JPH0595545A - High efficiency coder-decoder for picture signal - Google Patents

Abstract

PURPOSE:To perform the efficient field processing or frame processing even in the case of a picture with little movement, a picture with much movement, or picture consisting of both of them on the field dynamic picture. CONSTITUTION:The coder-decoder is provided with frame/field motion detecting circuits 22 and 21 detecting the motion vector between intra-frame and inter feed and the absolute value differential sum, frame/field mode decision circuit 33 discriminating the first and second modes for the blocking of the motion prediction and the orthogonal conversion, a coding processing mode decision circuit 34 discriminating the coding processing mode for the adaptive changeover of the blocking mode and the coding processing mode taking the blocking mode as the field, an address generator 35 controlling a frame memory group 10 based on the output of the circuit 33, and a frame memory group 20 with motion compensator operating based on the output of the circuits 33 and 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-efficiency coding apparatus for an image signal and a decoding apparatus for high-efficiency coding the image signal by orthogonal transformation.

[0002]

2. Description of the Related Art As a method for highly efficiently encoding an image signal, for example, MPEG (Moving Picture Experts Grou)
The standardization proposal by p) defines a high-efficiency coding method for image signals for so-called digital storage media. Here, the storage media targeted by this method are so-called CDs (Compact Discs) and D
A continuous transfer rate of about 1.5 Mbit / sec or less, such as an AT (digital audio tape) and a hard disk. It is also assumed that this is not only directly connected to the decoder, but also connected via a transmission medium such as a computer bus, LAN (local area network), and telecommunications.
Furthermore, not only the normal order reproduction but also special functions such as random access, high speed reproduction, reverse order reproduction, etc. are considered.

The principle of the high-efficiency encoding system of the image signal by the above-mentioned MPEG is as follows.

That is, in this high-efficiency coding system, the redundancy in the time axis direction is first reduced by taking the difference between the images, and then so-called discrete cosine transform (DCT) processing and variable length coding are used. To reduce the redundancy in the spatial axis direction.

First, the redundancy along the time axis will be described below.

Generally, in a continuous moving image, temporally preceding and succeeding images are very similar to an image of interest (that is, an image at a certain time). For this reason, for example, as shown in FIG. 22, if the difference between the image to be encoded now and the image preceding in time is calculated and the difference is transmitted, the redundancy in the time axis direction can be obtained. It is possible to reduce the amount of information to be transmitted by reducing the amount. The image coded in this way is a forward predictive coded image (Predictive-coded picture, P picture or P picture, which will be described later).
Frame). Similarly, the difference between the image to be encoded from now on and the interpolated image formed from the front or the rear or the front and the rear in terms of time is calculated, and the difference of a smaller value among them is transmitted. For example, it becomes possible to reduce the amount of information to be transmitted by reducing the redundancy in the time axis direction. The image coded in this way is a bidirectional predictive coded image (Bidirectio
nallyPredictive-coded picture, B picture or B
Frame). In FIG. 22, the image indicated by I in the figure indicates an intra-coded image (Intra-coded picture: I picture or I frame) described later, and the image indicated by P in the figure is the above P A picture is shown, and an image shown by B in the figure shows the B picture.

Further, so-called motion compensation is performed in order to create each predicted image. That is, according to this motion compensation, for example, a block of 16 × 16 pixels (hereinafter, referred to as a macroblock) composed of a unit block of 8 × 8 pixels is created, and the block near the position of the macroblock of the previous image is the closest. It is possible to reduce the amount of data that needs to be sent by searching for a place with a small difference and taking the difference with the searched macroblock. Actually, for example, in the above P picture (forward predictive coded image), the data of the difference between the predicted image after motion compensation and the difference between the predicted image after motion compensation and the predicted image after motion compensation is not included. A small amount is selected and coded in units of the macro blocks of 16 × 16 pixels.

However, in the above-mentioned case, a lot of data has to be transmitted with respect to, for example, a portion (image) coming out of the back of the moving object. Therefore, for example, in the above-mentioned B picture (bidirectional predictive coded image), the already decoded temporally forward or backward image after motion compensation, and an interpolated image created by adding both of them are encoded from now on. The difference between the image and the image to be encoded and the one that does not take the difference, that is, the one with the smallest data amount among the four images to be encoded from now on are encoded.

Next, the redundancy in the spatial axis direction will be described below.

The difference of the image data is not transmitted as it is, but discrete cosine transform (DCT) is applied to each unit block of 8 × 8 pixels. The DCT represents an image not by the pixel level but by how many frequency components of the cosine function are included. For example, the data of a unit block of 8 × 8 pixels is two-dimensional by the two-dimensional DCT. The DCT transforms the coefficient block into the 8 × 8 cosine function component. For example, an image signal of a natural image as taken by a television camera is often a smooth signal. In this case, the DCT is applied to the image signal.
The amount of data can be efficiently reduced by performing the processing.

That is, for example, in the case of a smooth signal such as the image signal of the above-mentioned natural image, by applying the DCT, large values are concentrated around a certain coefficient. When this coefficient is quantized, most of the 8 × 8 coefficient block becomes 0, and only large coefficients remain. Therefore, when transmitting the data of the 8 × 8 coefficient block, a non-zero coefficient and a so-called 0 run indicating how many 0s precede the coefficient are set in a so-called zigzag scan order. By transmitting the so-called Huffman code, the transmission amount can be reduced. On the decoder side, the image is reconstructed in the reverse procedure.

FIG. 23 shows the structure of data handled by the above-mentioned coding system. That is, the data structure shown in FIG. 23 includes, in order from the bottom, a block layer, a macroblock layer, a slice layer, a picture layer, a group of picture (GOP) layer, and a video sequence layer. .. In the following, description will be made in order from the lower layer in FIG.

First, in the block layer, the block of the block layer is composed of 8 × 8 pixels (pixels of 8 lines × 8 pixels) adjacent to each other in luminance or color difference. The DCT (discrete cosine transform) described above is applied to each unit block.

In the macroblock layer, the macroblocks in the macroblock layer are four luminance blocks (luminance unit blocks) Y0, which are adjacent to each other in the left-right direction and in the vertical direction.
Y1, Y2, Y3 and a color difference block (color difference unit block) C corresponding to the same position as the luminance block on the image
It is composed of a total of 6 blocks, r and Cb. The order of transmission of these blocks is Y0, Y1, Y2, Y3, C
The order is r and Cb. Here, in the encoding method, what is used for a prediction image (reference image for obtaining a difference),
Alternatively, whether or not the difference need not be sent is determined for each macro block.

The slice layer is composed of one or a plurality of macroblocks which are continuous in the scanning order of the image. At the beginning (header) of this slice, the difference between the motion vector and the DC (direct current) component in the image is reset, and the first macroblock has data indicating the position in the image, and thus the error is It is designed to be able to return even if it happens. Therefore, the length and starting position of the slice are arbitrary and can be changed depending on the error state of the transmission path.

In the picture layer, each picture, that is, each picture is composed of at least one or a plurality of slices. Then, each of the intra-coded images (I
Picture or I frame), the forward predictive coded image (P picture or P frame), the bidirectional predictive coded image (B picture or B frame), and the DC intra coded image (DC coded (D) picture). Classified into images.

Here, in the above-mentioned intra-coded image (I picture), only the closed information in one image is used at the time of encoding. Therefore, in other words, the image can be reconstructed only by the information of the I picture itself when decoding. Actually, the DCT processing is performed as it is and the encoding is performed without taking the difference. This coding method is generally inefficient, but if this coding method is put everywhere, random access and high-speed reproduction are possible.

In the forward predictive coded image (P picture), an I picture or P picture which is located earlier in time at the input and has already been decoded is used as a predictive picture (picture serving as a reference for taking a difference). To do. In practice, either the encoding of the difference from the motion-compensated predicted image or the encoding without taking the difference (intra code) is selected, whichever is more efficient, in units of the above macroblocks.

The bidirectional predictive coded image (B picture)
In the above, three types of I-pictures or P-pictures, which have been previously decoded in time, and interpolated pictures made from both of them, are used as prediction pictures. This allows
It is possible to select the most efficient one of the three types of differential encoding after motion compensation and the intra code in macroblock units.

The DC intra-coded image is an intra-coded image composed only of DC coefficients of DCT,
It cannot exist in the same sequence as the other three types of images.

The group of pictures (GOP) layer includes one or a plurality of I pictures and 0 or a plurality of non-I pictures.
And a picture. Here, the input order to the encoder is, for example, 1I, 2B, 3B, 4P * 5B, 6
B, 7I, 8B, 9B, 10I, 11B, 12B, 13
P, 14B, 15B, 16P * 17B, 18B, 19
When I, 20B, 21B and 22P are used, the output of the encoder, that is, the input of the decoder is, for example, 1I, 4
P, 2B, 3B * 7I, 5B, 6B, 10I, 8B, 9
B, 13P, 11B, 12B, 16P, 14B, 15B
* 19I, 17B, 18B, 22P, 20B, 21B. In this way, the order is changed in the encoder, for example, when the B picture is encoded or decoded, the I picture or P that is the temporally posterior part of the predicted image becomes the predicted image. This is because the picture must be encoded first. Here, the interval of the I picture (for example, 9) and the interval of the I picture or the B picture (for example, 3) are free. Also, I picture or P
The picture interval may change within the group of pictures layer. Note that the break in the group of picture layers is represented by * above. Further, the I is an I picture, the P is a P picture, and the B is a B picture.

The video sequence layer includes an image size,
It is composed of one or a plurality of group of picture layers having the same image rate and the like.

[0023]

As described above, in the case of transmitting a moving image standardized by the high-efficiency encoding method based on MPEG, first, an image obtained by compressing one image within a picture is sent. Then, the difference between this image and the motion-compensated image is transmitted.

However, in the above-mentioned one image, for example, when processing a field as a picture, 2
Since the vertical position will be different alternately in the field,
For example, when transmitting a still image, the difference information must be transmitted.

Further, for example, when processing a frame as a picture, it is necessary to process a so-called comb-shaped blurred image for a moving portion in the frame. That is, for example, as shown in FIG. 24, when there is a moving body CA such as a car in front of a stationary background, when one frame is viewed, there is movement between fields, and such a portion is a comb-shaped image. turn into.

Furthermore, for example, when processing an image in which a still portion and a moving image portion are mixed, no matter which method is used for processing the field as a picture or a frame as a picture, the picture is used. An image of a portion with poor compression efficiency will be created inside.

Therefore, the present invention has been proposed in view of the above-mentioned circumstances, and in a moving image having a field structure, an image with little motion, an image with many motion, and an image in which both are mixed are used. It is an object of the present invention to provide a high-efficiency coding apparatus for image signals and a decoding apparatus therefor capable of efficiently performing field processing or frame processing even if there is any.

[0028]

In order to solve such a problem, a high-efficiency coding apparatus according to the present invention uses a macroblock consisting of a two-dimensional array of a plurality of pixels as a unit for coding an image signal. In the high-efficiency coding apparatus, from the means for detecting the motion vector between frames and the sum of the absolute difference of each pixel in the macro block unit, and the one divided by the odd number or the even number of the pixel scan of the frame in the macro block unit. Motion detection means including a motion vector between fields and a means for detecting the sum of absolute differences between pixels, a frame prediction mode for performing motion compensation in units of frames in the macroblock, and units in fields in the macroblock. Which of the field prediction modes for motion compensation is more efficient for motion compensation? First mode selecting means for selecting and selecting an efficient prediction mode, a frame processing mode for performing orthogonal transformation in units of frames in the macroblock, and orthogonal transformation in units of fields in the macroblocks Which of the field processing modes is divided into blocks so as to be efficient in performing the orthogonal transform is determined by using the information output from the motion detecting means and the first mode selecting means, and the efficiency is high. Second mode selecting means for selecting a blocking mode and adaptively switching the blocking to the frame processing mode or the field processing mode for each macroblock in one frame, and each macroblock based on each mode The first encoding processing mode that encodes all macros in one frame A period in which only the odd field in the macroblock is coded by one frame in the odd cycle of the period in which the odd field is scanned in the interlace, and the scan is performed in the even field in the interlace. Of the second encoding processing modes for encoding one frame of the even field in the macroblock in the even cycle of 1) is effective in encoding, and the efficient encoding processing mode is selected. The third mode selecting means and the odd cycle or the even cycle are recognized, and when the encoding processing mode is the first encoding processing mode, the odd-numbered cycle corresponds to the blocking mode to form a block. Frame memory group to output selected macroblocks When the encoding processing mode is the second encoding processing mode, the frame memory group is configured to output a macroblock that is blocked in the odd-numbered cycle and the even-numbered cycle corresponding to the field processing mode. For receiving the motion prediction mode information selected by the first mode selection means and the blocking mode information selected by the second mode selection means, and moving in accordance with the mode information. And a motion compensating means for executing a compensation frame or inter-field prediction.

In other words, the high-efficiency coding apparatus of the present invention, in coding a moving image in which one frame is composed of two fields, has odd-numbered fields (first field) and even-numbered fields (first field) for all blocks in the frame. The second field) is divided into blocks, and a coding means (second coding processing mode) that enables motion prediction from the first field to the second field, the first field,
Coding means (first coding processing mode) for switching between division / non-division of the second field in units of macroblocks (first encoding processing mode) and adaptively switching these encoding means for each frame It is the one.
Further, in this case, 1-bit information indicating the encoding means (information indicating the selected mode) is added to the code.

Further, the high-efficiency decoding apparatus of the present invention receives the reproduced image coded data and the header information including the detected motion vector information, the motion prediction mode information, the blocking mode information, and the coding processing mode information. And variable decoding means for outputting the detected motion vector information, the motion prediction mode information, the blocking mode information, and the coding processing mode information together with the decoded image decoded data, and the code. An address increment means for calculating an address increment value in the frame buffer for accumulating the image decoded data from the encoding processing mode information, obtaining a start address of each macroblock, and giving the start address to the frame buffer; Add the relative address of the macro block other than the start address to the frame buffer To receive the detected motion vector information, the motion prediction mode information, the blocking mode information, and the encoding processing mode information, perform motion compensation corresponding to the mode information, and perform a motion-compensated image signal. Is sent to the frame buffer.

[0031]

According to the present invention, the first coding processing mode and the second coding processing mode can be switched in units of macroblocks. In the first encoding processing mode, efficient encoding can be performed by adaptively selecting the frame processing mode and the field processing mode according to the magnitude of the motion of the image. In the second encoding processing mode, by setting the block processing of all macroblocks in a frame to the field processing mode, for example, it becomes possible to predict motion from an odd field to an even field for a frame having particularly large motion, and to improve efficiency. You will be able to encode movies well.

[0032]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a high-efficiency coding apparatus for image signals according to a first embodiment of the present invention, which is a macroblock (for example, in raster scan order) consisting of a two-dimensional array of a plurality of pixels smaller than one screen. This is a high-efficiency encoding apparatus for image signals that performs encoding in units of 16 × 16 pixels in the spatial arrangement of input image data as one block.

The high-efficiency coding apparatus for image signals of the first embodiment shown in FIG. 1 has a frame (one screen) made up of a plurality of unit blocks (macroblocks) of 16 × 16 pixels. A frame memory group 10 that is stored as a plurality of original images, a frame motion detection circuit 22 that is a unit that detects a motion vector between frames and a sum of absolute values of respective pixels in the macroblock unit, and the macroblock unit in the macroblock unit. It has a motion detecting means including a field motion detection circuit 21 for detecting a motion vector between fields, which is formed by dividing an image of a pixel of a frame by odd number or even number, and a sum of absolute difference of each pixel.

Further, the apparatus of the present embodiment uses a frame prediction mode (hereinafter referred to as a frame motion prediction mode) for performing motion compensation in units of frames in the macroblock and a field prediction for performing motion compensation in units of fields in the macroblock. The first mode selection means for determining which of the modes (hereinafter referred to as the field motion prediction mode) is efficient in motion compensation and selecting the efficient motion prediction mode, and the frame in the macroblock A frame processing mode (hereinafter referred to as a frame orthogonal transform mode) in which a block is formed so as to perform orthogonal transform (for example, discrete cosine transform; DCT) as a unit.
The motion detecting means and the field processing mode (hereinafter referred to as a field orthogonal transform mode) in which a block is formed so as to perform orthogonal transform in units of fields in the macroblock are efficient in performing the orthogonal transform. It has a frame / field mode determination circuit 33 including a second mode selection means for making a determination using the information output from the first mode selection means and selecting an efficient blocking mode.

Further, the apparatus of this embodiment, together with the motion detecting means and the frame / field mode determination circuit 33, makes the block of the orthogonal transform for each macroblock in one frame the frame orthogonal transform mode or the field orthogonal transform. A first coding processing mode in which adaptive switching to a transform mode is performed to code each macroblock based on each mode, and blocking of the orthogonal transform of all macroblocks in one frame is performed in the field orthogonal transform mode. Even-numbered cycle (even cycle) of the period in which only one odd-numbered field in the macroblock is coded for one frame in the odd-numbered cycle (odd cycle) of scanning the odd-numbered field in the interlaced
A third mode for determining which of the second coding processing modes for coding the even field in the macroblock for one frame is more efficient in coding and selecting the efficient coding processing mode It has an encoding processing mode determination circuit 34 which is a selection means.

Furthermore, the apparatus of the present embodiment recognizes whether the odd-numbered cycle or the even-numbered cycle, and when the coding processing mode is the first coding processing mode, the block of the orthogonal transformation is performed in the odd-numbered cycle. The frame memory group 10 is controlled so as to output a macroblock that has been divided into blocks according to the encoding mode. If the encoding processing mode is the second encoding processing mode, the odd cycle and the even cycle. , An address generator 35 for controlling the frame memory group 10 so as to output a macroblock which is divided into blocks corresponding to the field orthogonal transform mode, and motion prediction mode information selected by the first mode selecting means. (Frame / field motion prediction mode data) and the blocking mode information selected by the second mode selection means ( Frame / field orthogonal transform mode data) it receives, in which a motion compensator with a frame memory group 20 is a motion compensation means in response to these mode information to perform the motion compensation frame or inter-field prediction.

First, prior to the description of the specific configuration of the first embodiment apparatus of the present invention shown in FIG. 1, the high-efficiency encoding processing of the image signal performed by the present embodiment apparatus will be described.

In the encoding apparatus of this embodiment, as shown in FIG. 2, for example, intra-frame encoding (I frame or I
Picture), unidirectional prediction inter-frame coding (P frame or P picture), and bidirectional inter-picture coding (B frame or B picture). Each picture is divided into blocks of 8 × 8 pixels and 2 × 2 blocks (that is, 16 × 16 pixels).
Configure a macroblock with.

Here, in the coding apparatus of this embodiment, the first mode selecting means described above selects which of the frame motion prediction mode and the field motion prediction mode is more efficient in motion compensation. The second mode selecting means can select which of the frame orthogonal transform mode and the field orthogonal transform mode is more efficient in performing orthogonal transform. In addition,
The first / second mode selection is performed by the frame / field mode determination circuit 33 described above.

Further, the apparatus of the present embodiment performs the mode selection processing by the first and second mode selection means, and performs the coding in each of the two coding processing modes, whichever is more efficient, for each frame. Has been done. That is, as described above, as the first encoding processing mode, each macroblock is encoded by adaptively switching between the frame orthogonal transform mode and the field orthogonal transform mode for each macroblock in one frame. . Further, as described above, as the second encoding processing mode, the block of the orthogonal transformation of all macroblocks in one frame is performed in the field orthogonal transformation mode, and the odd field (first
Only the odd field in the macroblock is coded for one frame in the odd cycle of the field scan period, and the even field in the macroblock is coded for one frame in the even cycle of the even field (second field) scan period. Turn into. The third mode selection means determines which of the first and second encoding processing modes is more efficient in encoding, and selects the efficient encoding processing mode.

That is, in the first encoding processing mode, each frame is not divided into the first field (odd field) and the second field (even field) but is divided into blocks and encoded (the frame orthogonal transform). Mode) and a mode in which each frame is divided into first and second fields and is divided into fields and coded (field orthogonal transform mode), for example, in the case of a macroblock having a small image motion, the frame orthogonal transform is performed. A mode is used, and conversely, for example, in a macroblock having a large image motion, processing for adaptively switching to use the field orthogonal transform mode is performed.

Therefore, when the frame orthogonal transform mode is selected in the first encoding processing mode,
For example, in the motion prediction of the P and B frames, motion prediction is performed from the preceding and subsequent frames, and the difference image from this predicted image is orthogonally transformed (DCT). When the field orthogonal transformation mode is selected in the first encoding processing mode, for example, the motion prediction of the P and B frames is performed before and after the first field and the second field of the macroblock, respectively. Motion prediction is performed from the first or second field of the frame, and the difference image from this prediction image is the DCT
To be converted. From this, it can be said that the first coding processing mode is coding without intra-frame inter-field prediction. Further, in this first encoding processing mode, the encoding processing is performed in the odd cycle. In addition,
This first coding processing mode can be said to be coding without intra-frame inter-field prediction.

Here, in the first encoding processing mode, it is impossible to predict motion between fields in a frame (odd field and even field in the same frame).

Therefore, in the second encoding processing mode of the present embodiment, as described above, the block formation of the orthogonal transformation of all macroblocks in each frame is performed in the field orthogonal transformation mode. In the odd cycle, only the odd field in the macroblock is coded for one frame, and in the even cycle, the even field in the macroblock is coded for one frame. Therefore, according to the second coding processing mode, since the odd field (first field) is coded first, the even field (second field) is predicted from the odd field (first field). Is possible. From the above, it can be said that the second coding processing mode is coding of a frame with intra-frame inter-field prediction.

Returning to FIG. 1 again, the main flow of image data encoded by the encoding apparatus of the present embodiment will be described using the configuration of FIG.

That is, in FIG. 1, the input terminal 1
Is supplied with a digital image signal and is stored in the frame memory group 10. Data of the unit macroblock of 16 × 16 pixels is read from the frame memory group 10 under the control of an address generator 35, which will be described later, and transmitted to the difference detector 12. The difference detector 12 includes a frame memory group 20 with a motion compensator described later.
The motion-compensated image data from is also supplied, and the difference detector 12 detects these differences.

The output of the difference detector 12 is sent to the DCT circuit 13 which performs orthogonal transform (DCT) processing. The DCT coefficient data obtained by the DCT processing in the DCT circuit 13 is sent to the quantizer 14. The quantizer 14
The quantized data from is output as encoded data from the output terminal 2 via the variable length coding circuit 15 and the buffer 16 that perform variable length coding processing such as so-called Huffman coding and run length coding. .

In the frame memory group 20 with motion compensator, the quantized data from the quantizer 14 is inversely quantized by the inverse quantizer of the quantizing process in the quantizer 14. Data is supplied via 17 and an inverse DCT circuit 18 that performs inverse DCT processing of the DCT processing in the DCT circuit 13, and further via an adder 19.
The adder 19 adds the output of the inverse DCT circuit 18 and the output of the frame memory group 20 with the motion compensator. From the buffer 16, the buffer 1
The information for preventing the overflow of 6 is fed back to the quantizer 14.

On the other hand, the image data output from the frame memory group 10 in units of the macro blocks is transmitted to the frame motion detection circuit 22 and the field motion detection circuit 21.

The frame motion detection circuit 22 detects the motion vector between frames and the sum of the absolute values of the respective pixels in the macroblock unit, and outputs these data (the motion vector data FMMV between the frames and the sum of the absolute values). Output data FMAD). Further, the field motion detection circuit 21 detects the motion vector between fields and the absolute value difference sum of each pixel in units of the above macroblocks, and outputs these data (data FDMV of the motion vector between fields and the absolute value difference sum). Data FDAD) is output. Data FMMV of each motion vector of these motion detection circuits 21 and 22
/ FDMV is transmitted to the selector 24.

Further, the data FMAD / FDAD of the sum of absolute difference from the field motion detection circuit 21 and the frame motion detection circuit 22 and the data FMMV / of each motion vector.
FDMV is the frame / field mode determination circuit 3 described above.
Also sent to 3.

The frame / field mode determination circuit 33 performs a motion described later on the basis of the absolute value difference sum data FMAD from the frame motion detection circuit 22 and the absolute value difference sum data FDAD from the field motion detection circuit 21. During the motion prediction process in the frame memory group with compensator 20, it is determined whether the motion prediction process is performed in the frame unit or in the field unit, whichever is more advantageous (the more efficient one). ) The data indicating the motion prediction mode is output. Specifically, in the frame / field mode determination circuit 33, for example, the difference between the absolute value difference sum data FMAD and the absolute value difference sum data FDAD is larger than a threshold value T1 (FMAD-FDAD> T1). Time),
The circuit 33 outputs the data (the data MPFD of the field motion prediction mode in the motion prediction) indicating that it is more efficient to perform the motion prediction process in the field unit. On the contrary, when it is determined that the difference between the absolute value difference sum data FMAD and the absolute value difference sum data FDAD is smaller than or equal to the threshold value T1 (when FMAD-FDAD≤T1), the frame unit is used. Outputs data (frame motion prediction mode data MPFM in motion prediction) indicating that it is more efficient to perform the motion prediction process.

Any one of these motion prediction mode data MP
FM / MPFD is a frame memory group 20 with the above motion compensator.
Sent to. Also, these motion prediction mode data MPFM
/ MPFD is also sent to the selector 24.

The selector 24 is responsive to the motion prediction mode data MPFM / MPFD from the frame / field mode determination circuit 33 to select the frame motion detection circuit 2 described above.
2 between-frame motion vector data FMMV and between-field motion vector data FDMV supplied from the field motion detection circuit 21.
Select one of the output. That is, the motion prediction mode data is data M indicating the field motion prediction mode.
In the case of PFD, the motion vector data FDMV from the field motion detection circuit 21 is selected and output, and the motion prediction mode data is data M indicating the frame motion prediction mode.
In the case of PFM, the motion vector data FMMV from the frame motion detection circuit 22 is selected and output. Motion vector data FMMV / FDMV selected by the selector 24
Are sent to the frame memory group 20 with the motion compensator. This allows the frame memory group 20 to perform motion compensation in frame units or field units based on the motion prediction mode data MPFM / MPFD and the motion vector data FMMV / FDMV.

Furthermore, the frame / field mode determination circuit 33 is also supplied with the image data of the macro block unit read from the frame memory group 10. Frame / field mode determination circuit 33
Then, a difference image is created using the motion prediction mode data MPFM / MPFD, the motion vector data FMMV / FDMV, and the image data from the frame memory group 10, and the frame memory group 1 is generated based on the difference image.
The processing for selecting the mode of the orthogonal transform blocking process (the frame orthogonal transform mode / field orthogonal transform mode) most suitable for the image output from 0 and DCT processed by the DCT circuit 13 is also performed at the same time. ing. In the case of the I picture (or I frame), data of the image (original image) of the frame memory group 10 is used instead of the difference image.

That is, it is assumed here that, for example, the macroblock of the difference image is the macroblock as shown in FIG. 3 (in the I picture, the macroblock of the original picture). In FIG. 3, odd lines (o1, o
2, o3, ... oN, where N is a macroblock 16) is shown by a solid line, and even lines (e1, e2, e3)
, ・ ・ ・ EN, where N is 1 for macroblock
6) is shown by a dotted line. Also, each pixel in the even line is expressed as e (i, j), and each pixel in the odd line o (i, j)
j). In the difference image or the original image (image of I picture) as shown in FIG. 3, the difference EFD of the difference image in the field unit can be expressed by the mathematical formula 1, and the difference EFM of the difference image in the frame unit is It can be shown by the mathematical formula of 2.

[0058]

[Equation 1]

[0059]

[Equation 2]

In the frame / field mode determination circuit 33, specifically, there is a threshold value having a difference between the difference EFM obtained in the frame and the difference EFD obtained in the field by using the mathematical expressions 1 and 2. Greater than T2 (EFM
-EFD> T2), the data indicating that the DCT in the DCT circuit 13 is performed in the unit of field (field MDFT in the orthogonal transformation block processing) is output. On the contrary, when it is determined that the difference between the difference EFM and the difference EFD is smaller than or equal to the threshold value T2 (when EFM-EFD≤T2), the DCT in the DCT circuit 13 is set to the above value. Data indicating to be performed in frame units (frame orthogonal transform mode data M in orthogonal transform block processing)
DFM) is output.

Here, the frame orthogonal transformation mode data MD from the frame / field mode determination circuit 33.
The output of the FM or field orthogonal transformation mode data MDFD corresponds to the coding mode data EN1 / EN2 corresponding to the first coding processing mode or the second coding processing mode from the coding processing mode determination circuit 34. To be made.

The encoding processing mode determination circuit 34 uses the image data of the macro block unit read from the frame memory group 10 as described above, and the first encoding processing mode and the second encoding processing mode. Which of the encoding processing modes is more efficient in encoding is determined, and the encoding mode data EN1 or EN2 corresponding to the determination result is determined.
Is output. Specifically, in the encoding processing mode determination circuit 34, for example, the absolute value difference sum of each pixel between the odd field (first field) and the even field (second field) of each frame is calculated. If the value of the sum of absolute difference is less than a certain threshold value T0 (that is, when the motion of the image is small), a code indicating that the encoding in the first encoding processing mode is more efficient If the value of the absolute value difference sum is greater than or equal to the threshold value T0 (when the motion of the image is large), the encoding mode data EN1 is output. Encoding mode data EN2 indicating that is efficient
Is output.

The encoding processing mode determination circuit 34 described above is used.
When making a decision in
It is also possible to make a determination using the motion vector data FDMV from 1. That is, if the motion vector data FDMV between the odd field and the even field is less than a certain threshold value t0, the first encoding processing mode is selected,
On the contrary, if the threshold value is equal to or more than the threshold value t0, the second encoding processing mode can be selected.

By transmitting the coding mode data EN1 / EN2 from the coding processing mode judging circuit 34 to the frame / field mode judging circuit 33,
From the frame / field mode determination circuit 33,
The frame orthogonal transform mode data MDFM or the field orthogonal transform mode data MDFD according to the coding mode data EN1 / EN2 is output.

That is, when the coding mode data from the coding processing mode determination circuit 34 is the data EN1 indicating the first coding processing mode, the frame / field mode determination circuit 33 determines whether the data is within one frame. The processing for adaptively switching the frame orthogonal transform mode or the field orthogonal transform mode is performed for each macro block. Therefore, the frame / field mode determination circuit 33 outputs the adaptively switched frame orthogonal transform mode MDFM or field orthogonal transform mode data MDFD.

On the other hand, when the coding mode data from the coding processing mode determination circuit 34 is the data EN2 indicating the second coding processing mode, the frame / field mode determination circuit 33 described above. As described above, all the macroblocks in one frame are converted into the blocks of the orthogonal transform in the field orthogonal transform mode. Therefore, the field / orthogonal mode data MDFD is output from the frame / field mode determination circuit 33.

Mode data MDFM / MDFD for block formation of orthogonal transformation of either frame / field output from the frame / field mode determination circuit 33,
The encoding mode data EN1 / EN2 from the encoding processing mode determination circuit 34 is the address generator 35.
And to the frame memory group with motion compensator 20.
The orthogonal transform mode data (MDFM / MDFD), the motion prediction mode data (MPFM / MPFD), the coding mode data EN1 / EN2, and the motion vector data (FMMV / FDMV) are the variable length codes described above. It is also sent to the conversion circuit 15.

The address generator 35 outputs the orthogonal transform mode data MDFM / MDFD in macroblock units.
Also, the frame memory group 10 is controlled so as to output the image data of the macroblock that is blocked according to the encoding mode data EN1 / EN2. That is, as described above, when the encoding mode data EN1 / EN2 is the data EN1 indicating the first encoding processing mode, the address generator 35 blocks the orthogonal transformation in the odd cycle as described above. Mode (data MD
FM / MDFD) controls the frame memory group 10 so as to output a macroblock divided into blocks, and in the case of the data EN2 indicating the second encoding processing mode, in the odd cycle and even cycle. The frame memory group 10 is controlled so as to output a macroblock that has been divided into blocks corresponding to the field orthogonal transformation mode (data MDFD).

In other words, for example, when the first encoding processing mode is selected and the encoding mode data EN1 is supplied to the address generator 35, for example, the orthogonal transformation mode data is in frame units. DC
If the data MDFM indicating the T processing is obtained, the address generator 35 is arranged so that as shown in FIG. The frame memory group 10 is controlled so that the block) is output. That is, the address generator 34 in this case
As shown in FIG. 4, the macro blocks consisting of 1 line to 16 lines are divided into 1 line to 8 lines and 9 lines to
The frame memory group 10 is controlled so that four 8 × 8 blocks (macroblocks) are output every 16 lines.

When the first encoding processing mode is selected and the encoding mode data EN1 is supplied to the address generator 35, for example, the orthogonal transformation mode data indicates DCT processing in field units. If the data is MDFD, the address generator 35 scans the even and odd scans separately as shown in FIG. The frame memory group 10 is controlled so as to output That is, the address generator 34 is the same as that shown in FIG.
1, 1 line, 3 lines, 5 lines, 7 lines, 9 lines, 11 lines, 13 lines, 15 lines (each line of the odd field or the first field),
It is divided into 2 lines, 4 lines, 6 lines, 8 lines, 10 lines, 12 lines, 14 lines, 16 lines (even lines or each line of the second field), and these odd fields and even fields are respectively divided. The frame memory group 10 is controlled so as to output two 8 × 8 blocks (macroblocks).

4 and 5, the odd lines are shown by solid lines and the even lines are shown by dotted lines.

In addition, for example, when the second encoding processing mode is selected and the encoding mode data EN2 is supplied to the address generator 35, the address generator 35 outputs the odd number as described above. The frame memory group 10 is controlled so as to output macroblocks that are blocked corresponding to the field orthogonal transform mode in cycles and even cycles. That is, the address generator 3 when the second encoding processing mode is selected
5 controls the frame memory group 10 so that two blocks of 8 × 8 are always output (however, only the luminance component is output as described later). Specifically, in the odd number cycle, the address generator 35 has one macro block for two 8 × 8 blocks only in the odd number field.
The frame memory group 10 is controlled so as to output one frame (one screen), and then, in the even cycle, only the even field has two macro blocks of 8 × 8 blocks for one frame (one screen). ) The frame memory group 10 is controlled to be output.

As described above, the image data output from the frame memory group 10 controlled by the address generator 35 is DCT processed by the DCT circuit 13 as described above. That is, for example, when the first coding processing mode is selected and the frame orthogonal transform mode is selected, the DCT circuit 13 performs DCT conversion in the unit block of 8 × 8 pixels as shown in FIG. I do. Also,
For example, when the first encoding processing mode is selected and the field orthogonal transform mode is selected, the DCT circuit 13 performs DCT conversion in the unit block of 8 × 8 pixels as shown in FIG. When the second encoding processing mode is selected, as described above, only the odd field in the odd-numbered cycle has the D in the 8 × 8 block.
CT conversion is performed, and in even cycles, DCT conversion is performed only in the even field in the above 8 × 8 block.

In addition, the motion prediction mode data MPFM / MP from the frame / field mode determination circuit 33.
FD and orthogonal transformation mode data MDFM / MDFD and motion vector data FMMV / F selected by the selector 24.
The DMV and the encoding mode data EN1 / EN2 from the encoding processing mode determination circuit 34 are also supplied to the frame memory group 20 with motion compensator. Therefore, the frame memory group 2 with the motion compensator
At 0, the motion prediction mode data M in the above motion prediction.
Orthogonal transformation mode data MDFM / MDFD and coding mode data EN1 / E in PFM / MPFD and DCT processing
N2 and the motion vector data FMMV /
Motion compensation using FDMV is performed.

From the above, the motion prediction of, for example, the P and B frames in the first coding processing mode and the frame orthogonal transform mode is performed as shown in FIG. The motion is predicted from the frame. Therefore, in the DCT circuit 13, the difference image from the predicted image is DCT-transformed (DCT-transformed in a unit block of 8 × 8 pixels). In FIG. 6, the previous frame,
The current frame and the subsequent frame are shown, and arrows in the figure show motion vectors and MB shows macroblocks. In addition, in the motion prediction of the P and B frames in the first encoding processing mode and the field orthogonal transform mode, FIG.
As shown in, the motion prediction is performed from the odd or even field (first or second field) of the previous and subsequent frames for each of the odd field and the even field of the macroblock. Therefore, in the DCT circuit 13, the difference image from the predicted image is DCT-transformed (DCT-transformed in a unit block of 8 × 8 pixels). Note that FIG. 7 shows the odd field and even field of the previous frame, the current frame, and the subsequent frame, respectively.
In the figure, arrows indicate motion vectors, and MBs indicate macroblocks.

Further, the motion prediction in the field orthogonal transform mode in the case of the second encoding processing mode is
For example, as shown in FIG. 8, for each of the odd field and the even field of the macroblock, motion prediction is performed from the odd or even field of the previous and subsequent frames, and the motion prediction between each field in each frame is also performed. . Therefore, in the DCT circuit 13, the difference image from the predicted image is DCT-transformed (DCT-transformed in a unit block of 8 × 8 pixels). It should be noted that FIG. 8 shows odd fields and even fields of the previous frame, the current frame, and the subsequent frame, respectively, and arrows in the drawing indicate motion vectors and MBs indicate macroblocks.

From the above, in the high-efficiency encoding apparatus for image signals of the first embodiment, according to the first and second encoding processing modes (that is, the magnitude of image movement), Since the coding without inter-field prediction in the frame and the coding with inter-field prediction in the frame are switched, the most efficient coding is possible. In particular, the second encoding processing mode is effective in a frame having a large motion.

By the way, specifically, the encoding apparatus of the first embodiment performs the following motion prediction and DCT conversion processing for each so-called digital VTR format, for example.

Here, in FIGS. 10, 11, and 12, the fields constituting the frame of the I frame (I picture) are the Io field (the odd field of the I frame) and the Ie field (the even field of the I frame). And the fields constituting the P frame (P picture) are Po field (odd field) and P field.
The e field (even field) is used, and the fields constituting the B frame (B picture) are Bo field (odd field) and Be field (even field).

Further, in the present embodiment, in the frame orthogonal transform mode of the block formation of the orthogonal transform, the macro block is constructed by combining the odd field and the even field as shown in FIG. 4 (that is, for each frame). This is a mode in which a macroblock is configured) and this macroblock is used as a processing unit. In addition, the field orthogonal transform mode of blocking of orthogonal transform is divided into an odd field and an even field as shown in FIG. In this mode, a macroblock is configured (that is, a macroblock is configured for each field) and the macroblock is used as a processing unit. Therefore, for example, in the I frame, the frame orthogonal transform mode and the field orthogonal transform mode are switched for each macroblock.

Furthermore, in the present embodiment, for one frame, the above-mentioned odd cycle (odd cycle) in the period in which the encoding process scans the odd field in the interlace and the above-mentioned even cycle in the period in which the scan of the even field is performed. It is divided into a cycle (even cycle).

Therefore, in the case of this embodiment, for example, a so-called 4: 2: 0 component digital VT is used.
When the R format is handled, for example, as shown in FIG. 9, when the orthogonal transform is made into a block orthogonal transform mode, for example, luminance blocks Y0, Y1, Y2, Y3 composed of odd fields and even fields are used. DCT processing is performed on each unit block of a macroblock including color difference blocks Cb0 and Cr1 of odd fields. On the other hand, when the block of the orthogonal transform is the field orthogonal transform mode, the luminance blocks Y02o and Y13o of each odd field and the luminance block Y02 of each even field are included.
e, Y13e and the color difference block Cb of the odd field
D of each unit block of a macroblock consisting of 0 and Cr1
CT processing is performed.

Further, in the first coding processing mode of this embodiment, when the frame motion prediction mode is used, FIG.
As shown in, for example, motion prediction MCP between I frame and P frame becomes possible. On the other hand, in the field motion prediction mode, the motion prediction MCo Po between the Io field and the Po field, the motion prediction MCoPe between the Io field and the Pe field, and the Ie field and the Po field.
A motion prediction MCe Po between the field and a motion prediction MCe Pe between the Ie field and the Pe field becomes possible. That is, in the case of FIG. 10, the motion prediction and orthogonal transform modes can exist independently in the frame motion prediction mode and frame orthogonal transform mode, and in the field motion prediction mode and field orthogonal transform mode. One vector is calculated, and two motion vectors are calculated in the field motion prediction mode.

Therefore, in the first encoding processing mode of the first embodiment, for example, when the blocking of the orthogonal transform of the I frame is the frame orthogonal transform mode, the odd cycle (odd cycle) is performed. , The Io field and the Ie field are combined to form the macroblock. For example, in the odd cycle, DCT conversion is performed for each macroblock (where DCT is 8 × 8).
Of each unit block), quantization, and variable length coding are performed. On the other hand, no data is sent in the even cycle of the frame orthogonal transform mode.

Further, in the first coding processing mode of the present embodiment, when the blocking of the orthogonal transformation is the field orthogonal transformation mode, the Io field and the Ie field are separately divided in the odd cycle. The macroblock is configured, and DC is provided for each macroblock.
T conversion (however, DCT is performed for each 8 × 8 unit block), quantization, and variable length coding are performed. On the other hand, in the even cycle of the field orthogonal transform mode, no data is sent as can be seen from FIG.

From the above, as shown in FIG. 11, further, in the case of the P frame in the first encoding processing mode, the following processing is performed. For example, when the P-frame orthogonal transform is divided into blocks in the frame orthogonal transform mode and the motion prediction is in the frame motion prediction mode, the reference image is used as the forward image (I-frame image) in the inter-frame in the odd cycle. Of the motion vector MVP is detected, and the difference from the original image is encoded by using the macroblock in which the Io field and the Ie field are alternately combined as a prediction image. On the other hand, no data is sent in the even cycle in these modes.

In the first encoding processing mode, when the P-frame orthogonal transform is blocked in the frame orthogonal transform mode and the motion prediction is in the field motion prediction mode, the Io field and Ie are used in the odd cycle. Using the fields (or Po field and Pe field) as reference images, the motion vectors MVo Po between the Io field and the Po field, and the motion vectors MVe Po and Io between the Ie field and the Po field.
Motion vector MV between field and Pe field
o Detect the motion vector MVePe between Pe, Ie and Pe fields, and predict the odd field, the even field, and both predictions (eg, the average of the even field prediction and the odd field prediction), Select the prediction with the smallest prediction error from the current P frame, and select I
The above macroblock in which the o field and the Ie field are combined is used as a prediction image to encode the difference from the original image. On the other hand, no data is sent in the even cycle in this mode.

Furthermore, in the first encoding processing mode, P
When the block of the orthogonal transform of the frame is in the field orthogonal transform mode and the motion prediction is in the frame motion prediction mode, in the odd cycle, the reference image is set as the image of the I frame (or the image of the P frame). The motion vector MVP is detected, and the difference from the original image (macroblock configured by separately dividing the Po field and Pe field) is used as a prediction image using the macroblock configured by separately dividing the Io field and the Ie field. Encode. On the other hand, in the even cycle in this mode, no data is sent as above.

In the first coding processing mode, when the P-frame orthogonal transform is blocked in the field orthogonal transform mode and the motion prediction is in the field motion prediction mode, the Io field and Ie are used in the odd cycle.
A field (or Po field and Pe field) is used as a reference image, and a motion vector MVo Po between the Io field and the Po field, and a motion vector MVe Po between the Ie field and the Po field, I
Motion vector M between o field and Pe field
The motion vector MVe Pe between the Vo Pe, Ie and Pe fields is detected, and the prediction of the odd field, the prediction of the even field and both of the predictions (for example, the average of the prediction of the even field and the prediction of the odd field) are performed. ,
Select the prediction with the smallest prediction error from the current P frame,
The above macroblock, which is configured by separately dividing the Io field and the Ie field, is used as a prediction image for the original image (P
The difference between the o field and the Pe field (macroblock configured separately) is encoded. On the other hand, no data is sent in the even cycle in this mode.

Further, in the case of the B frame in the first encoding processing mode, the following processing is performed. For example, when the B-frame orthogonal transform is blocked in the frame orthogonal transform mode and the motion prediction is in the frame motion predictive mode, in the odd cycle, the reference image is a forward and backward image and the motion vector between frames, that is, , I
Motion vector FMVB between frame and B frame and motion vector BMV between P frame and B frame
B is detected, and the prediction with the smallest prediction error from the current frame is selected from among the forward prediction, the backward prediction, and the bidirectional prediction (the average of the forward prediction and the backward prediction), and the odd field and the even field are alternated. A difference from the original image is encoded by using the combined macroblock as a prediction image. On the other hand, no data is sent in the even cycle in this mode.

Further, in the first coding processing mode, when the B-frame orthogonal transform is blocked in the frame orthogonal transform mode and the motion prediction is in the field motion prediction mode, the reference image is forwarded in the odd cycle. For these images as odd and backward images, odd field prediction and even field prediction are performed, and motion vectors FMVo Bo, Ie field and Bo field between Io field and Bo field are calculated. Between the motion vectors FMVeBo, Io
Motion vector F between field and Be field
MVo Be, motion vector FMVe Be between Ie field and Be field, motion vector BMVo Bo between Po field and Bo field, motion vector BMVe B between Pe field and Bo field
o, a motion vector BMVo Be between the Po field and the Be field, and a motion vector BMVe Be between the Pe field and the Be field are detected, and the prediction of the odd field and the prediction of the even field are performed by the respective vectors. (For example, the average of the prediction of the even field and the prediction of the odd field), the prediction with the smallest prediction error from the current frame is selected, and the Io field and the Io field are selected.
e field (or Po field and Pe field)
The above macroblocks combined with are used as a prediction image to encode the difference from the original image. On the other hand, no data is sent in the even cycle in this mode.

Further, in the first encoding processing mode, B
When the block of the orthogonal transform of the frame is in the field orthogonal transform mode and the motion prediction is in the frame motion prediction mode, in the odd cycle, the reference image is the forward and backward images and the motion vector between the frames, that is, the I frame. Motion vectors FMVB and P between B and B frames
A motion vector BMVB between a frame and a B frame is detected, and a prediction having the smallest prediction error from the current frame is selected from among the forward prediction, the backward prediction, and the bidirectional prediction (average of the forward prediction and the backward prediction). Then, the difference from the original image is encoded by using the above-mentioned macroblock composed of the odd field and the even field separately as the prediction image. On the other hand, no data is sent in the even cycle in this mode.

Further, in the first coding processing mode, when the B-frame orthogonal transform is blocked in the field orthogonal transform mode and the motion prediction is in the field motion prediction mode, the reference image is forward in the odd cycle. For these images as the rear images, odd field prediction and even field prediction are performed, and the respective motion vectors, that is, the motion vector FMVo Bo between the Io field and the Bo field, and the Ie field and the Bo field are calculated. Motion vector between FMVeBo and Io
Motion vector F between field and Be field
MVo Be, motion vector FMVe Be between Ie field and Be field, motion vector BMVo Bo between Po field and Bo field, motion vector BMVe B between Pe field and Bo field
o, a motion vector BMVo Be between the Po field and the Be field, and a motion vector BMVe Be between the Pe field and the Be field are detected, and the prediction of the odd field and the prediction of the even field are performed by the respective vectors. (For example, the average of the prediction of the even field and the prediction of the odd field), the prediction with the smallest prediction error from the current frame is selected, and the Io field and the Io field are selected.
e field (or Po field and Pe field)
The above-mentioned macroblocks, which are separately configured, are used as prediction images to encode the difference from the original image. On the other hand, no data is sent in the even cycle in this mode.

However, in the case of the first coding processing mode of the present embodiment, as can be seen from FIG. 10, the motion prediction between the Io field and the Ie field and the motion between the Po field and the Pe field are performed. Prediction and motion prediction between Bo field and Be field are not possible.

In this case, by using the second encoding processing mode of this embodiment, it is possible to predict from an odd field to an even field in each picture. That is, in the field orthogonal transformation mode in the second encoding processing mode, each unit of the luminance blocks Y02o and Y13o of the odd field and the color difference blocks Cb0 and Cr1 of the odd field in the odd cycle is used. DCT process the block. Then, in the even cycle, each unit block of each luminance block Y02e, Y13e of the even field is DCT processed.

As shown in FIG. 12, the motion prediction in the case of the second coding processing mode is carried out as shown in FIG.
In addition to Pe, motion prediction SMCI between Io and Io fields and motion prediction SMCP between Po and Pe fields are possible.

Therefore, in the case of the field orthogonal transform mode of the second coding processing mode, only the odd field of the macroblock is coded in the odd cycle and only the even field of the macroblock is coded in the even cycle. . As a result, for example, at the end of the odd cycle, the I
o You will get the full field. Therefore, in the even cycle of the I frame, as shown in FIG. 11, with respect to the macroblock of the Ie field in the field orthogonal transform mode, motion prediction is performed using the Io field as a reference image, and a motion vector SMVI and a predicted image are obtained. The difference image of can be encoded.

Further, as shown in FIG. 11, in the case of the P frame in the second coding processing mode, the following processing is performed. For example, when the P frame motion prediction is in the frame motion prediction mode, the inter-frame motion vector MVP is detected after the odd cycle and the even cycle, using the reference image as the forward image (I frame image), and Io The above macroblock in which the field and the Ie field are combined is used as a prediction image to encode the difference from the original image.

When the P frame motion prediction in the second encoding processing mode is the field motion prediction mode, the Io field and the Ie field are used as reference image images in the above odd cycle, respectively, and the Io field and the Ie field are used as reference image images. Motion vector MVoPo, Ie field and P
The motion vector MVe Po with respect to the o field is detected. In the even cycle of this mode, the motion vector MVoPe between the Io field and the Pe field, the motion vector MVe Pe between the Ie field and the Pe field, and the Po field and the Pe for the macroblock in the field orthogonal transform mode. Detecting a motion vector SMVP between a field and a field, and predicting from among the prediction of the odd field and the prediction of the even field by each vector, the prediction of the odd field of the current frame, and the prediction based on the average of two predictions among them. The prediction with the smallest error is selected, and the difference from the predicted image is encoded.

Further, for example, when the motion prediction of the B frame is the frame motion prediction mode in the second coding processing mode, the reference image is used as the forward and backward images after the odd cycle and the even cycle, and the motion between the frames is changed. A vector, that is, a motion vector FMVB between the I frame and the B frame and a motion vector BMVB between the P frame and the B frame are detected, and forward prediction, backward prediction, and bidirectional prediction (average of forward prediction and backward prediction) are performed. Among them, the prediction with the smallest prediction error from the current frame is selected, and the difference from the predicted image is encoded.

When the B frame motion prediction is the field motion prediction mode in the second encoding processing mode,
In the above-mentioned odd cycle, the reference image is forward and backward, the odd field prediction and the even field prediction are performed for these images, and the motion vectors FMVo Bo, Ie field and Bo between the Io field and the Bo field are calculated. Motion vector between the field FMVe Bo, Po field and Bo
Motion vector between the field BMVo Bo, Pe field and Bo field Motion vector BMV
Detect e Bo. In the same manner as described above, the prediction with the smallest prediction error is selected, and the difference from the predicted image is encoded. Furthermore, in the even cycle of this mode, Io
Motion vector FM between field and Be field
Vo Be, Motion vector FMVe Be between Ie field and Be field, Motion vector BMVo Be between Po field and Be field BMVe Be between Pe field and Be field
And the prediction of the odd field of the current frame (that is, the prediction by the motion vector SMVB between the Bo field and the Be field) is also performed, and the prediction with the minimum prediction error is selected and Encode the difference.

Further, in the case of this embodiment, for example,
When handling a so-called 4: 2: 2 content digital VTR format, for example, as shown in FIG. 13, in the frame orthogonal transform mode, for example, luminance blocks Y0 and Y1 composed of odd fields and even fields are used.
, Y2, Y3 and each unit block of the macro block composed of the color difference blocks Cb01, Cr01, Cb23, Cr23 composed of odd and even fields are subjected to DCT processing. In the field orthogonal transformation mode, the luminance blocks Y02o and Y13o of odd fields and the color difference blocks Cb0123o and Cr0123o of odd fields, and the luminance blocks Y02e and Y13e of even fields and the color difference blocks Cb0123e and Cr0123e of even fields are included. DCT processing is performed on each unit block of the macroblock.

Further, the motion prediction in the first coding processing mode in the case of the example of FIG. 13 is as shown in FIG. 10 described above. However, also in this case, similarly to the above, the motion prediction between the Io field and the Ie field, the motion prediction between the Po field and the Pe field, and the motion prediction between the Bo field and the Be field cannot be performed.

Therefore, in this case, the second encoding processing mode may be used as described above. That is, in the field orthogonal transformation mode in the second encoding processing mode, each unit of each luminance block Y02o, Y13o of the odd field and each color difference block Cb0123o, Cr0123o of the odd field in an odd cycle is used. DCT process the block. Then, in the even cycle, the unit blocks of the luminance blocks Y02e and Y13e of the even field and the color difference blocks Cb0123e and Cr0123e of the even field are DCT processed.

Motion estimation in the case of the example of FIG.
Same as 1.

Furthermore, in the present embodiment, the above 4: 2: 2 is used.
When handling the component digital VTR format, in addition to the processing shown in FIG.
As shown in FIG. 14, frame motion prediction is performed in units of macroblocks MB, but in the case of field motion prediction, a certain macroblock MB (i, j) and the macroblock MB ( It is also possible to make a combination of (i + 1, j) and perform the motion prediction of the odd field and the motion prediction of the even field for this macroblock group MBg.

FIG. 15 shows a part of macroblocks extracted from the frame in the case of the example of FIG. It is assumed that the process proceeds in the direction of the arrow in FIG. That is, in FIG. 15, for a certain macroblock MB (i, j), the next macroblock MB (i, j + 1) and the macroblock MB ((in the next line) located below them) i + 1,
j) and MB (i + 1, j + 1) are shown.

In the macroblock as shown in FIG. 15, for example, in the frame orthogonal transform mode, each macroblock MB (i, j), MB (i, j + 1), ..., M
For each B (i + 1, j), MB (i + 1, j + 1) ..., the luminance blocks Y0, Y1 and the color difference blocks Cb01, Cr01 are DCTs.
It is processed. Therefore, in the frame orthogonal transform mode, the processing of each macroblock is not affected by the orthogonal transform modes of other macroblocks.

On the other hand, in the case of the field orthogonal transformation mode, as shown in FIG. 16, the macroblocks MBg of the odd macroblocks MBgo are set to the macroblocks MBg of the macroblocks MBg. And macro blocks MBge of even fields, and each luminance block Y0o, Y1o and color difference blocks Cb01o, Cr0 in the macro block MBgo of the odd field.
DCT process 1o. Here, for example, the set of macroblocks MBg is the macroblock MB (i,
j) and MB (i + 1, j), the luminance blocks Y0o and Y1o in the macroblock MBgo of the odd field in the macroblock MBg are the macroblocks MB (i, j). ) Of the odd-field luminance block and the macroblock MB (i + 1, j) of the odd-field luminance block, and the chrominance block Cb01o in the odd-field macroblock MBgo,
Cr01o is also the color difference block of the odd field of the macro block MB (i, j) and the macro block MB (i
It consists of chrominance blocks of the odd fields of + 1, j). From the same, the luminance blocks Y0e and Y1e in the even-field macroblock MBge are the even-numbered luminance blocks of the macroblock MB (i, j) and the even-numbered macroblock MB (i + 1, j). The color difference blocks Cb01e, Cb in the macro block MBge of the even field
r01e is composed of the color difference block of the even field of the macro block MB (i, j) and the color difference block of the even field of the macro block MB (i + 1, j).

From the above, motion estimation and DC
The relationship with each mode of T conversion is as described below. That is, in the encoding apparatus according to the present embodiment, for example, when the macro block MB (i, j) is the motion prediction in the frame orthogonal transform mode and the DCT transform in the frame orthogonal transform mode, for example, the motion compensator is used. An image decoded in the attached frame memory group 20 is used as a reference frame, and a predicted image extracted from this reference frame,
DCT conversion is performed on the difference from the input image (original image). Then, the DCT coefficient and the frame motion vector are transmitted.

Also, for example, the macroblock MB
In (i, j), when the motion prediction is the field motion prediction mode and the DCT transform is the field orthogonal transform mode, the predicted image extracted from the odd field and the original of the odd field in the macroblock MB (i, j). The difference from the image and the motion vector of the odd field are encoded. In the macro block MB (i + 1, j), the difference between the predicted image extracted from the even field and the original image in the even field and the motion vector in the even field are encoded.

Further, for example, the above macroblock MB
In (i, j), when the motion prediction is the field motion prediction mode and the DCT transform is the frame orthogonal transform mode,
In the relevant macroblock MB (i, j), the frame difference between the predicted image and the input image for the position of the relevant macroblock MB (i, j) extracted from the reference frame, the motion vector of the odd field and the motion vector of the even field To transmit. In the macro block MB (i + 1, j), the macro block M extracted from the reference frame
The frame difference between the predicted image and the input image for the position of B (i + 1, j) is transmitted.

Still further, for example, the macroblock M
In B (i, j), when the motion prediction is the frame motion prediction mode and the DCT transform is the field orthogonal transform mode, in the macroblock MB (i, j), the prediction image extracted from the odd field and the odd field are extracted. The difference from the original image, the frame motion vector of the macroblock MB (i, j), and the frame motion vector of the macroblock MB (i + 1, j) are transmitted. Further, in the macro block MB (i + 1, j), the difference between the predicted image of the odd field and the input image is transmitted.

By the way, in the coding apparatus of the present embodiment, the main code is realized by adding extension bits to the conventional macroblock type and making it compatible with the conventional code.

That is, in the case of the first embodiment, for example, in the B frame, there are three macroblock types, that is, pre-prediction, post-prediction, and both predictions as described above. Since two types of prediction can be considered from the odd field and the even field of the previous frame, this code is realized by adding an extension bit for recognizing either prediction. The prediction in this case is 2
As described above, one bit may be added to the extension bit in one direction (forward and backward prediction). For example, in the case of the prediction from the odd field in the forward or backward prediction, the code "1"
In the case of prediction from an even field, the code “0” may be added as an extension bit to the conventional macroblock type. Also, in both predictions, both extension bits are added for the previous or subsequent prediction.

In the frame motion prediction mode, the extension bit is not added and the conventional bit stream (MPE
It has the same format as G).

The above is similarly applied to the case of P frame.

Next, in the case of the present embodiment, for example, in the B frame, the macro block type includes the pre-prediction, the post-prediction, and the both predictions as described above. Or the prediction from
An extension bit for recognizing whether the prediction is from the even field or the odd field in the own frame must be added to the macroblock type. That is, in the field motion prediction mode of pre-prediction, since there is prediction from within the self-frame, 1 or 2 extension bits are required to express three types of prediction with extension bits, including odd and even numbers. In the field motion prediction mode of post-prediction, since there are only two kinds of odd numbers and even numbers, one expansion bit is always required. For example, in the previous prediction,
A code "1" is added for prediction from the odd field of the previous frame, a code "01" is added for prediction from the even field of the previous frame, and a code "11" is added for prediction from the odd field of the current frame. , In the post-prediction, the code “1” in the case of the prediction from the odd field of the post-frame,
In the case of prediction from the even field of the subsequent frame, the code "0" may be added as an extension bit to the conventional macroblock type.

In the frame processing mode, the extension bit is not added and the format is the same as that of the conventional bit stream (MPEG). Also, in both predictions, both extension bits are added for the previous or subsequent prediction.

The above is similarly applied to the case of P frame.

Further, as a modification, the extension bit in the case of the above-mentioned prediction can be reduced to 1 bit. That is, in the even cycle in the field motion prediction mode, as shown in FIG. 17, the prediction indicated by the alternate long and short dash line in the figure from the odd field of the previous frame that is farthest in terms of time and position is abolished. To 2 and the forward motion prediction mode can be transmitted by extension of 1 bit. Specifically, in the previous prediction in the odd cycle, the code “1” is set in the case of the prediction from the odd field of the previous frame,
In the case of the prediction from the even field of the previous frame, the code "0", in the prediction of the even cycle, the code "1" in the prediction of the odd field of the current frame, and the prediction of the even field of the previous frame. In the case of post-prediction, the code "1" is used for the prediction from the odd field of the subsequent frame, and the code "0" is used for the prediction of the even field of the subsequent frame as the extension bit. It may be added to the macro block type of.

FIG. 18 shows an example of the configuration of the coding apparatus of the second embodiment. 18, the same components as those in FIG. 1 described above are designated by the same reference numerals, and detailed description thereof will be omitted.

The configuration of the apparatus of the second embodiment is a three-pass coding apparatus, and processing is performed three times for processing one frame.

That is, in the apparatus of the second embodiment, the processing of the second coding processing mode (with intra-frame prediction between frames) with the fixed quantization width is performed in the first pass, and the second pass is fixed. The processing of the first encoding processing mode (no intra-frame prediction between frames) by the quantization width is performed, and the processing in which the number of generated bits is small is selected from the first pass and the second pass in the third pass, The quantization width is controlled and processed.

Here, in the second embodiment, a macroblocking device 55, a changeover switch 57, a field blocking conversion circuit 56, and a changeover switch 58, which will be described later, are inserted and connected at the subsequent stage of the frame memory group 10. It
Further, the image data from the frame memory group 10 is sent to the motion detection circuit 51 which detects frame and field motion. The output from the motion detection circuit 51 is sent to a mode determination circuit 52 for selecting a frame / field mode for block formation and motion prediction for orthogonal transformation, the frame memory group 20 and the variable length coding circuit 15.

The output mode data from the mode judging circuit 52 is sent to the frame memory group 20 and the variable length coding circuit 15, and the field orthogonal transformation mode data among them is sent to one input terminal of the 2-input AND gate 53. Be done. The other input terminal of the two-input AND gate 53 is switched to another input terminal via the inverter 54 according to the first, second, and third paths.
The output of is supplied. The output terminal of the 2-input AND gate has the changeover switch 57,
It is connected to the switching control terminal 58.

Data of the number of generated bits is output from the variable length coding circuit 15, and the number of generated bits is smaller in either of the first and second coding processing modes based on the data of the number of generated bits. It is sent to a selection circuit (intra-frame inter-field prediction presence / absence determination circuit) 60 that selects one of the modes. Further, the accumulated amount data from the buffer 16 is transferred together with the variable length coding circuit 15 to the changeover switch 6
1 is supplied to one switched terminal. The fixed value of the first and second paths is supplied to the other switched terminal of the changeover switch 61.

In the apparatus of the second embodiment, the image input to the terminal 1 is once stored in the frame memory group 10, and the necessary frame or field data is called from the frame memory group 10. The motion vector is obtained by the motion detector 51 using these image data. The mode determination circuit 52 determines the field / frame mode for each macroblock from the motion prediction residual from the motion detector 51. Further, the macroblocking unit 55 connected to the subsequent stage of the frame memory group 10 receives the information (that is, the first encoding process) corresponding to the first pass, the second pass, and the third pass via the changeover switch 59. Mode or the second coding processing mode, ie, the presence / absence of inter-field prediction in a frame), and when the information of the second coding processing mode is received as this information, an odd field (first field) ), The even field (second field) is transmitted, and the block in the frame orthogonal transform mode is turned off. Further, the image data in which the macroblock is the block in the frame orthogonal transform mode based on the information of the first coding processing mode in the macroblocking unit 55 determines the mode from the residual from the motion detector 51. If the circuit 52 determines that the mode is the field mode, the field block conversion circuit 56 converts the block into the frame orthogonal conversion mode block.

In the first pass and the second pass, encoding is performed with a fixed quantization width, the bit generation amounts are compared by the selection circuit 60, and the mode in which the intra-frame interfield prediction is present or not produced is the smallest. Is selected for each frame, and the actual encoding is performed in the third pass. At this time, 1 bit is added to the information of the selected mode for each frame.

FIG. 19 shows a block diagram of an image signal decoder. That is, the high-efficiency decoding device of the present embodiment is
Receiving header information including reproduced image coded data, detected motion vector information, motion prediction mode information, blocking mode information (orthogonal transform mode information), and coding processing mode information (coding processing mode data) Decrypt,
An inverse variable length coding circuit 51 for outputting the detected motion vector information of the header information, the motion prediction mode information, the orthogonal transformation mode information, and the coding processing mode data together with the decoded image decoded data, and the coding From the processing mode data, the address increment value in the frame buffers 61, 62, 64 for accumulating the image decoded data is calculated, and the head address of each macroblock is calculated,
The head address is set to the frame buffers 61, 62, 6
4 and the address generators 81, 82, and 83, and the relative addresses of the macroblocks other than the start address are added to the frame buffers 61, 62, and 64 to access the data to detect the detected motion vector and the motion prediction mode. Information, the orthogonal transformation mode information, and the encoding processing mode data are received, motion compensation frame or inter-field prediction corresponding to the mode information is executed, and a motion compensated image signal is generated in the frame buffers 61 and 6.
Motion compensation circuit 59,6 configured to send to
0, 63, 65, 66.

In FIG. 20, the data encoded by the high-efficiency encoder of the above embodiment is once recorded on a storage medium such as a CD. The encoded data reproduced from the CD or the like is first decoded through the input terminal 50 by the inverse variable length encoding circuit 51 for the header information and the like for each sequence, each frame group, and each frame. In the odd cycle of the frame, the header information is decoded for each slice (group of macroblocks), and the quantization width is included in the header of this slice. Then, for each macroblock, the address of the macroblock, the frame / field motion prediction mode and the frame / field orthogonal transformation mode information, the encoding processing mode data, and the macroblock type indicating the decoding method are decoded, and the quantization width is Decrypted when updating.

When the block formation in the macroblock is the frame orthogonal transform mode, the entire macroblock is decoded in the odd cycle and nothing is decoded in the even cycle. When the block formation is in the field orthogonal transform mode, only the block including the odd field in the macroblock is decoded in the odd cycle, and the block including the even field is decoded in the even cycle.

The image information is decoded through the inverse quantizer 53 that performs the inverse quantization process and the inverse DCT circuit 54 that performs the inverse DCT conversion process, and it is determined whether it is a difference image or not by the macro block type. The adder 56 switches the mode switch 57 that switches addition or non-addition to the reference image (corresponding to non-intra / intra of MPEG encoding) according to the determination result. The decoded image is input to the frame buffer 64 or 61 (alternately every time I frame or P frame is processed) in the case of an I frame or a P frame, and B
In the case of a frame, it is input to the frame buffer 62.
Each frame buffer consists of two field buffers, and the odd / even field images are stored separately in the respective field buffers. The writing to the frame buffer is controlled by switching the switch 58.

At this time, the frame buffers 61, 62,
The address written in 64 is the address generator 81, 8
2,83. This address generator 81,
82 and 83, frame buffers 61 and 62, from the encoding process mode data in the header information of the macroblock,
The address increment value at 64 is calculated and the start address of each macroblock is obtained.

Further, the quantization width data is stored in the memory 52 for one field, respectively. This quantized width data is sent to the inverse quantizer 53 via the switch 55 which is switched according to the output of the inverse variable length encoding circuit 51. Here, in the even cycle, since only the macroblock processed in the field orthogonal transform mode is decoded, the macroblock type with the macroblock address decoded for each macroblock and the motion vector required for the prediction method indicated by this are The differential image that is decoded and further transmitted from the reference field to the motion-compensated image is added to obtain a reproduced image.

Further, each of the frame buffers 64 and 6 described above
The data Nos. 2 and 61 correspond to the motion compensation processing circuits 65, 66,
Motion compensation is performed by 59, 60 and 63. At this time, each motion compensation circuit switches frame motion compensation / field motion compensation according to the orthogonal transform mode (frame / field) in the DCT processing.

These motion-compensated images are sent to the selected terminals of the changeover selection switches 67, 68, 71. These changeover selection switches 67, 68, 71 are changed over so that the reference field or frame indicated by the macroblock type decoding system can be taken out. Here, the changeover selection switch 71 is supplied with a signal obtained by adding the outputs of the changeover selection switches 67 and 68 by an adder 69 and then halved by a divider 70, and the output of the switch 67. To be done. The output of the switch 71 is sent to the switch 57.

Further, each frame buffer 64, 61, 6
The output of No. 2 is sent to the display 73 via the changeover selection switch 72. The display 73 is supplied with the output of the changeover selection switch 72 which is switched so as to be displayed in the order of reproduced images, not in the order of decoding. This gives an image.

From the above, for example, as shown in FIG. 24 described above, the moving object CA is displayed in front of the stationary background.
If there is one, there is movement between fields when one frame is viewed, so such a part becomes a comb type KS,
According to the apparatus of the present embodiment, since such a moving part is encoded in the field orthogonal transform mode, it can be processed as a blur-free image divided for each field, and highly efficient by motion compensation between odd / even, High quality video can be played. That is, for example, as shown in FIG. 20, in the odd cycle, the moving part is processed in the field motion prediction mode and the stationary part is processed in the frame orthogonal transform mode. Note that the portion in which an image has already been formed in the even cycle is the portion indicated by the diagonal lines in FIG. The portions other than the shaded portions in FIG. 21, that is, the moving portions are decoded by motion compensation.

By the way, in the present embodiment, only the macroblock processed in the field orthogonal transform mode is decoded in the even cycle, so it is necessary to know the macroblock address. There are two methods of knowing this macroblock address. One is the method of transmitting the macroblock address for each macroblock of the even cycle described above, and the other is the field orthogonal for one field in the odd cycle. This is a method of storing information on the transform mode / frame orthogonal transform mode and converting the address of the macroblock in the field orthogonal transform mode from the column of each orthogonal transform mode. The advantage of the former is that no additional memory is required, and the advantage of the latter is that transmission information does not increase. The quantization width is similar, and can be realized by transmitting for each macroblock without using the method of storing one field in the odd cycle described above.

As described above, according to the decoding apparatus of this embodiment, the frame orthogonal transform mode and the field orthogonal transform mode are switched in macroblock units in accordance with the first and second coding processing modes. At the same time, switching the frame motion prediction mode and the field motion prediction mode, decoding both the odd field and the even field in the frame processing, decoding only the odd field in the field processing, and further storing the quantization width in this cycle. In the next even cycle, since the stored information is used to perform motion compensation on only the macroblocks in the field orthogonal transform mode to decode the reproduced image, efficient coded data can be transmitted. You can That is, it is possible to reproduce a high quality moving image with a small amount of transmission information.

[0142]

As described above, according to the high-efficiency coding apparatus for image signals of the present invention, in a moving image having a field structure, an image with little motion, an image with many motion, and an image in which both of them are mixed. Even now, it becomes possible to efficiently perform field processing or frame processing,
Therefore, it becomes possible to reproduce a high-quality moving image with a small amount of transmission information at the time of decoding in the high-efficiency decoding device of the present invention.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a high-efficiency encoding apparatus for image signals according to a first embodiment.

FIG. 2 is a diagram for explaining encoding according to the present embodiment.

FIG. 3 is a diagram showing a macro block.

FIG. 4 is a diagram showing a macroblock in a frame orthogonal transform mode.

FIG. 5 is a diagram showing a macroblock in a field orthogonal transform mode.

[Fig. 6] Fig. 6 is a diagram illustrating motion prediction in the frame orthogonal transform mode in the first encoding processing mode.

[Fig. 7] Fig. 7 is a diagram illustrating motion prediction in the field orthogonal transform mode in the first encoding processing mode.

[Fig. 8] Fig. 8 is a diagram illustrating motion prediction in the second encoding processing mode.

FIG. 9 is a diagram showing a unit block of DCT processing in a frame orthogonal transform mode / field orthogonal transform mode in a specific example format of a digital VTR.

[Fig. 10] Fig. 10 is a diagram illustrating a state of motion prediction in a first encoding processing mode.

[Fig. 11] Fig. 11 is a diagram showing a state of motion prediction in the present embodiment.

[Fig. 12] Fig. 12 is a diagram illustrating a state of motion prediction in a second encoding processing mode.

FIG. 13 is a diagram showing a unit block of DCT processing in a frame orthogonal transform mode / field orthogonal transform mode in another specific format of a digital VTR.

FIG. 14 is a diagram showing a set of macroblocks.

FIG. 15 is a diagram for explaining the manner of processing in the frame orthogonal transform mode in the example of FIG. 14;

FIG. 16 is a diagram for explaining the manner of processing in the field orthogonal transform mode in the example of FIG.

FIG. 17 is a modification example of adding extension bits (for pre-prediction).
It is a figure for explaining.

FIG. 18 is a block circuit diagram showing a schematic configuration of an encoding device according to a second embodiment.

FIG. 19 is a block diagram showing a configuration of a decoder.

FIG. 20 is a diagram showing an image of an odd cycle.

FIG. 21 is a diagram showing an image of an even cycle.

FIG. 22 is a diagram for explaining each predicted image.

FIG. 23 is a diagram showing a data structure.

FIG. 24 is a diagram showing an image with a moving object.

[Explanation of symbols]

10 ・ ・ ・ ・ ・ ・ Frame memory group 12 ・ ・ ・ ・ ・ ・ Difference detector 13 ・ ・ ・ ・ ・ ・ DCT circuit 14 ・ ・ ・ ・ ・ ・ Quantization Device 15 ・ ・ ・ ・ ・ ・ ・ Variable length coding circuit 16 ・ ・ ・ ・ ・ ・ ・ Buffer 17 ・ ・ ・ ・ ・ ・ ・ Inverse quantizer 18 ・ ・ ・ ・ ・ ・Inverse DCT circuit 20 ..... Frame memory group with motion compensator 21 ..... Field motion detection circuit 22 ..... Frame motion detection circuit 24 ..... Selector 33 ..... Frame / field mode determination circuit 34 ..... Encoding processing mode determination circuit 35 .. ..Address generators

Claims (2)

[Claims] 1. A high-efficiency coding apparatus for an image signal, which performs coding in units of a macroblock composed of a two-dimensional array of a plurality of pixels, wherein a motion vector between frames and an absolute value difference of each pixel in the macroblock unit. Motion detecting means including means for detecting a sum and means for detecting a sum of absolute value differences between pixels and a motion vector between fields formed by dividing the scan of pixels of the frame by the odd number or even number in the macro block unit And which of the frame prediction mode in which motion compensation is performed in units of frames in the macroblock and the field prediction mode in which motion compensation is performed in units of fields in the macroblock is more efficient in performing motion compensation. , A first mode selecting means for selecting an efficient prediction mode, and the macro block The frame processing mode in which the orthogonal transformation is performed in units of frames in the frame and the field processing mode in which the orthogonal transformation is performed in units of the fields in the macroblock are effective in performing the orthogonal transformation. Second mode selecting means for judging whether or not it is good using the information outputted from the motion detecting means and the first mode selecting means, and selecting an efficient block mode, and each macro in one frame A first coding processing mode in which the block formation is adaptively switched to the frame processing mode or the field processing mode for each block and each macroblock is coded based on each mode, and all macroblocks in one frame In the field processing mode, the above blocking of Only one odd field in the macroblock is coded for one frame in the odd cycle of scanning the odd field, and then one frame of the even field in the macroblock is coded in even cycle for the scanning of the even field in the interlace. The third mode selection means for determining which of the second encoding processing modes is efficient in encoding and selecting the efficient encoding processing mode and the odd cycle or the even cycle Recognizing, when the encoding processing mode is the first encoding processing mode, the frame memory group is controlled so as to output a macroblock that has been blocked corresponding to the blocking mode in the odd cycle, When the encoding processing mode is the second encoding processing mode, the odd number Address generating means for controlling the frame memory group so as to output the macroblocks which are divided into blocks corresponding to the field processing mode in the cycle and even cycles, and the motion prediction mode information selected by the first mode selecting means. And a motion compensation means for receiving the blocking mode information selected by the second mode selection means and executing motion compensation frame or inter-field prediction corresponding to the mode information. High efficiency encoder. 2. The reproduced image coded data, header information including detected motion vector information, motion prediction mode information, blocking mode information, and coding processing mode information are received and decoded, and the decoded information is received. Inverse variable length coding means for outputting the detected motion vector information, the motion prediction mode information, the blocking mode information and the coding processing mode information together with the image decoding data, and the image decoding data from the coding processing mode information Calculating the address increment value in the frame buffer for accumulating each of the macroblocks, obtaining the start address of each macroblock, and giving the start address to the frame buffer, and the relative address of the macroblock other than the start address. To the frame buffer to access the data and detect the motion To receive the motion information, the motion prediction mode information, the blocking mode information, and the encoding processing mode information, perform motion compensation corresponding to the mode information, and send the motion-compensated image signal to the frame buffer. And a motion compensation means configured as described above.