JPH0759069A - Codec - Google Patents

Abstract

PURPOSE:To obtain a CODEC device provided with a flow control function by which data terminal equipment communication is executed. CONSTITUTION:The CODEC device is provided with a multiplexer control means 10 multiplexing/demultiplexing a motion picture, an audio signal and terminal data, a terminal control means 7 controlling data transmission reception to/from a data terminal equipment and a buffer 8 storing tentatively transmission terminal data between the both. The terminal control means 7 outputs a data transfer interrupt or restart command to the multiplexer control means 10 when the start or end of flow control at a data terminal is detected to command the start or end of flow control to the data terminal. Upon the receipt of the data transfer interrupt or restart command, the multiplexer control means 10 informs it to an opposite party equipment to inform the data transfer interrupt or restart to the terminal control means 7. An expanded BAS code is used to inform it to a sender side equipment corresponding to the flow control of the receiver side to suppress data output quantity of the sender side data terminal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a codec device having a multiplex transmission function for moving images, voice and terminal data, and in particular, it is constructed so that data can be transferred in accordance with the receiving state of the receiving side. It is a thing.

[0002]

2. Description of the Related Art In recent years, CCITT (International Telegraph and Telephone Advisory Committee) has officially made a recommendation of a video encoding system, a multiplexing system and a communication procedure for audiovisual services, and in accordance with this, each company complies with CCITT recommendations. Apparatuses for multiplexing transmission of moving images, voice and data such as video conference systems and video phones have been put on the market.

As shown in FIG. 5, a conventional codec device having such a multiplex transmission function has, as an attached device, a handset 1 for inputting and outputting voice, a camera 2 for taking a self-portrait, an image from a partner device or a self-portrait. And a data terminal 4 for performing file transfer, data communication, and the like. Further, the apparatus body includes an audio codec section 5 for encoding and decoding audio data, and a code for moving image data. A moving image codec section 6 that performs encoding and decoding, and controls display of an image on the monitor 3,
The data terminal 4 includes a terminal interface unit 7 for controlling data transmission and reception, a multiplexing control unit 10 for controlling multiplexing / demultiplexing of transmission / reception signals, and a network control unit 11 for controlling connection with the communication network 12. ing.

The multiplexing control unit 10 sends moving image, voice and terminal data to CCIT Recommendation H.264. 221 (Audio
19 from 64 Kbit / s in visual teleservice
H.20 transmitted from the other device is multiplexed in a frame format of 20 Kbit / s channel).
221 frame, moving picture, audio and terminal data are separated, and CCITT Recommendation H.264 is added. 242
BAS (bit rate allocation signal) transmission control and reception control are performed by a communication procedure based on (a method of setting communication between audio-visual terminals using digital channels up to 1920 Kbit / s).

Further, FIG. 3 shows CCITT Recommendation H.264. 221
FIG. 4 shows a multiplexing frame structure defined by H.264, which is shown in FIG. 221 is a numerical table of BAS codes defined in 221.

In the conventional codec device, the network control unit 11 controls the connection of the communication channel with the partner device via the communication network 12, and when the connection is completed, the multiplexing control unit 10
Over the communication channel. 2. Activate the mode initialization procedure based on 242.

In the mode initialization procedure, first, synchronization is established by using FAS (frame synchronization signal) in the multiplexed frame shown in FIG. 3, and then audio / transfer rate capability and data / video are set at the position of BAS. B representing ability
The AS code (FIG. 4) is set and exchanged with the partner device, and the command BAS code is used to switch the operation mode to an appropriate mode corresponding to the capabilities of the own device and the partner device.

Thereafter, the voice, the moving image and the terminal data output from the voice codec section 5, the moving picture codec section 6 and the terminal interface section 9 are multiplexed by the multiplexing control section 10 and passed through the network control section 11. , To the communication network 12.

Further, the multiplexed data sent from the partner device is input to the multiplexing control unit 10 via the network control unit 11 and separated into moving image, voice and terminal data,
It is transferred to the audio codec unit 5, the moving image codec unit 6 and the terminal interface unit 9 and output from the handset 1, the monitor 3 or the data terminal 4.

In the conventional apparatus, when the data output from the data terminal 4 is transmitted to the partner apparatus, the terminal interface section 9 outputs a data transfer start command to the multiplexing control section 10. Receiving this, the multiplexing control unit 10 transmits a message to the effect that the data transfer is started to the partner device, and therefore the B controller shown in FIG.
L corresponding to the communication rate of the data terminal 4 by the AS code
The SD (low-speed data) / MLP command is notified to the partner device via the network control unit 11, and then the data of the data terminal 4 is transmitted to the partner device.

[0011]

However, in the conventional codec device, the data terminal cannot implement the "flow control" for restricting the input data amount in order to prevent the overflow of the received data. This is because when data is transmitted from a data terminal (sending side data terminal) connected to the codec device to a data terminal (receiving side data terminal) connected to the other side codec device, the flow control of the receiving side data terminal is set to the transmitting side. This is because there is no means for notifying the data terminal. Therefore, in the case of transmitting a large amount of data such as file transfer, there occurs a state in which the receiving side data terminal cannot receive it because the receiving capacity is exceeded.

The present invention solves these conventional problems, and an object thereof is to provide a codec device capable of performing data terminal communication having a flow control function.

[0013]

In view of the above, the present invention controls data transmission / reception to / from a connected data terminal in a codec device equipped with a multiplexing control means for multiplexing / separating moving image, voice and terminal data. Terminal control means,
A buffer for temporarily storing the terminal data transferred between the terminal control means and the multiplexing control means is provided, and when the terminal control means detects the start of the flow control in the data terminal, it responds to the accumulated amount of the buffer. And outputs a data transfer interruption command to the multiplexing control means, and when the end of the flow control in the data terminal is detected, outputs a data transfer restart instruction to the multiplexing control means, and further the data transfer interruption or data is transmitted from the multiplexing control means. Instructs the data terminal to start or end flow control when it is notified of the resumption of transfer, and
When the multiplexing control means receives the data transfer interruption command or the data transfer restart instruction from the terminal control means, the data transfer interruption or the data transfer restart is transmitted to the partner device by the extended BAS code, and the received data is extended. B
When the AS code is detected, the terminal control means is notified of the data transfer interruption or the data transfer restart.

Also, the multiplexing control means is configured to transmit the BAS code to the partner device by LSD (low speed data).

[0015]

Therefore, in response to the flow control in the data terminal on the receiving side, the fact is notified to the transmitting side device by using the extended BAS code, and the data output amount of the transmitting side data terminal is suppressed.

Further, by transmitting this BAS code as low-speed data, the load of code retrieval on the partner device is reduced.

[0017]

(First Embodiment) As shown in FIG. 1, the codec device in the first embodiment includes a data terminal control unit 7 for controlling data transmission / reception to / from a data terminal, and a buffer 8 for storing data. , A multiplexing control unit 10 for multiplexing / separating moving image data, voice data, and terminal data, and for transmitting the interruption / restart of data transfer to a partner device by using an extended BAS code. Other configurations are the same as those of the conventional device (FIG. 5).

The data terminal control unit 7 includes a data terminal 4
When the flow control start notification is received from the buffer 8
The data transfer interruption command is output to the multiplexing control unit 10 according to the storage amount of the data, and when the flow control end notification is received from the data terminal 4, the data transfer restart command is output to the multiplexing control unit 10. . Further, when the data transfer interruption notification or the data transfer restart notification is received from the multiplexing control unit 10, the data terminal 4 is instructed to start or end the flow control accordingly.

Further, the multiplexing control unit 10 sends the moving image, voice and terminal data to CCIT Recommendation H.264. 221 frames
The data is multiplexed in the format, and conversely, the H.264 transmitted from the partner device is transmitted. The moving image, voice, and terminal data are separated from the 221 frame. In addition, CCIT Recommendation H.264. Transmission control and reception control of BAS are performed by a communication procedure based on 242. Further, the multiplexing control unit 10 transmits the data transfer interruption command or the data transfer restart command to the partner device by the extended BAS code based on the data transfer interruption command or the data transfer restart command sent from the data terminal control unit 7. On the contrary, when the expanded BAS code transmitted from the partner device is detected, a data transfer interruption notification or a data transfer restart notification is output to the data terminal control unit 9.

The operation of this codec device when data communication is performed using a data terminal will be described.

When starting data transmission from the data terminal 4 (sending side data terminal) to the partner side apparatus, the terminal control section 7 outputs a data transfer start command to the multiplexing control section 10, and the data terminal 4 The data received from is transferred to the buffer 8. Upon receiving the data transfer start command, the multiplexing control unit 10 transmits the LSD / MLP command corresponding to the communication rate of the data terminal 4 by the BAS code shown in FIG. The partner device is notified via the network control unit 11, and thereafter, the transmission data input from the buffer 8 is transmitted to the partner device.

In the partner device, the multiplexing control unit 10 is the BAS
When the LSD / MLP command based on the code is detected, the terminal control unit 7 is notified of the start of data transfer, and subsequent received data is transferred to the buffer 8. Upon receiving the data transfer start notification, the terminal control unit 7 starts transferring the received data from the buffer 8 to the connected data terminal 4 (reception side data terminal).

In this way, the data of the transmitting side data terminal is transmitted to the receiving side data terminal, but when the receiving side data terminal is temporarily unable to receive the data, the receiving side data terminal is transferred to the receiving side codec device. Instruct to start flow control. Here, the flow control is a general XON / XO.
It is performed by FF control or RS / CS control.

Upon detecting the start of the flow control of the data terminal 4, the terminal control unit 7 of the receiving side codec device receives the data output from the transmitting side data terminal until the threshold value of the buffer 8 determined by the transmission rate of the data terminal 4 is reached. However, when the data reaches the threshold value, the data transfer interruption command is output to the multiplexing control unit 10.

When the multiplexing control unit 10 receives the data transfer interruption command, it outputs the extended BAS code of "data transfer interruption",
It is transmitted to the transmission side codec device via the network control unit 11. As shown in FIG. 2, the extended BAS code uses the attribute “(110)” which is not used in the BAS code table shown in FIG. 4, and is converted into “[0] to [31]”. Assign each content.

When the multiplexing control unit 10 of the transmission side codec device detects the extended BAS code representing "data transfer interruption", it outputs a data transfer interruption notification to the terminal control unit 7,
The data transfer from the buffer 8 is interrupted. Terminal control unit 7
Upon receiving the data transfer interruption notification, the instructing the transmitting data terminal 4 to start the flow control.

When the terminal control unit 7 of the receiving side codec device detects the end of the flow control output from the data terminal 4, it outputs a data transfer restart command to the multiplexing control unit 10, and the buffer 8 outputs the data. The transfer is started to the receiving side data terminal 4. Upon receiving the data transfer restart command, the multiplexing control unit 10 transfers the expanded BAS code representing “data transfer restart” to the transmission side codec device via the network control unit 11.

Multiplexing control unit 10 of the transmission side codec device
When detecting the extended BAS code representing "restart data transfer", outputs a data transfer restart notification to the terminal control unit 7 and restarts the data transfer from the buffer 8. Upon receiving the data transfer restart notification, the terminal control unit 7 instructs the transmission side data terminal 4 to end the flow control, and restarts the transfer of data from the transmission side data terminal to the buffer 8.

(Second Embodiment) In the codec device of the second embodiment, information on interruption / resumption of data transfer based on flow control is transmitted to the other side by LSD (low speed data).

The blocks constituting this codec device and their functions are the same as those of the device of the first embodiment (FIG. 1). However, when the multiplexing control unit 10 receives the data transfer interruption command or the data transfer restart command from the data terminal control unit 7, the multiplexing control unit 10 transmits the fact of the data transfer interruption or the data transfer restart to the partner device by the LSD, and When the LSD detects that the transfer is suspended or the data transfer is restarted,
The data terminal control unit 7 is notified of this.

In this codec device, when data communication is performed using the data terminal, the procedure for starting the data transfer from the transmitting side data terminal to the receiving side data terminal is as described in the first embodiment.

The terminal control section 7 of the receiving side codec device is
When the flow control start by the data terminal 4 is detected, the buffer 8 defined by the transmission rate of the data terminal 4 is detected.
The data of the data terminal on the transmitting side is received until the threshold value is reached, and when the threshold value is reached, a data transfer interruption command is output to the multiplexing control unit 10.

Upon receipt of the data transfer interruption command, the multiplexing control unit 10 uses the BAS code shown in FIG.
P command on (eg, 300 bps: “01100
001 ″), and data indicating interruption of data transfer (for example, “11000000” if the same as the extended command of the first embodiment shown in FIG. 2 is performed) is transmitted to the transmitting side terminal device by the LSD. The LSD / MLP command OFF is output.

Multiplexing control unit 10 of the transmission side codec device
Upon receiving the BAS code indicating that the LSD / MLP command is turned on, the subsequent LSD data is analyzed, and if data indicating interruption of data transfer is detected, a data transfer interruption notice is output to the terminal control unit 7, and the buffer 8 Interrupts data transfer from. The terminal control unit 7 instructs the transmission side data terminal 4 to start the flow control by the data transfer interruption notification.

When the data terminal 4 finishes the flow control,
The terminal control unit 7 of the receiving side codec device that has detected this
Outputs a data transfer restart command to the multiplexing control unit 10 to start data transfer from the buffer 8 to the receiving side data terminal 4. Upon receiving the data transfer restart command, the multiplexing control unit 10 informs the transmission side codec device by the LSD of the fact that the data transfer is restarted.

Multiplexing control unit 10 of the transmission side codec device
Upon receiving the BAS code indicating that the LSD / MLP command is turned on, the LSD data is analyzed thereafter, and when data notifying that data transfer is restarted is detected, a data transfer restart notification is output to the terminal control unit 7, and the buffer 8 is output from the buffer 8. Data transfer is restarted. Upon receiving the data transfer restart notification, the terminal control unit 7 instructs the transmission side data terminal 4 to end the flow control, and restarts the data transfer from the transmission side data terminal to the buffer 8.

As described above, in the apparatus of the second embodiment, the suspension / resumption of data transfer is notified by the LSD, so that the burden on the receiving side when detecting such information is reduced.

[0038]

As is apparent from the above description of the embodiments, since the codec device of the present invention has the data terminal communication function by flow control, it cannot be received even when transmitting a large amount of data. You can avoid falling.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a codec device according to an embodiment of the present invention,

FIG. 2 is an expanded BAS code table used in the codec device of the first embodiment;

FIG. 3 CCITT Recommendation H.264. 221 is a diagram showing a multiplexing frame structure defined by 221;

FIG. 4 CCITT Recommendation H. BAS defined in 221
Code table,

FIG. 5 is a block diagram showing a configuration of a conventional codec device.

[Explanation of Codes] 1 Handset 2 Camera 3 Monitor 4 Data terminal 5 Voice codec section 6 Video codec section 7 Terminal control section 8 Buffer 9 Terminal interface section 10 Multiplexing section 11 Network control section 12 Communication network

Claims (2)

[Claims] 1. A moving image, voice and terminal data are multiplexed.
In a codec device having a multiplexing control means for separating, terminal control means for controlling data transmission / reception to / from a connected data terminal, and terminal data transferred between the terminal control means and the multiplexing control means are temporarily stored. When the terminal control unit detects the start of flow control in the data terminal, it outputs a data transfer interruption command to the multiplexing control unit according to the amount of data stored in the buffer. When the end of the flow control in the data terminal is detected, a data transfer restart command is output to the multiplexing control means, and when the data transfer interruption or data transfer restart is notified from the multiplexing control means, the data The terminal is instructed to start or end the flow control, and the multiplexing control means causes the terminal control means to interrupt the data transfer. Or when a data transfer restart command is received,
Data transfer interruption or data transfer restart is transmitted to the partner device by the expanded BAS code, and when the expanded BAS code is detected from the received data, the terminal control means is notified of the data transfer interruption or data transfer restart. Characteristic codec device. 2. The codec device according to claim 1, wherein the multiplexing control means transmits the BAS code to a partner device by LSD (low speed data).