RU2298885C2 - Device for encoding and decoding video-frames - Google Patents

Abstract

FIELD: radio engineering and television, possible use during generation, transmission and receipt of video-frames.

SUBSTANCE: in accordance to invention introduced additionally to encoder are video frames memory block, first function memory block, video frame transmission block, block for storing video frame being reproduced, while input of encoder serially, through block for forming video frames, video frames memory block, block for forming difference video frame, first frame memory block, video frame transmission block and block for memorizing video frame being reproduced is connected to second input of block for forming difference video frame, third input of which is connected to output of first function memory block, output of which is connected to second input of video frame transmission block, output of which is the output of device encoder. Introduced additionally to decoder are video frames receipt block, comparator and second function memory block, while input of decoder is serially, through video frame receipt block, second frame memory block and comparator, is connected to second video frame restoration block, third input of which is connected to output of second function memory device, and output is the output of decoder of device. Device realizes generation, transmission and receipt of code of function of distribution of screen point brightness in a series of frames, making it possible to increase the code compression coefficient.

EFFECT: increased coefficient of code compression of video frame information.

1 tbl, 1 dwg, 7 app

Description

The invention relates to the field of radio engineering and television and can be used in the formation, transmission and reception of video frames.

The device of the inter-frame encoder and video compression decoder (John Watkinson, A Handbook for Digital Stream Compression Engineers, Snell & Wilcox, translated into Russian by Snell and Wilcox, ZAO, Moscow, p. 11) was selected as an analogue. The encoder contains a block delays per frame, inter-frame difference calculation unit, spectral conversion unit, weighting unit, coefficient truncation and zero rejection unit, the decoder comprises a reverse weighting unit, an inverse conversion unit, a frame forming unit, bl a frame delay. In this device, an inter-frame difference is transmitted to the communication channel, while the code compression coefficient of the transmitted video information is increased, however, any errors in the transmission channel are visible in all subsequent video frames, which makes the video stream unsuitable for decoding. To eliminate errors, it is necessary to periodically transmit a complete video frame subjected only to intraframe coding, which reduces the code compression coefficient of video information.

The device of the inter-frame encoder and video compression decoder (John Watkinson, A Handbook for Digital Stream Compression Engineers, Snell & Wilcox, translated into Russian by Snell and Wilcox, ZAO, Moscow, p. 51) was selected as a prototype. The encoder consists of a differential video frame forming unit, a differential video frame compression unit, a differential video frame decoding unit, a video frame forming unit, a first frame memory unit, wherein the encoder input is connected in series through the differential type forming unit frame, differential video frame compression unit, differential video frame decoding unit, video frame formation unit, first frame memory unit, with a second input of the video frame formation unit and with a second input of the differential video frame formation unit, the output of which is the output of the encoder of the device, the decoder comprises a decoding unit of the differential video frame, a video frame recovery unit, a second frame memory unit, the decoder input being sequentially through a differential video frame decoding unit, a recovery unit in ideo frames, the second frame memory unit is connected to the second input of the video frame recovery unit, and the output of the second frame memory unit is the output of the device decoder. The device, considered as a prototype, contains in the encoder and decoder identical decoders of the differential video frame to eliminate errors in the compression process. The disadvantage of the prototype is not a sufficiently high coefficient of code compression of video frames.

The technical problem to be solved is an increase in the code compression coefficient of video frames.

The solution of a technical problem in a video frame encoding and decoding device comprising an encoder consisting of a differential video frame forming unit, a video frame forming unit, a first frame memory unit, wherein the encoder output is connected to a decoder input consisting of a video frame recovery unit, the output of which is connected through the second unit frame memory with the second input of the video frame recovery unit, is achieved by the fact that the video frame memory unit, the first function memory unit, the block before the video frame, the memory block of the reproduced video frame, wherein the encoder input is sequentially through the video frame forming unit, the video frame memory unit, the differential video frame forming unit, the first frame memory unit, the video frame transmitting unit and the reproducing video frame memory unit is connected to the second input of the differential video frame forming unit, third the input of which is connected to the output of the first function memory block, the output of which is connected to the second input of the video frame transmission unit, the output of which is the output of the code and the device, the video frame receiving unit, the comparator and the second function memory block are additionally introduced into the decoder, the decoder input being sequentially through the video frame receiving unit, the second frame memory unit and the comparator connected to the second input of the video frame recovery unit, the third input of which is connected to the output of the second unit function memory, and the output is the output of the device decoder.

The drawing shows a structural diagram of a device for encoding and decoding video frames.

The encoding and decoding device of video frames consists of an encoder 1 comprising a differential video frame forming unit 2, a video frame forming unit 3, a first frame memory unit 4, wherein the output of the encoder 1 is connected to the input of the decoder 5 containing the video frame recovery unit 6, the output of which is connected through the second a frame memory unit 7 with a second input of the video frame recovery unit 6. An additional video frame memory unit 8, a first function memory unit 9, a video frame transmission unit 10, and a memory unit are restored to the device encoder 1 video frame 11. In this case, the input of the encoder 1 is sequentially through the video frame forming unit 3, the video frame memory unit 8, the differential video frame forming unit 2, the first frame memory unit 4, the video frame transmitting unit 10 and the memory block of the reproduced video frame 11 are connected to the second input of the differential forming unit video frame 2, the third input of which is connected to the output of the first function memory block 9, the output of which is connected to the second input of the transmission block of the video frame 10, the output of which is the output of the encoder 1. To decoder 5 of the triad, the video frame receiving unit 12, the comparator 13, and the second function memory unit 14 are additionally introduced. The decoder 5 input is sequentially through the video frame receiving unit 12, the second frame memory unit 7 and the comparator 13 connected to the second input of the video frame recovery unit 6, the third input of which is connected with the output of the second block of memory functions 14, and the output is the output of the decoder 5 of the device.

All blocks included in the device for encoding and decoding video frames can be performed according to standard schemes published in the literature. In applications No. 1-No. 6, the algorithms for the operation of the blocks are given: forming video frames 3, forming a differential video frame 2 in the mode of generating statistical video frames, forming a differential video frame 2 in the mode of generating dynamic video frames, transmitting a video frame 10, receiving video frames 12, restoring video frames 6. In the application No. 7 gives an approximate structure of the organization of memory cells in the first block of frame memory 4 and in the second block of frame memory 7. The system providing power to the blocks is not shown in the drawing.

Consider the operation of the device for encoding and decoding video frames. Functions that describe the nature of the change in the brightness of the screen point in the sequence of video frames and the function codes set in the corresponding function codes are given in table No. 1.

Table number 1 Function class Function code Function Change Character Bursting 000 Change abruptly Permanent 111 Keep constant value Nonlinear 1 001 Increase with speed Linear 1 010 Increase linearly Nonlinear 2 011 Increase with decrease speed Nonlinear 3 one hundred Decrease with increasing speed Linear 2 101 Decrease linearly Nonlinear 4 110 Decrease with a decrease in speed

The decoder 5 of the encoding and decoding device of video frames operates in the modes of receiving video frames and decoding video frames.

Video frame reception mode.

The video frame receiving unit 12 receives a video frame from the channel, recognizes the identifiers of the video frame and lines, and depending on their values generates information recorded in the second block of frame memory 7. In the cells of the second block of frame memory 7, records are stored in the format:

For this, the video frame receiving unit 12 can receive from a channel and process strings in the formats:

Where, 01:01 and 10:01 - identifier of the video frame and lines that determine what is recorded and (or) the voltage value of the screen point is transmitted;

01:10 and 10:10 - identifiers of the video frame and lines that determine what is recorded and (or) transmitted the value of the function code and the value of the number of frames;

10:11 - identifiers of the video frame and lines, which determine that the contents of the memory cells remains unchanged.

If the unit for receiving video frames 12 receives a string in the format (2), then the voltage values from the string are sequentially copied to the corresponding cells of the voltage values of the second block of frame memory 7. Zero values are recorded in the cell values of the function codes, number of frames, frame numbers and scales.

If the unit for receiving video frames 12 receives a string in the format (3), then the values of the function codes and frame numbers from the string are overwritten into the cell values of the function codes and frame numbers of the second block of frame memory 7. Zero values are written to the cell values of the frame number. The block for receiving video frames 12 from the values of the number of frames forms the prices of the scales, recording them in the cells of the values of the scale, the contents of the cell voltage values are not changed.

If the block for receiving video frames 12 receives a string in the format (4) with identifier 01, then the voltage values from the string are sequentially overwritten only in those cells of the second block of frame memory 7 in which the value of the function code has a zero value. Zero values are written to other cells.

If the block for receiving video frames 12 receives a line in the format (5) with identifier 11, then the contents of the memory cells of the second block of frame memory 7 remain unchanged.

If the block for receiving video frames 12 receives a line in the format (6) with identifier 10, then the values of the function codes and the number of frames from the line are recorded only in those memory cells of the second block of frame memory 7 in which the value of the function code is zero. Zero values are written to the cell values of the frame number, and the contents of the voltage values of these cells are not changed.

Video frame decoding mode.

The video frame recovery unit 6 selects the memory cells of the second frame memory unit 7 in the format (1).

If the value of the function code is zero, no transformations are performed on the contents of the cells corresponding to this function, and the voltage value is transmitted to the output of the decoder.

If the value of the number of frames of a memory cell of the second block of frame memory 7 is not equal to zero and equal to the value of the frame number, then the video frame recovery unit 6 records the zero value of the function code. No other transformations are performed on the contents of this cell; the voltage value of the screen point is transmitted to the decoder output.

If the value of some function code in the corresponding memory cell of the second block of frame memory 7 is not equal to zero and the values of pairs the frame number and number of frames corresponding to this code are not equal, then the video frame recovery unit 6 selects an increment from the second function memory block 14 from the second function memory block 14 and, using the comparator 13, it modifies the voltage value of the selected memory cell of the second block of frame memory 7. Using the comparator 13, the video frame recovery unit 6 also modifies the frame number value of this cell Key contents of the scale value. The modified value of the voltage point of the screen is transmitted to the output of the decoder.

The encoder 1 of the device operates in the modes: the formation of statistical video frames, the formation of dynamic video frames, transmission of video frames.

The mode of formation of statistical video frames.

The source video frames are fed to the video frame forming unit 3, which records the brightness values of the brightness of the screen dots and the video frame number in the video frame memory unit 8, which is organized to store at least four consecutive video frames. Further, it is necessary to form in the memory cells of the first block of frame memory 4, entries in the form:

For this, the differential video frame forming unit 2 reads sequentially the video frames in the video frame memory unit 8, selects the voltage values from them and writes them to the corresponding memory cells of the first frame memory unit 4. The differential video frame forming unit 2 from the video frame memory unit 8 reads four cells defining values voltages for the point of the screen in four consecutive frames. Using four voltage values, the differential video frame forming unit 2 calculates the first and second order increments, and using the contents of the increments using the contents of the first function memory block 9, selects the type of function and determines the number of frames during which the function retains its significance. The values of these values, the block forming the differential video frame 2, writes to the corresponding memory cells of the first block of frame memory 4.

The mode of formation of dynamic video frames. The dynamics of the process of forming video frames in the General case is characterized by various combinations of the following states of the cells of the first block of frame memory 4:

If the point of the video frame in the first block of frame memory 4 is described (8), then the corresponding point of the video frame of the first block of frame memory 4 may not be transmitted to the receiver, since the dynamics of the states of this point is completely defined (1). If the current states of all cells of the first block of frame memory 4 are described (8), then the video frame will look like:

The video frame is transmitted to the channel and recorded by the transmission unit of the video frame 10 in the memory block of the reproduced video frame 11.

If the memory point of the first block of frame memory 4 is described (9), it is not known whether the voltage value from (9) should be stored or it is necessary to replace them with the corresponding voltage values from the video frame memory 8. Therefore, the differential video frame generation unit 2 reads three from the video frame memory 8 cells that determine the state of a point in three consecutive video frames. Together with the voltage value from the memory block of the reproduced video frame 11, the four voltage values are used by the differential video frame formation unit 2, which calculates the first and second order increments and, using the contents of the first function memory block 9, selects the type of function and determines the number of frames during which the function retains its significance. The values of these values, the differential video frame forming unit 2, writes to the corresponding memory cells of the first block of frame memory 4. Next, the differential video frame forming unit 2 calculates the scale division value by the number of frames and writes it to the selected cell of the first frame memory unit 4. As a result of the described procedure in the first block of frame memory 4, will not contain cells characterized by (9).

If the memory point of the first block of frame memory 4 is described (10), then the corresponding point of the video frame must be transmitted to the receiving device, since code 0 determines the discontinuous function. It is necessary to establish the nature of the change in the stress values at the point. The differential video frame forming unit 2 reads four cells from the video frame memory unit 8, whose states determine the voltage values for the screen point in four consecutive frames. Using these values, the differential video frame forming unit 2 calculates the values of the first and second order increments and, using the contents of the first function memory block 9, selects the function code and determines the number of frames during which the function retains its significance. If in the current state of cells in all lines of the memory block of the reproduced video frame 11 there are (10), then the video frame will look like:

If in some line of the memory block of the reproduced video frame 11 does not contain points defined by (9) or (10), such a line will be represented by identifier 11. The program for transmitting the video frame will correspond to:

Video Frame Transfer Mode.

The transmission block of the video frame 10 transfers to the communication channel the video frames recorded in the memory of the first block of the frame memory 4, and modifies the contents of the cells of the memory block of the reproduced video frame 11 depending on the frame identifiers and lines. The transmission unit of the video frame 10 may transmit formats (2) to (6).

The transmission block of the video frame 10 sequentially selects 4 video frames from the memory block of the first block of frame memory 4 and sequentially transmits them to the channel.

If the transmission unit of the video frame 10 transmits a string in the format (2), then the voltage values from the string are sequentially copied to the corresponding cells of the memory block of the reproduced video frame 11. In the cell values of the function codes, number of frames, frame numbers and scales, zero values are recorded.

If the transmission unit of the video frame 10 transmits a string in the format (3), then the values of the function codes and frame numbers from the string are overwritten into the cell values of the function codes and frame numbers in the memory block of the reproduced video frame 11. The frame number value of these cells is reset. The transmission unit of the video frame 10 from the values of the number of frames forms the prices of the scale divisions and writes them to the cell values of the scale of the memory block of the reproduced video frame 11. The voltage value of these cells does not change.

If the transmission unit of video frame 10 transmits a string in the format (4) with identifier 01, then the voltage values from the string are sequentially overwritten only to those cells of the memory block of the reproduced video frame 11 in which the function code value has a zero value, other values of these cells are reset. In the cells of the memory block of the reproduced video frame 11, in which the function code value is not equal to zero, the video frame transmission unit 10 modifies the voltage value with increment values selected by the function code from the first function memory block 9, and modifies the value of the frame number with the value of the scale division values selected from cells value scales.

If the video frame transmission unit 10 transmits a string in the format (5) with identifier 11, then it modifies the voltage values in all cells of the memory block of the reproduced video frame 11 with increment values selected by the function code from the first function memory unit 9, and modifies the value of the frame number with price values divisions of scales selected from the cells of the values of the scales of the first block of frame memory 4. The states of the other values of these cells do not change.

If the block for transmitting video frames 10 transmits a string in the format (6) with identifier 10, then the values of the function codes and the number of frames from the string are sequentially overwritten only in those cells of the memory block of the reproduced video frame 11 in which the function code has a zero value. The frame number value of these cells is reset. The transmission unit of the video frames 10, according to the values of the number of frames, forms the prices of the scale divisions and writes them to the cells of the scale values of the memory block of the reproduced video frame 11, the voltage value of these cells does not change.

Claims (1)

A video frame encoding and decoding device, comprising an encoder consisting of a differential video frame forming unit, a video frame forming unit, a first frame memory unit, wherein the encoder output is connected to an decoder input consisting of a video frame recovery unit, the output of which is connected through a second frame memory unit to a second input of the video frame recovery unit, characterized in that the video frame memory unit, the first function memory unit, the video frame transmission unit are additionally introduced into the device encoder, b ok memory of the reproduced video frame, wherein the encoder input is sequentially through the video frame formation unit, the video frame memory unit, the differential video frame generation unit, the first frame memory unit, the video frame transmission unit and the reproduced video frame memory unit is connected to the second input of the differential video frame formation unit, the third input of which is connected with the output of the first function memory block, the output of which is connected to the second input of the video frame transmission block, the output of which is the output of the device encoder, in The encoder of the device additionally includes a video frame receiving unit, a comparator and a second function memory block, the decoder input being connected in series through a video frame receiving unit, a second frame memory unit and a comparator with a second input of the video frame recovery unit, the third input of which is connected to the output of the second function memory unit, and the output is the output of the device decoder.

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