KR19990041939A - Compression Information Format of Image Coding System - Google Patents

Abstract

According to an embodiment of the present invention, an image signal applied from the outside is added to a data unit including a plurality of image groups (GOPs) consisting of one reference screen and a plurality of prediction screens for the reference screen, CLAIMS 1. A compression information format of a video encoding system for representing compressed information for a data, comprising: a data unit number for identifying the data unit; A data unit start position for indicating a start position of the data unit; A data unit end position for indicating an end position of the data unit; A GOP screen configuration number for indicating a screen configuration number of each of a plurality of picture groups (GOPs) constituting the data unit; By providing a compression information format of an image encoding system including information on an I picture start position for indicating a start position of an I picture, which is a reference screen for configuring the GOP screen, a variable that compresses and encodes a number of GOP picture configurations This has the effect of enabling compression coding.

Description

Compression Information Format of Image Coding System

The present invention relates to a video encoding system for compressing and encoding a video signal. More particularly, the present invention relates to a video encoding system suitable for a video encoding system configured to compress and encode a variable number of picture groups of a group of pictures (GOP). A compressed information format.

With the development of the industry, information media has been developed from text to voice, from voice to video, and more recently from multimedia integrated into it.

On the other hand, the amount of data in each information medium is about 16 kb for 1000 letters and about 8.5 Mb for newspapers, whereas for voice, about 230 Mb and CD (Compact Disc) for 1 hour. About 5.0Gb per hour, and 109Gb for video per hour, 360Gb for current TV, 4320Gb for high-definition TV (aka 'HDTV').

In addition, in order to transmit such information media in real time, voice is about 64kbps, CD (Compact Disc) is about 1.4Mbps, video is about 30Mbps, current TV is about 100Mbps, and high definition TV is about 1.2Gbps. Transmission speed is required.

Therefore, the development of information media inevitably requires the development of communication media and storage media. Such a requirement has been solved by information compression technology. In other words, information compression technology enables the recording of multimedia information such as video images on inexpensive storage media, and can reduce the amount of data occupied on the storage media. Communication is possible at low rates. In addition, high quality video can be transmitted without deterioration in broadcast media, and multi-channel can be achieved.

Such information compression techniques are known to be the most efficient hybrid coding scheme combining probabilistic coding and temporal and spatial compression. These techniques are, for example, MPEG-1, which has already been drafted by the World Standards Organization. And recommendations in MPEG-2 and the like.

In this case, the stochastic coding technique assigns a short code to a high probability of occurrence for a discrete cosine transform (DCT) coefficient or a motion vector and a long code length to a value having a low probability of occurrence. It is a technique to reduce the code length, and the temporal compression technique is a technique that encodes only the information about the moving coordinates (i.e., the motion vector) of the changed part in the full screen by using similarities between neighboring screens. Quantizes one screen into 8 × 8 pixel square blocks, performs DCT transform on each divided square pixel block, and then divides the transformed DCT coefficients by a predetermined number (quantization stem) to round the rest. Is a compression technique.

As described above, since a hybrid encoding scheme uses a correlation with neighboring screens to construct a screen, since only a single screen of information does not form a complete screen, a GOP (Group Of Pictures) structure is used. It is a group of data about several prediction screens including one reference screen as information on one screen.

That is, referring to FIG. 1, which shows an example of an arrangement of picture types in a GOP, one GOP includes a picture of I picture composed of information about one complete picture, and includes a prediction picture for a reference picture B and P. You can see that it consists of 14 pictures.

Here, an I picture (Intra Picture) is an intra picture encoded with only one piece of picture information without using inter-frame prediction in order to secure independence of the GOP, and P picture (Predictive-Picture) and B picture (Bidirectionally Predictive). A picture) is an inter picture generated by performing prediction from an I picture that is an intra picture.

However, since the GOP according to the related art described above is composed of a fixed number of screens irrespective of the degree of change between screens, image quality deterioration may occur when the degree of change between screens such as scene change is severe. If the degree of change in the liver is very fine, there was a problem that the compression efficiency is lowered.

Therefore, as a method for increasing the compression efficiency while maintaining high image quality, a method of compressing and encoding a variable number of screen configurations of a video group (GOP) in accordance with the degree of screen change has been proposed.

However, in the related art, since the number of screen configurations of the video group (GOP) is configured to be constant, information on a separate number of GOP screen configurations is not necessary. However, in the method of compressing and encoding the number of screen configurations of the video group, the compressed code is decoded. In order to do this, information on the number of GOP screen configurations is inevitably provided.

Accordingly, the present invention has been made to implement the above-mentioned variable compression coding system, an object of the present invention is configured to insert information about a video group (GOP) compression-coded with a variable number of screen configuration, into a compressed code, A compression information format of a video encoding system is provided.

In order to achieve the above object, in the present invention, an image signal applied from the outside is added to a data unit including a plurality of image groups (GOPs) composed of one reference screen and a plurality of prediction screens for the reference screen. A compression information format of a video encoding system for representing compressed information for the data unit, comprising: a data unit number for identifying the data unit; A data unit start position for indicating a start position of the data unit; A data unit end position for indicating an end position of the data unit; A GOP screen configuration number for indicating a screen configuration number of each of a plurality of picture groups (GOPs) constituting the data unit; A compression information format of an image encoding system including information on an I picture start position for indicating a start position of an I picture which is a reference screen for configuring the GOP screen is provided.

1 is an exemplary diagram showing an example of a screen type arrangement in a GOP according to the prior art;

2 is a block diagram showing a video encoding system suitable for using the compressed information format according to the present invention;

3 is a structural diagram showing a structure of a data unit according to the present invention;

4 is a structural diagram showing a data unit header according to the present invention;

<Description of Symbols for Main Parts of Drawings>

100: frame memory 200: screen change detection unit

300: system control unit 400: variable compression unit

500: compression information insertion section 10: data unit number

20: Data unit start position 30: Number of screen configurations of each GOP

40: I picture start position 50: Data unit end position

The above and other objects and advantages of the present invention will be apparent from the following description with reference to the accompanying drawings.

Hereinafter, the compression information format of the video encoding system according to the present invention will be described in detail with reference to FIGS. 2 to 4.

2 is a block diagram illustrating a video encoding system suitable for using a compressed information format according to the present invention, FIG. 3 is a structural diagram showing a structure of a data unit according to the present invention, and FIG. 4 is according to the present invention. It is a structural diagram which shows a data unit header.

Referring to FIG. 2, a video encoding system suitable for using the compressed information format according to the present invention includes a frame memory 100, a screen change detection unit 200, a system memory 300, a variable compression unit 400, and compression. It is configured to include an information insertion unit 500, each function is as follows.

First, the frame memory 100 sequentially stores image signals input from the outside, and when information on one screen is completed, the frame change degree detection unit 200 and the variable compression unit 400 sequentially store information on one screen. To provide.

The screen change detection unit 200 detects the change between screens from the information on the screens sequentially provided in the frame memory 100, and provides the detected screen change degree to the system controller 300.

The system controller 300 compares the inter-screen change degree provided by the screen change degree detector 200 with a preset reference value, and encodes an intra screen when the screen change degree is larger than the preset reference value based on the comparison result. If the screen change degree is smaller than the preset reference value, the variable compression unit 400 is controlled to encode the inter screen.

The variable compression unit 400 encodes screen information provided from the frame memory 100 into an intra screen or an inter screen under the control of the system controller 300. That is, a plurality of prediction screens are encoded based on the intra screen. In other words, the variable compression unit 300 performs compression encoding by varying the number of screen configurations of the image group GOP.

The compression information inserting unit 500 controls information about a variable compression ratio performed by the variable compression unit 400, that is, a variable number of screen configurations of the image group GOP, under the control of the system control unit 300. 400 is inserted into a compression code that is compression-encoded.

The compressed information format according to the present invention suitable for an image encoding system that performs the above function will be described below. In this case, according to an exemplary embodiment of the present invention, when a unit for storing a compressed code, the image signal of which is compression-coded, is called a data unit, as shown in FIG. 3, the data unit includes a plurality of sectors. And a data unit header containing sub video data, main video data, audio data, and compressed information about each data.

Here, the sub-picture data is data for an image added to an image based on the video data, such as a subtitle, and the main video data is video data for the main screen. Further, the audio data is data on audio information added to an image based on the main video data.

In this case, the data unit header contains compressed information according to the present invention, and the data unit of the data unit including sub-picture data, main video data, and audio data is stored. Referring to FIG. 4, the data unit according to the present invention. The header includes the data unit number 10, the data unit start position 20, the number of picture configurations 30 of each of the plurality of picture groups GOPs provided in the data unit, and the I picture included in each picture group GOP. Information about the start position 40, the end position 50 of the data unit, and the like are included.

The data unit number 10 is a kind of identifier for distinguishing the data units, the data unit start position 20 contains information on the start position of the data unit according to the present invention, and the data unit end position 50 is the data Contains the end position of the unit.

On the other hand, the screen configuration number 30 of the image group (GOP) will be stored in a table of information on the screen configuration number of each GOP constituting the main image data in the data unit, I picture start position 40 is respectively It indicates the start position of the I picture included in the GOP. Therefore, the decoding unit (not shown) may configure a predetermined GOP using information on the number of GOP screen configurations using the I picture placed at the start position 40 of the I picture as a reference screen.

According to the present invention as described above, by providing the compression information necessary for decoding the variable number of screen configuration of the video group (GOP), it is possible to increase the compression efficiency by the variable compression coding.

Claims (1)

Compressed information about the data unit is added to a data unit having a plurality of group of pictures (GOP) including a reference picture and a plurality of prediction pictures for the reference picture, which are applied from the outside A compressed information format of a video encoding system for representing A data unit number for identifying the data unit; A data unit start position for indicating a start position of the data unit; A data unit end position for indicating an end position of the data unit; A GOP screen configuration number for indicating a screen configuration number of each of a plurality of picture groups (GOPs) constituting the data unit; And a information about an I picture start position for indicating a start position of an I picture which is a reference screen for configuring the GOP screen.