JP2003299017A - Data storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate a delay difference between an image and a voice when sending image data and voice data to a communication network in a data storage device for storing the image data and the voice data. <P>SOLUTION: In order to transmit the image data and the voice data to a communication terminal via the communication network 3 by multiplexing the image data and the voice data, the image data and the voice data are stored in the data storage device 13 of the host computer 2. The image data and the voice data are packeted by a packet generating means of a multiplexed data transceiver 12, the generated packet is stored in a storage unit 13, and a time stamp showing the time of sending the image data and the voice data to the network 3 is generated by a time stamp generator of the transceiver 12. The packet is generated by adding the generated time stamp to the image data and the voice date, and stored in the storage device 13. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to image and audio data transmitted from a terminal that communicates video information represented by a TV telephone or the like, and particularly to image and audio data compliant with ITU (International Telecommunication Union) -T recommendation. The present invention relates to a data storage device capable of storing and reproducing stored data from an arbitrary terminal.

[0002]

2. Description of the Related Art In recent years, in addition to conventional interactive communication services such as telephone and FAX (facsimile), a storage-type service that can store voice information in a network center and reproduce it at any time. Is provided. Also, I
With the development of digital communication networks represented by SDN (Integrated Services Digital Network), it has become possible to use image communication services represented by, for example, videophones. Against this background, there is a growing demand for storage-type services that use images, and some of these services are being put to practical use.

FIG. 5 is a block diagram of a conventional data storage communication device. In the figure, 49 is a receiver of the multiplexed data transmitter / receiver, 50 is a transmitter of the multiplexed data transmitter / receiver, 51 is a line data separator, and 52 is a FEC (Forward Error Correcti).
on) error correction unit, 53 is a video frame extraction unit, 54
Is a packet generation unit, 55 is a packet decomposition unit, 56 is a data processing unit, and 57 is a line data multiplexing unit. The line data separation unit 51 follows the instruction from the system control unit.
Data such as image and voice is separated from the received circuit multiplexed data. The error correction unit 52 includes the line data separation unit 51.
The FEC error correction is performed on the image data output from.

The video frame extraction unit 53 extracts a video frame from the error-corrected data. The packet generator 54 generates a packet from the video frame extracted by the video frame extractor 53 and the audio data decomposed by the line data separator 51. The packet disassembly unit 55 disassembles the packet output from the storage device into image and audio data. The data processing unit 56 performs some processing on the data output from the packet decomposing unit 55.
The line data multiplexing unit 57 generates line multiplexed data from the data output from the data processing unit 56.

FIG. 6 is a conventional packet configuration diagram. In the figure, 61 is header information including information such as a transmission rate and a multiplexing rate of a terminal at the time of storage and a coding method of each data, 62 is a data length of an image, 63 is a data length of an audio, 6
4 is the number of video frames of an image, 65 is the data length of video frames and video frame data, and 66 is audio data. 7A and 7B are diagrams showing a conventional data multiplexing format, which is a diagram showing a data multiplexing format currently used in a videophone or the like. This data multiplex format has been adopted as an international standard, and by using this multiplex system, the interoperability of videophones and the like is secured.

In the figure, 71 and 72 are voice data,
An area assigned to image data, 73 is a frame synchronization bit, 74 is a capability / command communication bit between terminals, and 75 is a data transmission order to a communication line. The multiplexing condition of each data can be changed at any time between the terminal and the host using the capability / command communication bit 74. At the time of data storage, the line multiplexed data received from the network is separated into image and audio data by the line data separation unit 51 of FIG. 5, and the image data is FEC error correction unit 5
2. The voice data is output to the packet generator 54. F
The error correction unit 52 of the EC removes unnecessary data such as error correction of the received data and fill pits and outputs it to the video frame extraction unit 53.

In the video frame extracting section 53, the PSC
(Frame start code) is searched to extract a video frame and output to the packet generation unit 54. The packet generator 54 generates a packet according to the packet format of FIG. 6 and outputs it to the storage device. During data playback, the packet data output from the storage device is
It is received by the packet disassembly unit 55. The packet decomposing unit 5
5 notifies the system control unit of the header information of the packet. The system control unit instructs the line data multiplexing unit 57 to match the operation mode of the communication terminal at the time of storage and the operation mode of the communication terminal at the time of reproduction by using the BAS 74 of FIG.

When the line data multiplexing unit 57 completes the matching of the operation modes, the packet disassembling unit 55 disassembles the packets and outputs the image and voice data to the data processing unit 56, respectively. The data processing unit 56 performs some appropriate processing and outputs each data to the line data multiplexing unit 57. In the line data multiplexing unit 57,
Multiplexed data is generated according to the multiplexing format of FIG. 7 and sent to the communication network.

[0009]

As described above, in the conventional data storage / communication device, the multiplexed data is separated into images and sounds, and some processing is performed to store or send the data. There is a problem that a delay difference occurs between the image and the sound at the time of transmission. The present invention has been made in view of such a situation, and when the image data and the audio data are accumulated, the time stamp is added and packetized and accumulated, and the time stamp added at the time of transmitting the image data and the audio data is used. It is an object of the present invention to provide a data storage device that absorbs the delay difference between the image data and the audio data.

[0010]

A first invention of the present application is a data storage device for storing image data and audio data, which separates multiplexed data received from a communication network into image data and audio data. And a time stamp generating unit for generating a time stamp, and a time stamp is added to the image data and the audio data for storage.

According to a second aspect of the present invention, in the data storage device according to the first aspect, an error correction unit for correcting an error in the image data is provided, and the error in the image data separated from the multiplexed data is corrected. It is characterized by that.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram for explaining a data storage device according to an embodiment of the present invention. Figure 1
Inside, 1 is a communication terminal, 2 is a communication host, and 3 is a communication network such as ISDN. 4 is a camera for image input, 5 is a monitor for image output, 6 is a handset for audio input / output, 7 is a system control unit of the terminal, 8 is an image encoding / decoding unit, and 9 is an image encoding / decoding unit.
Is an audio encoding / decoding unit, 10 is a multiplexed data transmission / reception unit, and the multiplexed data transmission / reception unit 10 multiplexes encoded image data, encoded audio data, and control information and sends them to the line.

Reference numeral 11 is a system control unit of the host, 12 is a multiplexed data transmission / reception unit of the host, and the multiplexed data transmission / reception unit 12 separates and multiplexes control information from the multiplexed data. A recording device 13 stores and stores data. The moving image input from the camera 4 on the communication terminal 1 side is interframe predictive encoded by the image encoding unit 8. The encoded image data that has been encoded is input from the handset 6, is multiplexed by the multiplexed data transmission unit 10 together with the encoded voice data that has been encoded by the voice encoding unit 9 and control information, etc., and is transmitted through the communication network 3. It is transmitted to the host 2. On the communication host 2 side, the multiplexed data sent from the communication terminal 1 is received by the multiplexed data receiving unit 12. The multiplexed data receiving unit 1
In 2, the stored packet data is generated from the received data in which the image and sound are multiplexed, and the stored packet data is transferred to the storage device 13. The storage device 13 stores the file as a file of an appropriate form.

The stored data is read from the storage device 13 and sent to the multiplexed data transmission unit 12 of the host according to an instruction from the user or the host. In the multiplexed data transmission unit 12, according to an instruction from the system control unit 11,
The control information stored as it is at the time of storage is rewritten with new control information and transmitted to the communication terminal 1 through the communication network 3.
In the communication terminal 1, the multiplexed data rewriting the control information sent from the host is received by the multiplexed data receiving unit 10. The multiplexed data receiving unit 10 separates control information, image data, audio data, etc., and the control information is sent to the system control unit 7.

The coded image data received by the multiplexed data receiving unit 10 is sent to the image decoding unit 8, and the moving image is decoded and reproduced according to the instruction from the system control unit 7, and the reproduced image is reproduced. Is displayed on the monitor 5. The separated audio data is decoded and reproduced by the audio decoding unit 9 and output from the handset 6. Even during the storage / reproducing operation, the communication via the line is always bidirectional, and the control information can be communicated in the line connection state regardless of the presence or absence of image data.

FIG. 2 is a configuration diagram for explaining an example of the host multiplexed data transmission / reception unit of FIG. In FIG. 2, 14
Is a receiving unit, 15 is a transmitting unit, 21 is a line data separating unit, 2
2 is an error correction unit of FEC (Forward Error Correction), 23 is a video frame extraction unit, 24 is a packet generation unit, 25 is a time stamp generation unit, 26 is a packet decomposition unit, 27 is a data processing unit, and 28 is a delay difference absorption. Reference numeral 29 is a line data multiplexing unit.

The line data separating unit 21 separates the multiplexed data received from the communication network 3. Error correction unit 22
Is the F of the image data separated by the line data separation unit 21.
EC error correction is performed. The video frame extraction unit 23
A video frame is extracted from the image data that has undergone error correction. The packet generator 24 generates packets from data such as images and sounds. Time stamp generator 25
Generates a time stamp from the octet timing output from the line data separation unit 21.

The packet disassembling unit 26 disassembles the received packet into data such as image and voice. Data processing unit 27
Performs some appropriate processing on images and sounds. The delay difference absorbing unit 28 absorbs a delay difference generated between images and sounds based on an accompanying time stamp. The line data multiplexing unit 29 generates line multiplexed data from the image and audio data output from the delay difference absorbing unit 28.

FIGS. 3A to 3C show the receiving unit 14 of FIG.
It is a figure showing the image data between the modules of. Figure 3
2A corresponds to the signal a in FIG. 2, a synchronization signal for establishing FEC synchronization, a parity bit for performing FEC error correction, a fill bit for adjusting the amount of encoded data, and It consists of information bits.

FIG. 3B corresponds to the signal b in FIG.
FEC error correction is performed to remove extra data such as fill bits. FIG. 3C corresponds to the signal c in FIG. 2 and is a video frame extracted for each PSC (frame start code).

FIG. 4 is a packet configuration diagram when performing accumulation. 41 is header information in which information such as a multiplexing rate at the time of storage, a coding method and a coding capability is specified, 42 is a data length of an image, 43 is a data length of an audio, 44 is the number of video frames of an image, and 45 is An image time stamp, a video frame data length and video frame data, 46 is an audio time stamp, and 47 is audio data.

Next, the operation of the data storage device of this embodiment will be described. At the time of data storage, the line data demultiplexing unit 21 demultiplexes the multiplexed data received from the communication network 3 into images, sounds, etc., and the image data is FEC error correction unit 2
2, the voice data is output to the packet generator 24, and the octet timing is output to the time stamp generator 25. The time stamp generation unit 25 generates a time stamp for each octet and outputs it to the video frame extraction unit 23 and the packet generation unit 24. FEC error correction unit 22
Then, the image data in the signal state shown in FIG. 3A is received, the FEC error correction is performed, and the image data in the signal state shown in FIG. 3B is output to the video frame extraction unit 23. .

The video frame extraction unit 23 searches the received data for a PSC, and outputs the data in the signal state shown in FIG. 3C and the time stamp at the time when the PSC is found to the packet generation unit 24. . The packet generation unit 24 generates a packet according to the packet format shown in FIG. 4 from the received image and audio data and the accompanying time stamp, and the header information includes a multiplexing rate, an encoding method, an encoding capability, etc. at the time of reproduction. The necessary information is specified and output to the storage device 13.

At the time of data reproduction, the packet disassembling unit 26
Then, the packet output from the storage device 13 is received.
The packet disassembling unit 26 that has received the packet extracts the header information and notifies the system control unit 11 of it. The system control unit 11 sends the line data multiplexing unit 29 to the system shown in FIG.
Using the BSA 74 shown in (1), it is instructed to match the operation mode of the communication terminal during storage with the operation mode of the communication terminal during reproduction. When the line data multiplexing unit 29 completes the matching of the operation modes, the packet disassembling unit 26 disassembles the packet and outputs the image and audio data and the associated time stamp to the data processing unit 27. The data processing unit 27 performs some appropriate processing on the image and audio data, and outputs the data and time stamp to the delay difference absorbing unit 28. The delay difference absorbing unit 28 absorbs the delay difference from the associated time stamp, and the line data multiplexing unit 29.
Output to. The line data multiplexing unit 29 multiplexes data such as images and voices according to the multiplexing format shown in FIG. 7 to generate line multiplexed data and sends it to the communication network 3.

[0025]

As is apparent from the above description, according to the present invention, a time stamp indicating the timing of sending image data and audio data to a communication network is added to the image data and audio data and packetized, It becomes possible to absorb the delay difference between the image data and the audio data contained in the packet based on the time stamp contained in the reproduced packet, which is stored in the storage means, and send out to the communication network.

[Brief description of drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of a data storage device of the present invention.

FIG. 2 is a configuration diagram of a multiplexed data transmission / reception unit in FIG.

FIG. 3 is a configuration diagram of image data between modules in the receiving unit in FIG.

FIG. 4 is a diagram showing a packet format during storage according to an embodiment of the data storage device of the present invention.

FIG. 5 is a configuration diagram of a multiplexed data transmission / reception unit in a conventional storage-type image communication system.

FIG. 6 is a diagram showing a conventional packet format during storage.

FIG. 7 is a diagram showing a conventional data multiplexing format.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Communication terminal, 2 ... Communication host, 3 ... Communication network such as ISDN, 4 ... Camera for image input, 5 ... Monitor for image output, 6 ... Handset for voice input / output, 7 ... System control unit of terminal , 8 ... Image encoding / decoding section, 9 ... Audio encoding / decoding section, 10 ... Terminal multiplexed data transmission / reception section, 11 ... Host system control section, 12 ... Host multiplexed data transmission / reception section , 13 ... storage device, 14 ... receiving unit,
15 ... Transmission unit, 21 ... Line data separation unit, 22 ... FEC
Error correction unit, 23 ... video frame extraction unit, 24 ... packet generation unit, 25 ... time stamp generation unit, 26 ... packet decomposition unit, 27 ... data processing unit, 28 ... delay difference absorption unit, 29 ... line data multiplexing Department.

Continued front page    (72) Inventor Keiichi Hibi             22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka             Inside the company (72) Inventor Tsuneaki Iwano             22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka             Inside the company (72) Inventor Hirotaka Nakano             2-3-1 Otemachi, Chiyoda-ku, Tokyo Nihonden             Shin Telephone Co., Ltd. (72) Inventor Osamu Nakamura             2-3-1 Otemachi, Chiyoda-ku, Tokyo Nihonden             Shin Telephone Co., Ltd. F-term (reference) 5C053 GB15 GB21 JA22 LA05 LA11                       LA14                 5C064 AA01 AD12                 5K101 KK04 LL03 MM07 NN06 NN07                       NN14 NN18 NN22 NN34 SS07                       SS08

Claims (2)

[Claims] 1. A data storage device for storing image data and audio data, comprising: a separation unit for separating multiplexed data received from a communication network into image data and audio data; and a time stamp generation unit for generating a time stamp. And a time stamp is added to the image data and the audio data to store the data. 2. The data storage device according to claim 1, further comprising an error correction unit that corrects an error in the image data, and corrects an error in the image data separated from the multiplexed data. Storage device.