JPH07184189A - Video information storage controller - Google Patents

Abstract

PURPOSE:To prevent disturbance of the screen when coded video information is reproduced by using correlation between consecutive coding object video frames. CONSTITUTION:An H.261 decoding section 14 decoding coded video data and an H.261 intra coding section 15 coding the decoded video data in the in-frame mode (intra mode) are provided to the video information storage controller comprising a reception section 11, a communication section 12 and a transfer section 13. Then coded video data for an initial pattyern to be stored are transferred via said H.261 decoding section 14 and the H.261 intra coding section 15 and the coded video data (intra pattern) coded in the intra mode are stored as an initial pattern, then the initial pattern without disturbance in the reproduction is warranted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video information storage control device, and more particularly to a video information storage control device for displaying and playing back a stored video file from a video information storage / playback center (storage device). Regarding

[0002]

2. Description of the Related Art In recent years, with the development and spread of digital transmission lines and the progress of image processing technology, high-speed digital signal processing,
And the development of LSI technology for that, ISDN
It is expected that the video information service using the high-speed digital transmission network represented by (Integrated Services Digital Network) will be effectively used. As a typical image communication service,
Videophone services, videoconference services, etc. have become real, but as the latest new service, a service that mediates information to an unspecified number of users at an unspecified time is expected.

For this reason, in order to enable the information to be distributed to an unspecified number of users, the information is accumulated in an accumulating (recording) device such as a host center and reproduced to an unspecified number of terminals. , And a system for controlling storage from an unspecified number of terminals is required. As one of the systems, there is a video information storage controller, which controls the storage of video information in a host center.

FIG. 3 is a block diagram of a conventional video information storage control system. In the figure, 21a to 21e are terminal devices, 22 is a digital transmission network, 23 is a video information storage control device, and 24.
Is a receiving unit, 25 is a communication control unit, 26 is a transfer unit, and 27 is a storage (recording) device. At present, it is assumed that the video information storage control device is connected to an audiovisual terminal device (hereinafter referred to as an AV terminal), but the AV terminal complies with CCITT (International Telegraph and Telephone Consultative Committee) recommendation. The coding of video information is recommended by H.264. It is supposed to be unified with the method of 261.

As shown in FIG. 3, the configuration of the conventional video information storage control device comprises a communication control unit 25, a receiving unit 24 and a transfer unit 26, and the communication control unit 25 starts the storage. In response to the instruction, the encoded video data received by the receiving unit 24 is transferred to the storage (recording) device 27 such as the host center via the transfer unit 26, and the transfer is ended by the instruction to end the storage. The coded video data at this time is as described above in Recommendation H.264. It is video data compliant with H.261. This encoding method will be described below.

[0006] FIG. FIG. 26 is a diagram showing a hierarchical structure of encoded video data in H.261. From the top, video frame (Frame), group of blocks (G
OB: Group Of Block, MB: Macro Bloc
It can be considered as a two-dimensional division unit in the frame of the video information in the encoding process such as k) and block. Among these, unique words (PSC,
Since it includes self-synchronization information according to GBSC), the decoder can perform synchronization recovery in these units at the start of communication or when a transmission error occurs. Therefore,
The above two structures can be regarded as a transmission structure unit of encoded data.

[0007] FIG. In the block diagram of the H.261 encoder,
In the figure, 31 is an information source coding unit, and 32 is a transmission line coding unit. Recommendation H. In H.261, in addition to the information source coding unit 31 that reduces the amount of information included in a video to generate coded data, the coder adds information on transmission error resistance and information on coded data after coding. A transmission line coding unit 32 is provided for adapting to the transmission line, such as inserting dummy information in order to absorb fluctuations in the amount. The transmission path coding unit 32 mainly performs error correction coding (Forward Error Correction: FEC) on the coded video data.

FIG. 6 is a block diagram of an error correction frame. Recommendation H. In H.261, (511, 493) BCH
(Bose Chaudhuri Hocquenghem) code is used. The error-correction-coded data is 1-bit error-correction frame bit for synchronizing an error-correction frame (FEC frame) with a synchronization bit pattern, 1-bit fill identifier (Fi), and 492-bit encoded video data. Alternatively, 1 FEC frame is constructed and transmitted from fill bits (all 1 data) and 18-bit error correction parity.

FIG. 7 is a block diagram of motion-compensated interframe predictive coding. In the figure, 41 is a difference calculation unit, 42 is an error coding unit, 43 is an error decoding unit, 44 is an addition unit, and 45 is a frame. The memory unit 46 is a motion compensation inter-frame prediction unit. On the other hand, Recommendation H.264. In the H.261 encoding algorithm,
Video information is coded by a hybrid coding method that combines motion-compensated interframe prediction and intraframe orthogonal transform coding. In this hybrid coding method, an intra mode called a synchronous refresh (a mode in which coding is performed only within a frame) is used in combination with the information amount of video data reduced by using motion-compensated inter-frame prediction. The intra mode is inserted when there is a screen that cannot be correlated with the previous screen or is inserted at regular time intervals to prevent a mismatch between the sender and the receiver due to a transmission error or the like. In this encoding method, encoding is performed mainly by using the difference between consecutive encoding target video frames by motion compensation.

FIG. 8 is a block diagram of a decoder (decoder). In the figure, 51 is a transmission line decoding unit and 52 is an information source decoding unit. Recommendation H. The decoding method of H. 261 is based on the above-mentioned Recommendation H.264. It is considered that the reverse flow of the coding method of H.261 is followed.

[0011]

At the time of storage, the transmitting AV terminal is provided with the above-mentioned Recommendation H.264. In accordance with H.261, coding is performed using motion-compensated interframe prediction between consecutive coding target frames, and coded video data is transmitted as shown in FIG. 9A. When the storage operation is started in the video information storage center, for example, the encoded video data B _{0 to} B _n in FIG. 9A is cut out and stored in a storage device such as a host machine. At this time, the screen B ₀ is predicted and coded with reference to the screen B _-1 .

Next, considering the operation at the time of reproduction, the coded video data B _{0 to} B _n stored successively from the screen A _-1 is read from the video information storage center from the host machine, As shown in FIG. 9 (b), it is sent to the receiving AV terminal. Since the integrity of the encoded video data is maintained in these data, the reception AV terminal can normally decode the data.

However, at the time of storage (coding), the screen B ₀
Was predicted with reference to the screen B _-1 , whereas during reproduction, the screen A _-1 , which is the previous video to be encoded, is referred to. Thus, the screen B ₀ at the time of coding and at the time of decoding occurs a mismatch that is predicted from the different screen, the screen B ₀ at the receiving AV terminal successfully recovered, it can not be displayed. Further, since the video after B ₁ is also sequentially inter-frame predictive coded, this influence spreads to the subsequent video information, and the phenomenon of screen disorder occurs.

The present invention has been made in view of such circumstances, and the encoded video data of the initial screen to be stored is encoded video data (intra screen) encoded in the intra-frame mode (intra mode). Accordingly, it is an object of the present invention to provide a video information storage control device that eliminates the disturbance of the initial screen during reproduction.

[0015]

In order to achieve the above object, the present invention transfers video information from a high speed digital transmission network to a storage device which records encoded video information and controls the storage process. In order to do so, the receiving unit, the communication control unit,
In a video information storage control device including a transfer unit, a video decoding unit that decodes encoded video data, and an intraframe video code that encodes the video data decoded by the video decoding unit in an intraframe mode Encoding data of the initial screen to be stored is transferred via the video decoding means and the intra-frame video encoding means, and is stored as encoded video data encoded in the intra-frame mode. It is characterized by doing.

[0016]

In the video information storage control device of the present invention, the H.264 video decoding means. The H.261 decoding unit decodes the coded video data, and H.264 which is an intra-frame video coding means.
The 261 intra encoding unit encodes the decoded video data in intra mode. The encoded video data in the intra mode, which is not the motion-compensated inter-frame predictive coded video data, is stored in the stored encoded video data of the initial screen through the video decoding means and the intra-frame video coding means. Only the initial screen can be configured. Therefore, the disturbance of the initial screen at the time of reproduction is eliminated and the reference screen of the next screen which is correlated at the same time is eliminated, so that the disturbance of the screen does not spread.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram for explaining an embodiment of a video information storage control device according to the present invention. In the figure, 11 is a receiving unit, 12 is a communication control unit, 13 is a transfer unit, and 14 is a decoding unit ( H.261) and 15 are intra encoding units (H.2).
61).

First, when the receiving unit 11 receives the encoded video data, the following H.264 signal is received under the control of the communication control unit 12. 26
1 The encoded video data is sent to the decoding unit 14 or the transfer unit 13. The coded video data here is the conventional coded video data that is coded by the hybrid coding method, which is a combination of motion-compensated interframe prediction and intraframe orthogonal transform coding, similar to general video data. is there.

The communication control unit 12 switches the control of the transfer unit 13 and the transmission path of the video data depending on the operation state of accumulation start and accumulation. H. The 261 decoding unit 14 decodes the coded video data to restore the temporal video information. Here, motion-compensated interframe prediction decoding, inverse DCT
(Discreat Cosine Transform) etc. Processing similar to that of the H.261 decoder is performed.
H. In the H.261 intra encoding unit 15, the recommendation H.264 is provided. Two
The decoded video data decoded in 61 is encoded in the intra mode. In the transfer unit 13, the H.264. The encoded video data sent from the 261 intra-encoding unit 15 or the receiving unit 11 is transferred to a storage device such as a host center under the control of the communication control unit 12.

FIG. 2 is a flow chart for explaining the operation of the video information storage control device according to the present invention. Hereinafter, each step will be described in order. If the accumulation operation status is video data from the end of accumulation to the initial screen when accumulation starts, first, when encoded video data is received (step 1), it is judged whether accumulation is in progress (step 2), and accumulation is performed. If not, the received encoded video data is decoded (step 3). Next, it is judged whether or not it is the initial screen for starting the accumulation (step 4). If the accumulation is not started, the process returns to the step 1, and if the accumulation is started, the H. The initial screen is read from the frame memory of the H.261 decoding unit 14 (step 3),
H. It is sent to the transfer unit 13 via the 261 intra encoding unit 15 (step 5). The transfer unit 13 receives a transfer start command from the communication control unit 12, starts transfer of video data,
When the storage is completed, the transfer of the video data is completed (step 6).

This H.264 In the H.261 intra coding 15,
This initial screen is recommended by H. It is encoded using only the in-frame mode in the regulations of H.261 and is output as encoded video data. Therefore, H.264. The 261 intra coding unit 15 does not need to perform interframe predictive coding,
Normal H. The motion-compensated prediction process, which is considered to occupy most of the processing load in the H.261 coder, and the frame memory therefor are not required.
It is a very simple process and hardware for it.

When the state of the accumulation operation is the image data being accumulated, that is, when it is judged that the accumulation is being performed in the step 2, as the encoded image data subsequent to the initial image encoded in the intra mode, H ． H.261 decoding unit 14 and H.264. The H.261 intra-encoding unit 15 is not used, and the receiving unit 1
From 1 directly sent to the transfer unit 13 in video frame units,
Transferred.

As described above, according to the embodiment of the present invention, the initial screen of the coded video data to be stored is the intra mode screen (intra screen) which is the reference screen of the next screen to be correlated, and the subsequent screens are the conventional screens. As described above, since the screen of video data is encoded by the hybrid coding method that combines motion-compensated interframe prediction and intraframe orthogonal transform coding, the initial screen of the above-mentioned intra mode is added to the top screen of the conventional video data. And can be transferred to the storage device.

[0024]

As is apparent from the above description, in the video information storage control device of the present invention, the coded video data of the initial screen to be stored and the coded video data of the subsequent screens are separated and the initial video data is stored. By making the screen an intra screen that serves as a reference screen for the next screen to be correlated, it is possible to eliminate the disturbance of the initial screen during reproduction and the disturbance of the screen that spreads thereafter.

[Brief description of drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of a video information storage control device according to the present invention.

FIG. 2 is a flow chart of video data for explaining the operation of the video information storage control device according to the present invention.

FIG. 3 is a configuration diagram of a conventional video information storage control system.

FIG. 4 is an explanatory diagram for explaining a conventional hierarchical structure of video data.

FIG. 5 is a configuration diagram of a conventional encoding unit.

FIG. 6 is an explanatory diagram for explaining conventional error correction.

[Fig. 7] Fig. 7 is a configuration diagram for explaining conventional motion-compensated interframe predictive coding.

FIG. 8 is a block diagram of a conventional decoder.

[Fig. 9] Fig. 9 is an explanatory diagram illustrating the principle of a motion-compensated interframe predictive coding method.

[Explanation of symbols]

11 ... Receiving unit, 12 ... Communication control unit, 13 ... Transfer unit, 14
Decoding unit (H.261), 15 Intra coding unit (H.261).

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical indication location H04M 3/56 C H04N 5/92 7/32 H04N 5/92 H 7/137 Z (72) Inventor Tsuneaki Iwano 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Prefecture Sharp Corporation (72) Inventor Hirotaka Nakano 1-1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Osamu Nakamura Tokyo 1-1-6 Uchisaiwaicho, Chiyoda-ku Nihon Telegraph and Telephone Corporation

Claims (1)

[Claims] 1. A receiving unit, a communication control unit, for transferring video information from a high-speed digital transmission network to a storage device for recording coded video information and controlling the storage processing,
In a video information storage control device including a transfer unit, a video decoding unit that decodes encoded video data, and an intraframe video code that encodes the video data decoded by the video decoding unit in an intraframe mode Encoding data of the initial screen to be stored is transferred via the video decoding means and the intra-frame video encoding means, and is stored as encoded video data encoded in the intra-frame mode. A video information storage control device characterized by: