controller for displaying the video data of the third format obtained by the decoding means on a display monitor. The CPU further comprises editing means for causing the CPU to edit the video data in the third format in accordance with the editing performed on the image displayed by the display controller. The video data of the third format edited by the editing means is digitally compression-encoded again in the fourth format, and the secondary storage device re-digitally encodes the video data of the fourth format. 2. The moving image editing apparatus according to claim 1, wherein 3. The second conversion means for causing the CPU to convert the video data of the third format into the video data of the second format, and the second conversion means obtained by the second conversion means. It further comprises a memory that holds a plurality of frames of video data of a format, and a video encoder that digitally compresses and encodes the video data of the second format in the first format based on the correlation of the plurality of frames. The moving image editing apparatus according to claim 1, wherein the moving image editing apparatus is a moving image editing apparatus. 4. The display controller converts a work memory holding the video data of the second format, and the video data of the second format held in the work memory into video data of the third format. Conversion circuit, a video memory holding the video data of the third format obtained by the conversion circuit, a bit block transfer circuit for performing high-speed data transfer between the work memory and the video memory, and the video 4. The moving image editing apparatus according to claim 2, further comprising means for displaying on the display monitor the video data of the third format held in the memory. 5. The apparatus further comprises means for causing the CPU to transfer the video data of the third format to a video memory of the display controller, and the edited result of the editing means can be visually confirmed immediately. The moving picture editing device according to claim 4. 6. The display controller includes a circuit for decoding the data in the first format, a circuit for decoding data in the fourth format, and the first controller.
6. The moving picture editing apparatus according to claim 2, further comprising a circuit for compressing data in the above format and a circuit for compressing data in the fourth format. 7. A moving picture editing system for editing moving picture data, comprising: a CPU; decoding means for causing the CPU to decode the moving picture data of the first format which has been digitally compressed and encoded using interframe prediction; and the CPU. The second obtained by the decoding of the decoding means
Conversion means for converting the video data of the above format into video data of the third format for display, and the third means obtained by the conversion of the conversion means by the CPU.
Compression means for digitally compressing and coding video data of the above format into a fourth format which does not use inter-frame prediction, and holding the video data for display digitally compressed and coded in the fourth format by this compression means. A moving image editing apparatus comprising: a secondary storage device, wherein a moving image is edited using the display video data of the fourth format held in the secondary storage device. 8. A moving image editing system for editing moving image data, comprising: a CPU; a conversion unit for causing the CPU to convert input video data into display video data; and a conversion unit for causing the CPU to perform conversion by the conversion unit. A compression means for digitally compression-encoding the obtained display video data without using inter-frame prediction, and a secondary storage device for holding the display-video data digitally compression-encoded by the compression means. Then, the moving picture editing apparatus is characterized in that a moving picture is edited using the video data for display held in the secondary storage device.