JP2663692B2 - Digital audio signal recording method - Google Patents

Description

The present invention relates to a digital video tape recorder (hereinafter, referred to as a digital video tape recorder).
The present invention relates to a digital audio signal recording method for recording a digital audio signal together with a digital video signal using DVTR.

2. Description of the Related Art In recent years, there has been a remarkable progress in digitalization of audio / video equipment. One of them is a DVTR.

As a digital audio signal recording method used in a conventional DVTR, for example, a method described in "D-2 NTSC Composite Digital VTRW" (Oct. 29, 1987), Technical Report of the Institute of Television Engineers of Japan is available.

Hereinafter, a digital audio signal recording method used in the above-described conventional DVTR will be described with reference to the drawings.

FIG. 7 is a diagram showing an audio data block arrangement for recording a digital audio signal used in a conventional DVTR. In FIG. 7, the row direction is a parity addition direction called an inner code, and the column direction is an outer code. Parity 0 to 266 in the matrix are digital audio signal sample locations consecutive in time series, and AUX0 to AUX3. Is the auxiliary data area, PV0 ~
3 is the outer code, and the inner code is the 7th in the same format as the video signal.
It is provided in addition to the matrix in the figure.

The operation of the digital audio signal recording method configured as described above will be described below.

First, the input digital audio signal having a maximum length of 20 bits is sequentially written to the sample 0 to 266 portion of the matrix in FIG. 7 in accordance with the sampled time series.
At this time, since the video signal and the audio signal are synchronized, the sample 266 becomes empty every five fields. Subsequently, necessary auxiliary data is written in AUX0 to AUX3, outer codes PV0 to PV3 are arithmetically added, and then inner codes are arithmetically added. Then, a synchronous block of the format shown in FIG. 8 is formed from two rows of the matrix, and is recorded on the tape.

However, in the above-described conventional configuration, it is assumed that a digital audio signal synchronized with a video signal is recorded on one track per channel. It is not possible to simultaneously record video signals and audio signals that are appropriate and that are not synchronized with each other, and the recording capacity of auxiliary data is small.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has as its object to provide a digital audio signal recording method for recording an audio signal using a plurality of tracks per channel.

Means for Solving the Problems To achieve the above object, a digital audio signal recording method according to the present invention divides a track formed by a rotary head into a video signal section and an audio signal section,
In synchronism with a video signal using tracks (M is a natural number), independent N-channel (N is a natural number) digital audio signals are transmitted to the respective M / N tracks (M
/ N is a natural number), each track is divided into K (K is a natural number) synchronous blocks, and L (L is a natural number of K> L) audio signal data, (KL) pieces are assigned to parity data, and an auxiliary data area having the same capacity is added to the L pieces of synchronous blocks to which audio signals are assigned at the same position in each synchronous block.

In addition, the present invention interleaves digital audio signal data within a time corresponding to one frame to M / N tracks and to a two-dimensional area having L synchronization blocks per track, and optimizes the data according to the video signal format. Stipulates interleaving.

In addition, the present invention uses a rotating head whose rotation frequency is synchronized with a video signal, and when recording a digital audio signal that is asynchronous with the video signal, the number of samples of the digital audio signal within a time corresponding to one frame is determined by one frame. An integer value is divided by the number of the latest sample that does not exceed the time, and recorded together with a value indicating the number of samples.

Operation The present invention provides a digital audio signal recorded using a plurality of tracks per channel by the above configuration.
It is possible to record digital audio signals asynchronous with the video signal with high accuracy, while having an optimum correction / correction capability for errors caused by editing and burst errors, having a useful auxiliary data area.

Embodiments Hereinafter, embodiments of the digital audio signal recording method of the present invention will be described with reference to the drawings.

First, FIG. 2 shows the configuration of a recording track used in the digital audio signal recording method of the present invention.

In FIG. 2, reference numeral 21 denotes a recording track formed by a rotary head, and one track is composed of 22 preambles, 23 video signal sections, 24 edit gaps, 25 audio signal sections, and 26 postamples. Is done. The video signal is a video signal portion 23 continuous in the tape running direction. The television system is 525 line-60 field system such as NTSC (hereinafter abbreviated as 525 system), and 625 line-50 field such as PAL / SECAM. In the system (hereinafter abbreviated as 625), 12 frames are collected to form one frame and recorded. The audio signal is two channels in the television system, and the audio signal of each channel is converted into an audio signal portion 25 continuous in the tape running direction.
Five audio streams are collected for the 525 series and five audio streams for the 625 series to form and record one audio block.

Regarding the method of recording a digital audio signal recorded with the above-described track configuration, first, a synchronous block configuration around an audio signal portion in one track according to the first invention of the present invention will be described.

FIG. 1 is a diagram showing a configuration of a synchronous block in one block in an embodiment of the first invention of the present invention.

In FIG. 1, 1 is a video signal portion, 2 is an edit gap, 3 is a synchronization signal (SYNC), 4 is an ID code, 5 is an audio signal data portion, 6 is an AUX data portion, 7 is a vertical parity,
8 is a horizontal parity and 9 is a postamble. The vertical parity 7 corresponds to the outer code in the conventional example, and the horizontal parity 8 also corresponds to the inner code.

The method of the embodiment of the first invention configured as described above will be described below with reference to FIG. The audio signal part provided between the edit gap 2 and the postamble 9 is composed of nine synchronous blocks, and mainly comprises six audio signal data parts and three vertical parity parts. Each synchronization block has a synchronization signal 3 for establishing synchronization during reproduction.
ID code 4 including (SYNC) and block address
And a horizontal parity 8 for error correction in the synchronization block.
have. The input digital audio signal is written into the audio signal data section 5, necessary auxiliary data is written into the AUX data section 6, and vertical and horizontal parities are generated and added by the two to form a recording block. At this time, as a method of arranging the AUX data section 6, a configuration in which one synchronous block is all allocated to the AUX data is possible, but in this embodiment, the AUX data section 6 is concentratedly arranged behind the audio signal data section 5. In other words, a method is adopted in which an auxiliary data area having the same capacity is added to the same position in each synchronous block to which the audio signal is allocated.

As described above, according to the present embodiment, the auxiliary data area having the same capacity is added to the same position in each synchronous block to which the audio signal is allocated, so that the auxiliary data is distributed over a plurality of synchronous blocks. This makes it possible to reduce the loss of auxiliary data to be reproduced even when synchronization is lost, and to reproduce auxiliary data with a high probability during intermittent reproduction such as high-speed search.

Of course, the AUX data 6 does not necessarily need to be arranged behind the audio signal data unit 5 and may be at the middle or at the beginning.

And it goes without saying that the same configuration can be similarly applied to the video signal section.

FIG. 1 illustrates the number of synchronous blocks constituting each section and the number of bytes of each element constituting a synchronous block, but it is apparent that the present invention is not limited to these.

Next, an interleaving method in the audio signal data section according to the second invention will be described with reference to the drawings.

3 and 4 are diagrams showing a first embodiment of the audio data block arrangement according to the second invention. FIG. 3 is for the 525 system and FIG. 4 is for the 625 system.

In FIG. 3, the horizontal direction shows the track configuration of the audio signal corresponding to one frame of the video signal, and the track number 0
4 to the Lch of the stereo signal and track number 5-
9 corresponds to the Rch of the stereo signal. The vertical direction is a synchronous block, which is roughly divided into synchronous block numbers 0 to 2 of the audio signal even-numbered sequence data, synchronous block numbers 3 to 5 of the audio signal odd-numbered sequence data, and synchronous block number 6
Vertical parity is written to 8. The data of each digital audio signal is written with the values shown in FIG. 3 as initial values and thereafter written in the order of sampling time series at 30 sample periods, and a synchronous block is formed and recorded on the tape.

FIG. 4 is the same as the configuration of FIG. 3, except that the number of tracks is 12 for the 625 system and the interleave sequence is extended to 36 sample periods.

By using the first embodiment configured as described above, when recording an audio signal using 5 tracks or 6 tracks per channel, data loss in both tracks, which is likely to occur at the time of editing, that is, in the 525 system, In the system of track numbers 0, 4 or 5, 9 and 625, it is possible to increase the interpolation length due to the missing track of track numbers 0, 5 or 6, 11.

 Next, a second embodiment of the second invention will be described.

5 and 6 are diagrams showing a second embodiment of the audio data block arrangement according to the second invention. FIG. 5 is for the 525 system and the sixth product is for the 625 system.

The basic concept is the same as that of the first embodiment, and the data content included in the same track is the same. The difference from the first embodiment is that the recording system is apt to cause scratches in the tape running direction. On the other hand, the odd-numbered data sequence and the even-numbered data sequence are independently rotated, and the data array is rotated for each track, thereby taking measures to improve the error correction capability.

With the above configuration, it is possible to provide a digital audio signal recording method having a high correction correction capability even for a recording system in which scratches tend to occur in the tape running direction.

 Next, an embodiment of the third invention will be described.

Using a rotating head whose rotation frequency is synchronized with the video signal,
In order to record a digital audio signal that is asynchronous with the video signal, it is necessary to control the number of samples of the digital audio signal recorded in a time corresponding to one frame of the video signal in units of frames. For this reason, in the embodiment of the third invention, as a sample to be recorded in one frame, the number of samples is indicated together with the sample divided in units of one frame by dividing the sample by the nearest sample not exceeding one frame time into an integer value. The value or a code corresponding to the value is recorded.

With the above configuration, simultaneous recording is possible even for a digital audio signal that is not synchronized with a video signal, and reproduction can be performed with high accuracy while suppressing jitter in the sampling frequency during reproduction.

As a matter of course, the auxiliary data section 6 in FIG. 1 may be used as the recording portion of the value indicating the number of samples or the code corresponding thereto, or another portion may be used.

As described above, the present invention provides a plurality of tracks per channel by providing an auxiliary data area distributed for each synchronization block, an interleaving method, and a means for changing the number of recording samples per frame. A digital audio signal recorded using a digital audio signal that has an optimal correction correction capability against errors caused by editing and burst errors, has a useful auxiliary data area, and is asynchronous with the video signal. Can be recorded with high accuracy for each channel, and the practical effect is great.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing the configuration of a synchronous block in one block in an embodiment of the first invention of the present invention, FIG. 2 is a pattern diagram showing the configuration of a recording track used in the digital audio signal recording method of the present invention, FIGS. 3 and 4 are data block layout diagrams showing a first embodiment of the audio data block layout according to the second invention. FIGS. 5 and 6 are second diagrams of the audio data block layout according to the second invention. FIG. 7 is a data block layout diagram showing an audio data block layout used in a conventional DVTR, and FIG. 8 is a schematic diagram showing a configuration of a conventional synchronous block. 1 ... video signal section, 2 ... edit gap, 3 ... synchronization signal (SYNC), 4 ... ID code, 5 ... audio signal data section, 6 ... AUX data section, 7 ... vertical parity, 8 ...... Horizontal parity, 9 ... Postamble.

Claims (5)

(57) [Claims] 1. A track formed by a rotary head is divided into a video signal section and an audio signal section, and each frame has M
In synchronism with the video signal using the track (M is a natural number), an independent N channel (N is a natural number) digital audio signal is converted into M / N tracks (M / N is a natural number) for each channel. , The audio signal portion of each track is divided into K (K is a natural number) synchronous blocks, and L (L is a natural number of K> L) audio signal data, (KL) A digital audio signal recording method, in which an auxiliary data area of the same capacity is added at the same position in each synchronous block to each of the L synchronous blocks to which the audio signal is allocated, while allocating the auxiliary data areas to the parity data. 2. A track formed by a rotary head is divided into a video signal section and an audio signal section, and M tracks per frame.
In synchronism with the video signal using the track (M is a natural number), an independent N channel (N is a natural number) digital audio signal is converted into M / N tracks (M / N is a natural number) for each channel. , The audio signal portion of each track is divided into K (K is a natural number) synchronous blocks, and L (L is a natural number of K> L) audio signal data, (KL) And an auxiliary data area of the same capacity is added to the same position in each of the L synchronization blocks, and the digital audio signal of each channel within a time corresponding to one frame is converted to L × M / M / N = 5 in a two-dimensional area composed of N synchronization blocks
For a 525 line-60 field video signal, L × 5 sample period and M / N = 6, 625 line-50
A digital audio signal recording method for recording a video signal of a field system by sequentially arranging chronologically continuous audio samples in each synchronous block at an L × 6 sample period and performing interleaving. 3. M = 10, N = 2 for a 525 line-60 field video signal, and M = 12, N = 2 for a 625 line-50 field video signal. Item 3. The digital audio signal recording method according to Item 1 or 2. 4. When a rotary head whose rotation frequency is synchronized with a video signal is used to record a digital voice signal asynchronous with the video signal, the number of samples of the digital voice signal within a time corresponding to one frame is determined by one frame. 3. The digital audio recording method according to claim 2, wherein the recording is performed together with a value indicating the number of samples as an integer value divided by the latest sample value not exceeding the time. 5. The digital audio recording method according to claim 4, wherein an auxiliary data area is used as a recording area of a value indicating the number of samples of the audio signal recorded within one frame time.