JP2914053B2 - Image transmission device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image transmitting apparatus for encoding analog image data and analog audio data with high efficiency and transmitting the encoded data.

[0002]

2. Description of the Related Art FIG. 4 shows a standard J.H.H. standardized by, for example, the Telegraph and Telephone Technical Committee (hereinafter referred to as TTC). 32
0 is a block diagram showing a conventional image transmission device shown in "teleconference system terminal device". In the figure, reference numeral 91 denotes a video which digitizes input analog image data and performs a conversion operation to a predetermined image format. A video input / output device 92 comprising an input unit and a video output unit for converting the digitized image data into analog image data. 92 is a video input / output device for efficiently encoding the image data input from the video input / output device 91. The video codec includes an encoding device and a video decoding device that restores encoded image data to data before encoding.

Reference numeral 93 denotes an audio input / output device for inputting / outputting audio data in the same manner as the image data, and reference numeral 94 denotes an audio input / output device for encoding and decoding audio data input / output to / from the audio input / output device 93. Codec. Reference numeral 95 denotes a delay circuit that adjusts the time so that the audio data decoded by the audio codec 94 matches the image data decoded by the video codec 92 in time.

Further, reference numeral 96 denotes encoded image data,
A multiplexing / demultiplexing control device (hereinafter, referred to as MUX / DMUX) 97 for multiplexing / demultiplexing voice data and control data, a network interface device 97 connected to the MUX / DMUX 96 for interfacing with a transmission line of a partner station that performs transmission and reception. It is.

Reference numeral 98 denotes a telematic device connected to the MUX / DMUX 96, 99 denotes a system control device for controlling the entire system, and 100 denotes a device connected between the system control device 99 and the network interface device 97. It is an end network signal control device.

Next, the operation will be described. First, the analog image data input to the video input device 91 is digitized, and the video codec 92 encodes the image data with high efficiency. The encoding algorithm is specific to the video codec and is defined in ITU-T Rec. 261 "P × 64Kbit /
A discrete cosine transform method (hereinafter referred to as a DCT method) based on the "s video coding method for audiovisual services" is common. The encoded image data is sent to the MUX / DMUX and multiplexed.

On the other hand, audio data input from the audio input / output device 93 is also encoded by the audio codec 94. The audio coding algorithm is, for example, μ-law PCM
In general, several types such as SB-ADPCM and LD-CELP are supported and can be selectively used depending on user settings. The encoded audio data is sent to the MUX / DMUX and multiplexed like the image data.

[0008] The multiplex format is defined in the ITU-T Rec.
221 "6 in audiovisual teleservices
4 kbps to 1920 kbps channel frame structure ". In MUX / DMUX 96, image data, audio data, etc. are stored in the ITU-T Rec. 221
Multiplexed into the multiplexed format specified in, and demultiplexed in reverse. FIG. 5 shows the TTC standard JT-H. FIG. 3 is a diagram showing a multiplex format at the time of 64 kbps specified by H.221. In the figure, data transmission and reception are performed in units of 8 bits,
It is managed by octet numbers from 1 to 80. The most significant bit of the 8-bit data is 1-bit data of sub-channel # 1 in FIG. 5, and the least significant bit is 1-bit data of sub-channel # 8 in FIG.

The least significant data of eight 8-bit data from octet 1 to octet 8 indicates control data for frame synchronization and is called FAS.
Further, the least significant data of the eight 8-bit data of octets 9 to 16 indicates control data for defining a demultiplexing pattern and the like, and is called BAS.

In this way, when transmission from the 8-bit data of octet 1 to the 8-bit data of octet 80 is repeated, 8 bits × 80 octets = 6
The FAS and the BAS are transmitted in units of 40 bits. If the transmission of the 640-bit data is performed in 10 milliseconds, the transmission will be exactly 64 kbps. For example, FIG. 6 shows a state in which, while transmitting at 64 kbps, audio is multiplexed at 16 kbps and the rest is multiplexed as image data. At this time, BAS indicating a transfer speed of 64 kbps and BA indicating a voice of 16 kbps are used as the BAS.
S are transmitted alternately.

On the other hand, in the receiving process, MUX / DMUX 9
6 detects the FAS, and notifies the system controller 99 when the FAS is detected. With this as a trigger, the system controller receives the BAS from the MUX / DMUX and
By analyzing S, it is possible to recognize the multiplex format in the reception state, and it is also possible to separate audio data and image data.

Incidentally, the BAS is used not only as a command indicating a multiplexed state but also as a command indicating the receiving capability of the apparatus. TTC standard JT-
H. According to 242, "method for setting communication between audiovisual terminals using digital channels up to 1920 kbps", in order to perform simultaneous multiplex communication of images and sounds, BASs indicating capabilities are exchanged with each other. It is necessary that the initialization information exchange sequence for grasping the receiving capability of the other party ends normally. After the call connection is completed, the system controller 99 executes an initialization information exchange sequence, and as a result, determines a multiplex pattern. Such an operation is called negotiation. The command indicating the multiplex pattern determined by the negotiation is BAS
To send periodically.

[0013]

Since the conventional image transmission apparatus is configured as described above, simultaneous communication of image and audio between image transmission apparatuses having different connection procedures and different encoding algorithms is completely impossible. There is a problem that it is possible, and the interconnectivity with the image transmission device of a different encoding algorithm already on the market is lost.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and recognizes whether or not the encoding algorithm and the interconnection procedure are different at the time of negotiation even if the encoding algorithm and the interconnection procedure are different. It is an object of the present invention to obtain an image transmission device that enables simultaneous communication of an image and a voice by matching one of the encoding algorithms and an interconnection procedure.

[0015]

An image transmission according to the first invention is provided.
The transmission device has a plurality of encoding modes for image data.
Encoding means that can be set, image data and control procedures
Multiplexed control data containing
Interface section for receiving and the above interface
The data received by the unit includes image data and control procedures
Separation control means for separating the data into control data;
System included in control data separated by
Recognizes the connection procedure from the
Control means for setting an encoding mode to the image encoding means;
It is provided with.

An image transmission device according to a second aspect of the present invention comprises:
In addition to the image transmission device according to the invention, the image encoding means is
Standard encoding and non-standard encoding as encoding modes
In addition to being able to make settings, the control
Connection procedure or non-standard connection procedure.
Connection procedure with the partner device, and
Encoding method corresponding to the connection procedure that selected the image encoding means
This is set in the expression.

[0017]

According to the first aspect of the present invention, there is provided an image transmitting apparatus comprising:
The control means recognizes the connection procedure from the hand system and
Execution of the corresponding image coding algorithm for the coding means
Instruct and perform the corresponding connection procedure.

The image transmission apparatus according to the second invention is, for example,
For example, see TTC Standard JT-H. Standard interconnection according to 242
Connection procedure and non-standard proprietary mode connection procedure
Can be selected, and the selected connection
And the image transmission device.
Set the encoding method corresponding to the selected connection procedure.

[0019]

【Example】

Embodiment 1 FIG. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 91 denotes a video input unit for digitizing input analog image data and performing a conversion operation to a predetermined image format, and a video output unit for converting digital image data into analog image data. The video input / output device 92 comprises a video encoding device for encoding the image data inputted from the video input / output device 91 with high efficiency, and a video decoding device for restoring the encoded image data to the data before encoding. It is a video codec (an example of an encoding unit).

Reference numeral 93 denotes an audio input / output device for inputting / outputting audio data in the same manner as the image data, and reference numeral 94 denotes an audio signal for encoding and decoding audio data input / output to / from the audio input / output device 93. Codec. Reference numeral 95 denotes a delay circuit that adjusts the time so that the audio data decoded by the audio codec 94 and the image data decoded by the video codec 92 match in time.

Further, reference numeral 96 denotes encoded image data;
A multiplexing / demultiplexing control device (hereinafter, referred to as MUX / DMUX) 97 for multiplexing / demultiplexing voice data and control data, a network interface device 97 connected to the MUX / DMUX 96 for interfacing with a transmission line of a partner station that performs transmission and reception. It is.

Reference numeral 98 denotes a telematic device connected to the MUX / DMUX 96, and reference numeral 99 denotes a system control device for controlling the entire system, and also instructs a video codec 92 on an encoding algorithm. Reference numeral 100 denotes an end network signal control device connected between the system control device 99 and the network interface device 97.

A transmission control unit 101 monitors the BAS output from the MUX / DMUX and executes an interconnection procedure. Reference numeral 102 denotes a control unit including the system control device 99 and the transmission control device 101.

Next, the operation will be described. This image transmission apparatus is based on ITU-T Rec. Whether to execute the connection procedure of H.242 (hereinafter, referred to as a standard procedure) or to execute a unique connection procedure (hereinafter, referred to as a non-standard procedure) can be arbitrarily set by, for example, a switch setting. When a calling process is performed from the own station, or when a call is received from a partner station, the image transmission apparatus starts its operation according to the standard procedure setting or the non-standard procedure setting set at that time. here,
Even if it operates in the standard procedure setting, if the partner station recognizes that it operates in the non-standard procedure, it can shift to the non-standard procedure, but if it starts operation in the non-standard procedure, it will not be possible to change the connection procedure Control.

In this embodiment, it is specified that the BAS having the same value is not transmitted continuously in the standard procedure, and the BAS having the same value is transmitted eight times continuously in the non-standard procedure. A case will be described in which a rule that the BAS is determined at the time when the BAS is received is used.

First, FIG. 2 shows the processing when operating according to the standard procedure.
This will be described based on the flowchart shown in FIG. The system controller 99 activates the video codec 92 using the DCT algorithm (step ST1). The system control device 99 waits until receiving a notification of the setting completion from the video codec 92 (step ST2), instructs the transmission control device 101 to perform negotiation by a standard procedure (step ST3), and waits for a response from the transmission control device 101. (Step ST11).

The transmission control device 101 monitors the received BAS, and upon receiving the beginning of the BAS indicating the capability (step ST4), executes the initialization information exchange sequence of the standard procedure (step ST5). 1 for other BAS
The BAS is compared with the previously received BAS (step ST6), and if different, the BAS counter is cleared (step ST6).
9) Return to monitoring the received BAS. If the BAS is the same, it is checked whether five consecutive receptions have been made (step ST).
7). If it is less than five times, the BAS counter is incremented (step ST10), and the BAS to be received is incremented.
Return to monitoring. If five consecutive receptions have been made, the partner station determines that the procedure is a non-standard procedure, notifies the system controller 99 (step ST8), and ends the process.

On the other hand, when the transmission control device 101 notifies that the partner station is in a non-standard procedure, the system control device 9
9 activates the video codec 92 using a non-standard algorithm (step ST12). On the other hand, the video codec 92 immediately interrupts the process currently being executed, changes the program area, starts the process with another algorithm, and notifies the system controller 99 of the setting completion. When recognizing the setting completion notification (step ST13), the system controller 99 instructs the transmission controller to negotiate in a non-standard procedure (step ST13).
14).

Next, the processing when operating according to the non-standard procedure will be described with reference to the flowchart shown in FIG. The system control device 99 activates the video codec 92 using a non-standard algorithm (step ST21). The system control device 99 waits until receiving the notification of the setting completion from the video codec 92 (step ST22), and the transmission control device 1
01 is instructed to perform negotiation by a non-standard procedure (step ST23), and the process ends.

The transmission control device 101 monitors the received BAS and compares it with the BAS received immediately before (step ST).
26) If they differ, the BAS counter is cleared (step ST29), and the process returns to monitoring the received BAS. BAS
If they are the same, it is checked whether they have been received five times continuously (step ST27). BA when less than 5 times
The S counter is incremented (step ST3
0), return to monitoring the received BAS. If five consecutive receptions have been made, the partner station determines that the procedure is a non-standard procedure and executes a non-standard connection procedure (step ST25).

As described above, if one of them is non-standard, connection is made in a non-standard procedure, and simultaneous communication of image data and audio data encoded by a non-standard image encoding algorithm becomes possible.

As described above, this embodiment digitizes analog image data and performs a conversion operation of a predetermined image format, while a video input / output for converting the digitized image data into analog image data. Device, a video codec for efficiently encoding image data input from the video input / output device, and restoring encoded image data to pre-encoding data, and digitizing analog audio data; Audio input / output device for converting encoded audio data into analog audio data, and audio for efficiently encoding audio data input from the audio input / output device, while restoring encoded audio data to pre-encoded data. A codec is multiplexed with the encoded image data, the encoded audio data, and the control data. Code KASUMI image data, demultiplexing controller for separating the code haze audio data and control data, and the network interface device is connected to the demultiplexing control device to interface with the other for transmitting and receiving,
A transmission control device that is connected to the demultiplexing control device and performs an interconnecting procedure with a transmission / reception partner; and a system control device that controls the entire device, and uses control data separated from the demultiplexing control device. And enables interconnected communication between different encoding modes.

Also, in this embodiment, the image transmission apparatus has means for arbitrarily specifying an image encoding mode, and performs an interconnection procedure corresponding to the specified image encoding mode using control data. The image encoding mode is determined by determining the difference in the interconnection procedure.

Also, in this embodiment, a plurality of image coding algorithms can be executed in the image transmission apparatus, and means for switching the algorithms is provided, and it is possible to arbitrarily switch to the image coding algorithm designated by the means. It is characterized by.

Embodiment 2 FIG. In the above-described embodiment, when interconnected by the non-standard procedure, the encoding algorithm is limited to one type because the encoding algorithm is also non-standard. However, after shifting to the non-standard procedure, negotiation for determining the encoding algorithm is performed. This method allows communication between image transmission apparatuses having different encoding algorithms and communication of asymmetric image data having different transmission and reception encoding algorithms.

Embodiment 3 FIG. In the above embodiment, the standard procedure specifies that the same value of the BAS is not transmitted continuously, and the non-standard procedure transmits the same value of the BAS eight times in succession. Although the description has been given of the case of using the rule that the BAS is determined at the point of time, the standard procedure and the non-standard procedure may be determined regardless of the number of BAS transmissions. For example, BAS
If there is an unused one of the 8-bit signals, the unused bit may be used to determine that it is a non-standard procedure.

Embodiment 4 FIG. Further, in the above-described embodiment, even if the other station operates in the standard procedure setting and recognizes that it operates in the non-standard procedure, the procedure can be shifted to the non-standard procedure. Although the case where control is performed so as not to be changed has been described, even when the operation is started in a non-standard procedure, it may be possible to shift to the standard procedure.

[0038]

As described above , according to the first aspect of the present invention , interconnection is possible and simultaneous image data and audio data can be communicated between image transmission apparatuses having different encoding algorithms. There is an effect that the system can be easily reconfigured and the system can be expanded easily and at low cost without changing the past system already on the market.

According to the second invention, the standard procedure and the non-standard
By connecting in any of the sub-procedures, there is an effect that image data suitable for the user's intention can be selected.

[Brief description of the drawings]

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

FIG. 2 is a flowchart illustrating processing of a connection procedure when setting a standard procedure according to an embodiment of the present invention.

FIG. 3 is a flowchart illustrating processing of a connection procedure when setting a non-standard procedure according to an embodiment of the present invention.

FIG. 4 is a block diagram showing a conventional image transmission device.

FIG. 5 is a format diagram showing a multiplex format at 64 kbps.

FIG. 6 is a format diagram showing a multiplex format in which audio and video are multiplexed at 64 kbps.

[Explanation of symbols]

 Reference Signs List 91 video input / output device 92 video codec 96 demultiplexing control device 99 system control device 101 transmission control device

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-225650 (JP, A) JP-A-4-129466 (JP, A) JP-A-4-297176 (JP, A) JP-A-2- 94788 (JP, A) JP-A-4-156773 (JP, A) JP-A-2-305283 (JP, A) JP-A-62-242458 (JP, A) JP-A-63-311872 (JP, A) (58) Field surveyed (Int.Cl. ⁶ , DB name) H04M 11/00-11/10 H04N 7/10 H04N 7/24

Claims (3)

(57) [Claims] 1. An image transmission apparatus having the following elements: (a) image encoding means capable of setting a plurality of types of encoding modes for image data; (b) image data and information specifying an encoding mode I interface unit for receiving multiplexed data from the other unit control data, (c) separating control means for separating the data received by the interface unit to the image data and control data, separating the (d) the separation control means Control data
Control means for setting the coding mode designated by the partner system based on the image coding means based on the other system. 2. An image encoding means may be set a standard encoding scheme and the non-standard coding method as the coding mode, the control means, the target as the connection procedure for connecting a mating device
Standard connection procedure corresponding to the quasi-encoding method or the above non-standard code
Select one of the non-standard connection procedures corresponding to the encoding method , execute the selected connection procedure with the partner device, and set the image encoding means to the encoding method corresponding to the selected connection procedure. The image transmission device according to claim 1, wherein: 3. The system according to claim 1, wherein the control means receives the information from a partner system.
If the above control data is the same multiple times,
Changing a procedure from a standard connection procedure to a non-standard connection procedure
The image transmission device according to claim 2, wherein: