JPH07107463A - Moving picture input/output device - Google Patents

Abstract

PURPOSE:To simplify the constitution and the control of a moving picture input/ output device. CONSTITUTION:Input picture data S1 are converted into a digital signal by an A/D converter 1 and is stored in an input data line memory 21 as first picture data S2. First picture data S2 are stored in a picture input/output memory 22 from the input data line memory 21 line by line. A data processing part 10 subjects picture data S2 to operation processing to generate second picture data S5 for reproduced picture. Second picture data S5 is transferred to an output data line memory 23 through the picture input/output memory 22 line by line. Second picture data S5 are read out from the output data line memory 23 with one picture element as the unit and is converted into output picture data S6 by a D/A converter 5 and is outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving picture input / output apparatus used in a moving picture coding apparatus or the like to process a moving picture.

[0002]

2. Description of the Related Art Conventionally, as a technique in such a field,
For example, some documents were described in the following documents. Reference 1: Image information, [6] (1992), Industrial Development Organization,
Kazuo Komatsu "Overview of Image Coding and Decoding Chips with IIT's VC & VP Configuration" p.91-100 Moving picture coding is a core technology of multimedia processing, and in recent years the performance of moving picture coding devices has improved. Remarkably,
In addition, the development of coding LSIs is also active. First Conventional Example FIG. 2 is a configuration block diagram of a moving image input / output device of the first conventional example. The moving image input / output device of FIG. 2 is a device that uses a coding LSI as described in Document 1 and performs a coding process on a moving image to output a reproduced image. This input / output device is an analog / digital converter (hereinafter referred to as an A / D converter) that converts input image data S1 that is an analog signal for each pixel into a digital signal to generate image data S2 that is first image data. 1) and data bus B
1 has an image memory 2 for storing image data S2. The moving image input / output device of FIG. 2 compresses the data amount of the image data S2 read from the image memory 2 by encoding and outputs the output encoded data S3 composed of a plurality of bits to the outside. And a decoding unit 4 for generating image data S5 which is second image data for a reproduced image by decoding the input encoded data S4 having a structure of a plurality of bits input from the outside. I have it. The encoding unit 3 and the decoding unit 4 form a data processing unit 10, and the image data S5 is stored again in the image memory 2 via the data bus B1. The moving image input / output device of FIG.
Further, a digital / analog converter (hereinafter, referred to as D / A) for converting the digital reproduction image data S5 into analog and outputting the output image data S6 of the display signal to an external display or the like.
5).

Next, the operation of the moving picture input / output device shown in FIG. 2 will be described. Input image data S1 for each pixel of a moving image composed of a matrix of pixels is converted into image data S2 of a digital signal via the A / D converter 1, and this image data S2 is transferred via a data bus B1. It is transmitted to and stored in the image memory 2. Encoding unit 3 in data processing unit 10
Is, for example, 8 × 8 pixels or 16 × 16 for a moving image.
A two-dimensional block of a small area made up of pixels is one processing unit, and the encoding unit 3 reads the image data S2 stored in the image memory 2 in block units. The image data 2 in the block unit is encoded, and as a result, the encoded data S3 is output to the external storage device. The decoding unit 4 in the data processing unit 10 also outputs, for example, 8 to the reproduced image.
2 in a small area consisting of × 8 pixels or 16 × 16 pixels
The dimensional block is one processing unit, and the decoding unit 4
Inputs the encoded data S4 encoded from an external storage device in block units. The decoding unit 4 decodes the encoded data S4 in block units, and the encoded data S5 is written in the image memory 2 in block units. Image memory 2
The encoded data S5 stored in 1 is sequentially read to the D / A converter 5 in units of one pixel of the reproduced image. The D / A converter 5 sequentially converts each encoded data S5 into analog, and the conversion result is output as output image data S6. The input image data S1 and the output image data S6 are
Input and output are performed according to the order called raster scan. That is, in the frame of the moving image, the scanning from the left end to the right end of the pixel matrix is the main scanning direction,
Input and output are performed in the order in which the scanning from the upper end to the lower end of the pixel matrix is the sub-scanning walking. For example, when inputting / outputting a moving image of 720 × 480 pixels, the input / output frequency per pixel is usually 13.5 MHz, and the cycle is about 74 ns.
Is. On the other hand, since the encoding unit 3 and the decoding unit 4 execute the processing in units of two-dimensional blocks, it is not possible to directly input the image data S2 input by the raster scan to the encoding unit 3 to perform the encoding process. It is impossible. Also, the image data S5 for reproduction which is decoded in units of two-dimensional blocks is D /
It is also impossible to directly output to the A converter 5 to display the reproduced image.

Second Conventional Example FIG. 3 is a block diagram showing the configuration of a moving image input / output device of the second conventional example. The device shown in FIG. 3 is an input / output device using a multi-port video RAM that has become widespread in recent years, and, like FIG. 2, is a device that performs a coding process on a moving image and outputs a reproduced image. The moving image input / output device of FIG. 3 includes an A / D converter 1 for converting an analog input image signal S1 into digital image data S2, an input dual port image memory 11 for storing the image data S2, and an input dual port. The image data S2 read from the image memory 11 has a coding unit 3 which compresses the data amount by coding and outputs the output coded data S3 composed of a plurality of bits to an external storage device. There is. Further, this moving image input / output device is a decoding device which generates image data S5, which is second image data for a reproduced image, by decoding input coded data S4 having a structure of a plurality of bits input from the outside. The image data S5 is output via the unit 4 and the data bus B2 to the dual port image memory 12 and the digital image data S5.
And a D / A converter 5 for analog-converting and outputting the output image data S6 for display to an external display or the like. The input dual-port image memory 11 and the output dual-port image memory 12 are multiport video RAs.
The multi-port video RAM is a memory including an ordinary dynamic RAM (DRAM) and another data input / output port (hereinafter referred to as a serial port) for inputting / outputting one line of data to / from the DRAM. Is.
Each multi-port video RAM can input / output data asynchronously at its input / output port. Therefore, the input dual-port image memory 11 can read the encoding data in block units from the DRAM side input / output port (hereinafter referred to as a random port) while inputting the video signal from the serial port. Also,
The output dual-port image memory 12 writes the reproduced image data in block units from the random port, and at the same time,
Data can be read from the serial port by raster scan.

Next, the operation of the moving picture input / output device shown in FIG. 3 will be described. Input image data S1 for each pixel of a moving image formed of a matrix of pixels is converted into digital image data S2 via the A / D converter 1, and this image data S
2 is written into the input dual-port image memory 11 by raster scan via the serial port of the input dual-port image memory 11. The encoding unit 3 uses, as one processing unit, a two-dimensional block of a small area composed of, for example, 8 × 8 pixels or 16 × 16 pixels for a moving image, and the encoding unit 3 uses the input dual port image memory 11 The image data S2 is read in block units from the random port. The image data S2 in block units is encoded, and the resulting encoded data S3 is output to an external storage device (not shown). The decoding unit 4 also uses, as one processing unit, a two-dimensional block of a small area composed of, for example, 8 × 8 pixels or 16 × 16 pixels with respect to the reproduced image, and the decoding unit 4 receives a code from an external storage device. The encoded data S4 that has been encoded is input in block units. In the decoding 4, the encoded data S4 is decoded in block units, and the decoded image data S5 is written in the output dual port image memory 12 via the random port of the output dual port image memory 12 in block units. . In the output dual port image memory 12, the image data S5 is write-transferred from the DRAM to the serial port by one line of the reproduced image. The image data S5 stored in the serial port of the output dual port image memory 12 is sequentially read from the serial port to the D / A converter 5 by raster scan. D
The / A converter 5 sequentially converts each image data S5 into analog, and the conversion result is output to the display as output image data S6.

[0006]

However, the conventional moving image input / output device has the following problems. In the moving image input / output device configured as shown in FIG. 2, the memory for storing the image data is one place of the data image memory 2,
The control circuit of the memory can also have a simple structure that requires only one place. However, the data bus B1 for transferring the image data needs to transmit the data S2 and S5 in a time-divisional manner in raster scan or block units, and it is necessary to increase the bus width in order to secure the transfer capability of the data bus B1. there were. Further, even if the bus width is increased, if the image size to be processed is increased, the transfer capability is limited. In the moving image input / output device having the configuration shown in FIG. 3, the input / output dual port image memory 1 is used by using the multiport video RAM.
1 and the output dual-port image memory 12, the transfer capability of the data bus is improved. However, since the memory is divided into two parts, the expensive memory is
They are used individually and the control of both becomes complicated. Further, the input / output dual-port image memory 11 and the output dual-port image memory 12 are dedicated for input or output, respectively, and are less flexible, for example, when the memories are used for other purposes. SUMMARY OF THE INVENTION The present invention has a problem that the above-mentioned conventional technique has to widen a bus width of a data bus with respect to a memory for storing image data. A moving image input / output device which solves the problem that two or more expensive memories are required.

[0007]

In order to solve the above-mentioned problems, the first invention is to convert the input image data for each pixel forming a moving image into analog / digital signals at a predetermined cycle, and to obtain the first image data. An analog / digital converter for sequentially generating the first image data, a data processing unit for processing the first image data to generate second image data, and a digital / analog for the second image data at the predetermined cycle. In a moving image input / output device, which has a digital / analog converter for converting and sequentially generating output image data corresponding to each pixel, and outputs a reproduced image corresponding to the moving image, the following means are provided. I am using. That is, an input data line memory that sequentially stores the first image data in synchronization with the timing of the analog / digital conversion, and the first image data read from the input data line memory are stored and Image input / output memory for storing two image data, and the first image data for one pixel line of the moving image from the input data line memory, and the read first image data via the data bus. Image data writing means for writing image data into the image input / output memory, image data reading means for reading out the first image data stored in the image input / output memory to the data processing section, and the data processing section From the second image data to the image input / output memory. The moving image input / output device also stores the second image data read from the image input / output memory, and outputs the second image data in synchronization with the digital / analog conversion timing. An output data line memory for sequentially reading out to a digital / analog converter and one line of pixel data of the reproduced image among the second image data stored in the image input / output memory are passed through the data bus. Reproduction image writing means for reading and writing in the output data line memory, and writing the first image data in the image input / output memory and reading the second image data in the image input / output memory. It is performed within a time-divided period of the input period of the input image data for one line of the moving image or the output period of the output image data for one line of the reproduced image. And division processing unit is provided. In a second invention, the data processing unit in the moving image input / output device of the first invention performs encoding and decoding on the first image data to generate the second image data. It is composed of an encoding processing unit.

[0008]

According to the first aspect of the invention, since the moving image input / output device is configured as described above, the first image data is written in the input data line memory in synchronization with the A / D conversion timing. . The image writing unit writes the first image data from the input data line memory to the image input / output memory for each line of the first input image data continuously input to the input data line memory. On the other hand, the second image data stored in the image input / output memory is read by the reproduced image writing means into the output line data memory for each line, and then output for each pixel via the D / A converter. It The time division processing means causes the first image data to be written in the image input / output memory and the second image data to be read from the image input / output memory in a time division manner. According to the second invention, the data processing unit in the first invention compresses the first image data by, for example, encoding, and then reproduces the second image data for reproduction, which is expanded by decoding. To generate. Therefore, the above problem can be solved.

[0009]

1 is a block diagram showing the configuration of a moving image input / output apparatus according to an embodiment of the present invention. The apparatus shown in FIG. 1 is a moving image input / output apparatus which is controlled by a controller (not shown) including a microcomputer and which performs a coding process on a moving image and outputs a reproduced image as in FIGS. 2 and 3. . The moving image is composed of a matrix of 720 pixels in the horizontal direction and 480 pixels in the vertical direction. In FIG. 1, elements common to those in FIGS. 2 and 3 are designated by the same reference numerals. The moving image input / output device of FIG. 1 stores an image data S2 and an A / D converter 1 that converts an analog input image signal S1 into a digital signal to generate image data S2 that is first image data. The input data line memory 21, the image input / output dual port memory 22 of the image input / output memory for storing the image data S2 read from the input data line memory 21 in the writing RAM section from the serial port, and the image data S2 And a data processing unit 10 that performs arithmetic processing to generate second image data for a reproduced image.
The image input / output dual port memory 22 is composed of a multiport video RAM. The sampling frequency of the A / D converter 1 is 13.5 as in a normal video signal.
MHz and its period is about 74 ns. The memory capacity of the input data line memory 21 is a capacity for storing the image data S2 of pixels of two lines of a moving image, and its read cycle time is 35 ns. The data processing unit 10 includes an encoding unit 3 and a decoding unit 4, and the encoding unit 3 includes the image input / output dual port memory 2
The image data S2 from 2 is encoded to compress the data amount, and the output encoded data S3 composed of a plurality of bits is output to an external storage device (not shown). The decoding unit 4
Image data S5, which is the second image data, is generated by decoding the input encoded data S4 having a structure of a plurality of bits input from the external storage device, and the image input / output dual port memory 22 is generated via the data bus B3. It is a structure to write in. The moving image input / output device shown in FIG. 1 further outputs an output data line memory 23 for storing the image data S5 read from the image input / output dual port memory 22 and an analog image data S5 read from the output data line memory 23. A D / A converter 5 for converting the signal to output image data S6 to a display or the like is provided. The memory capacity of the output data line memory 23 is a capacity for storing the image data S5 of the pixels for one line of the reproduced image of the moving image, and the writing cycle time thereof is 35 ns. The sampling frequency of the D / A converter 5 is 13.5 MHz as in a normal video signal,
Its period is about 74 ns. The image data S5 is read from the output data line memory 23 at the same cycle as the sampling of the D / A converter 5.

Next, the operation of the moving picture input / output device shown in FIG. 1 will be described. Input image data S1 for each pixel of a moving image. A /
With the sampling period of 74 ns by the D converter 1, the first
Is converted into image data S2 which is image data of. This conversion is performed on the moving image by raster scanning. The image data S2 is sequentially written in the input data line memory 21 at a cycle of 74 ns. Input data line memory 21
The image data S2 stored in is read at a period of 35 ns or less, and this image data S2 is written to the serial port of the image input / output dual port memory 22 via the data bus B3. After the image data S2 for one pixel line of the moving image is written in the serial port, these data are written and transferred to the RAM section in the image input / output dual port memory 22 and stored therein. The image data S2 stored in the image input / output dual port memory 22 is stored in the image input / output dual port memory 2 under the control of the encoding unit 3.
The image data S2 is read in block units from the two random ports, and is input to the encoding unit 3. The encoding unit 3 encodes the image data S2, and the image data S3 obtained as a result of the encoding is sent to an external storage device (not shown) or the like.
The decoding unit 4 receives the encoded image data S4, and the image data S4 is decoded. The decoding unit 4 generates the image data S5 that is the second image data in the decoding process. The image data S5 is written in a block unit from the random port of the image input / output dual port memory 22 to the RAM section in the image input / output dual port memory 22. The data read from the encoding unit 3 to the image input / output dual port memory 22 and the data write from the decoding unit 4 to the image input / output dual port memory 22 are controlled to be performed in a time division manner. The image data S stored in the image input / output dual port memory 22 is also stored.
2 and S5 are stored in another storage area in the image input / output dual port memory 22. Image data S5 stored in the RAM section of the image input / output dual port memory 22
Is read and transferred to the serial memory for each one line of the pixel of the reproduced image, and then read from the serial port and written in the output data line memory 23 at a cycle of 35 ns or less. The image data S5 stored in the output data line memory 23 has the sampling cycle 74n of the D / A converter 5.
It is read by raster scanning in synchronization with s. The D / A converter 5 converts the image data S5 into an analog signal, and as a result, the output image data S6 is output to the display.

FIG. 4 is a diagram for explaining the timing of encoding and decoding for image input / output. In FIG. 4, an input frame synchronization signal input in each frame period of a moving image, an output frame synchronization signal transmitted in each frame of a reproduced image, an input image data valid signal, an output image data valid signal, a coded Busy signal. , And the decoded Busy signal is shown. In addition, "/" in FIG. 4 represents an inverted signal. The input frame sync signal of the input image is 30H
z, that is, input from the outside at a cycle of 33.3 ms, and the output frame synchronization signal of the output image is also input at the same cycle.
Both the input frame synchronization signal and the output frame synchronization signal are asynchronous with each other, and are valid in a portion excluding the input frame synchronization signal near time, that is, in the period when the signal indicating that the input image data is valid is “L”. The image is input by raster scan. The decoding unit 3 waits for a certain amount of line data to be input, and then starts reading data for each block area. Therefore, when the encoded Busy signal is “H”, the image input / output dual port memory outputs an image. The data S2 is read. A portion of the output frame synchronization signal excluding the neighborhood time, that is, output image data S6
Is valid, the valid output image data S6 is output by raster scan. The writing of the image data S5 into the image input / output dual port memory 22 by the decoding unit 4 is performed in time for the output image data S6 to be output by raster scanning. That is, by control, the image data S5 is written in block units while the decoded Busy signal is "H".

FIG. 5 is a time chart showing the input / output of an image and the operation of each memory, and the operation of FIG. 1 will be continuously described with reference to FIG. In the moving image input / output device shown in FIG.
Input / output of S2 and S5 is performed by time division. In FIG. 5, an input horizontal synchronizing signal and an output horizontal synchronizing signal which are horizontal synchronizing signals of a moving image and a reproduced image, and each input data line memory 2 are shown.
1 and the operation of the output data line memory 23 and the state of the serial port of the image input / output dual port memory 22 are shown. Each waveform in FIG. 5 is assigned a reference line number. The input horizontal sync signal is about 63.
It is input every 5 μs, and effective image data is input during the period excluding the time near the synchronization signal. That is, while the input data line memory write signal is “L”, the image data S2 corresponding to the line number is input to the input data line memory 21.
Written in. Similarly, the output horizontal synchronizing signal is input asynchronously with the input horizontal synchronizing signal at intervals of about 63.5 μs, and the valid image data S6 is output and displayed during the period excluding the time near the output horizontal synchronizing signal. That is, the image data S5 corresponding to the line number is read from the output data line memory 23 while the output data line memory read signal is “L”. Writing to the input data line memory and reading from the output data line memory are 13.5 MH
It is performed with a pixel period of z, that is, about 74 ns.

The input / output of the serial port of the image input / output dual port memory 22 is performed in the following steps (i) to (V) in synchronization with the output horizontal synchronizing signal. (i) Pseudo write transfer The transfer direction to the serial access memory (SAM) part of the serial input / output part in the multi-port video RAM is input. (ii) Serial write The image data S2 of 720 pixels for one line is read from the input data line memory 21 at a cycle of 35 ns, and the SAM is read.
Written in the department. This writing takes about 25.2 μs. (iii) Write transfer After writing one line of data to the SAM section, the image data S2
Is transferred to a predetermined ROW address part of the RAM part. This state corresponds to the portion indicated by N-1, N, N + 1 in FIG. (Iv) Read transfer Data of a predetermined ROW address part of the RAM part is transferred to the SAM part for one line. This state is M + 1,
It corresponds to the portions indicated by M + 2 and M + 3. (V) Serial Read Data for one line of the reproduced image of the image data S5 written in the SAM section is read from the SAM in 35 ns and written in the output data line memory 23. As described above, in the present embodiment, the image input / output dual port memory 2
By using the two serial ports in a time-sharing manner, the expensive memory of the moving image input / output device can be provided in one place and the transfer capability can be increased. As a result, it is possible to inexpensively realize a moving image input / output device that can cope with a large moving image size while keeping the memory control simple.

The present invention is not limited to the above embodiment, and various modifications can be made. The following are examples of such modifications. (1) Although the size of the moving image is 720 × 480 pixels, the size is not limited to this, and the same effect as that of the present embodiment can be obtained even if the size is, for example, 720 × 576 pixels. (2) The configuration of the input data line memory 21 and the output line data memory 23 is such that even in the RAM, the FIFO (First
It can also be configured with an in first out) type serial access memory or the like. (3) The sampling frequency 74 ns in the A / D converter 1 and the D / A converter 5 can be changed according to the purpose. (4) The data processing unit is not limited to the encoding unit 3 and the decoding unit 4, and may be configured to perform both encoding and decoding. Further, it may be configured by a circuit that performs another calculation. . For example, a low-pass filter may be used to perform arithmetic processing on the image data. (5) The multi-port video RAM used for the image input / output dual-port memory 22 may be a dual-port static RAM or the like.

[0015]

As described above in detail, according to the first aspect of the present invention, the first image data is written in the image input / output memory and the second image data is read out from the image input / output memory. Since the time-division processing means for performing the time-division is provided, for example, only one memory is required to store the first and second image data. This makes it possible to control the device with a simple structure for a moving image having a large image size. Further, since the input data line memory and the output line memory are provided for the image input / output memory, the input / output of data to / from the image input / output memory is speeded up. As described above, it is possible to configure a moving image input / output device that has a simple control configuration, can perform high-speed processing, and can handle a moving image having a large image size at low cost. According to the second invention, since the data processing unit of the first invention is configured to perform encoding processing on the first image data, moving image input / output for a moving image having a large amount of information can be performed. The output device can have a simple control configuration, can perform high-speed processing, can cope with a moving image having a large image size, and can have a low cost configuration.

[Brief description of drawings]

FIG. 1 is a configuration block diagram showing a moving image input / output device according to an embodiment of the present invention.

FIG. 2 is a configuration block diagram showing a moving image input / output device of a first conventional example.

FIG. 3 is a configuration block diagram showing a moving image input / output device of a second conventional example.

FIG. 4 is a diagram illustrating the timing of encoding and decoding for image input / output.

FIG. 5 is a time chart showing image input / output and operation of each memory.

[Explanation of symbols]

1 A / D converter 3 Encoding unit 4 Decoding unit 5 D / A converter 10 Data processing unit 21 Input data line memory 22 Image input / output dual port memory (image input / output memory) 23 Output data line memory S1 Input image Data S2 First image data S5 Second image data S6 Output image data

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Claims (2)

[Claims] 1. An analog / digital converter for sequentially generating first image data by analog / digital converting input image data for each pixel forming a moving image at a predetermined cycle, and the first image data A data processing unit that performs arithmetic processing to generate second image data, and digitally processes the second image data at the predetermined cycle.
A moving image input / output device which outputs a reproduced image corresponding to the moving image, and a digital / analog converter that sequentially generates output image data corresponding to each pixel by analog conversion, wherein the first image data An input data line memory for sequentially storing the data in synchronization with the timing of the analog / digital conversion, and an image for storing the first image data read from the input data line memory and the second image data. The input / output memory and the first image data for one line of pixels of the moving image are read from the input data line memory, and the read first image data is read through the data bus to the image input / output memory. And image data writing means for writing the first image data stored in the image input / output memory to the data processing unit. Image data reading means for outputting, reproduced image writing means for writing the second image data from the data processing section to the image input / output memory, and the second image data read from the image input / output memory. An output data line memory for storing and sequentially reading the second image data to the digital / analog converter in synchronization with the digital / analog conversion timing; and the second data stored in the image input / output memory. Reproduced image writing means for reading out one line of pixel data of the reproduced image in the image data via the data bus and writing the read data to the output data line memory; and the image input / output of the first image data. The writing to the memory and the reading of the second image data from the image input / output memory are performed by input image data for one line of the moving image. Moving image output apparatus characterized by a division processing section when performing, provided within the time obtained by dividing the time the output period of the output image data of one line of the input period or a reproduced image. 2. The data processing unit is configured by an encoding processing unit that performs encoding and decoding on the first image data to generate the second image data. The moving image input / output device according to item 1.