JPH08205170A - Moving picture decoding apparatus and moving picture coding apparatus - Google Patents

Abstract

PURPOSE: To provide the dynamic image decoding device and dynamic image encoding device which prevent picture quality from deteriorating by decoding a compressed and encoded image and then encoding the decoded signal in synchronism according to encoding information. CONSTITUTION: The dynamic image decoding device has an encoding information extracting means 101 which extracts the encoding information and performs an encoding process by one of an in-frame decoding means 104, a forward predictive decoding means 105, and a bilateral predictive decoding means 106 according to the extracted encoding information to multiplex the encoding information with part of a video signal. The dynamic image encoding device extracts the encoding information from the multiplexed video signal and synchronizes encoding by using the encoding information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving picture decoding apparatus for decoding and reproducing a compression coded picture which is intra-frame coded and inter-frame coded, and a reproduced signal thereof. The present invention relates to a moving picture coding device.

[0002]

2. Description of the Related Art A moving image coding (MPEG) standard is a typical one as a highly efficient moving image coding system.
This is discussed in ISO-IEC / JTC1 / SC2 / WG11 and proposed as a standard proposal. First, the difference in images is taken to reduce the redundancy in the time axis direction, and then the discrete cosine transform processing. And variable length coding are used to reduce the redundancy in the spatial direction.

Here, an image coded using only the information of one image is an intra-frame image (Intra-coded pictur).
e, I picture). Also, the difference between the image currently being encoded and the image that is temporally ahead is calculated, and the image obtained by encoding the difference is the forward predictive encoded image (Pred
ictive-coded picture, P picture). Similarly,
Taking the difference between the three images of the front image, the rear image, and the interpolated image created from the front and the rear of the image currently being encoded with respect to the image currently being encoded, and the image currently being encoded, the three images are obtained. If the smallest difference among them is transferred, the redundancy in the time axis direction is reduced and the amount of information is reduced.
The image coded in this manner is a bidirectionally predictive-coded picture (B picture).

A series of image sequences consisting of one or a plurality of I pictures and zero or a plurality of non-I pictures (P pictures and B pictures) is a group of pictures.

When the break of the group of pictures is: I picture is I, P picture is P, and B picture is B, the input order to the encoder is, for example, I1, B2, B.
3, P4: B5, B6, I7, B8, B9, I10, B
11, B12, P13, B14, B15, P16: B1
7, B18, I19, B20, B21, P22.

[0006]

As described above, the transfer efficiency of B pictures and P pictures is taken into consideration, and the information amount of the actual image data is reduced in the time axis direction and the space direction. Therefore, the B picture and P picture are inferior in image quality to the I picture.

Therefore, an image coded by a coding method using a difference between frames such as MPEG is decoded,
When the reproduced image is to be encoded again, if the image which was originally a B picture or a P picture is started to be encoded as an I picture, the one with poor image quality is selected as a reference frame for encoding. , The image quality is deteriorated in the encoded result.

For example, as shown in FIG. 10, the order of input to the encoder is B3 (1004), P4 (1005), B5 (1
006), B6 (1007), P7 (1008), B8
(1009) and B9 (1010), B3
(1004) is added to the intra image I1 (1001) and B6
(1007) is P4 (1002) of the forward prediction image,
B9 (1010) is selected as the forward prediction image P7 (1003), and the B picture with poor image quality is selected as the reference frame. Therefore, a frame P4 (100
5), B5 (1006), P7 (1008), B8 (1
009), the image quality deteriorates. The image quality also deteriorates at B6 (1007) and B9 (1010) that refer to past frames.

[0009]

In order to achieve this object, a moving picture decoding apparatus according to the present invention uses a field or frame intra-frame coding and a field or frame coded with reference to past and future pictures. Coding information extraction means for extracting coding information indicating field or intra-frame coding or field or inter-frame coding by inputting a code string compression-coded by inter-coding, and the extracted coding Decoding means for performing field or intraframe coding or field or interframe coding using the information and outputting as a decoded video signal, and a part of the decoded video signal of the extracted coded information. It is constituted by the coded information multiplexing means for multiplexing into.

Further, the moving picture coding apparatus of the present invention is a coding which receives a video signal as an input and which is multiplexed into a part of the video signal and indicates whether it is field or intra-frame coding or field or inter-frame coding. Coding information detecting means for detecting information, and a signal or video signal obtained by removing the coding information from the video signal as input, and coding from the video signal indicating field or intraframe coding using the detected coding information And the detected encoded information is used once every frame or several frames to encode and output as a compressed encoded signal.

Further, the moving picture coding apparatus of the present invention receives a video signal as an input, and is a code indicating a field or intra-frame coding or a field or inter-frame coding, which is multiplexed in a part of the video signal. Encoding information detecting means for detecting the encoded information, and a signal or video signal obtained by removing the encoded information from the video signal as an input, the detected encoded information is encoded every frame or every several frames once, It is composed of encoding means for outputting as a compression encoded signal.

Further, the moving picture coding apparatus of the present invention receives, as an input, incidental information relating to a video signal, which is input from an input line other than the video signal, and is multiplexed with a part of the incidental information.
Coded information detecting means for detecting coded information indicating field or intra-frame coding or field or inter-frame coding, and field or intra-frame code using the detected coded information as a video signal input The encoding means starts encoding from a video signal indicating encoding, uses the detected encoded information once every frame or several frames to encode, and outputs as a compressed encoded signal.

[0013]

According to the present invention, with this construction, a moving picture decoding apparatus for detecting the coding mode of the intra-frame coding and inter-frame compression coding video signal and inserting it into the decoded video signal. The encoding mode is detected from the video signal in which the encoding mode is inserted, and the encoding is started when the encoding mode becomes the intra-frame encoding mode, and the encoding mode is started. A video encoding device that identifies whether an image currently being encoded from an I-picture, a P-picture, or a B-picture is encoded from a video signal and encodes a video signal by synchronizing the I-picture, the P-picture, and the B-picture. By providing it, the deterioration of image quality is prevented. The original coding mode is changed to perform coding by resetting the group of picture size and the reference frame interval as necessary.

Further provided is a moving picture decoding / coding apparatus which is a combination of the moving picture decoding apparatus and the moving picture coding apparatus, starts coding with an I picture, and sets I based on a coding mode. The picture quality is prevented from being deteriorated by synchronizing the coding of the picture, P picture, and B picture.

[0015]

(Embodiment 1) An embodiment of a moving picture decoding apparatus and a moving picture coding apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of a moving picture decoding apparatus according to the first embodiment of the present invention. In FIG. 1, 101 is encoded information extracting means, 102, 108 and 111 are switching means, 103 is a synchronizing signal generating means, 104 is intraframe decoding means, 105 is forward predictive decoding means, and 106 is bidirectional predictive decoding. Reference numeral 107 is a delay means, 109 is a horizontal scanning line counter, 110 is an insertion position determination means, and 112 is a waveform generation means.

The operation of the moving picture decoding apparatus configured as described above will be described below. A coding mode 114 indicating which of intra-frame coding, forward predictive coding, and bidirectional predictive coding is extracted from the compression code string 113 that is intra-frame and inter-frame compression coded by the coding information extracting means 101. To do.

When the coding mode 114 is intraframe coding, the output of the switching means 102 is switched to the intraframe decoding means 104, and the intraframe decoding means 104 performs the decoding process. Then, the coding mode 114 is delayed by the delay means 107 by the time required for the intraframe decoding means 104 to perform the decoding processing, and switches the input of the switching means 108 to the intraframe coding means 104.

When the coding mode 114 is forward predictive coding, the output of the switching means 102 is switched to the forward predictive decoding means 105, and the forward predictive decoding means 105 performs decoding processing. Then, the encoding mode 114 is delayed by the delay unit 107 by the time required for the decoding process of the forward predictive decoding unit 105, and switches the input of the switching unit 108 to the forward predictive decoding unit 105.

When the coding mode 114 is bidirectional predictive coding, the output of the switching means 102 is switched to the bidirectional predictive decoding means 106, and the bidirectional predictive decoding means 106 performs decoding processing. Then, the coding mode 114 is delayed by the delay means 107 by the time required for the bidirectional predictive decoding means 106 to perform the decoding processing, and switches the input of the switching means 108 to the bidirectional predictive decoding means 106.

The synchronizing signal generating means 103 outputs a vertical synchronizing signal 115 indicating the first field starting point and the second field starting point, and a horizontal synchronizing signal 116 for synchronizing the horizontal scanning lines, for intra-frame decoding. The means 104, the forward predictive decoding means 105, and the bidirectional predictive decoding means 106 control the output timing of the video signal decoded using these synchronization signals.

The horizontal scanning line counter 109 resets the count value to 0 by the vertical synchronizing signal 115 from the synchronizing signal generating means 103 and counts up by the horizontal synchronizing signal 116. When the count value from the horizontal scanning line counter 109 is 12, the insertion position determining means 110 switches the input side of the switching means 111 to the output side of the waveform generating means 112.

That is, when the count value of the horizontal scanning line counter 109 is other than 12, the decoded video signal waveform is output, but when the count value of the horizontal scanning line counter 109 is 12, it is generated by the waveform generating means 112. Waveform is output.

The operation of the waveform generating means 112 will be described in more detail. For example, if the pattern code representing the coding mode is "01" for intraframe coding, "10" for forward predictive coding, and "11" for bidirectional predictive coding, the waveform generation means 112 performs coding. Depending on the mode, a coded information waveform representing one of the pattern codes is generated.

For example, the waveform generating means 112 generates a pattern of "01" when the coding mode is intra-frame coding. Therefore, in the case of an NTSC signal, a square wave representing 0 is, for example, 0.5 horizontal scanning. 25 μs corresponding to a line segment is generated, and then a square wave representing 1 is generated for 25 μs. As a result, the coded information waveform representing "01" is inserted at the 12th horizontal scanning line.

FIG. 3 shows an example in which the coded information waveform is generated by the waveform generation means 112 as a pattern of "01" and the coded information waveform is inserted by the twelfth horizontal synchronizing signal. FIG.
(A) is an output signal waveform of the switching means 108, FIG.
(B) is an output signal waveform of the waveform generation means 112, FIG.
(C) is an output signal waveform of the insertion position determination means 110, FIG.
(D) shows the output video signal 117. That is, FIG. 3 (c)
When the signal waveform of FIG. 3 is HIGH, the input side of the switching means 111 switches to the output side of the waveform generating means 112, so the signal waveform of FIG. 3D becomes the signal waveform of FIG. 3B and the signal waveform of FIG. 3C. Is LOW, switching means 11
Since the input side of 1 is switched to the output side of the switching means 108, the signal waveform of FIG. At this time, the waveform generating means 112 generates a pattern of "01" within one horizontal scanning line and repeats this, and the input side of the switching means 111 switches the switching position 10 when the insertion position determining means 110 is LOW.
8 and the output side of the waveform generating means 112 when HIGH. Insertion position determination means 11
0 becomes HIGH only when the 12th horizontal scanning line. Therefore, "0" is displayed on the 12th horizontal scanning line in FIG. 3 (d).
The coded information waveform of "1" is inserted.

FIG. 2 shows the structure of the moving picture coding apparatus according to the first embodiment of the present invention. 201 in FIG.
Is a synchronizing signal detecting means, 202 is a horizontal scanning line counter, 2
Reference numeral 03 is an extraction position determining means, 204, 207 and 212 are switching means, 205 is an encoding mode detecting means, 206 is an encoding mode selecting means, 208 is an encoding information generating means,
Reference numeral 209 is an intra-frame coding means, 210 is a forward prediction coding means, and 211 is a bidirectional prediction coding means.

The operation of the moving picture coding apparatus configured as described above will be described below. Sync signal detecting means 2
At 01, the vertical synchronizing signal 214 and the horizontal synchronizing signal 215 are detected from the input video signal 213, and the horizontal scanning line counter 20
Output to 2.

The horizontal scanning line counter 202 resets the count value to 0 by the vertical synchronizing signal 214 from the synchronizing signal detecting means 201 and counts up by the horizontal synchronizing signal 215.

At the same time, when the count value of the horizontal scanning line counter 202 is 12, the extraction position determining means 203 switches the output of the switching means 204 to the input side of the encoding mode detecting means 205, thereby the encoding mode detecting means 2
05 detects the coding mode 217 from the coded information waveform 216. The count value of the horizontal scanning line counter 202 is 1
When the value is other than 2, the output of the switching means 204 is switched to the input side of the switching means 207.

For example, when 01 is read at the 12th horizontal scanning line by the coding mode detecting means 205, and 01 represents intraframe coding, the coding mode is intraframe coding.

When the synchronizing signal detecting means 201 detects the vertical synchronizing signal from the input video signal 213, it outputs the vertical synchronizing signal 214 to the coding mode selecting means 206, and the coding mode selecting means 206 switches the switching signals 220 and 221.
Control the timing to output.

The coding mode selecting means 206 switches the input of the switching means 212 to the output side of the coding information generating means 210 in response to the vertical synchronizing signal 214 from the synchronizing signal detecting means 201 to perform intra-frame coding or forward direction. The coding mode 218 indicating the predictive coding or the bidirectional predictive coding is output to the coding information generating means 208.

The coded information generating means 208 is, for example, 00.
A start code of 00000000111 or 0, for example
If a header information portion of a coded bit string such as a header code of 00000000111 is generated, and if the coding mode 218 is intraframe coding, then, for example, 01,
A code representing the coding information is generated, such as 10 for forward predictive coding and 11 for bidirectional predictive coding.

After the processing of the coding information generating means 208 is completed, the coding mode selecting means 206 sets the output side of the switching means 207 and the input side of the switching means 212 to the frame if the coding mode 218 is intraframe coding. If the coding mode 218 is forward prediction coding, the output side of the switching means 207 and the input side of the switching means 212 are forward prediction coding means. If the coding mode 218 is bidirectional predictive coding, the output side of the switching means 207 and the input side of the switching means 212 are switched to the bidirectional predictive coding means 211 to perform bidirectional prediction. Encoding process is performed.

By the above operation, it is possible to obtain a coded compressed video signal sequence using the coding mode extracted from the compression coded video signal as it is.

As shown in FIG. 7, the coding mode selection means 206 is connected to the group of picture size setting means 701,
The reference frame interval setting means 702 and the coding mode pattern determining means 703 are used.

Group of picture size setting means 70
In 1, the group of picture size is changed. For example, set the group of picture size to 1 by input from the outside.
When changing from 5 to 12, a header code indicating the start of a group of pictures at intervals of 12 frames, for example, 00
When 0010011 is written and the coding mode at the head of the group of pictures is other than intraframe coding, the coding mode is changed to intraframe coding.

Further, the reference frame interval setting means 702 changes the intervals of the reference frames of the intra-frame coded image and the forward prediction coded image. For example, if the reference frame interval is changed from 3 to 2 by an external input within a certain group of pictures, the coding mode is changed to forward prediction coding at a 2-frame interval asynchronously with the coding mode to be extracted. Change and output the encoding mode 218,
Change the reference frame interval. At this time, if the input coding mode 217 is intra-frame coding, it is not changed.

When the group of picture size and the reference frame interval are changed, the coding mode at the time of coding by the encoder is changed. In FIG. 8A, the coding mode when the group of picture size is 6 and the reference frame interval is 3 is shown. In FIG. 8B, the coding mode when the group of picture size is 12 and the reference frame interval is 3 is shown. Shows an example changed to.

In the case of FIG. 8, I7 (801) which is originally the intra-frame coded image becomes P7 (802),
The image quality deteriorates. However, on the contrary,
When changing from (b) to FIG. 8 (a), P7 (802) of the forward prediction image becomes I7 (801), and the image quality is not particularly deteriorated, but random access is possible.
Error propagation stops at this I7 (801) frame.

The coding mode selecting means 206 selects the coding mode detected by the coding mode detecting means 205 as the coding mode when coding unless the group of picture size and the reference frame interval are changed. Then
If there is a change, the coding mode at the time of coding is changed according to the change.

As described above, according to the present embodiment, when the encoding apparatus performs the encoding, the encoding mode at the time of reproduction by the decoding apparatus is known, so that the encoding is performed from the intra-frame encoded image. You can start and prevent the deterioration of image quality. In addition, since the coding mode is known in all frames, all frames of the intra-frame coded image, the forward predictive coded image, and the bidirectional predictive coded image are coded in synchronization with each other, resulting in deterioration of image quality. Can be prevented.

Further, since the coding mode is inserted in the video signal, a connection for transmitting the video signal is only required to connect the decoding device and the coding device, and a special connection is required. The connection is simple because it is unnecessary.

Although one horizontal scanning line is used as the position for inserting the coded information waveform, the position is not limited to this and may be two horizontal scanning lines or more.

For example, as shown in FIG. 4, coded information may be inserted as a waveform extending over two horizontal scanning lines. At this time, the waveform generation means 112 generates a pattern of "0" or "1" in one horizontal scanning line, and
The output signal is not changed within the horizontal scanning line. Figure 4 (a)
Is the output signal waveform of the switching means 108, FIG. 4B is the output signal waveform of the waveform generation means 112, FIG. 4C is the output signal waveform of the insertion position determination means 110, and FIG. 4D is the output video signal 117. Represents That is, the signal waveform of FIG.
When IGH, the input side of the switching means 111 switches to the output side of the waveform generating means 112, so the signal waveform of FIG. 4 (d) becomes the signal waveform of FIG. 4 (b), and when the signal waveform of FIG. 4 (c) is LOW. Since the input side of the switching means 111 is switched to the output side of the switching means 108, FIG.
Signal waveform. At this time, the waveform generation means 112
Generate a pattern of "0" in the th horizontal scan line, and
A pattern of "1" is generated in the 1st horizontal scanning line.
The input side of the switching means 111 is the insertion position determining means 110.
Is LOW, the output side of the switching means 108 is switched to, and when HIGH, the output side of the waveform generating means 112 is switched to. The insertion position determination means 110 has one horizontal scanning line.
It becomes HIGH only at the 2nd and 13th times. Therefore, a coded information waveform of "0" is inserted in the 12th horizontal scanning line and a coded information waveform of "1" is inserted in the 13th horizontal scanning line in FIG. 4D.

The duration of the encoded information waveform may be shorter or longer than one horizontal scanning line. The coding mode pattern may be written in one horizontal scanning line a plurality of times, one or more times.

The position where the coded information waveform is inserted is
It can be anywhere during the vertical blanking period.

The coded information waveform need not be a square wave, but may be a modulated waveform or a band-pass filtered waveform. That is, when expressing "01", it is sufficient if the waveform representing "0" and the waveform representing "1" are different.

The code pattern representing the encoded information is
The intraframe coding of the coding information is "01", the forward predictive coding is "10", and the bidirectional predictive coding is "11", but the invention is not limited to this, and at which position and in which pattern. The number of bits inserted may be determined between the decoding device and the encoding device.

The number of bits of the coded information is not limited to 2 bits, but may be any number of bits, or some redundant bits such as 4 bits of error correction code may be added. Also, the encoded information may be a variable-length pattern instead of a fixed-length pattern.

(Embodiment 2) An embodiment of the moving picture decoding apparatus and the moving picture coding apparatus of the present invention will be described below with reference to the drawings.

FIG. 5 shows the configuration of a moving picture decoding apparatus according to the second embodiment of the present invention. In FIG. 5, reference numeral 501 is a synchronizing signal generating means, 502 is an encoded information extracting means, 503,
511 is a switching unit, 504 is an intra-frame decoding unit, 505 is a forward predictive decoding unit, 506 is a bidirectional predictive coding unit, 507 is a delay unit, 508 is a time code extraction unit, and 509 is a coded information insertion unit. is there.

The same components as those of the moving picture decoding apparatus in the first embodiment are the coding information extracting means 101 and 50.
2, synchronization signal generating means 103 and 501, intra-frame decoding means 104 and 504, forward predictive decoding means 1
05 and 505, bidirectional predictive decoding means 106 and 50
6, delay means 107 and 507, switching means 102
And 503, and switching means 108 and 510.

The operation of the moving picture decoding apparatus configured as described above will be described below. The coding information extraction means 502 is the coding information extraction means 101 of the first embodiment, the intraframe decoding means 504 is the intraframe decoding means 104 of the first embodiment, and the forward prediction decoding means 505 is the forward direction of the first embodiment. Predictive decoding means 105, bidirectional predictive decoding means 50
6 produces a decoded video signal 517 by the same operation as the bidirectional predicting means 106 of the first embodiment.

The synchronizing signal generating means 501 is similar to the operation of the synchronizing signal generating means 103 of the first embodiment, and is for synchronizing the horizontal scanning lines with the synchronizing signal 515 indicating the start points of the first and second fields. The horizontal synchronization signal 516 is output, and the intraframe decoding means 504, the forward prediction decoding means 505, and the bidirectional prediction decoding means 506 control the output timing of the video signal decoded using these synchronization signals.

On the other hand, the time code extracting means 508 outputs the video signal 512 which is compression-coded within the frame and between the frames.
For example, the time code 513 appearing after the identification code indicating the beginning of the time code such as 00101101 is extracted for each unit indicating each time of hour, minute, second, and frame. The identification code is a pattern that is not included in the compression-encoded video signal sequence, and may be any pattern as long as it is determined between the encoder and the decoder.

When the time code 513 is, for example, 01 hours, 20 minutes, 10 seconds, and 00 frames, the coded information insertion means 509 sets the coding mode extracted by the coded information extraction means 502, for example, intraframe coding. It is inserted into the time code as encoded information such as a frame of 26 hours, 20 minutes, and 10 seconds. For example, it is assumed that the time code 513 can represent only 24 hours, 00 minutes, 00 seconds, and 00 frames, and the unit of time can represent only 00 to 24 frames.

Here, in the portion representing the time of the time code, 25 is set as an offset when the coding mode is intraframe coding, 50 is set as an offset in forward predictive coding, and is set as an offset in bidirectional coding. 75
If you decide to add, the unit of time is 25 to 4
Up to 9, the coding mode is intraframe coding, 50 to 7
4 is forward predictive coding, and 75 to 99 is bidirectional predictive coding.

FIG. 6 shows the configuration of the moving picture coding apparatus according to the second embodiment of the present invention. In FIG. 6, 601
Is a synchronizing signal detecting means, 602 is an encoding mode detecting means,
Reference numeral 603 is an encoding mode selecting unit, 604 is an encoding information generating unit, 605 is an encoding information separating unit, and 606 and 611.
Is a switching means, 607 is an intra-frame encoding means, 60
Reference numeral 8 is a forward predictive coding means, 609 is a bidirectional predictive coding means, and 610 is a time code coding means.

Synchronous signal detecting means 201 and 601, coding mode detecting means 205 and 603, coding mode selecting means 206 and 603, and coding information generating means 208 and 60.
4, intra-frame coding means 209 and 607, forward predictive coding means 210 and 609, bidirectional predictive coding means 21
1 and 611 and the switching means 207 and 606 may be the same as those of the moving picture coding apparatus in the first embodiment.

The operation of the moving picture coding apparatus configured as described above will be described below. Sync signal detecting means 6
When 01 detects a vertical synchronizing signal from the input video signal 612, the vertical synchronizing signal 614 is encoded mode selecting means 603.
To control the timing at which the coding mode selection means 603 outputs the coding mode 618 and the switching signal 620.

At the same time, the coded information separating means 605 reads the time code 613 synchronized with the video signal, and if the time code can represent only up to 24: 00: 0: 00, for example, if the time code 613 is within this range. Since the code information is not included in the time code 613, the time code 613 is output to the time code generating means 610 as it is. If the time code 613 is outside this range, the code information is included. The coding information is separated and the coding information 615 is converted into the coding mode detecting means 60.
2, the time code 617 from which the coded information is removed is output to the time code coding means 610.

Here, the operations of the coded information separation means 605 and the coded information detection means 602 will be described in more detail.

The coded information separating means is composed of a time code normal value comparison circuit 901 and an offset table 902 as shown in FIG. 9, for example.

For example, the time code 613 is 51 hours 1
If it is 5 minutes 30 seconds 18 frames, the coded information separating means 605 determines whether the normal time code does not exceed 24 hours 00 minutes 00 seconds 00 frames by comparing the normal time code values as shown in FIG. It is determined by the circuit 901 that the part of the unit of time 51 is not a normal time code.

Here, for example, the offset table 902
Describes that the offset value is 01 when the unit of time is 25 to 49, the offset value is 50 from 50 to 74, and the offset value is 75 from 75 to 99.

The offset value is the offset table 902.
And the determined offset value is output to the encoding mode detecting means 602 as encoding information 615.

The coding mode detecting means 602 is composed of an offset value comparison circuit 903 and an offset pair coding mode table 904 as shown in FIG. 9, for example.

In the offset value comparison circuit 903, it is written that the offset value is 01 for intra-frame coding, 50 for forward predictive coding, and 75 for bidirectional predictive coding.
4, since the offset value is 75, it is detected that the coding mode is forward predictive coding, and the coding mode 616 is output.

At this time, the coded information separating means 605 outputs a time code 617 of 01 hour 15 minutes 30 seconds 18 frames, which is obtained by subtracting the offset from 51 hours 15 minutes 30 seconds 18 frames, as the time code.
When output to 10, the time code encoding means 610,
For example, after the code pattern of the identification code 00101101 of the time code, for example, each digit is directly displayed in binary and 0000000100010101001100.
It is converted into a bit pattern representing a time code of 00000111000.

Further, when the synchronizing signal detecting means 601 detects the vertical synchronizing signal 614, the encoding mode selecting means 603.
When the coding mode detecting means 602 detects the coding mode 616, it outputs it to the coding mode selecting means 603.

The coding mode selecting means 603 switches the switching means 611 to the coding information generating means 604 according to the vertical synchronizing signal 614 from the synchronizing signal detecting means 601, and selects the intra-frame coding or the forward prediction coding. The coding mode 618 representing the bidirectional predictive coding is output to the coding information generation unit 609.

The coded information generating means 604, for example, 00
A start code of 00000000111 or 0, for example
If a header information portion of a coded bit string such as a header code of 00000000111 is generated, and if the coding mode 618 is intraframe coding, then, for example, 01,
A code representing the coding information is generated, such as 10 for forward predictive coding and 11 for bidirectional predictive coding.

Next, for example, the time code is written in the header information immediately after the coded information, and the coding mode selection means 603 switches the input of the switching means 611 to the output side of the time code coding means 610 to set the time. The bit pattern of the time code generated by the code coding means 610 is inserted after the coded information.

The coding mode 618 is the same as the coding mode 218 of the first embodiment, and the intraframe coding means 607 is 2
09, the forward predictive coding means 608 is the same as 210, the bidirectional predictive coding means 609 is the same operation as 211, and the coding mode selecting means 603 follows the coding mode 618 and the output side of the switching means 606 and the switching means 611.
The input side of is switched and encoding processing is performed.

By the above operation, the encoded compressed video signal sequence can be obtained by using the encoding mode extracted from the compressed and encoded video signal as it is.

Here, when it is desired to change the coding mode 616 detected from the coding information waveform, the coding mode selecting means 603 sets the group of picture size setting means 701 and the reference frame interval setting as shown in FIG. Means 7
02, and an encoding mode pattern determining means 703. Similar to the first embodiment, the group-of-picture size setting unit 701 changes the group-of-picture size, and the reference-frame interval setting unit 702 changes the reference frame interval of the intra-frame coded image and the forward prediction coded image. The coding mode 618 to be output is changed.

The coding mode selecting means 603 selects the coding mode detected by the coding mode detecting means 602 as the coding mode when coding unless the group of picture size and the reference frame interval are changed. Then
If there is a change, the coding mode at the time of coding is changed according to the change.

As described above, according to the present embodiment, even when another information is already written in the vertical blanking of the video signal or when it is not desired to write the coded information in the video signal, the coding apparatus can At the time of encoding, the encoding mode at the time of reproduction by the decoding device is known, so that encoding can be started from the intra-frame encoded image, and deterioration of image quality can be prevented.
In addition, since the coding mode is known in all frames, all frames of the intra-frame coded image, the forward predictive coded image, and the bidirectional predictive coded image are coded in synchronization with each other, resulting in deterioration of image quality. Can be prevented.

If there is a connection other than a connection for transmitting a video signal or a time code in the connection between the decoding device and the encoding device, the coding information may be inserted into the signal. Also, a signal line for transferring only the encoded information may be newly provided. .

When inserting the coding mode into the time code, any number of offset values may be used, and the same not only for the time part but also for the minute part, the second part and the frame part. The effect is obtained.

The insertion position is not limited to one unit, and the same effect can be obtained by straddling the minute part and the second part, for example. For example, if 01 represents intra-frame coding, and the actual time code is 00 hours 49 minutes 32 seconds 15 frames, inserting the pattern code 01 of the coding mode into the time code causes 00 hours 49 minutes 42 seconds 15 frames. Like This is to add 0 to 4/49 as an offset and 1 to 3 of 32 seconds as an offset.

The time code may be temporarily destroyed by inserting a coding mode. For example, when the portion of the time code is 66, it is intraframe coding, when it is 77, it is forward predictive coding, and when it is 88, it is bidirectional predictive coding. The part that represents the minute is to read further after reading the time code, or read from a newly provided connection.

The position where the coding mode is inserted may be anywhere on the signal line for transmitting the time code. For example, the pattern 0 of the coding mode representing the intraframe coding
1 after the true time code 00 hours 49 minutes 32 seconds 15 frames, then 00 hours 49 minutes 32 seconds 15 frames 0
It is read as 1.

The coding mode may be inserted by a signal other than the video signal and the time code, which is connected between the decoder and the encoder. For example, if there is a connection other than the video signal and time code, use the signal on that signal line, or if there is no connection, install a new signal line, connect the decoding device and the coding device, and insert the coding mode into that signal. You can do it or transfer it directly.

The code pattern representing the encoded information is
The intraframe coding of the coding information is “01”, the forward predictive coding is “10”, and the bidirectional predictive coding is “11”. However, the present invention is not limited to this, and at which position and in which pattern. The number of bits inserted may be determined between the decoding device and the encoding device.

The number of bits of the coded information is not limited to 2 bits, but may be any number of bits, or some redundant bits such as 4 bits for the error correction code may be added. Also, the encoded information may be a variable-length pattern instead of a fixed-length pattern.

[0089]

With the above configuration, when an image coded by a coding method such as MPEG which refers to video information between frames is decoded and the reproduced image is to be coded again, intra-frame coding is performed. Coding is started from the image, and deterioration of the image quality can be prevented.

Furthermore, since the coding modes of intra-frame coding, forward predictive coding, and bi-directional predictive coding can be used for all the pictures, the first intra-frame coding can be performed. Not only images but also all intra-frame coded images, forward predictive coded images, and bidirectional coded images can be synchronized, and deterioration of image quality can be prevented, which is a great practical effect.

[Brief description of drawings]

FIG. 1 is a block diagram of a moving picture decoding apparatus according to a first embodiment.

FIG. 2 is a block diagram of a moving picture coding apparatus according to the first embodiment.

FIG. 3 is a timing chart at the time of inserting the coded information waveform according to the first embodiment.

FIG. 4 is a timing chart at the time of inserting the coded information waveform according to the first embodiment.

FIG. 5 is a block diagram of a moving picture decoding apparatus according to a second embodiment.

FIG. 6 is a block diagram of a moving picture coding apparatus according to a second embodiment.

FIG. 7 is a block diagram of encoding mode change.

FIG. 8 is an explanatory diagram of a coding mode in the encoder.

FIG. 9 is a block diagram of encoding mode detection from time code.

FIG. 10 is an explanatory diagram of a coding mode in the encoder.

[Explanation of symbols]

102, 108, 111, 204, 207, 212, 5
03, 510, 606, 611 Switching means 101, 502 Encoding information extracting means 103, 501 Synchronous signal generating means 104, 504 In-frame decoding means 105, 505 Forward prediction decoding means 106, 506 Bidirectional prediction decoding means 107 , 507 delay means 109, 202 horizontal scanning line counter 110 insertion position determination means 112 waveform generation means 201, 601 synchronization signal detection means 203 extraction position determination means 205, 602 coding mode detection means 206, 603 coding mode selection means 208, 604 coded information generation means 209, 607 intra-frame coding means 210, 608 forward prediction coding means 211, 609 bidirectional prediction coding means 508 time code extraction means 509 coded information insertion means 605 coded information separation means 610 time Code coding means 701 Group of picture size setting means 702 Reference frame interval setting means 703 Coding mode pattern determining means 901 Time code normal value comparison circuit 902 Offset table 903 Offset value comparison circuit 904 Offset pair coding mode table

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H04N 7/088 11/04 A 9185-5C

Claims (8)

[Claims] 1. A field or intra-frame coding method using as an input a field or intra-frame coding and a field encoded by referring to past or future images or a code string compression-coded by inter-frame coding. , Coding information extraction means for extracting coding information indicating whether field or interframe coding, and performing field or intraframe decoding or field or interframe decoding using the extracted coding information And a decoding means for outputting as a decoded video signal, and a coding information multiplexing means for multiplexing the extracted coding information on a part of the decoded video signal. Image decoding device. 2. A field or intra-frame encoding is performed by using a field or intra-frame encoding and a field encoded by referring to past or future images or a code sequence compression-compressed by inter-frame encoding as an input. , Encoding information extracting means for extracting encoding information indicating whether field or inter-frame encoding, and incidental information extracting means for extracting incidental information on a video signal with the compression encoded code string as an input, Decoding means for performing intra-field or intra-frame decoding or inter-field or inter-frame decoding using the extracted coding information and outputting as a decoded video signal, and the extraction of the extracted coding information. And a coded information multiplexing means for multiplexing a part of the generated accompanying information. 3. Field or intra-frame coding, which is input to a video signal and is multiplexed into a part of the video signal,
Encoding information detecting means for detecting encoding information indicating field or inter-frame encoding, and a signal obtained by removing the encoding information from the video signal or the video signal is input, and the detected encoding information is An encoding device for encoding a video signal indicating intra-field or intra-frame encoding and performing intra-field or intra-frame encoding and outputting as a compression encoded signal. 4. A field or intra-frame coding or a field or inter-frame coding which is input from an input line other than a video signal and is multiplexed with a part of the accompanying information on the video signal as an input. Encoding information detecting means for detecting encoding information indicating whether or not encoding, and a video signal as an input, the detected encoding information performs field or intraframe encoding of the video signal indicating intrafield or intraframe encoding, and compression And a coding means for outputting as a coded signal. 5. The moving picture decoding apparatus according to claim 1, wherein the coded information multiplexing means inserts a different waveform for each of the extracted coded information into a vertical blanking position of the decoded video signal. 6. The coded information multiplexing means is any one of a unit representing time of the time code, a unit representing minute, a unit representing second, and a unit representing frame of the pattern code representing the extracted coded information. The moving picture decoding apparatus according to claim 2, wherein one or two or more are added. 7. The encoding information detecting means receives the video signal as an input and indicates the field or intra-frame coding or the field or inter-frame coding inserted at the vertical blanking position of the video signal. The moving picture coding apparatus according to claim 3, wherein the coded information is detected from a different waveform for each information. 8. The coded information detecting means receives the time code as an input, and selects any one or two of a time unit, a minute unit, a second unit, and a frame unit of the time code. The moving picture coding apparatus according to claim 4, wherein the coding information indicating the field or intra-frame coding or the field or inter-frame coding added above is detected.