JPS61159883A - Device for transmitting and receiving narrow bandwidth voice and moving image - Google Patents

Abstract

PURPOSE:To reduce the temporal delay of voice signals from the moving picture information to suppress the foreign feeling of the users by providing a delay circuit succeeding stage of an encoder for encoding voice information, said delay circuit delaying the encoder output a prescribed time. CONSTITUTION:The voice information is inputted via a microphone 23 and converted by an A/D converter 22 into digital data. It is then encoded by an encoder 20 and introduced into a multiplexing control circuit 24 through a delay circuit 19. The image information is inputted at an image input 14 and converted by an A/D converter 13 into digital signals. In an information deleter 12, thinning out is performed within the frame and between the frames and the result is stored in an image data storage frame memory 3. The data is then encoded in the encoder 11, converted in a converter 10 into serial data and transferred to the multiplexing control device 24. In the control device 24, the voice and image informations are multiplexed and transmitted to a modem 25.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention utilizes a narrowband transmission path to transmit audio information and
The present invention relates to a narrowband audio image transmitting/receiving device that reduces the sense of discomfort during conversation by delaying audio information and reducing the time difference between audio information and moving image information in a device that transmits personal information.

[Conventional technology]

In a transmitting/receiving device that transmits audio information and video information using a narrowband communication line, when encoding video information, the encoding section has to thin out the current 30 frames per second. It is common to perform processing to reduce the amount of information.

This will be explained with reference to FIG.

In FIG. 2, I and H are moving image transmitting/receiving apparatuses having the same configuration, and are connected via a tintal line 26, which is a narrowband transmission line.

Moving image transmitting/receiving device 1. II is the decoder 4. Display device 9 for displaying D/A converter 61 image data. #J image data encoder 11. A/D converter 13. Image input device such as a television camera 14.0/A converter 17. Speaker 1B, A/D
Converter 22. Microphone 23 for inputting audio information. It is composed of a multiplexing control device 24 and the like. Note that the part surrounded by the dashed line indicates the main body.

In such a moving image transmitting/receiving device, the image input 614
The input image is converted into a digital signal by the A/D converter 13, encoded by the encoder 11, and sent to the multiplex control unit [2].
The encoder 11 performs intra-frame thinning processing and frame skipping processing. When such encoding processing is performed, the image quality of the VC image information is degraded compared to the normal case of 30 frames per second, and the motion becomes a little unnatural. Further, audio information inputted from the microphone 23 is digitized by the A/D converter 22 and sent out.

[Problem that the invention seeks to solve]

In this way, when audio information and moving image information as shown in FIG. 2 are transmitted simultaneously, there is a problem that the moving image information, especially the mouth movements, do not match the audio information. Also,
When a user uses this type of device, there is a drawback that the user feels uncomfortable due to the temporal mismatch between the audio information and the moving image information.This invention has been made to eliminate these drawbacks. An object of the present invention is to provide a narrowband audio and video transmitting/receiving device that reduces the time difference between audio information and video information and does not give an unnatural feeling of display during conversation or the like.

Means for Solving Problem C] The narrowband audio/video transmitting/receiving device of the present invention is provided with a downstream stage K of an encoder that encodes audio information, and a delay circuit that delays the output from this encoder for a predetermined period of time. It is something.

[Effect]

In this invention, since the delay circuit delays the audio information, even if the moving image information is thinned out, there is no sense of incongruity between the moving image information and the audio information.

〔Example〕

FIG. 1 is a block diagram showing the configuration of an embodiment of a narrowband audio/video transmitting/receiving device according to the present invention.

In this figure, 1 is a signal control microprocessor (CP
U), 2 is a memory for storing control programs, 3 is a frame memory for storing image data, 4 is a decoder for decoding encoded data, and 5 is data for adding information corresponding to data on the transmission path. An interpolator, e is a D/A converter that converts data in a frame into analog data, 7 is a converter that converts serial data to parallel data, 8 is a common bus, 9 is a display that displays image data, 10 1 is a converter that converts parallel data into serial data; 11 is an encoder that encodes image data; 12 is an information deleter that thins out the image data; and 13 is an A/D converter that digitizes camera image data. , 14 is an image input device for inputting motion images, 15 is a memory for decoding audio information, 16 is a decoder for decoding audio information, and 17 is a D/D converter for converting digital data into analog data. A converter, 18 is a speaker, 19 is a delay circuit for delaying audio information, 20 is an encoder for encoding audio information, 21 is a memory for encoding audio information, 22 is for converting microphone analog information into digital information A/D converter for converting VcK, 23 is a microphone for inputting audio information, 24
25 is a modem that controls digital information; 25R is a reception line; 25T is a transmission line; and 26 is a digital line. In addition, among the above-mentioned symbols, the same symbols as in FIG. 2 are the same parts.

The narrowband audio and video transmitting/receiving device shown in FIG. 1 is installed at both ends of a narrowband transmission line and performs transmission and reception, but only one end is shown in FIG.

Next, the operation pressure setting process will be explained.

First, we will explain the reception operation. digital line 26
The information sent from the
The information enters the multiplexing control device 24 from the iA25R, is separated into audio information and image information, and is input to the main unit. Since the audio information is encoded, it is decoded by the decoder 16 using the memory 15. Furthermore, the decoded data is converted into analog information by the D/A converter 17, and sent to the speaker 18, where it is output as sound. The image information is converted into parallel data by the converter 7, and then the data decoded by the decoder 4 is stored in the KWJ image data storage frame memory 3 frame by frame.

The stored data is interpolated by a data interpolator 5 and then displayed on a display 9 through a D/A converter 6.

This series of processing is controlled by the signal control CPU VC, and the control program is stored in the control program storage memory 2.

Next, the transmission sequence will be explained. Audio information is input through the microphone 23 and converted into digital data through the A/D converter 22Y. Next, encoder 20
Encoded by Mata.

Audio information is input to the multiplexing control device 24 through the delay circuit 19, which is a feature of the present invention. -10,000, the image information is
The signal is input from the input device 1tK and converted into a digital signal by the A/Df converter 13.

Next, the information deleter 12 performs intra-frame and inter-frame thinning processing, and the data is stored in the image data storage frame memory 3VC.

Thereafter, the data is encoded by the encoder 11, converted into serial data by the converter 10, and then sent to the multiplexing control device 24. The multiplexing control device 24 multiplexes audio information and image information and sends them to the modem 25.

Regarding actual image information frame thinning processing, it is conceivable to perform control by reducing 30 frames per second to about 5 frames K. At that time, it is thought that a delay of about 200 mg at maximum will occur, and at that time the delay circuit 19 will have a delay of 10 mg.
By delaying K by 0 mg, it is possible to reduce the sense of incongruity between audio information and image information.

For example, when transmitting at 5 frames per second, a moving image is sent in units of 200 ms. In other words, a new image is sent only every 200 ms.

During this time, the audio information is being sent continuously, and there will be a lag between the audio information and the video information. Busy to solve this,
To realize simultaneous communication with moving image information by delaying audio information to such an extent that it does not feel strange in normal conversation.

〔Effect of the invention〕

As explained above, this invention provides a delay circuit that delays the output from the encoder for a predetermined period of time after the encoder that encodes audio information, so that there is a time lag between the audio information and the moving image information. This has the advantage that it is possible to reduce the amount of discomfort experienced by the user.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of a narrowband audio/video transmitting/receiving device according to the present invention, and FIG. 2 is a block diagram showing the configuration of a conventional narrowband audio/video transmitting/receiving device. In the figure, 1 is a CPU for signal control, 2 is a memory for storing control programs, 3 is a frame memory for storing image data, and 4 is a CPU for signal control.
．． 16 is a decoder, 5 is a data interpolator, 6 and 17 are D/A
Converter, 13.22 is an A/D converter, 7 and 10 are converters, 11.20 is an encoder, 12 is an information deleter, 14 is an image input device, 15.21 is a memory, 18 is a speaker, 19 23 is a delay circuit, 23 is a microphone, 24 is a multiplexing control device, 25 is a modem, and 26 is a digital line. Figure 1

Claims (1)

[Claims] An encoder that encodes audio information, a decoder that also decodes it, an encoder that encodes video information, and a decoder that also decodes it, and separates the audio information and video information. The information inputted via the narrowband transmission line is separated into audio information and video information and then encoded by each encoder and then sent to a narrowband transmission line. A narrowband audio and video transmitting/receiving device that performs post-display and notification of decoding information, characterized in that a delay circuit is provided at a subsequent stage of an encoder that encodes the audio information to delay the output from the encoder for a predetermined period of time. Narrowband audio/video transmitting/receiving device.