JP2001359103A - Moving picture data coder, moving picture data transmission method and moving picture data decoder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moving picture data decoder that can decode frames after a concerned frame even when an error takes place in the transmission of moving picture coded data resulting in disabling the concerned frame. SOLUTION: Frames whose time sequence is decided are divided into two groups, and coding data are generated by applying a prescribed inter-frame prediction coding algorithm to each group. A receiver side decodes the coded data by each group according to a decoding algorithm corresponding to the coding algorithm. On the occurrence of an error frame due to a communication error or the like, an image of a frame of other group is used when decoding a succeeding frame referencing the error frame in the group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving picture data coding apparatus for coding moving picture data, a moving picture data transmitting method for transmitting moving picture data, and a moving picture for decoding coded moving picture data. The present invention relates to a data decoding device.

[0002]

2. Description of the Related Art In recent years, multimedia that expresses different information such as characters, figures, sounds, and images by digital data, and integrates these media to handle them in a unified manner has been receiving attention in recent years. As an audio / video encoding system corresponding to this multimedia, ISO / IEC MPEG (Mo
ving Picture Experts Group) 2, etc., and various moving picture coding and transmission systems based on these are provided.

[0003] For example, in a moving picture coding and transmission system conforming to MPEG2, a transmitting apparatus performs coding of a moving picture in units of a GOP (Group of Picture) composed of a predetermined number of frames. This GOP includes at least one I (Intra) frame and a plurality of P (Predictive) frames following the IOP, as illustrated in FIG. And for the I frame,
Encoding (intra-frame encoding) is performed using only pixel data in a frame and independently of other frames.
For P frames, inter-frame predictive coding is performed using correlation with a temporally preceding frame.

[0004] Coded data corresponding to an I frame includes data obtained by intra-frame coding each of a plurality of macroblocks obtained by dividing the frame. In general, P
The encoded data corresponding to the frame includes inter-frame prediction encoded data for a plurality of macroblocks obtained by dividing the frame. The inter-frame predictive coded data includes an image corresponding to the macro block and an image of a reference macro block approximate to the macro block in another frame referred to for the inter-frame predictive coding of the macro block. DCT (Discrete Cosine)
Transform (Discrete Cosine Transform). In addition to the DCT coefficients, the inter-frame prediction coded data includes motion information indicating the motion between the reference macroblock and the frame. However, since these DCT coefficients and motion information have a small code amount for expressing each, the code amount of the inter-frame prediction coded data is significantly smaller than that of the intra-frame coded data. In a method based on MPEG2, the amount of information of moving image data is significantly reduced by using a P frame including such inter-frame predictive encoded data.

[0005]

In the above-mentioned conventional moving picture coding transmission system, if an error occurs in a certain frame during data transmission or the like, the receiving side decodes the frame after the frame in which the error has occurred. I can no longer do it. For example, in FIG. 14, if the third transmitted P frame results in an error,
Not only can this frame not be decoded, but this P
The fourth P frame decoded with reference to the frame cannot be restored. When the fourth P frame cannot be restored in this way, the fifth and subsequent P frames referring to this
The frame cannot be restored.

The present invention has been made in view of the above circumstances, and even when a frame in which an error has occurred during transmission of moving image encoded data cannot be decoded, the subsequent frames are not decoded. It is an object of the present invention to provide a moving image data transmission method, a moving image data decoding device, and a moving image data encoding device capable of decoding a frame.

[0007]

In order to solve the above-mentioned problems, a moving image data transmission method according to the present invention provides a moving image data comprising a plurality of frames in a sequence representing a moving image. The transmitting method, on the transmitting side, so that the adjacent frames in the order are not included in the same group, the moving image data is divided into a plurality of groups, the divided moving image data, Encoding is performed by an encoding algorithm including an inter-frame predictive encoding algorithm with motion compensation for each group to generate encoded data for each group, and the receiving side converts the received encoded data for each group. The frame is restored by decoding with the decoding algorithm corresponding to the coding algorithm, and the coded data corresponding to a certain frame is normally received. Otherwise, when decoding the encoded data corresponding to the subsequent frame encoded with reference to the frame, when the frame is correctly received by using the decoded frame in a group different from the group including the frame. An interpolated frame corresponding to a frame that has not been processed is created, and encoded data corresponding to the subsequent frame is decoded by referring to the interpolated frame.

[0008] A moving image data transmission method according to the present invention is a method for transmitting moving image data comprising a plurality of frames in a sequence representing a moving image from a transmitting side to a receiving side. Then, the moving image data is divided into a plurality of groups so that the adjacent frames in the order are not included in the same group, and the divided moving image data is divided into frames between each group with motion compensation. Encoding is performed by an encoding algorithm including a predictive encoding algorithm to generate encoded data for each group, and the receiving side converts the received encoded data for each group by a decoding algorithm corresponding to the encoding algorithm. When decoding and restoring a frame, and the encoded data corresponding to a certain frame is not normally received,
When decoding the encoded data corresponding to the subsequent frame encoded with reference to the frame, by referring to the decoded frame in a group different from the group including the frame, the frame corresponding to the subsequent frame is decoded. It is characterized by decoding encoded data.

A moving image data transmission method according to the present invention is a method for transmitting moving image data comprising a plurality of frames in a sequence representing a moving image from a transmitting side to a receiving side. In, the video data is divided into a plurality of groups so that adjacent frames in the order are not included in the same group with respect to frames other than some frames, and at least the some frames are divided. The moving image data divided and included in two or more groups is encoded by an encoding algorithm including an inter-frame prediction encoding algorithm with motion compensation for each group, and encoded data is encoded for each group. The receiving side generates a decoding algorithm corresponding to the coding algorithm for each of the groups. When the encoded data corresponding to a certain frame is not normally received, the frame is decoded with reference to the partial frame after the frame in the group to which the frame belongs. When decoding the encoded data corresponding to the subsequent frame, the encoded data corresponding to the subsequent frame is decoded by referring to the partial frame decoded in a group different from the group including the frame. It is characterized by:

Further, the moving picture data decoding apparatus according to the present invention comprises a plurality of frames representing a moving picture in a predetermined order, and a plurality of groups so that the adjacent frames in the order are not included in the same group. A moving image data decoding apparatus for decoding encoded data for each group generated by an encoding algorithm including an inter-frame prediction encoding algorithm with motion compensation for each group from the divided moving image data. , The encoded data
Decoding means for decoding a frame by a decoding algorithm corresponding to the encoding algorithm for each of the groups to restore the frame, wherein the decoding means, when encoded data corresponding to a certain frame is not normally received, When decoding the encoded data corresponding to the subsequent frame encoded by referring to, the frame corresponding to the frame that has not been normally received is decoded using a frame that is different from the group including the frame. An interpolated frame is created, and encoded data corresponding to the subsequent frame is decoded by referring to the interpolated frame.

Further, the moving picture data decoding apparatus according to the present invention comprises a plurality of ordered frames representing moving pictures, and a plurality of groups so that adjacent frames in the order are not included in the same group. A moving image data decoding apparatus for decoding encoded data for each group generated by an encoding algorithm including an inter-frame prediction encoding algorithm with motion compensation for each group from the divided moving image data. , The encoded data
Decoding means for decoding a frame by a decoding algorithm corresponding to the encoding algorithm for each of the groups to restore the frame, wherein the decoding means, when encoded data corresponding to a certain frame is not normally received, When decoding the encoded data corresponding to the subsequent frame encoded with reference to the reference frame, by referring to the decoded frame in a group different from the group including the frame, the encoding corresponding to the subsequent frame It is characterized by decoding data.

Further, the moving picture data decoding apparatus according to the present invention comprises a plurality of ordered frames representing moving pictures, and a plurality of groups arranged so that adjacent frames in the order are not included in the same group. A moving image data decoding apparatus for decoding encoded data for each group generated by an encoding algorithm including an inter-frame prediction encoding algorithm with motion compensation for each group from the divided moving image data. , The encoded data
Decoding means for decoding a frame by a decoding algorithm corresponding to the encoding algorithm for each of the groups to restore the frame, wherein the decoding means, when encoded data corresponding to a certain frame is not normally received, When decoding the encoded data corresponding to the subsequent frame encoded with reference to the partial frame after the current frame in the group to which the current frame belongs, the decoded one in a group different from the group including the current frame is decoded. The encoded data corresponding to the subsequent frame is decoded by referring to the frame of the unit.

Further, the moving picture data encoding apparatus according to the present invention is a moving picture data encoding apparatus for coding moving picture data composed of a plurality of frames in a predetermined order representing a moving picture. The video data is divided into a plurality of groups so that adjacent frames in the order are not included in the same group with respect to frames other than the frame of at least two or more groups obtained by dividing the partial frames. And dividing the moving image data divided by the dividing means using an encoding algorithm including an inter-frame prediction encoding algorithm with motion compensation for each group, and encoding the moving image data for each group. Encoding means for generating encoded data.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. A. First embodiment A-1. Moving Image Data Transmission Method FIGS. 1 and 2 are diagrams showing the principle of a moving image data transmission method according to the first embodiment of the present invention. The method of transmitting moving image data according to the present embodiment will be described with reference to these drawings.

In the moving picture data transmission method according to the present embodiment, the transmitting side sequentially compresses and codes moving picture data of a picture group consisting of a predetermined number of frames in a time sequence and transmits the compressed data. It performs processing such as decoding by decoding encoded moving image data,
First, the compression encoding process performed on the transmission side will be described with reference to FIG. Here, a case where moving image data of a picture group including 20 frames is compression-encoded will be described as an example.

As shown in FIG. 1, on the transmitting side, 1 to 20
The image data corresponding to each frame whose time order up to the number is determined is divided into two groups. Here, each frame is divided so that adjacent frames are not included in the same group. In the example shown in the figure, the first group has odd-numbered numbers such as the first, third, fifth,. Frames belong to the second group,
.., 20th, etc., belong to even-numbered frames.

After the moving image data is divided into two groups as described above, moving image data corresponding to each frame is encoded according to an encoding algorithm including an inter-frame prediction encoding algorithm with motion compensation for each group. Will be Here, the first and second frames at the head of each group are coded as I frames, and the other frames are coded as P frames. The I frame is a frame to be subjected to intra-frame encoding as described above, and the P frame is a frame that is encoded and decoded by referring to an image of a previous frame.

More specifically, the image data corresponding to the first and second frames at the head of each group is subjected to an intra-frame encoding process as an I frame. Then, in the encoding process on the frames belonging to the first group, the image data corresponding to the frames belonging to the first group other than the first frame is divided into macroblocks having a predetermined number of pixels, and DCT coefficients and motion information of the difference between the image of the frame of the frame two steps ahead (one immediately before in the group) and the image of the frame are obtained, and these data are subjected to variable length coding. In the encoding process for frames belonging to the second group, as in the first group, for the fourth and subsequent frames, for each macroblock, the order of the image of the frame that is two before (one in the group) DCT coefficients and motion information of image differences are obtained, and these data are subjected to variable-length coding. In this way, encoded data encoded for each group is generated and transmitted to the receiving side.

Next, the processing on the receiving side for decoding the encoded moving image data will be described. On the receiving side, the moving image data encoded for each group is decoded for each group. That is, when decoding the first group, the coded data corresponding to the first frame is decoded, and then when the coded data corresponding to the third frame is decoded, the image of the first frame is decoded. It is referred to. Thus, in the decoding processing of the P frame in the first group, the P
The P frame is decoded by referring to the image of the frame immediately before the frame. The decoding processing of the P frame in the second group is also decoded by referring to the image of the previous frame in the second group, as in the processing in the first group.

The moving image data that has been compression-encoded and transmitted on the transmitting side in this way is decoded on the receiving side and the moving image reproduction processing and the like are performed. When such moving image data is transmitted, A communication error or the like may occur for some reason. If the encoded data corresponding to a certain frame is destroyed due to a communication error or the like, the image of the frame cannot be restored on the receiving side, and the subsequent frame referring to the frame cannot be restored.

Therefore, in the moving image data transmission method according to the present embodiment, even when coded data including a frame in which such data is destroyed (hereinafter referred to as an error frame) is received, a plurality of coded data are received on the receiving side. A decoding process capable of restoring a moving image of a picture group composed of frames is performed. Hereinafter, this decoding process will be described with reference to FIG.

As shown in the figure, when the fourth frame belonging to the second group is received as an error frame, it is decoded with reference to the image of this error frame.
The image referenced by the encoded data corresponding to the fourth frame is changed from the image of the fourth frame to the image of the 4'th frame which simulates the fourth frame. here,
The image of the 4′-th frame is an interpolated image created based on the images of the third and fifth frames, which are frames whose order is before and after the error frame belonging to the first group. By doing
The encoded data corresponding to the sixth frame belonging to the group is decoded. Thereafter, in the decoding process in the second group, the image of the sixth frame decoded as described above is referred to, and the encoded data corresponding to the eighth and tenth subsequent frames is sequentially decoded.

A-2. Moving image data encoding device and moving image data decoding device The above is the moving image data transmission method according to the present embodiment,
Hereinafter, a moving image data encoding device and a moving image data decoding device for implementing the moving image data transmission method will be described.

A-2-1. Moving Picture Data Encoding Apparatus First, FIG. 3 is a block diagram showing a configuration of a moving picture data encoding apparatus which is a transmitting apparatus of the above moving picture data transmission method. As shown in the figure, the moving picture data encoding apparatus includes a group dividing unit 52 and a first group encoder 5.
0 and a second group encoder 51.

The group dividing section 52 divides moving picture data of a picture group composed of a plurality of frames into two groups. Here, as shown in FIG. 1 described above, each frame is divided into a first group and a second group so that frames adjacent in time order are not included in the same group.

The first group encoder 50 performs an encoding process on the moving image data of the first group divided by the group divider 52, and a subtractor 101
, A DCT unit 102, a quantizer 103, an inverse quantizer 104, an inverse DCT unit 105, a motion prediction and compensation unit 106, variable length encoders 107 and 108, and a multiplexing device 109. Have.

Here, the first group encoder 50 includes:
The current image of the first group divided by the group dividing unit 52 is input. Then, the first group encoder 50
Performs encoding processing with the first frame as an I frame and the subsequent frames as P frames.

First, in the encoding processing for the first frame, that is, in the encoding processing for the image corresponding to the I frame, the processing by each component of the first group encoder 50 is not performed, and a predetermined encoding algorithm is used. Performs intra-frame encoding of the image information of the current image, and the encoded data obtained as a result is transmitted to the receiving side. Also,
In the first group encoder 50, the image information of the I frame is decoded from the encoded data corresponding to the I frame in accordance with the decoding algorithm corresponding to the above encoding algorithm, and the memory (not shown) in the motion prediction and compensation unit 106 ) Is stored as a reference image.

Next, in the encoding process for the image corresponding to the P frame which is the third frame, the original image of the I frame which is the reference image is divided into a plurality of macro blocks. Here, each macro block is composed of 2 × 2 = 4 blocks, and each block is composed of 8 × 8 = 64 pixels. Then, the first group encoder 5
At 0, the following processing is performed for each macroblock.

First, the motion predicting and compensating unit 106 uses a reference macroblock of the same size similar to the macroblock to be processed of the original image of the P frame as a reference image.
Search within the frame. Then, it is considered that the searched reference macroblock has moved and has become the processing target macroblock, and the motion information V indicating the spatial movement distance and the direction is output. The output motion information V is converted by the variable length encoder 108 into a variable length code.

The subtracter 101 subtracts the image information of the reference macroblock from the image information of the macroblock to be processed to obtain the difference between the two images. The DCT section 102 calculates the difference between the image information and the DCT, which is a type of orthogonal transform. Is applied.

The quantizer 103 quantizes the DCT coefficients of the difference image obtained from the DCT unit 102, and the variable length coder 107 performs variable length coding on the data obtained by the quantization.

The variable-length code obtained by quantizing the DCT coefficient and the above-described variable-length code of the motion information V are multiplexed by the multiplexing device 109 and sent to the receiving side as coded data corresponding to the macroblock to be processed. Sent.

On the other hand, the output data of the quantizer 103 is inversely quantized by the inverse quantizer 104, and the output data of the inverse quantizer 104 is input to the inverse DCT unit 105.
As a result, the inverse DCT unit 105 outputs the difference image Δ. This difference image Δ is image information corresponding to the difference between the processing target macroblock of the original image (third frame) and the reference macroblock.

The motion prediction and compensation unit 106 performs inverse DCT
The image information of the macroblock to be processed in the original image (the third frame) is restored by a method such as adding the difference image Δ obtained from the unit 105 and the reference macroblock, and the subsequent frame (the fifth frame) Is stored in the memory as a reference image to be referred to at the time of encoding.

The above processing is performed for all the macro blocks constituting the third frame.

When the fifth frame is input, the same encoding processing as described above is performed with reference to the reference image (the image of the third frame) stored in the memory in the motion prediction and compensation unit 106. Is performed. The same encoding process is performed on the subsequent seventh and ninth frames. In this way, the coded data corresponding to the image information of all the frames belonging to the first group is transmitted from the first group encoder 50 to the transmitting side.

The second group encoder 51 performs an encoding process on the moving image data of the second group divided by the group dividing unit 52, and is similar to the first group encoder 50. Configuration. Here, the second group encoder 51 performs the same encoding processing as the first group encoder 50 with the second frame as an I frame and subsequent frames as P frames. Then, encoded data corresponding to the image information of all the frames belonging to the second group is generated and transmitted to the transmitting side. Here, the encoded data may be divided into a first group and a second group and transmitted on another channel,
These two groups of encoded data may be multiplexed and transmitted on one channel.

A-2-2. Moving Image Data Decoding Apparatus Next, a receiving side moving image data decoding apparatus that decodes encoded data generated by being divided into a first group and a second group by the moving image data decoding apparatus having the above configuration will be described with reference to FIG.
This will be described with reference to FIG.

As shown in the figure, the moving picture data decoding apparatus comprises buffers 200 and 201 and a first group decoder 2.
02, a second group decoder 203, an error information detection unit 204, an interpolated image creation unit 205, and a video display unit 20.
6 is provided.

Each of the buffers 200 and 201 has a first
The encoded data of the group and the encoded data of the second group are accumulated, and the accumulated encoded data is output to the first group decoder 202 and the second group decoder 203, respectively.

The error information detection unit 204 is provided in the buffer 20
It is detected whether or not there is an error frame in the encoded data stored in 0,201. Buffer 200, 201
If it detects that there is an error frame in the encoded data stored in the interpolated image generation unit 205, it outputs to the interpolated image creation unit 205 error information relating to the group of the frame number and the frame.

The first group decoder 202 performs a decoding process on the encoded data of the first group.
Demultiplexer 210a, variable length decoder 210, dequantizer 211, inverse DCT section 212, motion compensation section 213
, An adder 214, and a frame memory 215.

First, in the decoding processing of the encoded data corresponding to the first I frame, the processing by each component of the first group decoder 202 is not performed, and the decoding processing corresponding to the encoding algorithm of the first group encoder 50 is performed. Intra-frame encoded data is decoded according to the decoding algorithm thus set. As a result, the same I-frame image information as that stored in the memory in the motion prediction and compensation unit 106 in the first group encoder 50 is decoded, and
6 and stored in the frame memory 215 as a reference image.

Next, when coded data corresponding to the P frame, which is the third frame, is input, the coded data is quantized to a variable length code indicating motion information V for each macroblock included in the coded data. The variable length code indicating the DCT coefficient is separated by the demultiplexer 210a. The variable-length code indicating the motion information V for each separated macroblock and the variable-length code indicating the quantized DCT coefficient are returned to actual values by the variable-length decoder 210. Then, the following processing is performed for each macroblock in accordance with each of these pieces of information.

First, the inverse quantizer 211 and the inverse DCT section 212 return the quantized DC to the actual value.
From the T coefficient, a difference image Δ between the processing target macroblock and the reference macroblock in the I frame that is the reference image is restored.

In addition, the motion compensating unit 213 obtains the location of the reference macroblock in the I frame which is the reference image corresponding to the macroblock in accordance with the motion information V corresponding to the macroblock to be processed. Is read out from the frame memory 215. Then, the image information of the reference macroblock and the difference image Δ are added by the adder 214, and the image information of the processing target macroblock is restored.

The above processing is performed for all macroblocks, and all the images of the third frame are restored and output to the video display unit 206. The restored image of this frame is stored in the frame memory 215 as a reference image.

When coded data corresponding to the fifth frame, which is the next frame, is input, the above-described reference is made with reference to the reference image (the image of the third frame) stored in the frame memory 215. Similar restoration processing is performed. Similar decoding processing is performed on the subsequent seventh and ninth frames. In this way,
The first group decoder 202 outputs image information of all frames belonging to the first group to the video display unit 206.

The second group decoder 203 performs a decoding process on the encoded data of the second group.
The configuration is the same as that of the first group decoder 202. The second group decoder 203 restores the image information of all the frames belonging to the second group and outputs it to the video display unit 206.

In the video display unit 206, the first, second, third,... Image information of the frames of the first and second groups input from the first and second group decoders 202 and 203, respectively. ... the 19th,
The images are displayed in order, such as the 20th. In this way, a moving image of a picture group composed of 20 frames is reproduced.

The operation of the moving picture data decoding apparatus described above does not include an error frame in the encoded data of both groups received and stored in the buffers 200 and 201, and the data communication can be executed without any problem. This is the operation when it is performed. However, when a communication error or the like occurs, an error frame may be included in encoded data transmitted from the transmission side to the reception side. The operation of the moving picture data decoding apparatus when an error frame is included as described above will be described with reference to FIGS.

Here, as shown in FIG. 2, a case where the fourth frame belonging to the second group is an error frame will be described as an example. First, the error information detection unit 204
Accordingly, it is detected that the fourth frame of the second group is an error frame, and this information (hereinafter, referred to as error information) is output to the interpolated image creating unit 205.

When error information indicating that the error frame is the fourth frame of the second group is supplied from the error information detection unit 204, the interpolation image creation unit 205
Using the third and fifth decoded images stored in the frame memory 215 of the first group encoder 50, a 4'-th frame image that is an interpolation frame that simulates an error frame image is created. That is, the interpolated image creating unit 205 creates an image of an interpolated frame using decoded images of each frame immediately before and after an error frame in a group different from the group including the error frame indicated by the error information.

When the image of the interpolated frame is generated as described above, the interpolated image generating unit 205 generates the frame memory 215 of the decoder of the group to which the error frame belongs.
Is written as a reference image. That is, when the fourth frame is an error frame, when decoding the sixth frame, instead of the image of the fourth frame which is an error frame, the image of the interpolation frame 4 ′ is used as a reference image. The image of the second frame is written to the frame memory 215 of the second group encoder 51. When decoding the encoded data of the sixth frame, the decoding processing is performed with reference to the 4′-th frame image created by the interpolated image creating unit 205.

As described above, in the moving picture data decoding apparatus, when decoding the succeeding frame of the error frame, the restored image of each frame immediately after the straight line of the error frame belonging to another group is used to decode the reference image. By creating an interpolated frame as follows, decoding of the subsequent frame is enabled.

As described above, the interpolation frame used as the reference image instead of the error frame is preferably similar to the image of the frame (error frame) to be originally referred to, and an approximate interpolation frame is created. In order to do so, a restored image of a frame whose order is changed is required. In this embodiment, in consideration of this point, the frames in the adjacent order belong to another group when dividing the frame,
Even when an error occurs in a certain frame, the order used to create an interpolated frame as a substitute for this frame enables the immediately preceding and succeeding frames to be restored.

Incidentally, in order to create the above-described interpolated frame image, a restored image of the frame in the rear order is required. Therefore, the received moving image data is displayed on the video display unit 2.
For example, in the case of real-time reproduction at 06, the creation of an interpolated frame may not be in time. In such a case, the created interpolation frame is displayed on the video display unit 2.
06, it is sufficient to use only for reference of restoration of the subsequent frame without displaying.

A-3. Modified Example In the above-described first embodiment, the moving image data of the picture group including a plurality of frames whose time order is determined is divided into two groups on the transmitting side. It may be the above. Also in this case, it is necessary to sort the frames so that adjacent frames do not belong to the same group. For example, when dividing into three groups, as shown in FIG. 5, the first group has first, fourth, seventh,...
Frame, and the second
The frames having the second, fifth, and eighth orders may belong to the group, and the frames having the third, sixth, and ninth orders may belong to the third group.

As shown in FIG. 5, when the fifth frame belonging to the second group becomes an error frame when divided into three groups, the decoding processing of the frame following the error frame is as follows.

First, an interpolated frame is created from restored images of frames in the order before and after the error frame in a group other than the second group including the error frame. Specifically, to create a fourth frame and seventh image of the fifth 5 ₄₇ th frame pseudo the image of the frame using the restored image of a frame in the first group. Also, to create the third frame and the sixth image 5 ₃₆ th frame pseudo the image of the fifth frame using the restored image of a frame in the third group. Further, to create the fourth frame and the image of the sixth 5 ₄₆ th frame pseudo the image of the fifth frame using the restored image of a frame in the third group in the first group. Using these created interpolation frames as reference images, the coded data corresponding to the eighth frame in the second group is decoded. In the decoding process here, and 5 _47-th frame and the 5 _36-th frame 5
_Since there are three interpolated frames, such as the _46th frame, which can be referred to, here, the three 8th frame images are restored using the three as reference images. Then, the average of the three restored images may be used as the image of the eighth frame.

[0062] Incidentally, to restore the image of the frame of the three ways as described above may be used as the restored image of which the average is, 5 _47-th frame created, 5 ₃₆
One of the 5th and 5th _46th frames
One of them may be selected, and the coded data corresponding to the eighth frame may be decoded using the selected one as a reference image. Alternatively, two images may be selected from the above-described three types of frame images, and the images restored using the selected two images may be averaged.

B. Second embodiment B-1. Moving Image Data Transmission Method Next, a moving image data transmission method according to the second embodiment will be described. The moving image data transmission method according to the second embodiment is the same as the moving image data transmission method according to the first embodiment except for the decoding process when an error frame is detected. Therefore, the description of the processing on the transmission side and the processing on the reception side when good transmission is performed is omitted, and the processing on the reception side when an error frame is included in the transmitted encoded data is omitted. About processing FIG.
This will be described with reference to FIG.

As shown in the figure, when the fourth frame belonging to the second group is received as an error frame, it is decoded with reference to the image of this error frame.
The image referred to by the encoded data corresponding to the fifth frame is changed to the restored frame of the frame preceding the order of the error frame belonging to the first group, that is, the fifth frame. However, the encoded data corresponding to each macroblock of the sixth frame is a quantized D of the difference with respect to the image of the reference macroblock of the fourth frame.
A variable length code indicating a CT coefficient and a variable length code indicating motion information V between a reference macroblock of the fourth frame. Therefore, when the reference image is changed to the image of the fifth frame as described above, if the decoding is performed using these pieces of information as it is, the restored image is significantly different from the original image.

Therefore, in the moving image data transmission method according to the second embodiment, for each macroblock of the sixth frame, the D of the difference image with respect to the image of the fifth frame is determined.
The CT coefficients and the motion information are estimated, and the coded data corresponding to the sixth frame is decoded using the estimated DCT coefficients and the motion information. In the moving image data transmission method according to the present embodiment, by estimating the motion information and the DCT coefficient in this way, even if an error frame is included in the encoded data to be transmitted, The image of the subsequent frame can be restored.

The outline of the moving image data transmission method according to the second embodiment has been described above. The moving image data transmission method according to the second embodiment will be further understood by referring to the configuration and operation of the moving image data decoding device according to the embodiment described below.

B-2. Moving Image Data Decoding Device FIG. 7 is a block diagram showing a configuration of a moving image data decoding device for implementing the moving image data transmission method according to the second embodiment. In the figure, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

As shown in the figure, the moving picture data decoding apparatus includes buffers 200 and 201, a first group decoder 402, a second group decoder 403, an error information detection unit 204, and a video display unit. 206. The first group decoder 402 is configured to perform the first group decoding in the first embodiment.
Demultiplexer 210a, variable length decoder 210, dequantizer 211, and inverse DCT unit 21 similar to group decoder 202
2. It has a motion compensator 213, an adder 214 and a frame memory 215. When normal decoding processing is performed, that is, when an error frame is not included in the received encoded data, The encoded data of one group is decoded and output to the video display unit 206. Second
Similarly, the group decoder 403 decodes the encoded data of the second group and outputs it to the video display unit 206.

The first group decoder 402 and the second group decoder 403 include the motion information calculation circuit 300 in addition to the components of the first group decoder 202 and the second group decoder 203 of the first embodiment. , An image information calculation circuit 301 and a switch 302. Also,
An error information detection unit 204 is provided for each group, and when it is detected that an error frame exists in the corresponding buffer, the switch 30 in each group is provided.
2 and error information (ER1, ER
2) is supplied.

The switch 302 is normally connected to the inverse DCT unit 21
2 is set to be supplied to the adder 214. Then, the corresponding error information detecting unit 20
Only when the error information ER is supplied from 4, switching is performed so that the image information calculated by the image information calculation circuit 301 is supplied to the adder 214. Accordingly, when it is detected that an error frame exists in the buffer 200 and the error information ER1 is supplied, the switch 302 of the first group decoder 402 is switched, and the buffer 2
01, when the error information ER2 is supplied, the switch 30 of the second group decoder 403
2 will be switched.

The motion information calculation circuit 300 and the image information calculation circuit 301 are not used in the above-described ordinary decoding process, and are performed when the error information detection unit 204 detects that an error frame exists in the received encoded data. , The motion information calculation process and the image information calculation process are respectively performed. Hereinafter, the processing of the motion information calculation circuit 300 and the image information calculation circuit 301 when an error frame is detected will be described using a case where the fourth frame shown in FIG. 6 is an error frame as an example.

If the fourth frame in the buffer 201 is an error frame, as described above, the reference image for decoding the encoded data corresponding to the sixth frame, which is the succeeding frame, belongs to the first group. It is changed to the image of the fifth frame to which it belongs. Here, the buffer 201
Of the coded data corresponding to each macroblock of the sixth frame includes motion information and DCT coefficients corresponding to the image of the fourth frame, but includes information corresponding to the image of the fifth frame. Not. When the reference image is changed due to the occurrence of the error frame as described above, the motion information calculation circuit 300 and the image information calculation circuit 301 determine the motion information and the difference image for the changed reference image for each macroblock of the frame to be processed. Is calculated. The frame corresponding to the group including the error frame is decoded by using the calculated information.

More specifically, the motion information calculation circuit 3
00 calculates motion information V ′ for the image of the fifth frame, which is the reference image after the change, from the motion information V included in each macroblock of the sixth frame by the following equation. V ′ = V / 2 The motion information is calculated by the above operation, as shown in FIG. 8, when the moving image is the fourth frame, the fifth frame,
This takes into account the fact that transition is made at equal time intervals T in the order of the sixth frame. In other words, it is considered that the moving speed of the image that changes like the fourth, fifth, and sixth does not fluctuate abruptly and changes at almost the same speed. The spatial movement amount is estimated to be half of the movement amount from the fourth frame to the sixth frame.

This is impossible when the moving image data is divided into two groups as in the present embodiment. However, even when the moving image data is divided into three or more groups, or when divided into two groups, depending on how to divide the data, The frame set to be originally referred to by the sixth frame to be processed may be the third or second frame. For example, if the frame originally set to be referred to is the third frame, it is calculated by V ′ = V / 3. That is,
The motion information V ′ may be calculated by dividing the motion information V by the difference between the order of the processing target frame and the frame originally set to be referred to.

Next, the image information calculation circuit 301 uses the DCT coefficient of the sixth frame and the DCT coefficient of the fifth frame to calculate the difference image of each macroblock of the sixth frame with respect to the image of the fifth frame. The DCT coefficient is calculated. Hereinafter, the specific procedure will be described.

FIG. 9 shows one of the macroblocks included in the sixth frame to be processed. Each macro block is composed of four blocks as shown. In the inter-frame predictive encoding method based on the present embodiment, DCT of a difference image between frames is performed in block units. Hereinafter, a procedure for calculating the DCT coefficient of the difference image corresponding to one block (hereinafter, referred to as a processing target block) in the illustrated macro block will be described.

First, FIG. 9 shows one macroblock in the fifth frame, and this macroblock includes a block b ′ similar to the image of the processing target block in the sixth frame. . Hereinafter, for convenience,
This block b 'is called a prediction block.

In the image information calculation circuit 301, the DCT coefficient of the difference image between the third frame and the fifth frame corresponding to the predicted block b ′ and the fourth DCT coefficient corresponding to the processing target block of the sixth frame The DCT coefficient value D ₆₅ between the fifth frame and the sixth frame in the processing target block is calculated by the following equation using the DCT coefficient of the difference image between the frame and the sixth frame. D ₆₅ = D ₆₄ −D ′ ₅₃ where D ′ ₅₃ is the DCT of the difference image between the third and fifth frames corresponding to the prediction block b ′.
D ₆₄ is the value of the DCT coefficient of the difference image between the fourth frame and the sixth frame corresponding to the sixth processing target block.

The reason why the DCT coefficient between the fifth frame and the sixth frame in the processing target block is calculated will be described. The DCT coefficient in the encoded data handled by the moving image data decoding device is obtained by DCT of a difference image Δ from a reference image. Therefore, 6
The DCT coefficient D ₆₄ of the encoded data of the fifth frame and the DCT coefficient D ₅₃ of the encoded data of the fifth frame have a meaning represented by the following equation. D ₆₄ = DCT (image 6 to image 4) D ₅₃ = DCT (image 5 to image 3) In the present embodiment, DC is used to decode the sixth frame.
It is necessary to calculate the value of T (image 6-image 5). Here, when D ₆₄ −D ₅₃ is expressed using the above two equations, DCT (image 6−image 4−image 5 + image 3) = DCT
(Image 6-Image 5)-DCT (Image 4-Image 3). The value including the thus DCT (picture 6 image 5) can be calculated by using the values contained in coded in the data handled in the present embodiment, such D ₅₃ and D _64. Thus, in this embodiment, with each other to adopt the value calculated by D ₆₄ -D ₅₃ as DCT coefficient between the fifth frame and the sixth frame. Note that the value calculated in this way includes DCT (image 4 to image 3) as an error, but if the error can be ignored, the DCT (image 4 to image 3) is included in the second group without any problem. Since the sixth and subsequent frames to which the video data belongs can be decoded, it can be said that the moving image data transmission method according to the present embodiment is sufficiently significant.

As described above, if the DCT coefficients of the difference image between the third frame and the fifth frame corresponding to the prediction block b ′ can be obtained from the encoded data of the fifth frame, The DCT coefficient value between the sixth frame can be calculated. However, as shown in FIG. 8, the DCT coefficient included in the fifth frame is 3 for each of the blocks b1, b2, b3, and b4 obtained by dividing each macroblock of the fifth frame.
Reference blocks Sb1, Sb2, Sb of the th frame
3, which is obtained from the difference from the image of Sb4.
Among the DCT coefficients supplied from the inverse quantizer 211 to the image information calculation circuit 301, there is no DCT coefficient D' ₅₃ corresponding to the prediction block b '. Therefore, the image information calculation circuit 301 according to the present embodiment calculates a DCT coefficient corresponding to the prediction block b ′ as follows.

First, in FIG. 9, the prediction block b '
Extends over four blocks b1 to b4. The image information calculation circuit 301 uses the motion information V ′ calculated by the motion information calculation circuit 300, and calculates a horizontal length w1 and a height direction w1 of a portion of the predicted block b ′ that has entered the block B1. H1, the horizontal length w2 and the height length h2 of the portion invading the block b2,
The horizontal length w of the part penetrating into the block b3
3 and the length h3 in the height direction, and the horizontal length w4 and the length h4 in the height direction of the portion penetrating into the block b4 are obtained.

Next, when the matrix of DCT coefficients corresponding to each block bi (i = 1 to 4) is Bi (i = 1 to 4), the image information calculating circuit 301 corresponds to the prediction block b ′. A matrix B ′ of the calculated values of the DCT coefficients is obtained by the following equation.

(Equation 1) Here, H _Hi is the DCT coefficient of h _hi , and H _Wi is the DCT coefficient of h _wi
H _hi and h _wi are given as follows:

(Equation 2)

(Equation 3)

(Equation 4)

(Equation 5) However, the meaning of the notation of the matrix using I _hi and I _wi in each of the above expressions is as follows. That is, for example, assuming that hi = 4, the above equations are represented as follows.

(Equation 6)

(Equation 7) When the image information calculation circuit 301 calculates the DCT coefficient of the difference image between the third frame and the fifth frame corresponding to the prediction block b ′ as described above, the DCT coefficient is used as the processing target block. Is subtracted from the DCT coefficients of the fifth frame and the sixth frame to obtain the DCT coefficients of the motion-compensated difference image corresponding to the processing target block.

Then, the image information calculation circuit 301 performs the same processing as described above for the other blocks in the sixth frame, and calculates the DCT coefficients of all the blocks in the sixth frame. Then, the difference image Δ is restored by performing inverse DCT on the DCT coefficient calculated in this way.

The second information supplied with the error information ER2 is
In the motion compensator 213 of the group decoder 403, the reference image is changed to the fifth frame image stored in the frame memory 215 of the first group decoder 402 instead of the fourth frame image. Therefore, the motion compensator 2
In 13, the location of the reference macroblock in the fifth frame, which is the reference image corresponding to the macroblock, is obtained according to the motion information V ′ calculated by the motion information calculation circuit 300. Thereafter, the image information of the reference macroblock is read from the frame memory 215 of the first group decoder 402 and supplied to the adder 214. Then, the image information of the reference macroblock and the difference image Δ
Are added by the adder 214, and the image information of the macroblock to be processed is restored.

The above processing is performed for all the macroblocks, and all the images of the sixth frame are restored and output to the video display unit 206. The restored image of this frame is stored in the memory of the motion compensation unit 213 as a reference image. The encoded data corresponding to the frames belonging to the second group thereafter are decoded with reference to the image of the sixth frame thus decoded. Therefore, according to the moving image data decoding device, even when an error frame is included in the encoded data received due to a communication error or the like, the image of the subsequent frame can be restored.

In the second embodiment as well, the transmitting side may divide the moving image data of the picture group composed of a plurality of frames whose time order is determined into three or more groups. In this case, when an error frame is detected, when decoding the subsequent frame, the reference image may be changed to a frame in the order immediately before the frame to be processed in another frame. When the reference image is changed in this way, the motion information and the DCT coefficient for the changed reference image may be calculated and used.

C. Third Embodiment Next, a moving image data transmission method according to a third embodiment will be described with reference to FIG. 10, FIG. 11, and FIG. In the moving image data transmission method according to the present embodiment, the transmitting side sequentially compresses and encodes moving image data of a picture group including a predetermined number of time-ordered frames, and transmits the compressed and encoded data. The decoding of the moving image data and the processing such as reproduction are performed.
The compression encoding process performed on the transmission side will be described with reference to FIG.

As shown in FIG. 10, on the transmitting side, 1 to 1
The image data corresponding to each frame whose time order up to the second is determined is divided into two groups. here,
Frames other than some predetermined frames are divided so that adjacent frames are not included in the same group. And some of the above frames are
It is to be included in both of the divided groups. In the example shown, the first group has the first, third,
Fifth,..., Eleventh, odd-numbered frames belong to the second group, second, fourth, sixth,.
Even-numbered frames such as the second basically belong to both groups, and the fourth, seventh,
Frames in the order such as the tenth are included in duplicate.

After dividing the moving image data into two groups, the moving image data corresponding to each frame is encoded according to an encoding algorithm including an inter-frame prediction encoding algorithm with motion compensation for each group. Will be Here, the first and second frames at the head of each group are coded as I frames, and the other frames are coded as P frames. The encoding process here is the same as in the first embodiment, and a description thereof will be omitted.

Next, processing on the receiving side for decoding moving picture data encoded as described above will be described. On the receiving side, similarly to the first embodiment, the moving image data encoded for each group is decoded for each group. Here, the frames included in both the fourth, seventh, and tenth groups are decoded in each group and the image is restored, but when performing processing such as reproduction, one of them may be used. I just need.

The processing on the receiving side when data communication is normally performed in this manner is the same as that in the first embodiment, except that an error frame is included in the transmitted encoded data. Since the processing on the receiving side is different, the processing on the receiving side in this case will be described with reference to FIG.

As shown in the figure, when the fourth frame belonging to the second group is received as an error frame, it is decoded with reference to the image of this error frame.
The encoded data corresponding to the first frame changes the image to be referenced from the image of the fourth frame belonging to the second group to the image of the fourth frame belonging to the first group. Here, since the fourth frame included in the first group and the second group is of course the same image,
When decoding the sixth frame in the second group, it is only necessary to change the reference image to the image of the fourth frame belonging to the first group, to calculate DCT coefficients and motion information, or to create an interpolation frame. Such processing is unnecessary. Thereafter, in the decoding process in the second group, the decoded image of the sixth frame is referred to, and the seventh and eighth frames are referred to.
The encoded data corresponding to the subsequent frames such as the tenth and tenth frames are sequentially decoded.

The above decoding process is a process in the case where an error frame is a frame which is included in both groups in an overlapping manner. However, when a frame which is included in only one of the groups is an error frame. The decoding process will be described with reference to FIG.

As shown in the figure, when the fifth frame belonging to the first group is received as an error frame, the seventh frame decoded with reference to the fifth frame which is an error frame in the first group. The frame cannot be decoded. However, the second group also includes encoded data corresponding to the seventh frame, and this encoded data can be decoded by referring to the image of the sixth frame belonging to the second group. When decoding the ninth frame belonging to the first group, the 7th frame decoded in the second group is used.
What is necessary is just to refer to the image of the th frame. As a result, decoding can be performed on frames other than the fifth frame that has become an error frame to restore an image.

Next, a moving picture data encoding apparatus and a moving picture data decoding apparatus for implementing the moving picture data transmission method according to the third embodiment will be described. First, a moving image data encoding device for implementing the moving image data transmission method according to the present embodiment has the same configuration as the moving image data encoding device described in the first embodiment (FIG. 3), only the method of dividing each frame by the group dividing unit 52 is different. That is, each frame is 2
In dividing into groups, the third embodiment is different from the first embodiment in that some frames determined in advance are included in both divided groups in an overlapping manner. Except for this, the components and operations thereof are the same as those of the first embodiment, and the moving image data encoding device transmits encoded data divided into two groups to the transmission side.

Next, the moving picture data decoding apparatus shown in FIG.
3 will be described. As shown in the figure, the moving picture decoding apparatus for implementing the moving picture data transmission method according to the present embodiment does not have the interpolation image creation unit 205 and thus the moving picture decoding apparatus described in the first embodiment. It differs from the device (see FIG. 4). Then, the error information detection unit 204
Is supplied to the motion compensation unit 213 of the group in which the error frame is detected.

The operation of the moving picture data decoding apparatus is the same as that of the first embodiment when data transmission is normally performed and there is no error frame. The operation in the case where the detection is performed will be described.

When the error information detecting section 204 detects that there is an error frame, the error information is supplied to the motion compensating section 213 of the group having the error frame. The motion compensation unit 213 to which the error information has been supplied changes the reference image referred to by the frame following the error frame to an image of a frame of another group. That is, the image of the frame stored in the frame memory 215 of another group is used as the reference image, and the location of the reference macroblock in the frame that is the reference image corresponding to the processing target macroblock is obtained according to the motion information. Thereafter, the image information of the reference macroblock is added to the adder 214.
Supplied to Then, the image information of the reference macroblock and the difference image Δ are added by the adder 214, and the image information of the processing target macroblock is restored. Here, the specific contents of the change of the reference image are as described above (see FIGS. 11 and 12).

In the third embodiment as well, the transmitting side may divide the moving image data of the picture group consisting of a plurality of frames whose time order is determined into three or more groups. In this case, when decoding the subsequent frame when an error frame is detected, similarly to the above embodiment, the image of the frame of another group included in the group and another group included in another group is changed to the reference image. do it.

[0100]

As described above, according to the present invention,
Even when a frame in which an error has occurred when transmitting encoded video data cannot be decoded, frames subsequent to the frame can be decoded.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating processing on a transmission side in a moving image data transmission method according to a first embodiment of the present invention.

FIG. 2 is a diagram showing processing on a receiving side in the moving image data transmission method according to the first embodiment.

FIG. 3 is a block diagram illustrating a configuration of a moving image data encoding device for performing the moving image data transmission method according to the first embodiment.

FIG. 4 is a block diagram showing a configuration of a moving image data decoding device for implementing the moving image data transmission method according to the first embodiment.

FIG. 5 is a diagram showing processing on the receiving side in a modified example of the moving image data transmission method according to the first embodiment.

FIG. 6 is a diagram illustrating processing on a receiving side in a moving image data transmission method according to a second embodiment of the present invention.

FIG. 7 is a diagram illustrating a configuration of a moving image data decoding device for performing the moving image data transmission method according to the second embodiment.

FIG. 8 is a diagram for explaining processing contents of a motion information calculation circuit and an image information calculation circuit of the moving image data decoding device for performing the moving image data transmission method according to the second embodiment.

FIG. 9 is a diagram showing processing contents of the image information calculation circuit.

FIG. 10 is a diagram illustrating processing on the transmission side in the moving image data transmission method according to the third embodiment of the present invention.

FIG. 11 is a diagram showing processing on the receiving side in the moving image data transmission method according to the third embodiment.

FIG. 12 is a diagram showing processing on the receiving side in the moving image data transmission method according to the third embodiment.

FIG. 13 is a block diagram illustrating a configuration of a moving image data decoding device for performing the moving image data transmission method according to the third embodiment.

FIG. 14 is a diagram showing processing on the transmission side of a conventional general moving image data transmission method.

[Explanation of symbols]

50: first group encoder, 51: second group encoder, 52: group division unit, 202: first group decoder, 203: second group decoder, 204
...... Error information detection unit, 205 ... Interpolated image creation unit, 2
06 ... video display unit, 300 ... motion information calculation circuit, 3
01 ... Image information calculation circuit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C059 KK00 LA00 MA00 MA05 MA23 MC11 ME01 NN01 NN21 NN28 PP05 PP06 RF09 SS06 SS11 UA02 UA05 5J064 AA02 BA09 BB03 BB06 BC01 BC08 BC16 BD02

Claims (12)

[Claims] 1. A method for transmitting moving image data including a plurality of frames in a predetermined order representing a moving image from a transmitting side to a receiving side, wherein, on the transmitting side, the adjacent frames in the order are the same. The moving image data is divided into a plurality of groups so as not to be included in a group, and the divided moving image data is encoded by an encoding algorithm including an inter-frame prediction encoding algorithm with motion compensation for each of the groups. Coded data is generated for each group, and the receiving side decodes the received coded data by a decoding algorithm corresponding to the coding algorithm for each group to restore a frame. If the corresponding coded data is not normally received, the corresponding frame is referred to the next frame. When decoding encoded data, an interpolation frame corresponding to the frame that has not been normally received is created using decoded frames in a group different from the group including the frame, and the interpolation frame is A moving image data transmission method comprising: decoding encoded data corresponding to the subsequent frame by referring to the encoded data. 2. The moving image data transmission according to claim 1, wherein the interpolation frame is created by using each frame immediately before and after the interpolation frame among the frames in the different group. Method. 3. A method for transmitting moving image data including a plurality of frames in a predetermined order representing a moving image from a transmitting side to a receiving side, wherein, on the transmitting side, the adjacent frames in the order are the same. The moving image data is divided into a plurality of groups so as not to be included in a group, and the divided moving image data is encoded by an encoding algorithm including an inter-frame prediction encoding algorithm with motion compensation for each of the groups. Coded data is generated for each group, and the receiving side decodes the received coded data by a decoding algorithm corresponding to the coding algorithm for each group to restore a frame. If the corresponding coded data is not normally received, the corresponding frame is referred to the next frame. When decoding the encoded data, the encoded data corresponding to the subsequent frame is decoded by referring to the decoded frame in a group different from the group including the frame. Transmission method. 4. The method according to claim 3, wherein a decoded frame whose order is one before the subsequent frame in the different group is set as a reference frame, and encoded data corresponding to the subsequent frame is decoded. 2. The moving image data transmission method according to 1. 5. The inter-frame encoding algorithm according to claim 1,
The motion compensation is performed for each macroblock obtained by dividing the frame, and the encoded data is generated by performing an orthogonal transformation of the difference image between the frames for each divided macroblock. When decoding the corresponding encoded data, the orthogonal transform coefficient and the motion information of the difference of the macroblock of the subsequent frame based on the reference frame are estimated from the encoded data, and the orthogonal transform coefficient of the estimated difference and 5. The moving image data transmission method according to claim 4, wherein encoded data corresponding to a macroblock of the subsequent frame is decoded using motion information. 6. When the subsequent frame is an m-th frame (m is a natural number of 3 or more) and the unsuccessfully received frame is an n-th frame (n is a natural number less than m), Assuming that motion information included in encoded data corresponding to the macroblock of the subsequent frame is V, the estimated motion information V ′ is calculated by V ′ = V / (mn). The moving image data transmission method according to claim 5. 7. An orthogonal transformation coefficient D of a difference between a macroblock of the succeeding frame with respect to the reference frame is obtained by calculating a prediction macroblock corresponding to the decoding target macroblock in the reference frame. The orthogonal transform coefficient of the block difference is D1,
When the orthogonal transform coefficient of the difference included in the encoded data corresponding to the macroblock of the subsequent frame is D2,
7. The moving image data transmission method according to claim 5, wherein D = D2-D1. 8. A method for transmitting moving image data including a plurality of frames in a predetermined order representing a moving image from a transmitting side to a receiving side, wherein the transmitting side transmits a frame other than some frames. While dividing the moving image data into a plurality of groups so that the adjacent frames in the order are not included in the same group,
The partial frames are overlapped and included in at least two or more divided groups, and the divided moving image data is encoded by an encoding algorithm including an inter-frame prediction encoding algorithm with motion compensation for each of the groups. Coded data is generated for each group, and the receiving side decodes the received coded data by a decoding algorithm corresponding to the coding algorithm for each group to restore a frame. When the corresponding coded data is not received normally, when decoding the coded data corresponding to the subsequent frame that has been coded with reference to the partial frame after the current frame in the group to which the current frame belongs. And some of the decoded frames in a group different from the group in which the frame is included. A moving image data transmission method, wherein encoded data corresponding to the subsequent frame is decoded by referring to a frame. 9. A group consisting of a plurality of frames in a predetermined order representing moving images and divided into a plurality of groups so that adjacent frames in the order are not included in the same group. A moving image data decoding device that decodes encoded data for each group generated by an encoding algorithm including an inter-frame prediction encoding algorithm with motion compensation for each group, wherein the encoded data is Decoding means for decoding and restoring a frame by a decoding algorithm corresponding to the encoding algorithm, wherein the decoding means refers to the frame when encoded data corresponding to a certain frame is not normally received. When decoding the encoded data corresponding to the encoded subsequent frame, the group including the frame is included. Using the decoded frames in different groups, create an interpolation frame corresponding to the unsuccessfully received frame, and decode the encoded data corresponding to the subsequent frame by referring to the interpolation frame. A moving picture data decoding device characterized by the above-mentioned. 10. A group comprising a plurality of frames in a predetermined order representing a moving image, the moving image data being divided into a plurality of groups so that the adjacent frames in the order are not included in the same group. A moving image data decoding device that decodes encoded data for each group generated by an encoding algorithm including an inter-frame prediction encoding algorithm with motion compensation for each group, wherein the encoded data is Decoding means for decoding and restoring a frame by a decoding algorithm corresponding to the encoding algorithm, wherein the decoding means refers to the frame when encoded data corresponding to a certain frame is not normally received. When decoding the encoded data corresponding to the encoded subsequent frame, the group including the frame is decoded. Differs by reference to decoded frames in the group, moving picture data decoding apparatus characterized by decoding the encoded data corresponding to the subsequent frame. 11. The moving image data is composed of a plurality of frames in a predetermined order representing a moving image, and frames other than some frames are arranged so that adjacent frames in the order are not included in the same group. Is divided into a plurality of groups, and an inter-frame predictive encoding algorithm with motion compensation for each of the groups is obtained from video data overlappingly included in at least two or more groups obtained by dividing the partial frames. A moving image data decoding apparatus that decodes encoded data for each group generated by an encoding algorithm including: the encoded data for each group, using a decoding algorithm corresponding to the encoding algorithm for each group. Decoding means for decoding and restoring a frame, wherein the decoding means comprises a code corresponding to a certain frame. If the data is not received normally, when decoding the encoded data corresponding to the subsequent frame encoded with reference to the partial frame after the current frame in the group to which the current frame belongs, A moving image data decoding apparatus, characterized in that the encoded data corresponding to the subsequent frame is decoded by referring to the partial frame decoded in a group different from the included group. 12. A moving image data encoding apparatus for encoding moving image data composed of a plurality of frames in a predetermined order representing a moving image, wherein the moving image data encoding device includes a frame other than a part of frames. While dividing the moving image data into a plurality of groups so that the matching frames are not included in the same group,
Dividing means for overlappingly including the partial frames in at least two or more divided groups; and inter-frame predictive encoding of the moving image data divided by the dividing means with motion compensation for each group. A moving image data encoding apparatus comprising: encoding means for encoding the data by an encoding algorithm including the algorithm to generate encoded data for each group.