JPH0591497A - Videophone signal transfer method for video - Google Patents

Abstract

(57) [Summary] [Purpose] Even if control such as fast-forwarding is performed on the terminal side, synchronous processing of coded video data for moving images and audio data is assured, and video distortion does not occur. [Configuration] Coded voice data to be stored in the host of the center is divided (blocking) at regular intervals,
V1, V2, V3 ... Is divided into blocks, and the encoded video data is divided into blocks P1, P2, P3 ... Starting with Pi for each inter-frame encoded data Pi that is periodically inserted in inter-frame encoding. The two pieces of data are arranged in time series, and the encoded audio data corresponding to each block of the encoded video data is combined and packetized. This packetized data is stored in the host and read from the video / telephone set (terminal).
The host transfers packets in packet units, and in response to commands such as fast forward and rewind, the host skips a certain number of transfer packets. Therefore, in the video-telephone set, the reproduction is always started from the intra-frame coded video data Pi, and the video is not disturbed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving picture video telephone signal storage and switching system using a center-to-end communication mode, in which a signal transmitted from a moving picture video telephone is transmitted to a host of the center in real time. Is about how to transfer to.

[0002]

2. Description of the Related Art Conventional center-to-end real-time information storage and exchange systems mainly deal with audio information only, and transfer in consideration of synchronous reproduction processing of coded video data for audio and audio data. There was no device.

[0003]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention When displaying a message consisting of video and audio of a videophone for moving pictures which employs an interframe coding system stored in a center on a terminal, VT is displayed.
When control is performed to change the playback start position on the terminal, such as fast-forwarding and rewinding as in R, the host performs playback for the amount of time supported by the terminal (the time corresponding to the amount of fast-forwarding or rewinding). The data whose start position has been changed will be transferred to the terminal, but at this time, the data does not always start from the intra-frame coded data, that is, the coded data for the first screen, so rather it is reproduced from the middle frame. In many cases, since there is no accumulated data up to that point, the inter-frame coded data cannot be reproduced correctly, and the image is disturbed for a relatively long time.

An object of the present invention is to always start from intra-frame coded data, that is, data of the first frame of inter-frame coding, even when performing control such as fast-forwarding, and synchronizing video data and audio data. An object of the present invention is to provide a videophone signal transfer method for moving pictures that guarantees processing.

[0005]

According to the present invention, coded audio data and coded video data transferred from a moving picture video telephone using two communication channels when a user makes a storage request. On the other hand, for coded audio data, blocking is performed at fixed time intervals, and for coded video data, the coded video data that is not inserted between frames is inserted periodically, that is, the initial frame of interframe coding. Blocking at least one frame of the data sequence starting from the one corresponding to the video data of 1 as a unit, and blocking at almost the same time interval as the audio,
By mixing and combining the blocking unit of the encoded audio data and the blocking unit of the encoded video data in the order of data generation time, the audio and the video are synchronized,
When the number of blocks of the combined coded video data reaches a certain number, the coded audio / coded video mixed combined data is transferred as a transfer packet to the host unit of the center in real time and transferred by the host. The packet is stored in the magnetic medium as it is, and when the user makes a reproduction request, the encoded audio / encoded video mixed combined data transferred from the host is separated into the encoded audio data and the encoded video data. , The separated encoded audio data and the encoded video data are transferred to the information user's moving picture video telephone in real time using two communication paths.

[0006]

According to the transfer method of the present invention, the audio and video signals transmitted from the video / telephone set using two communication paths are combined into one packet in which audio and video are mixed so as to guarantee the synchronous relationship between the audio and video. By assembling the data to the host and storing it in the host as it is, the handling of the audio and video synchronized reproduction by the host is simplified.

[0007]

Embodiments of the present invention will be described in detail below.
FIG. 1 shows a moving picture / videophone signal storage / exchange system to which an embodiment of the present invention is applied. The video and video phones 1 and 2 used by the user are connected to the ISDN communication network 3,
A center 4 is also connected to the ISDN communication network 3. The center 4 is composed of a host 5 and a videophone signal transfer device 6 for moving images.

The host 5 is mainly composed of an electronic computer, and is composed of a SCSI communication control unit 51, a call management unit 52, a service management unit 53, and a storage management unit 54. The moving picture videophone signal transfer device 6 includes an I interface control unit 60, a data control unit 61, a communication command buffer unit 62, an audio buffer unit 63, and a video buffer unit 64.
A refresh screen detecting section 65, a transfer packet assembling / disassembling section 66, an upstream SCSI communication buffer section 67, and a downstream SCSI communication buffer section 6
8 and a SCSI communication control unit 69.

The operation of this embodiment will be described below. When the user connects the video-video-phone 1 to the video-video-phone signal transfer device 6 via the ISDN communication network 3, the I-interface controller 60 in the video-video-phone signal transfer device 6 causes the video-video-phone 1 to transfer from the video video-phone 1. The incoming call information is transferred to the data control unit 61. As for the incoming call information, the data control unit 61 extracts the incoming call information, transfers it to the communication command buffer unit 62, and the SCSI communication control unit 69
After performing a SCSI (normally used computer interface) communication protocol process between the host and the SCSI communication control unit 51, the host 5 is notified. Then host 5
In the call management unit 52 inside, it is determined whether the call can be accepted,
The response is sent back to the video / telephone set 1 via the reverse route of the incoming notification.

On the other hand, in the host 5, the service management unit 53 is activated from the call management unit 52, and the storage management unit 54 instructs to transmit the initial menu data to the videophone 1 with which the call is established. The initial menu data is transferred to the video-telephone signal transfer device 6 for moving images after the SCSI communication control unit 51 and the SCSI communication control unit 69 perform the SCSI communication protocol process. Further, in the videophone signal transfer device 6 for moving images, the transfer packet assembling / disassembling unit 66 is passed via the downlink SCSI communication buffer 68.
, The encoded audio data and encoded video data are separated.

The downlink SCSI communication buffer 68 has a double buffer structure to guarantee real-time transfer. The encoded audio data and the encoded video data that have been separated are respectively the audio buffer unit 63 and the video buffer unit 6.
4, the data control unit 61 converts the data into a data format to be transmitted to the ISDN communication network 3 via the I interface control unit 60. In this way, the video-phone 1 receives the initial menu data, and the video and audio guidance is presented.

When the user issues a request from the video-telephone set 1 to store audio and video information of the video-telephone set 1 to the host, the above-mentioned coded video data and coded audio data of the ISDN communication network 3 are transferred. By using a part of the two B channels used in the above, it is transmitted to the videophone signal transfer device for moving image 6 as key input information, subjected to I interface communication protocol processing in the I interface control unit 60, and transferred to the data control unit 61. To be done. Further, only the key input information is extracted by the data control unit 61, transferred to the communication command buffer unit 62, and then notified to the host 5 by the SCSI communication protocol via the SCSI communication control unit 69. In the host 5, the SCSI communication control unit 51,
The service management unit 53 is notified via the call management unit 52. The service management unit 53 instructs the moving picture video phone signal transfer device 6 to transfer the coded audio data and the coded video data transmitted from the moving picture video phone 1 to the moving picture video phone signal transfer device 6. Give instructions. The instruction information is notified to the SCSI communication control unit 69 by a route opposite to that of the key input information for making the storage request.

The coded video data and the coded audio data from the moving picture videophone 1 are transmitted to the moving picture videophone signal transfer device 6 in real time using the two B channels of the ISDN communication network 3. Then, the I interface control unit 60 processes the I interface communication protocol and transfers it to the data control unit 61. Further, the data control unit 61 extracts the encoded audio data and the encoded video data, and respectively extracts the audio buffer unit 63 and the video buffer unit 64.
To store. Next, in the transfer packet assemble / disassemble unit 66, the encoded audio data stored in the audio buffer unit 63 is sequentially blocked (divided) at fixed time intervals and stored in the video buffer unit 64. For the encoded video data that has been encoded, the data is sequentially blocked (divided) in units of one cycle of the encoded video data that is not periodically inserted and is not encoded. Since the difference between frames is encoded, if the data is temporarily cut off in the middle for some reason, the reproduced video will be greatly disturbed after that. Similarly, the frame can be played by itself. For example, it is transmitted as inter-frame coded data. The encoded video data is blocked for each interframe encoded data.

The coded audio block data and the coded video block data are mixed and mixed in the order of data generation time to synchronize the audio information and the video information. When combining the data, audio and video flags are added to the beginning of each block data so that the audio information and the video information can be identified in the subsequent processing. Regarding the detection of the coded video data which is not subjected to the interframe coding which is periodically inserted as described above, the refresh screen detection section 65 is determined by the coded video data transferred from the video buffer section 64.
Done in. The detection trigger in the refresh screen detecting section 65 is the transfer packet assembling / disassembling section 66.
And the encoded video data is divided into blocks as described above.

In this way, when the above-mentioned coded video / coded audio mixed data reaches a fixed number, the upstream SCS
It is transferred to the I communication buffer 67. The upstream SCSI communication buffer 67 is the downstream SCSI communication buffer 6 described above.
As in the case of 8, the double buffer structure is adopted to guarantee real-time transfer to the host 5. Up SCS
The data in the I communication buffer 67 is stored in the SCSI communication control unit 6
Then, the SCSI communication control unit 69 determines whether or not the transfer to the host 5 is possible based on the presence / absence of the transfer instruction from the host 5 based on the command from the above-mentioned video / telephone set. If the transfer instruction is not received, it is discarded. If the transfer instruction is received, SCSI communication protocol processing is performed with the SCSI communication control unit 51, and the call management unit 52 and the service management unit 53.
The storage management unit 54 stores the mixed audio / video in a predetermined file in the magnetic medium.

FIG. 2 illustrates how to code mixed data of coded video and coded audio and assemble a transfer packet. The audio buffer 63 and the video buffer 64 are shown in FIG.
The data is transferred in time series as shown in (A). In this case, the encoded voice data is V
1, V2 ... V9 are divided into blocks. In the encoded video data, video data Pi that is not subjected to interframe coding is periodically inserted into the interframe coded data Pf, and at the generation cycle of the Pi, P1 and P2 start from this.
It is divided into blocks such as. This data is rearranged in time series, and in the example of FIG. 2B, an example is shown in which one block of encoded video data is packetized.

Next, the operation of retrieving the stored data and presenting it to the moving picture video telephone will be described. After making a call connection between the moving picture video phone 2 and the center 4, when the moving picture video phone 2 issues a request for reproducing the above-mentioned stored video phone signal to the host 5, the inside of the moving picture video phone signal transfer device 6 is described above. Of the storage request, the predetermined voice and video data stored in the storage management unit 54, which is recognized by the service management unit 53 in the host 5 and is stored in the storage management unit 54, are searched, A transfer packet containing a mixture of coded images is subjected to SCSI communication protocol processing with the SCSI communication control unit 69 via the service management unit 53, the call management unit 52, and the SCSI communication control unit 51, and then a videophone for moving images. The signal is transferred to the signal transfer device 6. Further, in the moving picture video telephone signal transfer device 6, the transfer packet assemble / disassemble unit 66 separates the encoded audio data and the encoded video data via the downlink SCSI communication buffer 68.

The downlink SCSI communication buffer 68 has a double buffer structure to guarantee real-time transfer. The encoded audio data and the encoded video data that have been separated are respectively the audio buffer unit 63 and the video buffer unit 6.
4, the data control unit 61 converts the data into a data format to be transmitted to the ISDN communication network 3 via the I interface control unit 60. In this way, the information received by the video-telephone set 2 and reproduced by video and audio is reproduced in real time.

Furthermore, when a reproduction instruction such as fast-forward is issued from the video / telephone set to the host 5, the service management unit 53 of the host 5 instructs the storage management unit 54 to
Control is instructed to skip a certain number of transfer packets in FIG. 2B stored in time series and transfer. In this case, since the beginning of the encoded video data in the transfer packet always includes the video that is not interframe-encoded, the video is not disturbed even when fast-forwarding is performed.

[0020]

As described above, according to the present invention, since each video which is not inter-frame coded is blocked and processed in this block unit, the audio / video input from the video / telephone set is controlled. It is possible to store video information in the host in real time, and to play back stored data that guarantees synchronization between voice and video. Furthermore, even when performing playback control such as fast-forwarding, no drooping of video occurs.

[Brief description of drawings]

FIG. 1 is a block diagram showing an internal configuration example of a center to which an example of the method of the present invention is applied.

FIG. 2 is a diagram for explaining how to block coded video / coded audio mixed data and assemble a transfer packet.

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Claims (1)

[Claims] 1. A video / video telephone having a video / audio input / output function, a video / video telephone signal transfer device having a video / video phone signal transfer device function comprising video / audio information, and a storage / exchange function. A video-telephone signal transfer method for a video in a center-to-end video-videophone signal storage and exchange system in which a center composed of a host equipped with is connected via an ISDN network. With respect to the encoded audio data and encoded video data that are transferred using the communication path, the encoded audio data is blocked at fixed time intervals, and the encoded video data is periodically inserted. Blocking one cycle of a data sequence starting from encoded video data that is not interframe-encoded as one unit, By mixing and combining the blocking unit of the encoded audio data and the blocking unit of the encoded video data in the order of data generation time, the audio and the video are synchronized, and the number of blocks of the combined encoded video data is a certain number. At that time, the encoded voice / encoded video mixed combined data is transferred in real time to the host unit of the center as a transfer packet, and the encoded voice / encoded video mixed combined data transferred from the host is encoded. It is possible to separate the encoded audio data and the encoded video data, and transfer the separated encoded audio data and the encoded video data to the information user's video / video telephone in real time using two communication paths. Characteristic videophone signal transfer method for video.