JPH01312781A - Digital signal recording or recording and reproducing device - Google Patents

Abstract

PURPOSE:To keep high sound quality even as to an audio signal after edit by dividing an audio signal by one frame into an odd number and an even number sample, recording the odd umber sample to one of two fields constituting one and same frame and recording the even number sample on the other. CONSTITUTION:The recording state of a signal in a field A on a tape is a state that the audio signal with respect to the video signal is sectioned in the unit of frames in the timing deviated by one field. Moreover, the signal is formed to be finished in a frame and the data sample of an odd number of the audio signal in a frame F is recorded during the period of the field A of the audio signal and the data sample of an even order of the audio signal of the frame F is recorded in the period of the field B of the audio signal. Through the constitution above, since the odd and even number sample of the audio signal are recorded respectively on separate fields, in case of post-recording in the unit of video frames, cross fade processing of the audio signal is attained and a smooth audio signal is obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a digital signal recording or recording/playback device that converts an analog audio signal into a digital signal and records it on a tape together with a video signal using a rotating head. It is.

[Conventional technology]

FIG. 7 is a block diagram showing a conventional VTR.

On the playback side, numeral 1 is a recording/reproducing head I for recording and reproducing signals on the tape, and 39 is a selector switch A2.2 for selecting a recording/reproducing head.2 is a selector switch A1.2 for selecting a head for reproducing a signal. 3 is a reproduction amplifier that amplifies the signal■
, 4 is a demodulation circuit I for demodulating the amplified signal, 5 is a recording/reproducing head for recording and reproducing signals, 40 is a changeover switch B for selecting a recording/reproducing head; 2.6 is for selecting a head for reproducing a signal. 7 is a playback amplifier that amplifies the signal, 8 is a demodulation circuit that demodulates the amplified signal, 21 is a distribution circuit that distributes the signal into an audio signal and a video signal, 10 is an audio signal error correction A playback audio signal processing circuit performs decoding, etc., 12 is a digital-to-analog (hereinafter referred to as D/A) converter 1 and 13 is an audio signal output terminal, and 14 is an error in the video signal. A reproduction side video signal processing circuit performs correction decoding, etc., 15 is a D/A converter (1) for converting a video signal into an analog signal, and 16 is a video signal output terminal.

On the recording side, 22 is an audio signal input terminal, 23 is an analog/digital (hereinafter referred to as A/D) converter 1) that converts an analog audio signal into a digital signal, and 24 is an audio signal error correction encoder, etc. 39 is a mixing circuit that mixes the audio signal and video signal, 25 is a modulation circuit I that modulates the encoded signal, 26 is a recording amplifier that amplifies the signal, and 27 is a signal Switch 0128 for selecting recording or playback is switch D which functions similarly to switch C27, 29 is a video signal input terminal, and 30 is an A/D converter for converting the video signal into a digital signal.
, 31 is a recording side video signal processing circuit that performs error correction encoding of the video signal, etc., and 32 is a modulation circuit that modulates the signal.
, 33 is a recording amplifier ■ that amplifies the signal, 34 is a switch E for selecting recording or playback of a signal, and 35 is a switch E.
Switches F and 40, which function similarly to 34, are
This is a sequence circuit that provides D information.

Further, F is a tape, and 38 is a rotating head drum.

In a digital VTR having a configuration as shown in FIG. 7, it is possible to edit signals recorded on a tape (dub-recording, etc.).

FIG. 8 is a schematic diagram of the D-2 formant on a tape, which is one of the recording formats of a conventional digital VTR.
is a video sector, 36 is an audio sector Uo located at the upper end of the tape, and 37 is an audio sector LD located at the lower end of the tape.

In this format, two tracks constitute one segment, and six segments constitute one frame. Furthermore, audio sectors are provided at both ends of each video sector.

When recording a signal, first the changeover switch A I (2) and the changeover switch 81 (61) are turned on to the Rec side.The audio signal is input from the audio signal input terminal 22, and the A/D converter 123 converts it into a digital audio signal. After the signal is converted into , it is subjected to processing such as error correction encoding in the recording side audio signal processing circuit 24. At this time, information regarding fs, emphasis, etc. is input from the sequence circuit 40 as ID information.

After this, it is mixed with the video signal in the mixing circuit 39,
After being further modulated by the modulation circuit 125, the signal is amplified by the recording amplifier 26 and recorded on the tape by the recording/reproducing head (1) or (5). At this time, the switch C27 and the switch D28 are ONa'tQ, and the recording/playback head 1) and the recording/playback head 5 alternately scan the segments on the tape 17 one segment at a time, recording continuous signals. Is going. Further, the video signal is inputted from the video signal input terminal 29, converted into a digital signal by the A/D converter 30, and then subjected to error correction encoding etc. in the recording side video signal processing circuit 31, and then in the mixing circuit 39. After being mixed with the audio signal and further modulated in the modulation circuit [32], it is amplified by the recording amplifier [33] and recorded on the tape 17 by the recording/reproducing head 1) or the recording/reproducing head 5. At this time, switch E
34 and switch F35 are both in the ON state.

When reproducing a signal, the changeover switch AI2 and changeover switch B16 are first turned on to the PB side.

In addition, changeover switch A2 (39) and changeover switch B2
According to (40), recording/reproducing head 1) and recording/reproducing head ■5
are switched so that they are alternately activated. The signal read out from the tape by the recording/reproducing head ■1 or recording/reproducing head ■5 is amplified by the reproduction amplifier I3 or reproduction amplifier ■7, demodulated by the demodulation circuit ■4 or demodulation circuit ■8, and then sent to the distribution circuit. 21 and is distributed into an audio signal and a video signal. Of the distributed signals,
The audio signal is subjected to error correction decoding and the like in the audio signal processing circuit 10 on the reproduction side, and further converted into an analog signal by the D/A converter 1) 2, and then outputted from the audio signal output terminal 13.

On the other hand, the video signal is subjected to processing such as error correction decoding in the reproduction side video signal processing circuit 14, and further converted into a digital signal in the D/A converter 15, and then outputted from the video signal output terminal 16. At this time, the audio signal mixed with the video signal is recorded in audio sector Uo36 or audio sector L037, respectively.

Consider a case where a digital VTR configured as described above is used to perform simple editing of signals recorded on a tape. Video editing is generally done frame by frame. FIG. 9(a) is a schematic diagram showing the state of the reproduced audio signal among the reproduced signals of the digital VTR.
In the figure, F is composed of two fields, field A and field B, and has a range equivalent to one frame. Further, the audio signal is completed for each field. That is, the audio signal of F is field A.
It is divided into two independent parts by the boundary between and B, and as shown in the figure, the first half is field A data and the second half is field B data.

Now, let us consider a case where an attempt is made to edit an audio signal recorded on tape 17 using the boundary between field A and field B as an editing point.

FIG. 9(b) is a schematic diagram showing the state of the audio signal at F when editing is performed. In F, when trying to connect field A and a certain field Y in another signal, the signal of field A (signal 1) and the signal of field Y (signal 2) are completely unrelated to each other, so they cannot be connected as is. This results in a discontinuous shape as shown in the figure, causing problems such as noise occurring at the editing point.

FIG. 10 is a schematic diagram showing the recording timing when recording and editing audio signals using a conventional digital VTR.

First, when recording a signal, an audio signal is input at the same timing as a video signal of the same field. That is, a signal input while the audio head 1 is scanning a certain field n is encoded, modulated, etc., and generated as data while the next field (n+1) is being scanned, and then In the next field (n+2), the data is recorded on the tape at the timing when the beginning and end of each segment is being scanned. That is, the master tape is in the playback mode up to field (n+1), and switches to the recording mode from field (rl+2) to record a new signal.

However, in reality, as shown in FIG. 9 (bl), signal 1 and signal 2 are discontinuous before and after the editing point, so noise will occur unless some measure is taken.

[Problem to be solved by the invention]

Conventional VTRs are configured as described above, so editing the audio signal requires complicated operations to prevent the generation of noise, and even if such operations are performed, the sound quality near the editing point may be affected. There was a problem in that deterioration of the material was unavoidable and it was extremely difficult to obtain satisfactory performance.

This invention was made in order to solve the above-mentioned problems, and provides a digital signal recording or The purpose is to obtain a recording/reproducing device.

[Means to solve the problem]

The digital signal recording device according to the present invention divides the audio signal into frames at positions shifted from the boundaries between the frames of the video signal, divides the audio signal for one frame into odd numbered samples and even numbered samples, and divides the audio signal into the same frame. Odd samples are recorded in one of the two fields making up the field, and even samples are recorded in the other field.

Further, the digital signal recording and reproducing apparatus according to the present invention performs after-recording (hereinafter referred to as dubbing) in units of video frames in the above-mentioned apparatus, and records at least the start and end points of the dubbing of the video frames that are simultaneously dubbed. recording an after-recording identification signal in one field; furthermore, means for detecting the above-mentioned after-recording identification signal, and in an audio frame including the field in which the after-recording identification signal is detected, each of an odd number sample and an even number sample of the audio signal of the frame; The playback side is provided with a means for performing interpolation processing and cross-fade.

[Effect]

In this invention, the audio signal is made into a complete frame, and odd-numbered samples and even-numbered samples are recorded separately for each field, so that information covering all signals within the frame can be obtained from either of the two fields within the same frame. At the same time, since the frames of the audio signal and the frame of the video signal are shifted, the video signal can be edited frame by frame and the audio signal can be edited by field, resulting in a smooth audio signal when dubbing is performed. .

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1(a) is a schematic diagram showing the state of a signal recorded on a tape using a digital signal recording/reproducing apparatus according to an embodiment of the present invention. FIG. 1('b) is a schematic diagram showing the state of the edited signal when the digital signal recording and reproducing apparatus of the present invention is used to edit the audio signal.

FIG. 2 is a block diagram showing the structure of the reproduction side of the digital signal recording and reproduction apparatus according to the present invention.

In the figure, reference numeral 1 indicates a recording/reproducing head I for reading signals from the tape, and 39 indicates a changeover switch A2 for selecting the recording/reproducing head.
2 is a changeover switch A1 which selects whether or not the recording/reproducing head 1 is in operation of the two heads. 3 is a reproducing amplifier which amplifies the signal read by the recording/reproducing head 1.
, 4 is a demodulation circuit ■ which demodulates the amplified signal, 5 is a recording/reproducing head ■ which reads the signal from the tape, 40 is a changeover switch B2.6 for selecting the recording/reproducing head, and 6 is the recording/reproducing head ■ 5 in the operating state. Selector switch B1.
7 is a playback amplifier that amplifies the signal read by the recording/reproduction head 5, 8 is a demodulation circuit that demodulates the amplified signal, 9 is a distribution circuit that distributes the signal into a video signal and an audio signal, and 10 is a a reproduction side audio signal processing circuit that performs error correction decoding of the audio signal, etc.; 39 is an after-recording identification signal detection circuit that detects an after-recording identification signal;
1) is an editing processing circuit that performs cross-fade processing of audio signals, 12 is a D/A converter that converts audio signals into analog signals, 13 is an audio signal output terminal, and 14 is an error correction decoding circuit for video signals, etc. 15 is a D/A converter (1) for converting a video signal into an analog signal; 16 is a video signal output terminal.

Furthermore, on the recording side, a conventional configuration as shown in FIG. 7 may be used.

FIG. 3 is a schematic diagram showing an example of a recording former on a tape for carrying out the present invention. 17 is tape, 18
19 is a video sector, 19 is an audio sector U located at the upper end of the tape, and 20 is an audio sector located at the lower end of the tape.

Also, FIG. 4 shows audio sector U19 and audio sector L20 when the audio signal has 4 channels.
FIG. 2 is a schematic diagram showing channel allocation in FIG. In the audio sector U19, even-numbered data samples of the audio signal of the frame immediately before frame F in FIG. 1+a) are recorded. Also audio sector L20
Odd-numbered data samples of the audio signal of frame F are recorded.

Furthermore, FIG. 5 is a schematic diagram showing the internal data structure of the audio sector 019. The audio sector U19 is divided into two by a gap, each divided sector is composed of 48 blocks, and data is recorded inside each block in the configuration shown in the figure.

Hereinafter, the function and operation of the present invention will be explained in more detail.

As shown in FIG. 1 (al), the recording state of the signal on the tape in field A is such that the audio signal is divided into frames at a timing shifted by one field with respect to the video signal. Also, the signal is set to be a complete frame, and the odd-numbered data samples of the audio signal of frame F are recorded in the period of field A of the audio signal, and the even-numbered data samples of the audio signal of frame F are recorded in the period of field B of the audio signal. Record the data sample. In this state, set the editing point as shown in the figure and edit.

Now, as shown in FIG. 1(b), it is assumed that editing is to be performed between field A of an audio signal and field Y in another audio signal.

If the signal recorded in the period of field A is signal 1, and the signal recorded in the period of field Y is signal 2, then signal 2 is the even-numbered data sample of the audio signal of the frame to which field Y belonged. It consists of Therefore, both signal 1 and signal 2 contain signal information spanning one frame, and it is possible to interpolate between samples and perform cross-fade processing between signal 1 and signal 2. be. Actually, in FIG. 2, first switch A12 and B16 are set to P.
Turn on the B side. Also, changeover switch A2 (39) and changeover switch B2 (40) are switched, and the recording/playback head 1
) and the recording/reproducing head (5) are operated alternately. The signal 1 read from the tape by the recording/playback head ■1 and the recording/playback head ■5 is amplified by the playback amplifier ■'3 or playback amplifier ■7, and then demodulated by the demodulation circuit I4 or demodulation circuit ■8 and distributed. Human power is applied to circuit 9. The distribution circuit 9 distributes the signal 1 into a video signal and an audio signal.

After the video signal undergoes processing such as error correction decoding in the playback video signal processing circuit 14, it is transferred to the D/A converter l1).
5, the signal is converted into an analog signal and output from the video signal output terminal 16.

On the other hand, the audio signal undergoes processing such as error correction decoding in the audio signal processing circuit 10 on the reproduction side.

FIG. 6 is a schematic diagram showing the recording timing when recording and editing audio signals in the present invention. When recording signals, use the recording/playback head 1) or the recording/playback head ■5.
For signals input while scanning certain fields (n+1) and (n+2), the following field (n+3)
While scanning fields (n+4) and (n+4), data is generated by decoding and modulating the signal, and is recorded on the tape 17 before and after the boundary between the two fields while scanning the following fields (n+5) and (n+6). .

Also, when editing the signal, for example, the field (n+5)
Editing processing (cross-fade, etc.) between the signal already recorded on the tape and the new signal is performed near the boundary between field (n+5) and field (n+5).

Here, the mode is switched and a new signal is recorded between field (n+6) and field (n+1)) of the tape that was in the playback state, and simultaneously both fields (n+5) are recorded.
) and (n+6) before and after the dubbing identification signal R3.
record on tape.

Now, in FIG. 6, after dubbing is performed from field (n+6) to field (n+1)),
+6) and (n+1)), the dubbing identification signal R3 is recorded. In other words, the area from field (n+6) to field (n+1)) is part of signal 2,
For the others, signal 1 is recorded. In this case, first, at the beginning of signal 2, since signal 1 of field (n+5) and signal 2 of field (n+5) are the same field, cross-fading is performed for both. That is, as for the output signal of the audio signal processing circuit 10, the signal 1 is inputted to the editing processing circuit 1), and the signal 2 is inputted to the editing processing circuit 1) via the dubbing identification signal detection circuit 39. Here, when the signal 2 of field (n+6) is input to the post-record identification signal detection circuit 39, the post-record detection signal is detected.

At this time, the editing processing circuit 1) performs interpolation processing on the signal of field (n+6) and the signal of field (n+5), which is a signal of the same frame, and after cross-fading, the signal after cross-fade is D/
After being converted into an analog signal by the A converter 1) 2, it is output from the audio signal output terminal 13.

Also, at the end of signal 2, field (n+1
The dubbing identification signal R3 is detected for the signal 2 of )). Therefore, in the editing processing circuit 1), the field (n
+ L O) signal 2 and field (
The signal after cross-fading is performed with the signal 1 of n+1)) in the same manner as the beginning of the signal 2 is output.

Further, when the identification signal is not detected in the after-recording identification signal detection circuit 39, the same operation as during normal reproduction is performed.

During normal playback, signal 1 and signal 2 are read from the tape and processed in the same way as during editing, from the time they are read from the tape to the playback audio signal processing circuit 10. However, after that, the post-recording identification signal is recorded in signal 2. Therefore, no identification signal is detected in the post-recording identification signal detection circuit 39.

In this case, signal 2 is input to the editing processing circuit 1) together with signal 1, and signal 1 and signal 2 are alternately selected and output by a selector, etc., and converted into an analog signal by a D/A converter 1) 2. , is output from the audio signal output terminal 13. Furthermore, the video signal is played back in the same way as before, simple editing is performed by switching to a new signal frame by frame, and no special processing is performed at the editing point.

In addition, in the above embodiment, the case where the crossfade time is the time for one frame is shown, but the crossfade time is variable, and even if it is performed over a certain period of time, the same result as in this embodiment will be obtained. be effective.

Further, in the above embodiment, a case is shown in which the dubbing identification signal is recorded at the beginning and end of a new signal, but the dubbing identification signal may be recorded over all new signals. It has the same effect as.

Furthermore, in the above embodiment, the signal recording format is the third one.
Although the format shown in the figure is shown, the same effects as in the above embodiment can be obtained with other recording formats.

〔Effect of the invention〕

As described above, according to the present invention, the audio signal is constructed by shifting the audio signal by one field from the video signal of the same frame, and the odd-numbered samples and even-numbered samples are recorded in separate fields. When dubbing is performed with , cross-fade processing of the audio signal is possible, which has the effect of obtaining a smooth audio signal.

[Brief explanation of the drawing]

FIG. 1 (al is a schematic diagram showing the state of a signal recorded on a tape using a digital signal recording and reproducing apparatus according to an embodiment of the present invention, and FIG. A schematic diagram showing the state of a signal after editing when an audio signal is edited using a signal recording and reproducing device. FIG. 2 is a block diagram showing the configuration of a digital signal recording and reproducing device according to an embodiment of the present invention. , FIG. 3 is a schematic diagram showing an example of a recording format of a signal on a tape for implementing the present invention, and FIG. 4 shows assignment of recording channels to audio tracks when the audio signal has four channels. FIG. 5 is a schematic diagram showing the internal data structure of an audio track. FIG. 6 is a schematic diagram showing the recording timing of an audio signal on a tape in an embodiment of the present invention. FIG. FIG. 8 is a schematic diagram showing an example of the recording format of a conventional digital VTR.
Figure 9 (al is a schematic diagram showing the state of a signal in a certain frame when a signal is edited in a conventional digital VTR, 9th box) is a diagram showing the state of a signal in a certain frame when a signal is edited in a conventional digital VTR. FIG. 10 is a schematic diagram showing the state of a frame signal. FIG. 10 is a schematic diagram showing the recording timing of a signal on a tape in a conventional digital VTR. 1 is the recording/playback head ■, 2 is the changeover switch AI, 39 is the changeover switch A2.3 is the playback amplifier ■, 4 is the demodulation circuit ■, 5
6 is a changeover switch B1. 40 is a changeover switch B2.7 is a playback amplifier ■, 8 is a demodulation circuit ■, 9 is a distribution circuit, 10 is a playback side audio signal processing circuit, 39
is an after-recording identification signal detection circuit, 1) is an editing processing circuit, 1
2 is a D/A converter■, 13 is an audio signal output terminal,
14 is a reproduction side video signal processing circuit, 15 is a D/A converter (2), and 16 is a video signal output terminal. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (2)

[Claims] (1) In a digital signal recording device that records a digital audio signal on a tape together with a video signal using a rotating head, one digital audio signal frame is defined as two consecutive video fields spanning two video frames, and one frame worth of audio signal is recorded on a tape. 1. A digital signal recording device characterized in that the frame is divided into odd samples and even samples, and the odd samples are recorded in one of the two fields constituting the frame, and the even samples are recorded in the other. (2) In the digital signal recording device according to claim 1, after-recording (hereinafter referred to as dubbing) is performed in units of video frames, and dubbing is identified in at least one field at the start and end of dubbing of the video frames that are simultaneously dubbed. means for recording a signal and further detecting the dubbing identification signal; performing interpolation processing on each of the odd and even samples of the audio signal of the frame in an audio frame including the field in which the dubbing identification signal is detected; 1. A digital signal recording and reproducing device, comprising means for performing a fade on a reproducing side.