JP2000216828A - Data storing communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a delay difference between a picture and voice generated at the time of sending picture data and voice data to a communication network in a storing-type picture communication system. SOLUTION: A data storing communication equipment multiplexing picture data and voice data and storing picture data and voice data in order to transmit to a communication terminal through the communication network is provided with a packet generating means 24 packetizing picture data and voice data, a storing device storing a packet generated by the means 24 and a time stamp generating means 25 generating a time stamp showing timing of sending the picture data and voice data to the communication network. Then, the means 24 adds the time stamp generated by the means 25 to the picture data and voice data to generate the packet to be stored in the storing device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for transmitting, in particular, image and audio data conforming to the ITU (International Telecommunication Union) -T recommendation, which is transmitted from a terminal for communicating video information such as a TV telephone. The present invention relates to a data storage communication 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 facsimile (facsimile), a storage service capable of storing voice information in a network center and reproducing it at any time. Is provided. Also, I
With the development of a digital communication network represented by an SDN (Integrated Services Digital Network), for example, it has become possible to use an image communication service represented by a videophone. Against this background, demands for storage-type services using images have increased, and some of them have been put into practical use.

FIG. 5 is a configuration diagram of a conventional data storage communication device. In the figure, 49 is a receiving section of the multiplexed data transmitting / receiving section, 50 is a transmitting section of the multiplexed data transmitting / receiving section, 51 is a line data separating section, and 52 is a FEC (Forward Error Correction).
on) error correction unit, 53 is a video frame extraction unit, 54
Is a packet generation unit, 55 is a packet decomposing unit, 56 is a data processing unit, and 57 is a line data multiplexing unit. The line data separation unit 51, according to an instruction from the system control unit,
It separates data such as images and sounds from the received line multiplexed data. The error correction unit 52 includes a line data separation unit 51
Performs FEC error correction on the image data output from.

[0004] The video frame extraction unit 53 extracts a video frame from the data on which error correction has been performed. The packet generation unit 54 generates a packet from the video frame extracted by the video frame extraction unit 53 and the audio data decomposed by the line data separation unit 51. The packet decomposing unit 55 decomposes a 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 diagram showing a conventional packet configuration. In the figure, reference numeral 61 denotes header information including information such as a transmission rate and a multiplexing rate of a terminal at the time of storage and an encoding method of each data; 62, a data length of an image; 63, a data length of audio;
4 is the number of video frames of the image, 65 is the data length and video frame data of the video frame, and 66 is the audio data. FIGS. 7A and 7B are diagrams illustrating a conventional data multiplexing format, and are diagrams illustrating a data multiplexing format currently used in videophones and the like. This data multiplexing format is adopted as an international standard, and by using this multiplexing method, interconnectivity of a videophone or the like is ensured.

In the figure, reference numerals 71 and 72 denote audio data,
An area allocated to image data, 73 is a bit for frame synchronization, 74 is a bit for capability / command communication between terminals, and 75 is an order of data transmission 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 in FIG.
2. The audio data is output to the packet generator 54. F
The EC error correction unit 52 corrects the error of the received data and removes unnecessary data such as fill pits and outputs the data 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 shown in FIG. 6 and outputs the generated packet to the storage device. During data reproduction, the packet data output from the storage device is
The packet is received by the packet decomposing 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 accumulation with the operation mode of the communication terminal at the time of reproduction using the BAS 74 of FIG.

When the operation mode matching is completed by the line data multiplexing unit 57, the packet decomposing unit 55 decomposes the packet and outputs image and audio 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,
The multiplexed data is generated according to the multiplexed format shown in FIG. 7 and transmitted to the communication network.

[0009]

As described above, in a conventional data storage communication device, multiplexed data is separated into images, sounds, and the like, and some processing is performed to store or transmit 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 circumstances, and adds a time stamp when accumulating image data and audio data, packetizes and accumulates the image data and audio data, and calculates the time stamp from the time stamp added when transmitting the image data and audio data. It is another object of the present invention to provide a data storage communication device which absorbs a delay difference between the image data and the audio data.

[0010]

According to a first aspect of the present invention, image data and audio data are multiplexed and transmitted through a communication network.
What is claimed is: 1. A data storage communication device for storing image data and audio data for transmission to a communication terminal, comprising: a packet generation unit configured to packetize image data and audio data; and a packet generated by the packet generation unit. Storage means for storing, and time stamp generating means for generating a time stamp indicating the timing of transmitting the image data and the audio data to the communication network, wherein the packet generating means has a time generated by the time stamp generating means. A stamp is added to the image data and the audio data to generate a packet to be stored in the storage unit.

According to a second aspect of the present invention, there is provided a storage unit for storing packetized image data and audio data to which a time stamp indicating the timing of transmitting image data and audio data to a communication network is added, and the storage unit A multiplexed data transmitting unit for multiplexing the image data and the audio data stored in the multiplexed data and transmitting the multiplexed data to a communication terminal via a communication network, wherein the multiplexed data transmitting unit comprises: Based on the time stamp included in the packet stored in the storage means, the image data and the audio data included in the packet are transmitted to the communication network at a predetermined timing.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram illustrating a data storage communication device according to an embodiment of the present invention.
In FIG. 1, 1 is a communication terminal, 2 is a communication host, and 3 is an ISDN.
And the like. 4 is a camera for image input, 5 is a monitor for image output, 6 is a handset for voice input / output, 7
Is a system control unit of the terminal, 8 is an image encoding / decoding unit, 9 is an audio encoding / decoding unit, 10 is a multiplexed data transmitting / receiving unit, and the multiplexed data transmitting / receiving unit 10 is an encoded image transmitting / receiving unit. The data, coded voice data and control information are multiplexed and transmitted to the line.

Reference numeral 11 denotes a system control unit of the host, and 12 denotes a multiplexed data transmitting / receiving unit of the host. The multiplexed data transmitting / receiving unit 12 separates and multiplexes control information from the multiplexed data. Reference numeral 13 denotes a recording device that stores data. The moving image input from the camera 4 of the communication terminal 1 is subjected to inter-frame predictive encoding by the image encoding unit 8. The coded image data is input from the handset 6 and multiplexed in the multiplexed data transmitting unit 10 together with the coded voice data coded by the voice coding unit 9 and control information and the like. It is transmitted to the host 2. On the communication host 2 side, the multiplexed data received from the communication terminal 1 is received by the multiplexed data receiving unit 12. The multiplexed data receiving unit 1
In step 2, the stored packet data is generated from the multiplexed data of the received image and voice and transferred to the storage device 13. The storage device 13 stores the data as a file in an appropriate form.

The stored data is read from the storage device 13 according to an instruction from the user or the host, and sent to the multiplexed data transmission section 12 of the host. In the multiplexed data transmission unit 12, according to an instruction from the system control unit 11,
The control information stored 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 receiving unit 10 receives the multiplexed data in which the control information sent from the host is rewritten. The multiplexed data receiving unit 10 separates control information, image data, audio data, and the like, and sends the control information to the system control unit 7.

The coded image data received by the multiplexed data receiving unit 10 is sent to an image decoding unit 8, and a moving image is decoded and reproduced according to an instruction from the system control unit 7. 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. Note that, even during the storage / reproduction operation, communication via the line is always performed bidirectionally, and control information can be communicated in the line connection state regardless of the presence or absence of image data or the like. FIG. 2 is a configuration diagram for explaining an example of the host multiplexed data transmission / reception unit of FIG. FIG.
Among them, 14 is a receiving unit, 15 is a transmitting unit, 21 is a line data separating unit, 22 is an error correcting unit of FEC (Forward Error Correction), 23 is a video frame extracting unit, 24 is a packet generating unit, and 25 is a time stamp generating unit. Unit, 26 is a packet decomposing unit, 27 is a data processing unit, 28 is a delay difference absorbing unit,
29 is a line data multiplexing unit.

The line data separator 21 separates 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
Video frames are extracted from the error-corrected image data. The packet generation unit 24 generates a packet from data such as images and sounds. Time stamp generation unit 25
Generates a time stamp from the octet timing output from the line data separation unit 21.

The packet decomposing unit 26 decomposes the received packet into data such as images and sounds. Data processing unit 27
Performs some suitable processing on images, audio, etc. The delay difference absorbing unit 28 absorbs a delay difference generated between an image and a sound 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. FIG.
FIG. 3C is a diagram illustrating image data between modules of the receiving unit 14 in FIG. 2. FIG. 3A corresponds to the signal a in FIG. 2, and includes a synchronization signal for establishing FEC synchronization and an FE signal.
It is composed of parity bits for performing C error correction, fill bits for adjusting the amount of encoded data, and information bits.

FIG. 3B corresponds to the signal b in FIG.
The error correction of the FEC is performed, and unnecessary data such as fill bits is removed. FIG. 3C is a video frame corresponding to the signal c in FIG. 2 and extracted for each PSC (frame start code). FIG. 4 is a diagram showing a packet configuration when accumulation is performed. Reference numeral 41 denotes header information in which information such as a multiplexing rate at the time of accumulation, an encoding method and an encoding capability is specified, 42 is the data length of an image, 43 is the data length of audio, 44 is the number of video frames of an image, and 45 is An image time stamp, a data length of a video frame and video frame data, 46 is an audio time stamp, and 47 is audio data.

Next, the operation of the data storage communication device of the present embodiment will be described. At the time of data storage, the line data separating unit 21 separates the multiplexed data received from the communication network 3 into images, sounds, and the like. The image data is an FEC error correcting unit 22, the sound data is a packet generating unit 24, and an octet. The timing is output to the time stamp generator 25. The time stamp generation unit 25 generates a time stamp for each octet and outputs the time stamp to the video frame extraction unit 23 and the packet generation unit 24. FEC error correction unit 2
In step 2, the image data in the signal state shown in FIG. 3A is received, error correction of FEC is performed, and the image data in the signal state shown in FIG. I do.

The video frame extraction unit 23 searches for a PSC from the received data, and outputs to the packet generation unit 24 the data in the signal state shown in FIG. 3C and the time stamp at the time when the PSC is found. . The packet generator 24 generates a packet from the received image and audio data and the accompanying time stamp in accordance with the packet format shown in FIG. 4, and includes, in the header information, a multiplexing rate, an encoding method, an encoding capability, and the like 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 decomposing unit 26
Then, the packet output from the storage device 13 is received.
The packet decomposing unit 26 that has received the packet extracts the header information and notifies the system control unit 11 of the extracted header information. The system control unit 11 controls the line data multiplexing unit 29 as shown in FIG.
Is instructed to match the operation mode of the communication terminal at the time of accumulation with the operation mode of the communication terminal at the time of reproduction using the BSA 74 shown in FIG. When the operation mode matching is completed in the line data multiplexing unit 29, the packet decomposing unit 26 decomposes the packet, and outputs image and audio data and the accompanying time stamp to the data processing unit 27. The data processing section 27 performs some appropriate processing on the image or audio data, and outputs data and a time stamp to the delay difference absorbing section 28. The delay difference absorbing unit 28 absorbs the delay difference from the accompanying time stamp, and
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.

[0022]

As is apparent from the above description, according to the present invention, a time stamp indicating the timing of transmitting image data and audio data to a communication network is added to the image data and audio data to form a packet. Based on the time stamp contained in the reproduced packet, the delay difference between the image data and the audio data contained in the packet is absorbed and transmitted to the communication network.

[Brief description of the drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of a data storage communication 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 of FIG. 2;

FIG. 4 is a diagram showing a packet format at the time of storage according to an embodiment of the data storage communication 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 at the time of accumulation.

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 unit, 9: audio encoding / decoding unit, 10: multiplexed data transmission / reception unit of terminal, 11: host system control unit, 12: multiplexed data transmission / reception unit of host , 13 ... storage device, 14 ... receiving unit,
15: transmission unit, 21: line data separation unit, 22: FEC
Error correction section, 23 video frame extraction section, 24 packet generation section, 25 time stamp generation section, 26 packet decomposition section, 27 data processing section, 28 delay difference absorption section, 29 line data multiplexing Department.

Continued on the front page (72) Inventor Keiichi Hibi 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka Inside (72) Inventor Tsuneaki Iwano 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka Sharp Corporation (72) Inventor Hirotaka Nakano 2-3-1 Otemachi, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Inventor Osamu 2-3-1 Otemachi, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation Inside

Claims (2)

[Claims] 1. A method for multiplexing image data and audio data,
A data storage communication device for storing image data and audio data for transmission to a communication terminal via a communication network, wherein the packet generation unit packetizes the image data and the audio data, and the packet generation unit Storage means for accumulating the packets generated by the above, and time stamp generation means for generating a time stamp indicating the timing of transmitting the image data and the audio data to the communication network, wherein the packet generation means comprises: A data storage communication device, wherein a packet to be stored in the storage unit is generated by adding a time stamp generated by a generation unit to the image data and the audio data. 2. A storage unit for storing packetized image data and audio data added with a time stamp indicating the timing of transmitting image data and audio data to a communication network, and image data stored in the storage unit. And a multiplexed data transmitting unit for multiplexing voice data and transmitting the multiplexed data to a communication terminal via a communication network, wherein the multiplexed data transmitting unit is stored in the storage unit. A data storage and communication device for transmitting image data and audio data included in a packet to the communication network at a predetermined timing based on a time stamp included in the packet.