JP2001045493A - Moving image encoding device, moving image output device and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moving image encoding device, a moving image output device and a storage medium capable of outputting moving image data by executing encoding of moving image data in a method being suitable for an environment where the throughput and storage capacity of data are limited to generate moving image coded data and by realizing decoding corresponding to the moving image coded data. SOLUTION: An image codec part 6 reduces the information amount of encoded moving image data and throughput at the time encoding processing and decoding processing are performed by appropriately inserting a B' picture and a B" picture being frames to which information for eliminating decoding processing is added when the decoding processing is performed in the case of generating the encoded moving image data having a GOP(Group Of Picture) consisting of an I picture, a P picture and a B picture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving picture coding apparatus, a moving picture output apparatus, and a storage medium for reducing the amount of processing in coding and decoding of moving picture data.

[0002]

2. Description of the Related Art In recent years, with the advance of technology, miniaturization of electronic devices has been rapidly progressing, and electronic devices having excellent portability have been developed. For example, a PDA (Personal Digital Assistan)
In the mobile terminal device called t), functions that are highly required when carrying the device include a handwriting input function for a tablet integrated on a liquid crystal display screen, communication functions such as e-mail and the Internet, and personal functions such as schedules, memos, and address books. It is equipped with an information management function, an information search function such as map information and timetable information, and various other functions such as a calculator and a clock. Further, in such a portable terminal device, a multimedia-compatible terminal equipped with a still image and moving image recording / reproducing function and an audio reproducing function has been developed.

[0003] The above-mentioned portable information terminal is presumed to be used at the time of carrying, and it is desired that the size of the portable information terminal is about the size of a palm. For this reason, in general, a portable information terminal is often placed in a very restricted environment in terms of the processing capacity, memory capacity, battery capacity, and the like of a CPU mounted thereon, as compared with that of a stationary personal computer or the like. .

On the other hand, since the amount of information of moving image data is very large, the necessity of information compression has been recognized, and international standardization of multimedia-related image coding has been rapidly advanced. For example, H.264, which is a coding standard for communication media for moving images, is used. H.263, Moving Picture Experts Group (MPEG), which is an encoding standard for moving image storage media. In each of these encoding methods, an encoding algorithm that realizes a bit rate (transmission rate) suited to each purpose is adopted.

For example, in MPEG1, 352 × 240
DCT (Discrete) in order to encode a moving image of 30 frames per second with a data size of 1.5 Mbits / sec.
Cosine Transform (Discrete Cosine Transform) and MC (Motio
n Compensation, a hybrid coding method that fuses two information compression coding processes called motion compensation.
The DCT operates so as to reduce the code amount by using the spatial correlation of each frame constituting the moving image, and the MC operates so as to reduce the code amount by using the temporal correlation between the frames. I do.

[0006] DCT is a type of Fourier transform. By transforming a two-dimensional image into a two-dimensional frequency, DCT can be separated into a low-frequency component that is easy for human eyes and a high-frequency component that is difficult to distinguish. Can be ubiquitous. 8x8
Is converted to the equation (1), and its inverse transform I
Equation (2) shows the DCT conversion equation.

[0007]

(Equation 1)

[0008]

(Equation 2)

Here, C (u) = 1 / √2 (u = 0) C (u) = 1 (u ≠ 0) C (v) = 1 / √2 (v = 0) C (v) = 1 (v ≠ 0) IDCT (i, j): pixel value DCT (u, v): DCT coefficient

The MC converts the input image data to 16 × 1
It is divided into macroblock MBs each of which is a square area of 6 pixels, and a predetermined search range in the reference image is searched to detect a block with the smallest error from the macroblock MB, and the motion is compensated for. This is the inter-frame prediction to be performed. A vector representing the horizontal and vertical movement amounts of the block having the smallest error in the detected reference image is called a motion vector.

In general, in a continuous moving image, since the preceding and succeeding images are very similar to the image of interest, the image to be encoded and the P-picture (inter-frame predictive encoded image) are temporally different. And the difference from the image ahead, and B
For pictures (bidirectionally coded images),
A difference between an interpolated image formed from the back or the front and the back is obtained, and the difference value is encoded and transmitted, thereby reducing the redundancy in the time axis direction and reducing the amount of information to be transmitted.

Next, referring to FIGS. 6, 7 and 8,
A conventional general encoding process and decoding process will be described. FIG. 6 is a block diagram illustrating a conventional encoding process, FIG. 7 is a diagram illustrating a block configuration of a macroblock MB, and FIG. 8 is a block diagram illustrating a conventional decoding process.

As shown in FIG. 6, the conventional encoding process is as follows.
A blocking unit 30a, a differentiator 30c, a DCT unit 30d, a quantization unit 30e, an inverse quantization unit 30g, and an inverse DCT unit 30 for realizing information compression based on spatial correlation.
h, a motion vector detecting unit 30b for realizing information compression based on temporal correlation, an image memory 30j, and an adder 30i, and a variable-length coding unit 30f for eliminating redundancy due to a bias in code appearance probability. Consists of

In the encoding process, when an image of one frame is input from the outside, first, the input image is divided into macroblocks MB of 16 × 16 pixels by the blocking unit 30a. As shown in FIG. 7, the macro block MB is configured by overlapping a luminance matrix and color difference matrices Cb and Cr. The luminance signal block Y has four 8 × 8 blocks, and the color difference signal blocks Cb and Cr each have one 8 × 8 block. The code given in each block is a macro block address (hereinafter referred to as MB
A). The MBA indicates an absolute position of a block in a picture.

When divided into macroblocks MB, prediction is used for an input block to be encoded,
Select not to use. Hereinafter, each case will be described.

When performing intra-frame encoding processing without performing inter-frame prediction, the DCT coefficient of the input block is calculated (DCT section 30d), and the calculated DCT coefficient is quantized (quantized) with an arbitrary quantization width. The encoding unit 30e) encodes the image data quantized together with the quantization width (variable length encoding 30f), and then transfers the encoded image data to a communication path or the like as an output code and outputs it. Further, as local decoding for restoring an image to be used as an original image for the next prediction, the quantized block is inversely quantized (inverse quantization unit 30g), and the IDCT of the DCT coefficient is calculated (inverse). Quantization unit 30h). Then, the restored reference image is transferred to the image memory 3 via the adder 30i.
0j.

When performing inter-frame predictive coding on a macroblock MB to be coded, it is created using motion compensation from an input block and a previously coded image output from the image memory 30j. The difference between the calculated predicted image and the calculated predicted image is calculated (difference device 30c), and the DC of the difference is calculated.
After calculating the T coefficient (DCT unit 30d), further quantizing the DCT coefficient, and encoding the quantization width and the quantized difference image (variable length encoding unit 30f), the output code is output to a communication path or the like. Transfer and output. The motion vector detected by the motion vector detection unit 30b is also encoded and then transferred as an output code (variable length encoding unit 30f). Furthermore,
The quantized difference image is inversely quantized (the inverse quantization unit 30
g) and calculate the IDCT of the DCT coefficient (the inverse DCT unit 30).
h) At the input stage, by adding the predicted image used for the difference calculation (adder 30i), local decoding for restoring the image used for the next prediction is performed, and the result is stored in the image memory 30j.

As shown in FIG. 8, the conventional decoding process is the reverse of the above-described coding. That is, the encoded block is divided into a motion vector and a quantized image by performing variable length decoding (variable length decoding unit 30k). Then, the quantized data is inversely quantized (the inverse quantization unit 3).
0l) and the inverse DCT (inverse DCT unit 30h), the difference image between the intra-frame predicted image and the inter-frame predicted image is obtained. If it is an intra-frame coded image, there is no difference, and if it is output as it is, the image is reproduced. Since there is difference data in the case of an inter-frame prediction coded image, a prediction image is reproduced from the already decoded image and the motion vector in the image memory 30o, and the difference data is added to the prediction image (adder 30n). The decoded image data is decoded and output to the output image buffer 30p.

The above is the flow of the general moving picture encoding and decoding processing. As described in MPEG1 and the like, the reproduction of moving picture data on a storage medium includes fast forward, rewind, In order to enable random access such as reproduction from the middle and reverse reproduction, a picture structure is adopted in which a group of pictures is grouped into GOPs (Group Of Pictures).

FIG. 9 shows the GO adopted in MPEG1 or the like.
FIG. 3 is a diagram showing a general picture structure in units of P.

As shown in FIG. 9, the picture type of each screen data included in the conventional general picture structure includes:
Reference is made to an intra-coded picture (Intra Picture; hereinafter referred to as an "I picture") to be compression-coded using spatial correlation and a past picture, and compression-coded using temporal correlation. Predictive inter-picture (Predictive
Picture; hereinafter, referred to as a “P picture”) and a picture that is ahead and temporally ahead and that is compression-encoded by bidirectional predictive coding (Bidirectional Picture;
"B picture").

In FIG. 9, "I" indicates an I picture, "P" indicates a P picture,
“B” indicates a B picture, and the characteristics of each picture (each picture constituting a moving image) are as follows.

I picture: When encoded, only closed information in one picture is used. In other words, when decoding, an image can be reconstructed using only the information of the I picture itself. Although this encoding method is generally inefficient, random insertion and high-speed reproduction are possible if it is inserted anywhere. P picture: Predicted image (image used as a reference for taking a difference)
Use the previously decoded I-picture or P-picture that is temporally earlier in the input. B-picture: made from an I-picture or P-picture that is located earlier in time and has already been decoded as a predicted picture, an I-picture or P-picture that is located later in time and has already been decoded, and both. Three types of interpolated images are used.

The order of the encoding process is as follows.
The picture 201 is coded, and the B pictures 202 and 203 input at the time t2 and t3 are not coded. At the time t4, the P picture 204 based on the I picture 201 coded at the time t1 is used as a reference. Is encoded. Then, the previously encoded I picture 201 and P
B pictures 202 and 20 with reference to picture 204
3 are encoded and inserted. Further, the B pictures 205 and 206 input at times t5 and t6 are not coded,
At time t7, the P picture 207 is encoded based on the P picture 204 encoded at time t4. Thereafter, in the same order, each picture is encoded and stored in a storage medium or the like.

In the decoding process, the I and P pictures are displayed after decoding the intervening B picture even after decoding.

[0026]

However, in order to perform the above-described conventional encoding and decoding processes, the above-described relatively large data amount is targeted, and 30 frames per second or less are required. Since it does not support moving images, high processing power and large memory capacity are required for hardware. Therefore, in the above-mentioned portable information terminal or the like, since the environment in which the data processing capability and the storage capacity are extremely limited, it may not be possible to operate with the conventional moving image data encoding and decoding methods. There was a problem.

In view of the above problems, it is an object of the present invention to generate moving image encoded data by executing moving image data encoding processing in a method suitable for an environment where data processing capacity and storage capacity are limited. It is another object of the present invention to provide a moving image encoding device, a moving image output device, and a storage medium capable of outputting moving image data by realizing a decoding process corresponding thereto.

[0028]

The present invention has the following features in order to achieve the above object. In the following description of the means, a configuration corresponding to the embodiment will be exemplified by parentheses as an example. Reference numerals and the like are reference numerals and the like in the drawings described later.

According to the first aspect of the present invention, a moving image data encoding process using information compression based on a spatial correlation within a frame and information compression based on a temporal correlation between frames is executed. Intra-frame coded pictures (for example, the I picture shown in FIG. 2), inter-frame prediction coded pictures (for example, the P picture shown in FIG. 2), and bidirectional prediction coded pictures (for example, the B picture shown in FIG. 2)
In a moving picture coding apparatus for generating coded moving picture data having a picture structure composed of: a frame having coding information for omitting a decoding process between frames forming the picture structure (for example, Frame inserting means for inserting a predetermined number of B ′ pictures and B ″ pictures shown in FIG. 2 (for example, the image codec unit 6 shown in FIG. 1)
It is characterized by having.

According to the moving picture coding apparatus of the first aspect of the present invention, moving picture data utilizing information compression based on a spatial correlation within a frame and information compression based on a temporal correlation between frames. Moving image encoding apparatus for generating encoded moving image data having a picture structure composed of an intra-coded picture, an inter-frame predicted coded picture, and a bidirectional predicted coded picture In the method, a predetermined number of frames having encoding information for omitting decoding processing are inserted between frames constituting the picture structure by frame insertion means.

Therefore, a frame having information for omitting the decoding process is appropriately inserted between each frame having a normal picture structure, and compared with the encoded moving image data having the same number of frames. To reduce the amount of information of the encoded moving image data,
The amount of processing at the time of encoding can be reduced, and the required storage capacity and processing capacity can be reduced. As a result, it is possible to compress and encode moving image data even in an environment where the processing capacity and storage capacity of hardware are limited.

Further, as in the second aspect of the present invention, in the video encoding apparatus of the first aspect of the present invention, encoded information indicating that there is no change compared to the previous frame (for example, motion vector = 0, DCT coefficient = 0) or a first storage unit (for example, as shown in FIG. 4) that stores at least one of encoded information (macroblock address increment) in a block range in which the decoding process is skipped. B 'picture encoding memory 6q), and it is effective that the frame inserting means inserts a frame having the encoding information stored in the first storage means between each frame constituting the picture structure. It is.

According to the moving picture coding apparatus of the present invention, the coding information indicating that there is no change compared with the previous frame, or the coding information of the block range in which the decoding process is skipped At least one of which is stored in the first storage means, and the frame insertion means converts the frame having the encoding information stored in the first storage means into each frame constituting the picture structure Insert between.

Therefore, since the encoding information on the frame to be inserted is stored in advance, a huge amount of encoding processing such as motion compensation and DCT operation can be omitted when generating and inserting the frame. The amount of processing required for encoding moving image data can be reduced, and the processing time can be reduced.

According to a third aspect of the present invention, in the moving picture encoding apparatus according to the first aspect of the present invention, the second storage means (2) for storing the same encoding information as the immediately preceding frame. For example, it further comprises a B ″ picture coding memory 6r) shown in FIG. 4, and the frame inserting means converts the frame having the coding information stored in the second storage means into each frame constituting the picture structure. It is effective to insert in between.

According to the moving picture coding apparatus of the third aspect of the present invention, the same coded information as the immediately preceding coded frame is stored in the second storage means, and the frame inserting means stores A frame having the encoded information stored in the second storage means is inserted between each frame constituting the picture structure.

Therefore, the same coded information as the immediately preceding frame is stored, and when generating and inserting a frame, the coded information is generated using the stored coded information as it is. In addition, it is possible to omit enormous processes such as motion compensation and DCT calculation for a frame to be inserted, reduce the amount of processing required for encoding moving image data, and shorten the processing time.

According to a fourth aspect of the present invention, in the moving picture encoding apparatus according to the first aspect of the present invention, the coding information indicating that there is no change compared with the previous frame, or the decoding processing is performed. A first storage unit (for example, a B 'picture encoding memory 6q shown in FIG. 4) that stores at least one of the encoded information of the block range to be skipped;
Second storage means (for example, a B ″ picture coding memory 6r shown in FIG. 4) for storing the same coding information as the immediately preceding frame, and counting means for counting the number of output frames (for example, 4, the frame number counter 6 shown in FIG.
s), the encoded information stored in the first storage means,
A switching unit (for example, a switching unit that switches which of the encoded information stored in the second storage unit and the encoded information of each frame constituting the picture structure encoded by the encoding process is output) , A switch SW1) shown in FIG. 4, wherein the frame inserting means controls switching of the switching means according to the number of frames counted by the counting means, and switches between the frames constituting the picture structure. It is effective to insert a predetermined number of frames having encoded information stored in the first storage means or frames having encoded information stored in the second storage means.

According to the moving picture coding apparatus of the present invention, the frame insertion means stores the coding information stored in the first storage means and indicating that there is no change compared with the previous frame. Or at least one of the encoded information of the block range to skip the decoding process,
Either of the same coded information as the previously coded frame stored in the second storage means or the coded information of each frame constituting the picture structure coded by the coding processing, Is controlled in accordance with the number of frames counted by the counting means, and between each frame constituting the picture structure, a frame having encoded information stored in the first storage means or A predetermined number of frames having encoded information stored in the second storage unit are inserted.

Therefore, which frame is to be output with the coding information is controlled according to the number of output frames, so that it is possible to insert frames in an appropriate order and to utilize the stored coding information. Since a frame that does not require an encoding process is appropriately inserted, a reduction in processing amount in the encoding process of moving image data is realized.

According to a fifth aspect of the present invention, a frame encoded by a moving picture encoding method using information compression based on a spatial correlation within a frame and information compression based on a temporal correlation between the frames. From an inner coded picture (for example, the I picture shown in FIG. 2), an inter-frame predictive coded picture (for example, a P picture shown in FIG. 2), and a bidirectional predictive coded picture (for example, a B picture shown in FIG. 2) In a moving image output device that decodes and outputs encoded moving image data having a structured picture structure,
Detecting means for detecting the picture type of the input coded moving image data (for example, the picture type detecting unit 6 shown in FIG. 5)
t), output image storage means (for example, an output image buffer 6p shown in FIG. 5) for sequentially storing image data of the decoded and output frames, and decoding in accordance with the picture type detected by the detection means. Image output control means (for example, the image codec unit 6 shown in FIG. 1) for outputting the image data of the frame output immediately before, out of the image data stored in the output image storage means,
And, it is characterized by having.

According to the fifth aspect of the present invention, a moving picture encoding apparatus utilizing information compression based on a spatial correlation within a frame and information compression based on a temporal correlation between frames. Output device that decodes and outputs encoded video data having a picture structure composed of an intra-frame coded picture, an inter-frame predictive coded picture, and a bidirectional predictive coded picture coded by the system In the method, the picture type of the encoded moving image data inputted by the detecting means is detected, the image data of the frame outputted by being decoded by the output image storing means is sequentially stored, and the detected image data is outputted by the image output controlling means. The decoding process is omitted according to the type of the picture, and the image data stored in the output image storage unit is output immediately before. To output the image data of the frame.

Accordingly, since the picture type can be detected and the decoding process can be omitted according to the picture type, the processing amount required in the decoding process can be greatly reduced. As a result, it is possible to output a moving image even in an environment where the processing capacity of hardware is limited.

According to a sixth aspect of the present invention, in the moving picture output apparatus according to the fifth aspect of the present invention, the picture type of the input coded moving picture data includes the intra-coded picture, the frame Inter prediction coded picture,
And a frame having information for omitting the decoding process in addition to the bidirectional prediction coded picture (for example, B ′ shown in FIG. 2).
Picture, B '' picture), and when the picture type detected by the detection means is a frame having information for skipping the decoding process, the image output control unit skips the decoding process. In addition, it is effective to output the image data of the immediately preceding frame among the image data stored in the output image storage means.

According to the moving picture output apparatus of the present invention, the picture types of the input coded moving picture data include the intra-coded picture, the inter-frame predictive coded picture, and the When a frame having information for omitting the decoding process is included in addition to the directional prediction coded picture, the image output control unit determines that the picture type detected by the detection unit omits the decoding process. If the frame has information for decoding, the decoding process is omitted, and among the image data stored in the output image storage means, the image data of the frame output immediately before is output.

Therefore, it is possible to omit the decoding process for the frame to which the encoding information indicating that the decoding process is to be omitted, so that the processing amount required for the decoding process of the encoded moving image data is required. Can be greatly reduced. As a result, it is possible to output a moving image even in an environment where the processing capacity of hardware is limited.

According to a seventh aspect of the present invention, in the moving picture output apparatus according to the sixth aspect of the present invention, the information for omitting the decoding process has no change in comparison with the previous frame. It is effective to include any one of the encoded information, the encoded information in the block range in which the decoding process is skipped, and the same encoded information as the immediately preceding frame.

According to the moving picture output apparatus of the present invention, a frame having coding information indicating that there is no change with respect to the previous frame and coding information of a block range in which decoding processing is skipped is performed. According to the encoded information, processing such as motion compensation and inverse DCT operation can be skipped. In a frame having the same encoded information as a frame encoded immediately before, decoding immediately before that frame is performed. Since the converted and output image can be output as it is, the amount of processing required in the decoding process can be significantly reduced.

[0049]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a moving picture compression / decompression apparatus 1 to which a moving picture coding apparatus and a moving picture output apparatus according to the present invention are applied will be described in detail with reference to FIGS.

Moving picture compression / expansion apparatus 1 in the present embodiment
G is a general picture structure in MPEG1 or the like, and is composed of an I picture, a P picture, and a B picture.
When generating encoded moving image data having an OP (Group Of Picture), B ′ picture and B ″ picture, which are frames to which information for skipping the decoding process is added at the time of decoding process, are appropriately inserted. By doing so (see FIG. 2), the amount of information of the encoded moving image data can be reduced, and the amount of processing at the time of encoding and decoding can be reduced. As a result, it is possible to reproduce moving image data in an environment where the processing capacity and storage capacity of hardware are limited.

First, the configuration will be described. FIG. 1 is a circuit configuration diagram of the moving image compression / decompression device 1. As shown in FIG. 1, the moving image compression / decompression device 1 includes a control unit 2, an input unit 3, a display unit 4, a communication I / F (InterFace) unit 5, an image codec unit 6, an audio codec unit 7, a RAM (Random Access). Memory)
8, a storage device 9, and a storage medium 10, and each unit except the storage medium 10 is connected by a bus 11.

The control unit 2 stores an application program specified from various application programs corresponding to the image compression / decompression device 1 stored in the storage device 9 and various instructions or data input from the input device 3 into the RAM 8. In accordance with the input instructions and the input data, various processes are executed in accordance with the application program stored in the RAM 8, and the processing results are stored in the work memory in the RAM 8 and displayed on the display device 4. I do. Then, the processing result stored in the work memory is stored in a storage destination in the storage device 9 which is instructed to be input from the input device 3.

The control unit 2 multiplexes the image encoded data encoded by the image codec unit 6 and the audio encoded data encoded by the audio codec unit 7 when encoding the image data. Then, a bit stream of one column is generated and stored in the storage medium 10 in the storage device 9 or output to the outside via the communication I / F unit 5. On the other hand, at the time of decoding the encoded moving image data, the control unit 2 transmits the bit stream read from the storage medium 10 in the storage device 9 or the communication I / F.
The image data and the audio data are separated from the bit stream input from the outside via the unit 5 and transferred to the image codec unit 6 or the audio codec unit 7, respectively.

The input unit 3 includes a keyboard having cursor keys, numeric input keys, various function keys, and the like, and a mouse as a pointing device. The input unit 3 outputs a key press signal of the keyboard to the control unit 2. And outputs an operation signal from the mouse to the control unit 2. Further, a tablet integrally provided on the display unit 4 may be included. The tablet detects data input by a dedicated pen or the like based on a coordinate reading principle such as an electromagnetic induction method, a magnetostriction method, and a pressure-sensitive method, and outputs the input data to the control unit 2.

The display unit 4 is a CRT (Cathode Ray Tub).
e) It is constituted by a liquid crystal display device or the like, and displays display data according to a display control signal input from the control unit 2. The display unit 4 displays a moving image according to the image data decoded by the image codec unit 6.

The communication I / F unit 5 includes a modem (MODEM:
MOduler / DEModuler), terminal adapter (TA: Ter)
a communication adapter such as a telephone line, an ISDN line, or a dedicated line to control communication with an external device.

The image codec 6 encodes image data stored in a storage medium 10 in a storage device 9, moving image data input from a video camera (not shown), and the like (see FIG. 4), and decodes the data. Conversion processing (see FIG. 5). FIG.
FIG. 3 is a diagram showing a picture structure of encoded moving image data generated by the encoding processing of the moving image compression / decompression device 1 of the present invention. As shown in FIG. 2, in the encoded moving image data generated by the moving image compression / decompression device 1 of the present invention, B ′ pictures and B ″ pictures are inserted as appropriate in addition to I pictures, B pictures and P pictures. Picture structure. In FIG. 2, "I" is an I picture, "B" is a B picture,
"P" is a P picture, "B '" is a B' picture,
“B ″” is a frame representing a B ″ picture.

The B 'picture has, as coding information for omitting decoding processing, coding information indicating that there is no change compared to the previous frame and coding information of a block range to be skipped in decoding processing. Frame. FIG. 3 is a diagram illustrating an example of encoding information for a B ′ picture. As shown in FIG. 3, in the B 'picture, the head macroblock MBF is
It is coded as “0”, DCT coefficient = “0”, macroblock address increment (hereinafter referred to as MBAI) = “0”, and the final macroblock MBL is coded as motion vector = “0”, DCT coefficient = “0” , MBAI = “the total number of macroblocks MB in the picture−1”. As a result of encoding in this way, the B ′ picture can skip all macroblocks MB in the picture, and has only two macroblocks MB to be encoded, so that the information amount is small. The amount of processing at the time of encoding and decoding can be reduced.

A B ″ picture is a frame having the same encoding information as the B picture encoded immediately before in time, as encoding information for omitting decoding processing. That is, when encoding information of a B picture is generated in the encoding process, the encoding information of the B picture is output as an output code, and at the same time, stored in a B ″ picture encoding memory 6r to be described later. At the time of generation, a B ″ picture is generated using the coding information of the immediately preceding B picture stored in the B ″ picture coding memory 6r.

FIG. 4 is a block diagram illustrating an encoding process performed in the image codec unit 6 of the moving picture compression / decompression apparatus 1 according to the present invention. In FIG. 4, a blocking unit 6a, a motion vector detecting unit 6b, a differentiator 6c, a DCT
Unit 6d, quantization unit 6e, variable length coding unit 6f, inverse quantization unit 6g, inverse DCT unit 6h, adder 6i, image memory 6j
Is the same as the conventional image data encoding process. However, in the encoding process performed by the image codec unit 6 according to the present invention, the above-described B ′ picture and B ″ picture are generated and inserted. B ′ picture encoding memory 6q, B ″ picture encoding memory 6r, and frame number counter unit 6
s, and switches SW1 and SW2.

The B 'picture coding memory 6q is a memory in which coding information for generating a B' picture is stored. And coding information on a block range in which is skipped. Here, a motion vector is a zero vector as coding information indicating that there is no change compared with a previous frame (a frame serving as a reference in motion compensation; for example, an immediately preceding I picture or P picture).
Encoding information indicating that the motion compensation prediction error is 0 is stored, and MBAI (macroblock address increment) is stored as encoding information regarding a block range in which decoding processing is skipped. MBAI is coding information indicating the number of macroblocks MB to be skipped.

For example, motion vector = 0, DCT coefficient =
0, motion vector = 0, DCT coefficient = 0, MBAI = “total number of macroblock MBs in picture−1” as coding information corresponding to MBAI = 0 and coding information for the last macroblock MBL Encoding information to be stored.

The B ″ picture coding memory 6r is a memory in which coding information for generating a B ″ picture is stored, and stores the same coding information as the immediately preceding frame. . Here, for example, the same encoding information as the immediately preceding B picture is stored.

The frame number counter 6s is a counter for counting the number of output frames. The switches SW1 and SW2 are switched according to the picture type corresponding to the count value of the frame number counter 6s. Since the count value and the picture type differ depending on the picture structure to be generated (the period in which I-pictures, P-pictures, and B-pictures appear, and the number of B′-pictures and B ″ -pictures to be inserted), when the picture structure is determined, It is assumed that the correspondence between the count value of the frame number counter and the picture type is set in advance.

The switch SW1 is used to set the coding information stored in the B 'picture coding memory 6q, the coding information stored in the B''picture coding memory 6r, or the variable length, depending on the picture type to be coded. A switch for switching which of the I picture, P picture, and B picture coding information output from the coding unit 6f is output. The image codec unit 6 includes the frame number counter 6
The switch SW1 is switch-controlled in accordance with the count value counted by s.

When the picture type determined from the count value of the frame number counter is an I picture, a P picture, or a B picture, the coded information output from the variable length coding unit 6f is directly transferred to the transfer path. To turn on the variable length coding unit 6f, and turn off the B 'picture coding memory 6q and the B ″ picture coding memory 6r.
If the picture type is a B 'picture, the B' picture coding memory 6q is turned on, and the variable length coding unit 6f and the B "picture coding memory 6r are turned off.
f, and if the picture type is a B ″ picture,
The B ″ picture coding memory 6r is turned on, and the B ′ picture coding memory 6q and the variable length coding unit 6f are turned off.

The switch SW2 has a frame number counter 6
If the picture type determined from the count value of s is a B ″ picture, it is turned on to the B ″ picture encoding memory 6r side, and if it is another picture type, it is of
f.

The image codec unit 6 executes a decoding process for expanding moving image data encoded by the encoding process of the present invention, and outputs decoded moving image data.

FIG. 5 is a block diagram for explaining a decoding process executed in the image codec unit 6 of the moving picture compression / expansion apparatus 1 according to the present invention. In FIG. 5, a variable length decoding unit 6k, an inverse quantization unit 61, an inverse DCT unit 6m, an adder 6
n, the image memory 6o, and the output image buffer 6p are the same as those in the conventional decoding processing of encoded image data.
The decoding process performed by the image codec unit 6 according to the present invention further includes a picture type detection unit 6t and a switch SW3 in order to omit the decoding process of the B ′ picture and the B ″ picture described above.

The picture type detector 6t detects a picture type. The encoded moving image data includes encoding information (PCT; Picture Coding Typ) indicating a picture type.
Since e) is added, the picture type can be detected by performing variable length coding when the coding information is input. The output image buffer 6p sequentially stores the image data of the frames already decoded and output.

The image codec unit 6 according to the present invention switches the switch SW3 when any of the I picture, P picture, B picture and B 'picture is detected by the picture type detection unit 6t in the decoding process. It is turned on to the inverse quantization unit 61 and performs the same decoding processing as the conventional decoding processing. If a B ″ picture is detected, the switch SW3 is turned off, and the image data of the immediately preceding frame stored in the output image buffer 6p is output without performing the decoding process. Further, in the present embodiment, since the B ′ picture is encoded so that all the macroblocks MB in the frame are skipped, processes such as inverse quantization and inverse DCT are substantially omitted. Have been.

The audio codec unit 7 encodes audio to be added to the encoded moving image data encoded by the image codec unit 6, and transfers the encoded audio data to the control unit 2. The audio codec unit 7 includes the control unit 2
The decoding processing of the encoded audio data separated from the encoded moving image data is performed.

The RAM 8 has a work memory for storing designated application programs, input instructions, input data, processing results, and the like.

The storage device 9 has a storage medium 10 in which programs, data and the like are stored in advance, and this storage medium 10 is formed of a magnetic or optical recording medium or a semiconductor memory. This storage medium 10 is a storage device 9
The storage medium 10 stores data processed by various application programs corresponding to the moving image compression / expansion apparatus 1 and the like.

The program, data, and the like stored in the storage medium 10 may be configured to be received and stored from another device connected via a communication line or the like. A storage device provided with the storage medium 10 is provided on the other device side connected through the communication I / F unit 5 to transfer programs, data, and the like stored in the storage medium 10.
It may be configured to be used via a.

Next, the operation will be described. T shown in FIG.
1 to t13 represent time, and illustrate the reproduction order of each picture. In the encoding process, this time t
Encoding processing of each picture is performed in an encoding order different from the arrangement of 1 to t13. The encoding order of each picture in the encoding processing according to the present embodiment and the location where each picture is inserted are as follows.

First, the image codec unit 6 sets the I picture 1
01, the P picture 107 is coded first, and then
The B picture 104 is encoded from the I picture 101 and the P picture 107, and this B picture 104 is
It is inserted between the picture 101 and the P picture 107. Further, the image codec unit 6 creates a B ′ picture and inserts it between the I picture 101 and the B picture 104. In this example, two B 'pictures 102 and 103 are created and inserted. Further, the image codec unit 6 outputs the B picture 104
A B ″ picture is created using the same coding information as that of the B picture 104 and inserted after the B picture 104. In this example, two B ″ pictures 105 and 106 are inserted.

The encoding process of the pictures 101 to 107 will be described in detail with reference to FIG. First, the frame number counter unit 6s of the image codec unit 6 has its count value set to "0", the switch SW1 is switched to the variable length coding unit 6f side, and the switch SW2 is turned off. When one frame image is input from outside, the input image is divided into macroblocks MB of 16 × 16 pixels (blocking unit 6a). The block configuration of the macro block MB is the same as the conventional one. When divided into macroblocks MB, coding starts for the input block to be coded.

First, the coding process of the I picture 101 is started. Since the I picture does not use prediction, the DCT of the input block is calculated (DCT section 6d), and the calculated DC is calculated.
The T coefficient is quantized with an arbitrary quantization width (quantization unit 6e), and the quantized image data is coded together with the quantization width (variable length coding 6f), and transferred to a communication path or the like as an output code. . At this time, the count value of the frame number counter unit 6s is incremented (+1), and the switches SW1 and SW2 maintain the same state.

Further, as local decoding for restoring an image to be used as an original image for the next prediction, the quantized block is inversely quantized (inverse quantization unit 6g), and the IDCT of DCT coefficients is calculated. (The inverse quantization unit 6h). Then, the restored reference image (I picture 101) is stored in the image memory 6j via the adder 6i.

Next, the image codec unit 6 performs an inter-frame prediction based on the reference image (I picture 101) to create a P picture 107. Macro block M
The difference between the input block divided into B and the predicted image created by using motion compensation from the reference image (I picture 101) output from the image memory 6j is calculated (differentiator 6c). Calculate DCT (DCT section 6d),
Further, the DCT coefficient is quantized to encode the quantized difference image (variable length decoding unit 6f), and then transferred as an output code to a communication path or the like. The motion vector detected by the motion vector detection unit 6b is also encoded and then transferred as an output code (variable length encoding unit 6f). In addition, the quantized difference image is inversely quantized (inverse quantization unit 6g), the IDCT of the DCT coefficient is calculated (inverse DCT unit 6h), and the prediction image used for the difference calculation is added in the input stage (adder). 30i), perform local decoding for restoring an image to be used for the next prediction, and store it in the image memory 6j.

When the encoding processing of the P picture 107 is completed, the count value of the frame number counter 6s is incremented (+1), the switch SW1 is kept as it is, and the switch SW2 is turned on.

In the processing so far, the I picture 10
1 and the P picture 107 are coded, and the I picture 101 and the P picture 107 are locally decoded and stored in the image memory 6j.

Next, the image codec unit 6 performs bidirectional inter-frame prediction based on the reference image (I picture 101 and P picture 107) to create a B picture 104. The difference between a predicted image created by using motion compensation from the I picture 101 and the P picture which are reference images stored in the image memory 6j and the input block is calculated (differentiator 6c), and the DCT of this difference is calculated. Calculate (DC
The T unit 6d) further quantizes the DCT coefficient, encodes the quantized difference image (variable length decoding unit 6f), and transfers it to a communication path or the like as an output code. Motion vector detector 6
After the motion vector detected in b is also encoded, it is transferred as an output code (variable-length encoding unit 6f). Since the switch SW2 is turned on, the same encoded information as the encoded information transferred as the output code is stored in the B ″ picture encoding memory 6r.

The quantized difference image is inversely quantized (inverse quantization unit 6g), the IDCT of the DCT coefficient is calculated (inverse DCT unit 6h), and the prediction image used for the difference calculation is added at the input stage. (Adder 6i) performs local decoding for restoring an image to be used for the next prediction, and stores the result in image memory 6j.

When the encoding process of the B picture 104 is completed, the image codec 6
Is incremented (+1), and the switch S
W1 is switched to the B 'picture encoding memory 6q side, and the switch SW2 is turned off.

Next, the image codec 6 inserts a B 'picture. As shown in FIG. 3, the B ′ picture coding memory 6q stores, as coding information indicating that there is no change compared to the previous frame and coding information for skipping all blocks in the frame, as shown in FIG. Block MBF
, "Motion vector = 0, DCT coefficient = 0, MB
AI = 0 ”, and“ Motion vector = 0, DCT coefficient =
0, MBAI = “total number of macroblock MBs in picture−1” is stored, and the stored coded information is transferred to a communication path or the like by a predetermined number of frames, and Insert before picture 104. In the present embodiment, the number to be inserted is two frames. Therefore, B 'pictures 102 and 103 are inserted.

When the insertion of the B 'pictures 102 and 103 is completed, the count value of the frame number counter 6s is incremented (+2) for each output, and the switch SW1 is switched to the B ″ picture encoding memory 6r side. S
W2 is kept off.

Next, the image codec 6 inserts a B ″ picture. In the B ″ picture encoding memory 6r,
Since the same coded information as the coded information of the B picture 104 is stored, a predetermined number of frames having the stored coded information are transferred to a communication path or the like, and
Insert after picture 104. In the present embodiment, 2
It has a frame. Therefore, the B ″ picture 105
And 106 are inserted.

When the insertion of the B ″ pictures 105 and 106 is completed, the count value of the frame number counter unit 6s is incremented by the number of inserted frames (+2), and the switch SW1 is switched to the variable length encoding unit 6f side. S
W2 is kept off.

By repeating the above processing, a predetermined number of B 'pictures are inserted before the B picture and a predetermined number of B' pictures are inserted after the B picture. That is, in the example shown in FIG. 2, the P picture 113 is encoded using the P picture 107 as a reference image, the B picture 110 is encoded from the P picture 107 and the P picture 113, and the B picture 110 is encoded.
Picture 110 is converted to P picture 107 and P picture 113
And interpolate between Further, the image codec unit 6 creates a B 'picture, and outputs a P picture 107 and a B picture 110.
Insert between In this example, two B 'pictures 10
Insert 8,109. Further, the image codec unit 6
A B ″ picture is created using the same coding information as the coding information of the picture 110, and is inserted after the B picture 110. In this example, two B ″ pictures 111 and 11
Insert 2.

Thereafter, the image codec unit 6 generates an I picture 114 which is a frame for which prediction is not performed, and thereafter repeats the above-described processing in the same manner, and repeats the above process for the I picture, P picture, B picture, B 'picture, B'' The encoded moving image data having a picture structure composed of pictures is generated, and the generated encoded moving image data is stored in the storage medium 10.

Next, the flow of the decoding process of the encoded moving image data generated by the above-described encoding process will be described. FIG. 5 is a block diagram for explaining a decoding process of the image data encoded by the above-described encoding process. As shown in FIG. 2, the coded moving image data generated by the above-described coding processing includes a B ′ picture and a B ″ picture in addition to an I picture, a P picture, and a B picture.

First, when an encoded block of encoded moving image data stored in the storage medium 10 is input, the encoded block is variable-length decoded (variable-length decoding unit 6k). Further, when the picture type detection unit 6t determines that the picture type is an I picture,
The switch SW3 is turned on, the quantized data is inversely quantized (inverse quantization unit 61), and the inverse DCT is calculated (inverse D).
The CT unit 6m) outputs and displays the decoded I picture and stores it in the output image buffer 6p. Also, the image memory 6o is used for prediction by motion compensation of the next image.
Stores the decoded image data.

If the input coded block is a B 'picture, the motion vector is 0, the motion compensation prediction error is 0, and MBAI which is block range information to be skipped.
Therefore, the inverse quantization by the inverse quantization unit 61 and the calculation of the IDCT by the inverse DCT unit 6m are skipped according to the skipped block range. In the present embodiment, B ′ picture is set with block range information for skipping all macroblocks MB in a frame, so that all macroblocks MB are skipped and decoding processing is not performed. Output and display the decoded I picture stored in the output image buffer 6p.

When it is determined that the input coded block is a B picture, the switch SW3 is kept on, and the quantized data subjected to variable length decoding is dequantized (inverse quantization unit 61). ), And calculate an inverse DCT to obtain a difference image from the reference image (inverse DCT unit 6m). Further, the reference image stored in the image memory 6o is motion-compensated with the variable-length-decoded motion vector to obtain a predicted image, and the difference image is added to the predicted image (adder 6n) to obtain a B picture. Is generated, output and displayed, and stored in the output image buffer 6p.

If the input coded block is determined to be a B ″ picture, the switch SW3 is turned off,
The B picture that has already been output and stored in the output image buffer 6p is output and displayed without undergoing the decoding process.

When the input coded block is determined to be a P-picture, the switch SW3 is turned on to inversely quantize the variable-length-decoded quantized data (inverse quantization unit 61). The DCT is calculated to obtain a difference image from the reference image (the inverse DCT unit 6m). Further, the reference image stored in the image memory 6o is motion-compensated with the variable-length decoded motion vector to obtain a predicted image, the difference image is added to the predicted image (adder 6n), and P
A decoded image of the picture is generated, output and displayed, and stored in the output image buffer 6p.

By repeating the above processing, the decoding processing is performed on the coded moving image data consisting of the I picture, B 'picture, B picture, B "picture, and P picture, and the image data is output and displayed. In the decoding process, the decoding process is skipped according to the block range information to be skipped in the B ′ picture, and the same screen as the previous I picture or P picture is displayed. A B picture, which is a picture output immediately before, is output without undergoing the conversion process.

As described above, the image codec unit 6 of the moving picture compression / decompression apparatus 1 uses the DCT and the MC to encode and display a coded moving picture having a picture structure composed of an I picture, a P picture, and a B picture. In an encoding process for generating image data, a predetermined number of B ′ pictures and B ″ pictures, which are frames to which information for skipping the decoding process is added, are inserted between the frames constituting the picture structure.

That is, the image codec unit 6 in the above-mentioned encoding process, “motion vector = 0, prediction error of motion compensation = 0 'and a B' picture encoding memory 6q storing MBAI which is encoding information of a block range to be skipped, and a B '' picture code storing the same encoding information as the B picture encoded immediately before The switch SW1 and the switch SW2 are controlled in accordance with the number of frames counted by the frame number counter unit 6s, and the code stored in the B 'picture coding memory 6q is provided before the B picture. A predetermined number of B 'pictures to which encoding information is added are inserted, and after the B picture, B "to which encoding information stored in the B" picture encoding memory 6r is added. The puncturing to insert a predetermined number.

The image codec unit 6 of the moving picture compression / decompression apparatus 1 has a picture structure composed of I pictures, P pictures, and B pictures coded by a moving picture coding method using DCT and MC. In the decoding process for decoding and outputting the encoded moving image data having the following, the picture type of the input encoded moving image data is detected by the picture type detection unit 6t, and the image of the frame output after being decoded is output. Output data to image buffer 6
p, and when the detected picture type is a B ′ picture or a B ″ picture, decoding processing such as inverse quantization and calculation of an inverse DCT coefficient is omitted, and stored in the output image buffer 6p. The image data of the frame output immediately before the image data is output.

Therefore, in the encoding process executed in the present invention, the video data having the picture structure composed of the I picture, B picture, and P picture is added with information for omitting the decoding process. 'Picture, B' generates encoded video data with picture inserted,
As compared with the encoded moving image data having the same number of frames and having a picture structure, the information amount of the encoded moving image data can be reduced, and the required storage capacity can be reduced. Further, in a decoding process for decoding moving image data encoded by such an encoding process, a required processing amount can be significantly reduced. As a result, it is possible to compress and decompress a moving image even in an environment where the processing capacity and storage capacity of hardware are limited.

Also, the coding information for the range of blocks to be skipped is stored in advance in the B 'picture coding memory 6q as the coding information for generating the B' picture, and the coding information for generating the B '' picture is stored. By storing, in advance, in the B ″ picture coding memory 6r, coding information indicating that there is no change with respect to a frame that has already been coded, calculation of a DCT coefficient requiring an enormous amount of processing is performed. And the like, the B ′ picture and the B ″ picture can be created, and the amount of processing in the encoding processing can be reduced.

Furthermore, the type of picture to be created is determined by the count value in the frame number counter 6s for counting the number of frames to be output, and output switching control of encoded information is performed. Make it possible.

In this embodiment, the inserted B '
Although the picture and the B ″ picture are two frames before and after the B picture, compression and decompression are possible at an apparent frame rate of 10 frames per second, but the number of inserted frames is not limited to this, and may be increased or decreased as appropriate. Is also good. That is, in the case of moving image data having a gradual motion, even if the number of B ′ pictures and B ″ pictures to be inserted is increased, there is little possibility that smooth reproduction of the moving image is hindered. , B ′ picture and B ″ picture may be increased, and conversely, in the case of moving image data with strong movement, the number of B ′ pictures and B ″ pictures may be reduced to reduce the number of I pictures, It is advisable to shorten the period in which P-pictures appear. Also, details such as the frame insertion order at the time of encoding can be appropriately changed without departing from the spirit of the present invention.

Although the present embodiment has been described based on the encoding system in MPEG1, the present invention may be applied to other encoding systems (for example, an encoding system such as MPEG4).

[0108]

According to the first and eighth aspects of the present invention, a frame having information for omitting decoding processing is appropriately inserted between each frame having a normal picture structure. The amount of information of the encoded moving image data can be reduced as compared with the encoded moving image data having the following picture structure, and the amount of processing at the time of encoding can be reduced. Processing capacity can be reduced. As a result, it is possible to compress and encode moving image data even in an environment where the processing capacity and storage capacity of hardware are limited.

According to the second aspect of the present invention, since the coding information on the frame to be inserted is stored in advance, the motion compensation and the D
A huge amount of encoding processing such as CT operation can be omitted,
Reduce the amount of processing required for encoding video data,
Processing time can be reduced.

According to the third aspect of the present invention, the same encoding information as that of the immediately preceding frame is stored, and when generating and inserting a frame, the stored encoding information is used as it is. Coded information is generated, so that enormous processing such as motion compensation and DCT calculation for a frame to be inserted can be omitted, the amount of processing required for coding moving image data is reduced, and the processing time is shortened. can do.

According to the fourth aspect of the present invention, which frame to output the coded information for is controlled according to the number of output frames, so that frames can be inserted in an appropriate order and stored. By using the encoding information, a frame that does not require the encoding process is appropriately inserted, so that the processing amount in the encoding process of the moving image data can be reduced.

According to the fifth and ninth aspects of the present invention, the picture type can be detected and the decoding process can be omitted according to the picture type. It can be significantly reduced. As a result, it is possible to output a moving image even in an environment where the processing capacity of hardware is limited.

According to the sixth aspect of the present invention, it is possible to omit the decoding process for the frame to which the encoding information indicating that the decoding process is to be omitted. The amount of processing required for processing can be significantly reduced. As a result, it is possible to output a moving image even in an environment where the processing capacity of hardware is limited.

According to the seventh aspect of the present invention, for a frame having coding information indicating that there is no change with respect to the previous frame and coding information of a block range in which decoding processing is skipped, the coding information is Depending on motion compensation or inverse DC
Processing such as T operation can be skipped.
For a frame having the same encoding information as the immediately preceding frame, the image decoded and output immediately before the frame can be output as it is, so the processing amount required in the decoding process Can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of a moving image compression / decompression device 1 according to the present invention.

FIG. 2 is a diagram showing a picture structure of encoded moving image data generated by the encoding processing of the moving image compression / decompression device 1 of the present invention.

FIG. 3 is a diagram illustrating an example of encoding information for a B ′ picture.

FIG. 4 is a block diagram illustrating an encoding process performed in the image codec unit 6 of the moving image compression / decompression device 1 of the present invention.

FIG. 5 is a block diagram illustrating a decoding process performed in the image codec unit 6 of the moving image compression / decompression device 1 of the present invention.

FIG. 6 is a block diagram illustrating a conventional encoding process.

FIG. 7 is a diagram showing a block configuration of a macro block MB.

FIG. 8 is a block diagram illustrating a conventional decoding process.

FIG. 9 is a diagram showing a general picture structure in GOP units adopted in MPEG1 and the like.

[Explanation of symbols]

 Reference Signs List 1 moving image compression / expansion device 2 control unit 3 input unit 4 display unit 5 communication I / F unit 6 image codec unit 6a blocking unit 6b motion vector detection unit 6c differentiator 6d DCT unit 6e quantization unit 6f variable length encoding unit 6g Inverse quantization unit 6h Inverse DCT unit 6i Adder 6j Image memory 6k Variable length decoding unit 6l Inverse quantization unit 6m Inverse DCT unit 6n Adder 6o Image memory 6p Output image buffer 6q B 'Picture encoding memory 6r B' ' Picture coding memory 6s Frame number counter 6t Picture type detector SW1 to SW3 Switch 7 Audio codec 8 RAM 9 Storage 10 Storage medium

Claims (9)

[Claims] An encoding process for moving image data using information compression based on a spatial correlation within a frame and information compression based on a temporal correlation between frames, to execute an intra-frame coded picture, In a moving picture coding apparatus for generating coded moving picture data having a picture structure composed of an inter-frame predictive coded picture and a bidirectional predictive coded picture, decoding is performed between frames constituting the picture structure. A moving picture coding apparatus comprising a frame inserting means for inserting a predetermined number of frames having coding information for eliminating processing. 2. A first storage for storing at least one of coding information indicating that there is no change compared to a previous frame, and coding information of a block range in which the decoding process is skipped. 2. The image processing apparatus according to claim 1, further comprising: a frame inserting unit that inserts a frame having the encoded information stored in the first storage unit between the frames constituting the picture structure. Video encoding device. 3. The apparatus according to claim 2, further comprising: a second storage unit for storing the same coded information as a frame coded immediately before, wherein the frame inserting unit stores the coded information stored in the second storage unit. 2. The moving picture coding apparatus according to claim 1, wherein a frame having the plurality of frames is inserted between frames constituting the picture structure. 4. A first storage for storing at least one of coding information indicating that there is no change compared to the previous frame, and coding information of a block range in which the decoding process is skipped. Means, second storage means for storing the same coded information as the previously coded frame, counting means for counting the number of output frames, coded information stored in the first storage means , The second
Switching means for switching which one of the encoded information stored in the storage means or the encoded information of each frame constituting the picture structure encoded by the encoding processing is output. The frame insertion unit controls the switching of the switching unit according to the number of frames counted by the counting unit, and encodes the encoding stored in the first storage unit between each frame constituting the picture structure. 2. The moving picture coding apparatus according to claim 1, wherein a predetermined number of frames having information or frames having coding information stored in said second storage means are inserted. 5. A moving picture coding method using information compression based on a spatial correlation within a frame and information compression based on a temporal correlation between frames.
A moving picture output apparatus for decoding and outputting coded moving picture data having a picture structure composed of an intra-coded picture, an inter-frame predictive coded picture, and a bidirectional predictive coded picture, Detecting means for detecting a picture type of moving image data; output image storing means for sequentially storing image data of decoded and output frames; and decoding processing in accordance with the picture type detected by the detecting means. A moving image output apparatus comprising: an image output control unit that outputs image data of a frame output immediately before among image data stored in the output image storage unit. 6. The picture type of the coded moving image data to be input is to omit decoding processing in addition to the intra-coded picture, the inter-frame predicted coded picture, and the bidirectional predicted coded picture. If the picture type detected by the detection unit is a frame having information for skipping the decoding process, the image output control unit skips the decoding process. 6. The moving image output device according to claim 5, wherein, out of the image data stored in the output image storage means, the image data of the frame output immediately before is output. 7. The information for omitting the decoding process includes coded information indicating that there is no change in comparison with the previous frame, coded information of a block range in which the decoding process is skipped, or the immediately preceding frame. 7. The moving image output apparatus according to claim 6, wherein the moving image output apparatus includes any one of the same coded information. 8. A storage medium storing a computer-executable program, comprising: moving image data using information compression based on a spatial correlation in a frame and information compression based on a temporal correlation between frames. Is executed by a computer for generating coded moving image data having a picture structure composed of an intra-coded picture, an inter-frame predicted coded picture, and a bidirectional predicted coded picture. Program code, and a computer-executable program code for inserting a predetermined number of frames having encoding information for omitting decoding processing between frames constituting the picture structure. A storage medium characterized by being stored. 9. A storage medium storing a computer-executable program, comprising: a moving image code using information compression based on a spatial correlation in a frame and information compression based on a temporal correlation between frames. For decoding and outputting coded video data having a picture structure composed of an intra-frame coded picture, an inter-frame predictive coded picture, and a bidirectional predictive coded picture coded according to a coding scheme Executable program code, a computer-executable program code for detecting a picture type of input encoded moving image data, and decoded image data of a frame output to an output image storage unit. Computer-executable program code for sequential storage and detected picture type And a computer-executable program code for outputting the image data of the immediately preceding frame among the image data stored in the output image storage unit, by omitting the decoding process according to the other. A storage medium characterized by being stored.