JP2623594B2 - Digital signal recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital signal recording device, and more particularly, to a recording device capable of recording a digital video signal and a digital audio signal on the same recording medium.

[Conventional technology]

Conventionally, in digital video tape recorders,
An audio signal can be recorded by securing a recording area for a digital audio signal separately from a recording area (video area) for a digital video signal on a recording track. Recording and reproduction were performed by a circuit.

[Problems to be solved by the invention]

As described above, in a digital signal recording apparatus that records an audio signal and a video signal on the same recording medium, separate signal processing is performed for each of audio and video signals, so two signal processing circuits are required. However, there is a problem that the circuit scale becomes large.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a digital signal recording apparatus which can handle audio signals and video signals as commonly as possible and which simplifies the circuit.

[Means for solving the problem]

A digital signal recording device according to the present invention is a device for recording a digital video signal and a digital audio signal on the same recording medium, wherein a video signal for one screen is divided into two-dimensional areas vertically and horizontally divided on the screen. Sync data is added in units of a predetermined amount of data including data of a plurality of lines and parity data for error correction to form a video sync block.
By adding sync data to a part of the audio signal corresponding to the video signal for the screen and the predetermined amount of data including error correction parity data to form an audio sync block, Equal number of video sync blocks and audio sync blocks
A sync block forming unit for forming a block, and a data string in which the video sync block and the audio sync block formed by the sync block forming unit are time-division multiplexed are recorded on a recording medium. Recording means.

[Action]

By forming a video sync block from a plurality of lines of data and error correction parity data located in a two-dimensional area obtained by dividing a video signal for one screen vertically and horizontally on the screen, a video signal and an audio signal are formed. The transmission unit including the sync data can be the same length, and the video signal and the audio signal can share the recording processing system.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a block diagram of the configuration.

Reference numeral 10 denotes a video signal input terminal to which a 4: 1: 1 component signal is input. The data compression circuit 12 sub-samples the luminance signal Y at 2 f _sc (f _sc is a subcarrier frequency), sub-samples the two color signals I and Q at a rate of 1/2 f _sc , respectively, The video ECC encoding circuit 1 reduces the data on the invalid screen when 0.844 / 0.914 is set.
Supply 4 16, 18 are audio signal input terminals,
The two-channel audio signals are sampled at 48 KHz in the A / D converters 20 and 22, respectively, quantized by 16 bits, and applied to the audio interleave circuit 24. An audio interleave circuit 24 rearranges both input data and outputs an audio ECC encoding circuit 26.
To supply.

Here, the encoding operation of the video signal and audio signal ECC encoding circuits 14 and 26 will be described.

The Y signal of the video signal whose data has been reduced is considered as a two-dimensional array of 240 bytes vertically and 384 bytes horizontally (that is, 240 rows and 384 columns) shown in FIG. The vertical length shown in FIG.
Consider a two-dimensional array of 0 bytes and 128 bytes wide (240 rows and 128 columns). Then, the data array of Y, I, and Q is further divided into 12 as shown in the figure. The video ECC encoding circuit 14 is configured to output one of Y, I, and Q.
By mixing the divided parts, 6 bytes vertically and horizontally shown in FIG.
First, a C2 encoding process is performed in the vertical direction on a data matrix of 192 bytes (60 rows and 192 columns) to generate and add 4-byte C2 parity data. As a result, a two-dimensional data matrix of 64 bytes in length and 192 bytes in width (64 rows and 192 columns) including the C2 parity is obtained. Next, this data
Apply C1 encoding process to the matrix in the horizontal direction
Generate and add byte C1 parity data. As a result, a two-dimensional data matrix of 64 bytes in length and 196 bytes in width (64 rows and 196 columns) including C1 parity and C2 parity is finally obtained. This data is output to the switch 28 in order from the top row.

Note that Reed-Solomon codes, adjacent codes, and the like can be used as the C1 and C2 codes.

The audio signal interleaved by the audio interleave circuit 24 becomes 8008 samples in five field periods of the video signal. This is due to the fact that the one-field period of the video signal is not exactly 1/60 second, but the processing of the leave field is not the gist of the present invention.
It is assumed that the data is 1602 samples. Since the audio signal is quantized by 16 bits, 1602 samples correspond to 3204 bytes of information. It is assumed that there are four audio signals of 3204 bytes / field, each having a data matrix of 9 rows and 94 columns (9 rows and 94 columns) shown in FIG. 3A as one unit. With 4 rows of 9 rows and 94 columns, 3384 (= 9 × 94 × 4) bytes of data can be processed, but since the audio signal has only 3204 bytes of data per field, 180 bytes of other data per field is inserted. 3384 per field
Byte data.

The audio ECC encoding circuit 26 first applies the data matrix of 9 rows and 94 columns shown in FIG.
A C2 encoding process is performed to generate and add 3-byte C2 parity data to form a data matrix of 12 rows and 94 columns including C2 parity. Next, the data matrix is subjected to the C1 encoding process in the horizontal direction to generate and add 4-byte C1 parity data, and the 12 rows 9 including the C1 and C2 parities are added.
Obtain an 8-column data matrix. As the C1 and C2 codes, a Reed-Solomon code, an adjacent code, and the like can be used as in the case of the video signal. The data of 12 rows and 98 columns is output to the switch 28 in order from the upper row.

The switch 28 switches between a video signal and an audio signal in a time-division manner. The output of the switch 28 is applied to a sink adding circuit 30, where a sync pattern is added. For the video signal, as shown in FIG.
A 1-byte sync pattern is added to two rows of the six-column data matrix. Hereinafter, this 393-byte data is called a sync block. As shown in FIG. 3B, a sync pattern of 1 byte is added to the audio signal for four rows of the data matrix of 12 rows and 98 columns. As a result, the audio signal also becomes 1
393 bytes per sync block.

The modulation circuit 32 converts the output of the sync addition circuit 30 into a signal form suitable for digital recording with a small DC component.
The output of the modulation circuit 32 is amplified by a recording amplifier 34 and magnetically recorded on a magnetic tape 38 by a magnetic head 36.

FIG. 4 shows an example of a recording format of the magnetic tape 38 recorded by the recording device of FIG. In FIG. 4, S indicates a recording position of the sync information, A indicates an audio signal, and V indicates a video signal. According to such a recording format,
Even if a window signal is created at the time of reproduction, it is not necessary to form separate window signals for the video signal and the audio signal at the time of sync detection, so that the reproduction circuit system can be greatly simplified.

〔The invention's effect〕

As can be easily understood from the above description, according to the present invention, the minimum transmission unit of the video signal and the audio signal including the sync data can be made the same length, and the recording and reproducing system circuit can be shared, Circuit size can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is an explanatory diagram of video signal blocking, FIG. 3 is an explanatory diagram of audio signal blocking, and FIG. 4 is recording on a magnetic tape. It is an example of a format. 10 video signal input terminal, 14 video ECC encoding circuit, 16, 18 audio signal input terminal, 24 audio interleave circuit, 26 audio ECC encoding circuit, 36 magnetic head, 38 …… Magnetic tape

Claims (1)

(57) [Claims] A digital video signal and a digital video signal.
An apparatus for recording an audio signal on the same recording medium, comprising: data for a plurality of lines located in a two-dimensional area obtained by dividing a video signal for one screen vertically and horizontally on a screen, and parity data for error correction. A sync signal is added in units of a predetermined amount of data to form a video sync block, and a portion including an audio signal part corresponding to the video signal for one screen and parity data for error correction. Sync block forming means for forming a video sync block and an audio sync block having the same data number by adding sync data to a fixed amount of data to form an audio sync block; The video sync block and the audio sync formed by the sync block forming means. Recording means for recording the data string and the block is time-base multiplexed onto a recording medium, a digital signal recording apparatus characterized by comprising and.