JPH04192984A - Video and audio signal multiplexing transmission system - Google Patents

Abstract

PURPOSE:To enhance transmission efficiency and to improve image quality by adding the flag bits to the extent that audio signals are not inputted into a frame format when the audio signals are not inputted. CONSTITUTION:A voice signal off detecting section 1 detects whether an audio signal AUDIO is inputted or not. A video signal VIDEO is inputted to the part of the audio signals in the frame format by a signal transmission side selector section 2S and the flag bits to this extent are inserted into the transmission frame format if the AUDIO is not inputted or not used. The video multiplexing signal VIDEO is then transmitted. The selection section 2R on the signal reception side judges whether the transmitted signal is both of the VIDEO and the AUDIO or only the VIDEO in accordance with the flag bits. The signals are then selected and outputted. The information on the videos which can be transmitted is increased in this way, by which the transmission efficiency is enhanced. Further, the resolution of the image quality is improved.

Description

[Detailed Description of the Invention] [Summary] A video/audio signal that multiplexes a video signal and an audio signal and transmits these multiplexed signals using a required frame format.
Regarding the audio signal multiplex transmission method, by adding a flag bit to the frame format, it is possible to input the video signal into the time slot of the audio signal, and by increasing the information of the video signal that can be transmitted,
The purpose is to increase transmission efficiency and further improve resolution of image quality.When multiplexing detects that no audio signal is being input, it multiplexes only the video signal and also changes the frame format. The configuration is such that a flag bit to that effect is inserted and the video multiplexed signal is transmitted.

[Industrial Application Field] The present invention relates to a video/audio signal multiplexing transmission system for multiplexing video signals and audio signals and transmitting these multiplexed signals using a required frame format.

In recent years, video conference systems and remote monitoring systems have been developed, but in such systems it is necessary to transmit both video signals and audio signals.

[Prior Art] FIG. 5 is a block diagram showing a conventional video/audio signal multiplex transmission system. In FIG. 5, 111 is a television camera, and the analog video signal from this television camera 111 is The signal is digitally converted by the A/D converter 112A and encoded by the Cog 113.

114 is a video signal multiplexing section, and this video signal multiplexing section 114
This multiplexes the video signals encoded by the Cog 113 and outputs a video multiplex signal VIDEO.

115 is a microphone, this microphone 115
The analog audio signal from is digitally converted by the A/D converter 112B.

116 is an audio signal multiplexing section, and this audio signal multiplexing section 116
is an audio multiplex signal AU by multiplexing digital audio signals.
It outputs DIO.

117 is a multiplexing unit, and this multiplexing unit 117 outputs the frame pulse FP, the video multiplexed signal VIDEO, and the audio multiplexed signal AUD.
The IO is multiplexed to generate a required frame format as shown in FIG.

Reference numeral 118 denotes a control section, and this control section 118 generates control signals and the like for generating a frame format as shown in FIG.

And these television cameras 111. A/D converter 1
12A, 112B, kneader 113. Video signal multiplexing section 11
4. Microphone 115. Audio signal multiplexing section 116. Multiplexing section 117. Control unit 118 is provided on the transmitting side.

119 is a synchronization section, and this synchronization section 119 is connected to the transmission line 120.
121 is a separation unit, and this separation unit 121 separates the signal sent from the transmission side through the transmission line 120 into a video signal and an audio signal. The signal is separated into two parts.

122 is a control section, and this control section 122 is connected to the separation section 121.
This is used to generate control signals for separating each signal.

123 is a video signal separation section; this video signal separation section 123
is to separate the video multiplex signal VIDEO, and the separated video signal is decoded by the decoder 124 and then sent to the D
The signal is converted into an analog video signal by the /A converter 125A and then displayed on the monitor 126.

127 is an audio signal separation section, and this audio signal separation section 127
is for separating the audio multiplex signal AUDIO, and the separated audio signal is converted into an analog audio signal by the D/A converter 125B and then output from the speaker 128.

And this synchronization section 119. Separation unit 121° control unit 122. Video signal separation section 123. Decoder 124, D/
A conversion units 125A, 125B, monitor 126. Audio signal separation unit 127. Speaker 128 is provided on the receiving side.

With such a configuration, on the transmitting side, the television camera 11
The analog video signal from 1 is digitally converted by an A/D converter 112A, encoded by a cog 113, and further multiplexed by a video signal multiplexer 114 to be output as a video multiplex signal VIDEO.

Further, the analog audio signal from the microphone 115 is digitally converted by the A/D converter 112B, and multiplexed by the audio signal multiplexer 116 to produce an audio multiplex signal AUDI.
Output as O.

After that, the multiplexing section 117 sends the video multiplexed signals VIDEO,
The audio multiplex signal AUDIO is multiplexed with the frame pulse FP to generate a required frame format as shown in FIG. 6, and is sent onto the transmission line 120.

On the other hand, on the receiving side, a separation unit 121 separates the signal sent from the transmission side through the transmission line 120 into a video multiplex signal and an audio multiplex signal, and the video multiplex signal is separated in a video signal separation unit 123. The separated video signal is decoded by the decoder 124 and then sent to the D/A converter 125A.
After the signal is converted into an analog video signal, it is displayed on the monitor 126.

Further, after the audio multiplexed signal is separated into one signal by the audio signal separating section 127, the separated audio signal is transferred to the D/A converting section 125.
After being converted into an analog audio signal at B, the speaker 12
Output from 8.

[Problems to be Solved by the Invention] However, in such a conventional video/audio signal multiplex transmission system, the video multiplex signal and the audio multiplex signal are
Since it is transmitted in the format shown in the figure, when no audio signal is input, nothing is input into the time slot of the frame format audio signal. Poor transmission efficiency.

The present invention was made in view of these problems, and by adding a flag bit to the frame format, it is possible to input a video signal into a time slot of an audio signal, thereby increasing the information of the video signal that can be transmitted. The object of the present invention is to provide a video/audio signal multiplexing transmission system that can increase the transmission efficiency and further improve the resolution of image quality by increasing the number of signals.

[Means to solve the problem] FIG. 1 is a block diagram of the principle of the present invention.

In FIG. 1, reference numeral 1 denotes an audio signal interruption detection section, and this audio signal interruption detection section 1 detects whether or not an audio signal AUDIO is input.

2S is a transmitting side selector section, and this transmitting side selector section 2S
The multiplexed video signal VIDEO and audio signal AUDI are
If the audio signal AUDIO is not input and the audio signal disconnection detection unit 1 determines that the audio signal AUDIO is not input, only the video signal VIDEO is selected. It is configured to insert a flag bit FG and transmit the video multiplexed signal VIDEO.

2R is a receiving side selector section, and this receiving side selector section 2R
This determines, based on the flag bit FG, whether both the video signal VIDEO and the audio signal AUDIO are being transmitted, or only the video signal VIDEO, and selects and outputs the signal according to the result of this determination. be.

[Function] In the video/audio signal multiplexing transmission system of the present invention described above, when the audio signal AUDIO is in an unmanned state or is not used at all, the transmitting side selector unit 2S selects the part of the audio signal in the frame format. The video signal VIDEO is input to and transmitted.

At this time, a flag bit FG to that effect is inserted into the transmission frame format, and the video multiplexed signal VIDEO is transmitted.

Then, on the receiving side, the selector unit 2R determines whether both the video signal VIDEO and the audio signal AUDIO that have been transmitted are only the video signal VIDEO based on the flag bit FG, and depending on the result of this determination, , select and output the signal.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 is a block diagram showing one embodiment of the present invention.
The embodiment shown in FIG. 2 can be applied to, for example, a remote monitoring system or a video conference system, and a television camera 11.
A/D converter 12A.

12B, kneader 13. Video signal multiplexing section 14. Microphone 15. Audio signal multiplexing section 16. Multiplexing section 17, control section 1
8. An audio hexagonal detection section 18A is provided.

Here, the video signal multiplexing unit 14 multiplexes the video signal outputted from the television camera 11, digitally converted by the A/D conversion unit 12A, and encoded by the Cog 13, and outputs the video signal as a video multiplex signal VIDEO. It is.

The audio signal multiplexer 16 multiplexes the audio signal picked up by the microphone 15 and digitally converted by the A/D converter 12B, and outputs the multiplexed audio signal AUDIO.

The multiplexing unit 17 outputs a frame pulse FP and a flag bit FG.
, a video multiplex signal VIDEO, and an audio multiplex signal AUDIO are multiplexed to generate a required frame format as shown in FIG. In addition, flag bit FG
is inserted using the first bit of the part where the audio multiplex signal AUDIO is to be inserted.

The audio input disconnection detector 18A detects an audio input disconnection when an audio signal below a required level is input for a certain period of time, and the detection result of the audio input disconnection detector 18A is transmitted to the controller , 18.

The control unit 18 generates control signals, flag bits FG, etc. for generating a frame format as shown in FIG. Then, flag bit FG is set.

Further, on the receiving side as a signal decoding/separating side, a synchronizing section 192, a separating section 21 . Control unit 22. Video signal separation section 23.
Decoder 24. D/A converter 25A.

25B, monitor 26. Audio signal separation unit 27. speaker 2
8 is provided.

Here, the synchronization section 19 performs synchronization detection based on the frame pulse FP sent from the transmitting side through the transmission line 20, and also detects the presence or absence of the flag bit FG.

The separation unit 21 separates a signal sent from the transmission side through the transmission path 20 into a video signal and an audio signal.

The control unit 22 controls the flag bit F detected by the synchronization unit 19.
A control signal for separating each signal in the 1-separation unit 21 is generated based on G.

The video signal separation section 23 separates the video multiplexed signal VIDEO, and the separated video signal is decoded by the decoder 24, converted to an analog video signal by the D/A conversion section 25A, and then sent to the monitor. It will be displayed at 26.

The audio signal separator 27 separates the audio multiplex signal AUD I○, and the audio signal after separation is sent to the D/A converter 25.
After being converted into an analog audio signal at B, the speaker 28
is output from.

With such a configuration, on the transmitting side, the analog video signal from the television camera 11 is transferred to the A/D converter 12A.
The digital signal is converted into a digital signal, encoded by a KOG 13, and multiplexed by a video signal multiplexer 14 to produce a video multiplex signal V.
In addition to being output as IDEO, microphone 1
The analog audio signal from 5 is converted into a digital layer by the A/D converter 12B, multiplexed by the audio signal multiplexer 16, and output as an audio multiplex signal AUDIO.

By the way, if the audio input disconnection detecting section 18A does not detect the audio input disconnection state, the multiplexing section 17 outputs the video multiplexed signal V.
IDEO, audio multiplex signal AUDIO to frame pulse F
P and flag bit FG (0), the fourth
A frame format as shown in FIG. 2(a) is generated and sent onto the transmission path 20.

Further, when the audio input disconnection detection unit 18A detects an audio input disconnection state, the flag bit FG is set to 1 and the video multiplex signal VIDEO is sent to the audio multiplex signal AUDIO area, as shown in FIG. 4(b). Put it in and send it out.

By the way, if the audio input is not interrupted, the flag bit F
Since G is 0, on the receiving side, this flag bit FG
(0), the separation unit 21 separates the signal sent from the transmission side through the transmission line 20 into a video multiplex signal and an audio multiplex signal. The separated video signal is decoded by the decoder 24, and then converted to an analog video signal by the D/A converter 25A, and then displayed on the monitor 26, and the audio multiplexed signal is Audio signal separation section 27
After being separated by 1, the separated audio signal is converted into an analog audio signal by the D/A converter 25B, and then output from the speaker 28.

On the other hand, if the audio input is interrupted, the flag bit FG is 1, so when this flag bit FG (1) is detected,
In the separation unit 21, only the video multiplex signal is separated from the signal sent from the transmitting side through the transmission line 20, and the video multiplex signal is separated in the video signal separation unit 23, and the video signal after separation is sent to the decoder. After being decrypted with 24, D/
After being converted into an analog video signal by the A converter 5A, it is displayed on the monitor 26. At this time, since there is no audio input, no sound is output from the speaker 28.

In this way, when the audio signal is unattended, by putting the video signal in the frame format audio signal part and outputting it, more information of the video signal can be output, achieving high transmission efficiency. In addition to this, you can expect an improvement in image quality.

[Effects of the Invention] As detailed above, according to the video/audio signal multiplex transmission system of the present invention, when it is detected that no audio signal is input during multiplexing, only the video signal is multiplexed. At the same time, since the video multiplexed signal is transmitted by inserting a flag bit to that effect in the frame format, it is possible to increase the information of the video signal that can be transmitted, thereby increasing transmission efficiency and further This has the advantage of improving the resolution of image quality.

[Brief explanation of the drawing]

Figure 1 is a block diagram of the principle of the present invention, Figure 2 is a block diagram showing an embodiment of the present invention, and Figures 3, 4 (a) and (b) are each an embodiment of the present invention. FIG. 5 is a block diagram illustrating a conventional example, and FIG. 6 is a diagram illustrating a frame format according to a conventional example. In the figure, 1 is an audio signal disconnection detection unit, 2R and 2S are selector units, 11.111 is a television camera, and 12A, 12B, 112A, and 112B are A/D conversion units. 13.113 is Korg, 14.114 is video signal multiplexing unit, 15.115 is microphone, 16.116 is audio signal multiplexing unit, 17.117 is multiplexing unit, 18.118 is control unit, 18A is audio input disconnection detection 19.119 is a synchronization section, 20.120 is a transmission line, and 21.121 is a separation section. 22.122 is a control unit, 23.123 is a video signal separation unit. 24.124 is a decoder. 25A, 25B, 125A, and 125B are D/A conversion sections, 26.126 is a monitor, 27.127 is an audio signal separation section, and 28.128 is a speaker.

Claims (1)

[Claims] A video/audio signal that multiplexes a video signal and an audio signal and transmits these multiplexed signals using a required frame format.
In the audio signal multiplexing transmission system, when it is detected that the audio signal is not input during multiplexing, only the video signal is multiplexed, and a flag bit to that effect is inserted in the frame format to create the video signal. A video/audio signal multiplex transmission method characterized by transmitting multiplexed signals.