JPH06339138A - Video telephone system - Google Patents

Abstract

(57) [Abstract] [Purpose] It is an object to provide a videophone device capable of promptly changing modes and capabilities even in an area where the communication line is unstable and the partner terminal is often out of synchronization. . [Structure] When transmitting a BAS command code including the capability and mode after switching to the other terminal, an internal timer is started,
Even if the A bit of the received signal is 1 due to the temporary out-of-sync of the partner terminal, it does not notify itself as a failure until the internal timer expires. When the internal timer expires, it notifies itself as a failure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a videophone device,
In particular, the present invention relates to a videophone device that switches capabilities and modes according to CCITT recommendations.

[0002]

2. Description of the Related Art Conventionally, there have been the following techniques in this type of field.

That is, a terminal desiring to change its capability or mode is H.264 of CCITT recommendation. According to 242, the BAS command code including the changed capability and mode is transmitted to the partner terminal. If the A bit of the signal from the partner terminal is 0, the ability or mode switching operation is completed, and if the A bit is not 0 (A bit = 1), the terminal is notified as a failure.

[0004]

However, in the above-mentioned conventional video telephone apparatus, the synchronization of the partner terminal is not possible in a region where the communication line is unstable and the partner terminal is often out of synchronization. Even if the signal is temporarily disengaged and the A bit is 1 and the signal is immediately impaired, the terminal itself has a problem that the capability and mode cannot be changed.

In view of the above-mentioned conventional problems, the present invention provides a videophone device capable of promptly changing modes or capabilities even in an area where the communication line is unstable and the synchronization with the other terminal is often out of sync. The purpose is to do.

[0006]

[Means for Solving the Problems] In order to achieve the above object, H. In a videophone device that communicates according to H.242, at least a timer starting means for starting an internal timer when transmitting a BAS command code to a partner terminal to change a mode or capability, and a failure when the internal timer expires Therefore, a failure notification means for executing failure notification is provided.

[0007]

According to the present invention, according to the present invention, the internal timer is started when the BAS command code including the capability and the mode after switching is transmitted to the partner terminal, and the A signal of the received signal is transmitted when the partner terminal temporarily loses synchronization. Even if the bit is 1, it does not notify itself as a failure until the internal timer expires. When the internal timer expires, it notifies itself as a failure.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

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

In the figure, 1 is a handset which is one of the voice input / output means of this device, 2 is a microphone which is one of the voice input means of this device, and 3 is one of the voice output means of this device. Some speakers are connected to the voice interface unit 4. The voice interface unit 4 performs a switching process of switching between the handset 1, the microphone 2, and the speaker 3 according to an instruction from the system control unit 14 described later.
An on / off hook detection process for detecting whether the handset 1 is in an on-hook state or an off-hook state, an echo canceling process for canceling an echo when the microphone 2 and the speaker 3 are used, and dial tone, ringing on, Performs tone generation processing such as busy tones and ring tones.

A voice encoding / decoding unit 5 is connected to the output side of the voice interface unit 4. The voice encoding / decoding unit 5 receives 64 kb according to an instruction from the system control unit 14.
psPCM A-law, 64kbps PCM μ-law, 64kbp
s / 56kbps SB-ADPCM, 32kbps ADPC
M, 16 kbps (for example, APC-AB), 8 kbps, etc. are used to encode the transmission voice and decode the reception voice signal in accordance with a voice signal encoding / decoding algorithm.

Further, 6 is one of the image inputting means of the present apparatus and is a camera for inputting a self-portrait, and 7 is one of the image inputting means of the present apparatus, which is a document for inputting a picture or a drawing. A camera 8 is a display unit that displays an input image from the camera 6 or the document camera 7, a received image from the other party, an operation screen, and the like, and these are connected to the video interface unit 9. The video interface unit 9 is instructed by the system control unit 14 to switch the image input means, switch the display of the input image, the received image, and the operation screen, and display the divided image signals on the display unit 8. Performs synthesis processing and the like.

The video codec 10 connected to the output side of the video interface unit 9 is a CCITT recommendation draft H.264. According to H.261, the transmission image is encoded and the reception image signal is decoded.

Further, 11 is a data terminal for performing data communication, and the data interface section 12 on the output side of the data terminal 11 notifies the demultiplexing section 16 of the transmission data from the data terminal 11 and the system control 14. At the same time, the received data is notified to the terminal 11 or the system control unit 14. An operation unit 13 such as a keyboard and a touch panel used for inputting control information for performing overall control of the apparatus is connected to the system control unit 14.

The system controller 14 includes a CPU, ROM,
A RAM, an auxiliary storage device, and the like are provided, and the state of each unit is monitored, the entire device is controlled, an operation / display screen is created according to the state, and an application program is executed. 15 is CCITT Recommendation H.264. 242 is a mutual connection procedure control unit for setting communication between terminals according to 242, and the mutual connection procedure control unit 15 is a voice coding / decoding unit 5 and a video codec 10.
And the data interface unit 12 and the multiplex transmission unit 16. The interconnection procedure control unit 15
Is an internal timer 15A that is activated when a BAS command code is transmitted to the partner terminal to change the mode or capability.
Is provided.

The multiplexing transmission unit 16 is a CCITT recommendation H.264.
221, the audio signal from the audio encoding / decoding unit 5,
The image signal from the video codec 10, the data from the data interface unit 12, and the BAS from the interconnection procedure control unit 15 are multiplexed in transmission frame units, and the reception frame is separated into each medium of constituent units and notified to each unit. To do. The line interface 17 on the output side of the multiplexing transmission unit 16 controls the line according to the ISDN user / network interface.

The fault notification operation of the videophone device configured as described above will be described with reference to the flowchart of FIG.

The terminal which desires to change the capability or mode is C
H.C. of the CITT recommendation. According to 242, the BAS command code including the changed capability and mode is transmitted to the partner terminal. At that time, first, The internal timer 15A held inside 242 is started (step S1), and the BAS
The command code is transmitted to the partner terminal (step S2).
After that, the process proceeds to step S3, it is determined whether or not the A bit of the reception signal from the partner terminal is 0, and the answer is negative (N
O), that is, when the A bit of the received signal is 1, the process proceeds to step S4. In step S4, the internal timer 15
Determine whether A has expired. The answer is negative (N
O), that is, when the internal timer 15A has not yet expired, the process returns to step S3.

The answer to step S3 is affirmative (YES),
That is, when the A bit of the signal received from the partner terminal is 0, the process proceeds to step S5, resets the internal timer 15A, and completes the ability and mode switching operation (step S6). On the other hand, the answer in step S4 is affirmative (YE
S), that is, when the A bit of the received signal is 1, and the internal timer 15A has not expired, the self-terminal is notified as a fault in step S7.

As described above, in this embodiment, even if the other terminal is temporarily out of synchronization and the A bit of the received signal is 1, the synchronization is restored before the internal timer 15A expires. For example, since it is possible to proceed to steps S5 and S6 to change the mode and ability, it is possible to quickly change the mode and ability even in an area where the communication line is unstable and synchronization is often lost temporarily.

[0021]

As described in detail above, according to the present invention, the H. In a videophone device that communicates according to H.242, at least a timer starting means for starting an internal timer when transmitting a BAS command code to a partner terminal to change a mode or capability, and a failure when the internal timer expires Therefore, even if the other terminal temporarily loses synchronization, the mode and ability can be changed if the synchronization is restored before the internal timer expires. Even in areas where the line is unstable and the synchronization is often out of sync, it is possible to change modes and capabilities quickly.

[Brief description of drawings]

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

FIG. 2 is a flowchart showing a fault notification operation of the above embodiment.

[Explanation of symbols]

 1 Handset 2 Microphone 3 Speaker 4 Audio interface unit 5 Audio encoding / decoding unit 6 Camera 7 Document camera 8 Display unit 9 Video interface unit 10 Video codec 11 Data terminal 12 Data interface unit 13 Operation unit 14 System control unit 15 Interconnection procedure Control unit 15A Internal timer 16 Multiplex transmission unit 17 Line interface

Claims (1)

[Claims] 1. The CCITT recommended H.264 standard. In a videophone device that performs communication in conformity with H.242, at least a timer starting unit that starts an internal timer when transmitting a BAS command code to a partner terminal to change a mode or capability, and a failure occurs when the internal timer expires. Therefore, the videophone device is provided with a failure notification means for executing a failure notification.