JPH0715728A - Coding device and data transmission system - Google Patents

Abstract

PURPOSE:To compress and code the data with a single device in response to the required quality of each user by detecting a reference slot out of the output of a multiplexing part, sending the data on the reference slot and its compression rate to a coding part with synchronization secured between them, and coding the data at the designated compression rate. CONSTITUTION:The video signal supplied from a multiplexing part 102 via a data line 109 is coded at the compression rate received via a control line 108. That is, the compression rate is varied for each slot of the input signal for coding. These coding data are transmitted from an output circuit 120 via a circuit controller 105 which serves as an interface device. A constitution setting part 206 sets a compression rate, and a processing part 103 informs the part 102 of the compression rate via the line 108. Then a coding part 104 codes the data at the compression rate received via the line 108 and sends the coded data to the controller 105.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information transmission technique, and more particularly to a technique which is particularly effective when applied to a system for encoding and transmitting or accumulating audio and moving images. -In a deck, the present invention relates to an encoding device that has a plurality of inputs and performs encoding with different compression ratios for each input, and a technique effectively used for a data transmission system using the same.

[0002]

2. Description of the Related Art Since multimedia data, especially moving picture data, has a large amount of data, it is necessary to compress it when transmitting or storing it. Conventionally, a video input signal is compression-encoded, multiplexed with other control signals, the code amount of this multiplexed signal is detected, the number of transmission paths is determined from the code amount and transmission speed, and the multiplexed signal is transmitted. To do. Then, when the code amount exceeds the transmission rate of a predetermined transmission line, since the divided transmission is performed through a plurality of transmission lines, there is an invention relating to a video transmission apparatus capable of transmitting compressed data with a constant image quality. It has been proposed (Japanese Patent Laid-Open No. 61-231638).

[0003]

However, the present inventors have clarified that the above-mentioned technique has the following problems. That is, the above conventional technology is
The amount of encoded compressed moving image data is detected, and the number of transmission paths is selected from the amount of data detected. In other words, the smaller the compression rate of a moving image, the better the image quality. Therefore, it is desirable to compress the moving image according to the input / output device to be transferred to a data amount close to the transfer speed of this input / output device. Therefore, in the prior art, in order to maintain the quality of the image, compression is performed without raising the compression rate so much that the transmission path is secured according to the amount of compressed data.

However, the above-mentioned prior art discloses only the processing after compression and encoding, and does not disclose how to change the compression rate. In general, an encoding codec can make the compression rate variable, but has only one input port, so it is impossible to compress and encode a plurality of images. It was An object of the present invention is to realize an apparatus capable of compressing and encoding data with a quality corresponding to the needs of a plurality of users with a single encoding apparatus. The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0005]

The typical ones of the inventions disclosed in the present application will be outlined below. That is, according to the present invention, in consideration of the fact that when the compression rate is increased, the amount of data can be reduced, but the image quality is deteriorated, a multiplexer for multiplexing a plurality of inputs is provided, and the slot of the multiplexed inputs is provided. It associates the position with the line and the compression ratio, instructs the multiplexer about the relationship between the input line and the slot, detects the reference slot from the output of the multiplexer, and recognizes the relationship between the slot position following the reference slot and the compression ratio. , Slot data
The data is output to the encoding unit in synchronization with the compression rate and the compression rate, and is encoded at the specified compression rate.

[0006]

According to the above-mentioned means, a codec capable of varying the compression ratio is used in a system for encoding audio and moving images, and the code from a plurality of input sources is used with this one codec. By performing encoding with different compression rates for each input, it is possible to change the compression rate according to the purpose and perform encoding. With this, one encoding device can be used for each of a plurality of users. The object of realizing the compression coding of data with the quality according to the needs is achieved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an encoding device for encoding a plurality of inputs having different compression rates, which is an embodiment of the present invention. The coding apparatus 100 of this embodiment is one in which a plurality of video signals respectively input with a quality according to a user's request are coded by one apparatus. Therefore, the encoder is provided with a plurality of input ports and a plurality of lines 110 are connected,
Multiplex these inputs. Moreover, each input port, slot, and compression rate have a fixed relationship, and encoding is performed at different compression rates according to the output timing of the multiplexing unit.

As shown in FIG. 1, the coding apparatus 100 according to the present embodiment has a multiplexing section 102, a processing section 103, a coding section 104, a line control section 105 and a configuration setting section 10.
6 and 6. The multiplexing unit 102 includes
In this embodiment, three input lines 111 to 113 are connected. The coding apparatus 100 of this embodiment performs coding with different compression rates according to the contents set in the configuration setting unit 106, which will be described later, for each line. That is, the lines 111 to 11 connected to different video sources
Encoding with different compression rates is performed for each of the three. The multiplexing unit 1
02 multiplexes inputs from the input lines 111 to 113, adds a reference slot at a predetermined cycle in synchronization with a clock, and outputs the reference slot to the processing unit 103. The processing unit 103 extracts the input timing of the video signal from the multiplexing unit 102, takes in the contents set in the configuration setting unit 106, and changes the configuration via the control line 108 to the multiplexing unit 102 and the encoding unit. Notify 104.

In addition, the data line 109 from the multiplexing unit 102
The signal input via the is supplied to the encoding unit 104. Then, the encoding unit 104 encodes the video signal input via the data line 109 according to the compression rate input via the control line 108. That is, the compression rate is changed for each slot (minimum unit to be multiplexed) of the input signal for encoding. Then, this coded data is transmitted from the output line 120 via the line control device 105 as an interface device. Note that the configuration setting unit 106 described above
Is for the user to arbitrarily set the compression rate for each slot when multiplexing video signals, and can be realized by using a DIP switch or the like.

The hardware configuration of the encoding device 100 has been shown by the functional blocks as described above.
05 can be realized by a microcomputer system. An example of the system configuration in that case is shown in FIG. In FIG. 2, reference numeral 202 denotes a multiplexing interface that realizes the function of the multiplexing unit 102 that multiplexes video signals and the like input from the video cameras 211 to 213 via the input lines 111 to 113, and 203 denotes the processing unit 103. A microcomputer (CPU) for realizing the function of the above, 204 is a codec for realizing the function of the encoding unit 104, 20
A line interface 5 realizes the function of the line control unit 105.

Reference numeral 206 designates the input lines 111 to 11 mentioned above.
3 and a switch that realizes the function of the configuration setting unit 106 for presetting the relationship between the slot position and the compression rate, and 207 is the input line 111 created by the processing unit 103.
~ 113, a correspondence table of slot positions and compression ratios, and a semiconductor memory for storing multiplexed image data (frames), 208 is a magnetic disk device constituting a file for storing transmitted / received image data, A disk interface unit 209 controls the magnetic disk device 204. The image codec used here is H.264 of CCITT recommendation. 261 is a codec that encodes the difference between the image frames from the video camera, and the compression rate can be made variable.

[0012]

[Table 1]

FIG. 3 shows a procedure of compression coding processing by the CPU 201 when the function of the processing unit 103 is realized by software of a microcomputer. First, in step S101, the configuration setting unit 106 to the multiplexing unit 10
The relationship between the two input lines 110 and the multiplexed time slot and the relationship between each time slot and the compression rate are read. For example, if there are three input lines 110 of the encoding device 100 and there are encoding requests with different compression rates,
The input from the input line 111 is encoded with a compression rate of A, the input from the input line 112 is encoded with a compression rate of B, and the input from the input line 113 is encoded with a compression rate of C.

Here, the fact that the compression rate is small means that the amount of data to be deleted is small and the original data can be more faithfully restored. That is, the transmission amount increases but the image quality improves. In a surveillance system using a camera, it is preferable to set the compression rate to be small when performing local monitoring, and to set the compression rate to be large for input from a camera that monitors the whole and to perform encoding. .

Next, the relationship between the multiplexed data and the compression rate will be described with reference to FIG. The data multiplexed by the multiplexing unit 102 is input to the processing unit 103 as a time series signal as shown in FIG. In FIG. 4, 301a, 30
1b indicates the position of the reference slot. The reference slot is inserted at a constant cycle so that the position of the data slot in which the image data is stored can be recognized. On the other hand, 30
Reference numeral 2 denotes a data slot, of which the data slots 302a, 302b, 302c are input lines 11
It is assigned for the transmission of data from 1.
The data slots 302d and 302e are assigned to transmit data from the input line 112, and the data slot 302f is assigned to transmit data from the input line 113. In this way, the data
Determine the taslot. This relationship is related to the configuration setting unit 20 described above.
6 is set, and the setting content is read by the processing unit 103.

Next, these relations (correspondence between the slot positions and the compression ratios assigned to the input lines by multiplexing) are created as a table as shown in Table 1 in step S102. It can be seen from Table 1 that the slot positions of the input line 111 are defined as 302a, 302b, 302c and the compression rate is A. According to this definition, the processing unit 103 notifies the multiplexing unit 102 of the slot configuration via the control line 108 (processing S103). Multiplexer 10
2 receives the data from the input lines 111 to 113 according to this instruction.
Data to each of the slots 302a to 302f. After the above-described preprocessing is completed, the processing unit 103 takes in the data from the multiplexing unit 102 and first detects the reference slot 301 from the multiplexed data (S104).

Next, in step S105, the reference slot 301
The position of the data slot from is detected. Then, the process S
Next, the data slot position is recognized at 106, and the slot positions are identified as 302a,
If 02b and 302c, the compression rate is set to A, and the process S107
If it is 302d or 302e, the compression rate is set to B, and the process S1
If 08 and 302f, the compression rate is C. Then, in step S109, the encoding unit 1 synchronizes the compression rate with the data.
Output to 04. The encoding unit 104 performs encoding according to this compression rate. Each data slot 302a to 302f
After the end of the processing for (1), it is recognized whether the detected slot is the reference slot data slot, and if it is a data slot, processing S105 to processing S109 are repeated.

Next, FIG. 5 shows an example of the configuration of a decoding device for restoring the encoded data. Decoding device 500
The respective elements that make up are substantially the same as the encoding device 100,
The demultiplexing unit 502, the processing unit 503, the decoding unit 504, the line control unit 505, and the configuration setting unit 506 are included, but the connection configuration is different from that of the encoding device 100. In addition,
The decoding device 500 of this embodiment can be realized by the same hardware as the system shown in FIG. Next, the operation when the transmission data from the encoding device 100 is input to the decoding device 500 through the output line 120 will be described. Data from the line 120 is input to the processing unit 503 via the line control unit 505. Processing unit 50
3 recognizes the compression rate by the relative position from the reference slot 301 according to the correspondence table 1 of the slot position and the compression rate created from the information read from the configuration setting section 506, and outputs it to the decoding section 504 together with the reception data. To do.

The correspondence between the slot 302 and the line is notified to the demultiplexer 502. The data decoded by the decoding unit 504 is output to the demultiplexing unit 502, and the demultiplexing unit 502 separates the received data and separates the lines 511 to 51.
Output to 3. Details of the operation of the processing unit 503 are the same as those of the processing unit 103 of the encoding device 100, and will not be described. As described above, by multiplexing a plurality of input data and recognizing the compression rate from the position of the time slot, 1
Coding of different quality can be realized by one coding device, and the amount of transmission information can be changed by changing the compression rate for each input port to effectively use the line.

Further, it is possible to dynamically change the compression rate of each input line 110, that is, the compression rate of each slot 302. In this case, the encoding device 100
Since it is necessary to reflect the content of the change in the processing in the decoding device 500, a slot for notifying the content of the change is provided. For example, when the compression rate is automatically changed, the slot 302a is fixedly assigned for control. Then, the data is transferred in the remaining slots. In this case, the slot allocation (Table 1) of the compression rate of the above-described embodiment cannot transmit data due to a large amount of data. At this time, the configuration setting unit 106 shows the relationship between each line, the slot position and the compression rate. Need to change. For example, if the slot position of the input line 111 is 302b,
302c and the compression rate is A → A ′ (A ′> A).

Further, the processing unit 103 of the encoding apparatus 100
Causes an interrupt to occur each time the contents of the configuration setting unit 106 is changed, and executes the control flow of the processing unit shown in FIG. 3 from the beginning. When the processing unit 103 senses an interrupt due to the configuration change, the configuration setting unit 106
The change contents are read out, the correspondence table is newly created, and the multiplexing unit 102 is notified, and the multiplexing unit 102 changes the slot allocation accordingly. Further, the processing unit 103 sets the change information in the slot 302a for the change notification at the same time as the notification to the multiplexing unit 102, and outputs it to the line control unit 205 for transmission to the decoding device 500.

On the other hand, in the compression rate changing operation in the decoding device 500, the change information is extracted from the slot 302a in the signal input to the processing section 503 via the line control section 505, and the line, slot and compression rate are changed. This is performed by recognizing the relationship, outputting this information to the demultiplexing unit 502, and the demultiplexing unit 502 determining the output to each output line 510 based on this information. With the above operation, it becomes possible to automatically change the compression rate for each line in the decoding device 500.

As described above, in the above-described embodiment, the multiplexer for multiplexing a plurality of inputs is provided, the slot position of the multiplexed input is associated with the line and the compression rate, and the input line is connected to the multiplexer. And the slot is specified, the reference slot is detected from the output of the multiplexer, the relationship between the slot position following the reference slot and the compression rate is recognized, and the slot
Since the data and the compression rate are output to the encoding unit and encoded at the specified compression rate, the compression rate can be changed according to the purpose and the encoding can be performed. Data with quality according to the needs of multiple users
There is an effect that compression encoding of data can be realized.

Although the invention made by the present inventor has been specifically described based on the embodiments, the invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say. For example, in the above embodiment, the relationship between the input lines 111 to 113 and the slot position and the compression rate is set by the switch, but the relationship between the input lines 111 to 113 and the slot position and the compression rate is shown in Table 1. It may be stored in advance in a non-volatile memory in the form of a table as shown in FIG. Moreover, in the above description, the invention mainly made by the present inventor has been described by exemplifying the encoding of the image data in the surveillance system which is the field of use which is the background of the invention, but the present invention is not limited thereto and the transmission In general, it can be used for storing image data.

[0025]

The effects obtained by the representative one of the inventions disclosed in the present application will be briefly described as follows. That is, different encoding qualities can be realized by one encoding device, and compression encoding can be performed with the quality according to the needs of each of a plurality of users. Also, the amount of information can be changed by changing the compression rate for each input port, and the line can be used effectively.

[Brief description of drawings]

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

FIG. 2 is a system configuration diagram showing an embodiment of an encoding device according to the present invention,

FIG. 3 is a flowchart showing an example of a control procedure in a processing unit,

FIG. 4 is an explanatory diagram showing an example of a data array at the time of multiplexing,

FIG. 5 is a functional block diagram showing an embodiment of a decoding device.

[Explanation of symbols]

 100 Encoding Device 102 Multiplexing Unit 103 Processing Unit 104 Encoding Unit 105 Channel Control Unit 106 Configuration Setting Unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location H04M 11/06 7406-5K H04N 7/08 7/081 (72) Inventor Hisanobu Aoki Kodaira, Tokyo 5-22-1 Jousuihonmachi, Hitachi Microcomputer System Co., Ltd. (72) Inventor Katsumi Maeda 5-22-1 Kamisuihoncho, Kodaira-shi, Tokyo Inside Hitachi Microcomputer System Co., Ltd.

Claims (3)

[Claims] 1. A multiplexing unit for multiplexing a plurality of video or audio inputs, a relationship between a slot position of the multiplexed inputs, an input line, and a compression rate is recognized, and the data and the compression rate of the recognized slot are recognized. A processing unit having a function of outputting, an encoding unit that encodes data from the processing unit at a specified compression ratio, a line control unit that transmits the output of the encoding unit to a line,
An encoding device, comprising: an input line used in the processing unit, a slot position, and a configuration setting unit for setting a relationship of a compression rate, and capable of encoding with a different compression rate for each input. 2. When the relationship between the input line, the slot position, and the compression rate is changed, the change information is output to the line,
The encoding device according to claim 1, wherein the encoding device is configured to notify the decoding device. 3. The encoding device according to claim 1, a line control unit for receiving an output from the encoding device via a line, and data from the line control unit for a compression rate for each slot. A processing unit that correlates and outputs this information, and a decoding unit that decodes the data according to the compression ratio received from the processing unit,
A data transmission system comprising a decoding device having a demultiplexing unit for outputting data to each line in accordance with the relationship between the slot position received from the processing unit and the line.