JPH06303210A - Data multiplex transmission device and data multiplex reception device - Google Patents

Abstract

PURPOSE:To prevent the occurrence of error correction even if a data multiplex transmission device provided with the error correction function of auxiliary data and a data multiplex transmission device which is not provided with the function co-exist when video data and auxiliary data are multiplexed and transmitted. CONSTITUTION:A code calculation circuit 1 calculating an error correction code for data in an auxiliary data packet, a code addition circuit 2 adding the calculated result to auxiliary data, a correction flag writing circuit 3 writing an error correction flag showing that error correction data is added to auxiliary data into a position where digital blanking is decided and a blanking data multiplex circuit 4 multiplexing data in a digital blanking period including auxiliary data with video data are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for multiplexing and transmitting video data and auxiliary data (audio data, control data, etc.), and more particularly to a data multiplex transmitting device and a data multiplex receiving device for error correction of auxiliary data. is there.

[0002]

2. Description of the Related Art In recent years, there has been a demand for higher quality video, and due to advances in semiconductor technology that supports this, video signals have been digitized as in the case of audio signals, and processing such as signal processing and storage is performed using digital data. There are more and more people being told. In this way, when various processes are performed on digital data, the transmission of these data maintains high quality, and therefore is meaningless unless it is digital transmission. Especially in broadcasting equipment and the like, high quality transmission is required.

Further, in such data transmission between devices, the connection between the devices must be easy. Therefore, the format of data transmitted between devices, the signal level, etc. are specified. As an example of such regulations, the conventional NTSC
SMPTE259M (SMPTE: Society of Motion P
icture and Television Enginners) and BTA (Broadcasting Technology Development Association) S-002 for HDTV signals. In any case, auxiliary data (audio data, control data, etc.) other than the video data can be multiplexed and transmitted during the blanking period of the video data.

An example of multiplexing auxiliary data during the blanking period of video data according to BTA S-002 defined as a bit parallel interface standard for HDTV signals as a conventional example and then transmitting the auxiliary data will be described with reference to FIGS. Will be explained. As shown in FIG. 4, a digital line forming one horizontal period is composed of a digital effective line composed of video data and a digital line blanking corresponding to horizontal blanking.

The first (EAV) and last (SAV) four words of digital line blanking are timing reference codes including synchronization information. Auxiliary data such as voice data will be transferred from this digital line blanking period to EAV, SAV
It is possible to multiplex in a packet format in the period excluding.
The auxiliary data packet has the format shown in FIG.
It consists of ANC code and data field. The ANC code is composed of a fixed pattern indicating the beginning of the auxiliary data packet, a word indicating the type of data, and a word indicating the number of words of data or a line number. A video data word is stored in the data field.

As shown in FIG. 3, the auxiliary data packet is multiplexed in the blanking data multiplex circuit of the data multiplex transmission device in the data multiplex transmission device. In the data multiplexing receiver, the blanking data separation circuit separates the blanking data multiplexed on the digital line blanking, and the auxiliary data separation circuit separates the auxiliary data packet to reproduce the auxiliary data.

[0007]

However, in the above-mentioned conventional structure, there is no means for correcting an error in the data forming the auxiliary data packet. In this case, it is possible to add error correction data to the auxiliary data packet in the data multiplex transmission device and correct the error of the data existing in the auxiliary data packet in the data multiplex reception device. Reed-Solomon, BCH and other error correction codes can be used as the error correction data.

In this case, even if there is an error in the data making up the auxiliary data packet, the problem that there is no means for correcting this error can be solved, but all of the data multiplex transmission devices connected to each other are data multiplexed. The transmitter must be provided with means for adding the error correction data and the data multiplex receiver for correcting the error. However, in an actual data multiplex transmission device, there is a possibility that there is an existing device that does not have the above-existing means, and in order to reduce the cost, an inexpensive data multiplex device that does not have the above-mentioned means is provided. There is a high possibility that a transmission device will be used.

Therefore, in a system using the above-mentioned data multiplex transmission apparatus, a data multiplex transmission apparatus having the error correction means for the auxiliary data, or a data multiplex transmission apparatus having no data multiplex reception apparatus and the error correction means for the auxiliary data. Devices or data multiplex reception devices are mixed. In this case, for example, if the data multiplex transmitting apparatus does not have the function of adding error correction data and the data multiplex receiving apparatus has the error correcting function, there is a possibility that the data may be erroneously corrected.

The present invention is to solve this problem, and in a system using the above-mentioned data multiplex transmission apparatus, a data multiplex transmission apparatus having the above-mentioned auxiliary data error correction means, or a data multiplex reception apparatus and the above-mentioned auxiliary data. Even if the data multiplex transmitters or the data multiplex receivers without the error correction means are mixed, the interconnection can be performed without any trouble.

[0011]

In order to achieve the above object, a data multiplex transmission apparatus of the present invention is a code calculation circuit for calculating an error correction code for data in a packet of auxiliary data, and a calculation result thereof. To the auxiliary data, a correction flag writing circuit that writes an error correction flag indicating that the error correction data is added to the auxiliary data at the position where the digital blanking is determined,
It is provided with a blanking data multiplexing circuit that multiplexes data of a digital line blanking period including auxiliary data and video data.

The data multiplex receiving apparatus includes a blanking data separation circuit for separating data in a digital line blanking period including video data and auxiliary data, and auxiliary data for separating auxiliary data from data in the digital line blanking period. A separation circuit, a correction flag detection circuit that detects an error correction flag indicating that error correction data is added to auxiliary data, and determines the necessity of performing error correction processing of auxiliary data, and a correction flag detection circuit If it is determined that error correction is necessary, error correction processing of auxiliary data is performed, and if it is determined that error correction processing is not necessary, error correction processing is not performed and auxiliary data is output as it is. It has a correction circuit.

[0013]

According to the present invention, when the auxiliary data is multiplexed with the video data and transmitted by the above configuration, the data multiplexing transmitter calculates an error correction code for the data in the packet of the auxiliary data. This calculation result is added to the position where the auxiliary data packet is determined. In addition, an error correction flag indicating that the error correction data is added to the auxiliary data packet is written at a position where the digital line blanking is determined. Next, the data of the digital line blanking period including the video data and the auxiliary data is multiplexed.

Further, in the data multiplex receiving apparatus, the data of the digital line blanking period including the video data and the auxiliary data is separated. The auxiliary data is separated from the separated data in the digital line blanking period. If the error correction flag is detected and it is determined that the error correction process needs to be performed, the error correction process is performed on the separated auxiliary data. If it is determined that the error correction processing does not need to be performed, the error correction processing is not performed on the auxiliary data.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings.

(Embodiment 1) An embodiment of the data multiplex transmission apparatus of the present invention will be described with reference to FIGS. 1, 4, 5, and 6. As a method for multiplexing and transmitting the digitized video data and the auxiliary data including the digitized audio data and control data, the BTA (Broadcasting Technology Development Association) provides 1125/60 HDTV video signal Coding and bit parallel interface standard (BT
AS-002) has been established. This embodiment will be described based on this standard.

FIG. 1 is a block diagram of a data multiplex transmission apparatus according to an embodiment of the present invention. As video data shown in the drawing, parallel video data defined by S-002 is input. The timing relationship between the digitized video data and the original analog video signal in this case is as shown in FIG. 4, and the synchronization timing reference code EAV (End of Active Vial) of the digital line blanking 280T is shown.
deo) and SAV (Start of Active Video), the auxiliary data is multiplexed in a portion excluding a total of 8T. On the other hand, as the auxiliary data, the data shown in FIG. 5 is input.

This data is packetized data and is composed of an ANC code and a data field. AN
The C code is composed of a fixed pattern indicating the beginning of auxiliary data and information indicating the type and number of data. In addition, the data field is the part that contains data such as voice data,
The number of words changes depending on the number of data to be transmitted. The error correction data of the input auxiliary data is calculated by the code calculation circuit 1 shown in FIG. Reed-Solomon code, BCH code, and other error correction codes can be used as the error correction code. The error correction data calculated by the code calculation circuit 1 is sent to the code addition circuit 2 and added to a predetermined position of the auxiliary data to form a new auxiliary data packet.

Next, the correction flag writing circuit 3 writes an error correction flag indicating that the error correction data is added to the auxiliary data at the position where the digital line blanking is determined. As the position where the error correction flag is written, the MSB of the fourth word of EAV or SAV can be used as shown in FIG. Normally, this bit is fixed to "1", but when the error correction flag is turned on (indicating that error correction data is added to auxiliary data), this bit is set to "0". However, in the case of SAV, all bits forming this word may be "0", and it is more appropriate to use the fourth word of EAV.

Further, as the position for writing the error correction flag, the MSB of the word indicating the number of data words of the ANC code of the auxiliary data packet shown in FIG. 5 is normally fixed to "0", but the error correction flag is turned on. If so, this bit is set to "1". Furthermore, it is also possible to write this error correction flag at a specific fixed position of digital line blanking. For example, EAV4
A line number is written in two words immediately after the word, and a bit array for this line number is shown in FIG. 7, and a spare bit in this array can be used as an error correction flag.

In this case, the b0 and b1 bits are also used, and a plurality of bits can be assigned as an error correction flag. Therefore, the type of error correction code can be transmitted and a plurality of error correction codes can be selected. it can. The digital blanking data thus configured is multiplexed with the video data by the blanking data multiplexing circuit 4.

(Embodiment 2) An embodiment of the data multiplex reception apparatus of the present invention will be described in detail with reference to FIG. Data obtained by multiplexing auxiliary data during digital line blanking of video data is input to the data multiplex receiving device. This input data is separated by the blanking data separation circuit 5 into digital line blanking period data including auxiliary data and video data. Further, the auxiliary data separation circuit 6 detects the fixed pattern included in the ANC code from the separated data of the digital line blanking period, thereby separating the auxiliary data.

Next, the correction flag detection circuit 7 detects the error correction flag, determines the necessity of error correction processing of the auxiliary data, and when it is determined that the error correction is necessary, the following is performed. The correction circuit 8 performs error correction processing on the auxiliary data. If it is determined that the error correction processing is not necessary, the correction circuit 8 does not perform the correction processing and the auxiliary data sent to the correction circuit 8 is output as it is.

(Embodiment 3) Next, an embodiment of the data multiplex transmission apparatus of the present invention will be described. The output signal from the data multiplex transmission device having the function described in the first embodiment is transmitted to the data multiplex reception device having the function described in the second embodiment by using a transmission medium such as an optical fiber or a coaxial cable. Auxiliary data multiplexed during the digital line blanking period of data is transmitted. Further, based on the correction flag written in the data multiplex transmission device, the data multiplex reception device determines whether or not to perform error correction processing of auxiliary data, and performs error correction processing as necessary.

[0025]

As described above, according to the present invention, in the case of transmitting auxiliary data including video data, audio data, control data, etc., if the data multiplex transmission device and the data multiplex reception device have the above-mentioned functions. A data multiplex transmission device capable of correcting an error in auxiliary data can be realized.

In particular, there are provided a data multiplex transmission apparatus or data multiplex reception apparatus having no error correction function and a data multiplex transmission apparatus or data multiplex reception apparatus having an error correction function for cost reduction. In the case where they are mixed, or when there are data multiplex transmitters and receivers that do not already have such an error correction function in the market and there are devices that do not have such functions and devices that do not, such as data When the multiplex transmission device does not have the function of adding data for error correction of auxiliary data and the data multiplex reception device has the function of performing error correction, the reception device does not receive the auxiliary data. There is a possibility of making an erroneous correction.

However, the data multiplex receiving apparatus according to the present invention has the function of detecting the correction flag and determining the necessity of the correction process, and the error correction flag is turned off (in the data multiplex transmitting apparatus which does not have the above function). Since the correction flag bit is selected so that the error correction data is not added to the auxiliary data), the receiving device performs the correction process on the auxiliary data to which the error correction data is not added. There is no need to make any corrections.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a data multiplex transmission apparatus according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a data multiplex receiving apparatus according to an embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a conventional data multiplex transmission device.

FIG. 4 is a timing relationship diagram of digitized video data and an analog video signal.

FIG. 5 is a diagram showing an auxiliary data packet format.

[Figure 6] Configuration diagram of EAV (End of Active Video)

FIG. 7 is a diagram showing an example of a bit array of line numbers.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 code calculation circuit 2 code addition circuit 3 correction flag writing circuit 4 blanking data multiplexing circuit 5 blanking data separation circuit 6 auxiliary data separation circuit 7 correction flag detection circuit 8 correction circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04N 7/12 A

Claims (6)

[Claims] 1. A code calculation circuit for calculating an error correction code for data in an auxiliary data packet, a code addition circuit for adding the calculation result to auxiliary data, and auxiliary data at a position where digital blanking is determined. A correction flag writing circuit for writing an error correction flag indicating that the error correction data is added to the blanking data, and a blanking data multiplexing circuit for multiplexing the data of the digital line blanking period including the auxiliary data and the video data. A data multiplex transmission device characterized by: 2. A blanking data separation circuit for separating data in a digital line blanking period including video data and auxiliary data, an auxiliary data separation circuit for separating auxiliary data from data in the digital line blanking period, and auxiliary data. A correction flag detection circuit that determines the necessity of performing error correction processing of auxiliary data by detecting an error correction flag indicating that the error correction data is added to the error correction flag detection circuit. If it is determined that the auxiliary data is error-corrected, the error correction process is not performed. If the error is not detected, the auxiliary data is output as it is. A data multiplex receiver characterized by the above. 3. A data multiplex transmission device according to claim 1,
A data multiplex transmission device comprising: the data multiplex reception device according to claim 2, wherein an output of the data multiplex transmission device is transmitted to an input of the data reception device via a transmission line. 4. An error correction flag indicating that error correction data is added to the auxiliary data is set to EAV (End of
The data multiplex transmission device according to claim 1, wherein the data is written in a specific position in the Active Video. 5. An error correction flag indicating that error correction data is added to the auxiliary data is written at a specific position in the auxiliary data packet.
The described data multiplex transmission device. 6. An error correction flag indicating that error correction data is added to the auxiliary data is set to EAV (End of
2. The data multiplex transmission device according to claim 1, wherein the data is written in a specific position within the next two words of Active Video.