JPS62184661A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To record and reproduce sound of 20sec to/form a medium having a capacity recording the sound for, e.g., 10sec without deteriorating the articulation by omitting the redundancy of sound. CONSTITUTION:A vari-speed cassette player 12 reproduces a source sound 21 from a sound software 10 at a double speed to obtain a similar waveform 22 whose time axis is halved. A pitch processing device 13 eliminates waveforms 23 to be given up, the time axis of the preceding one cycle is expanded twice and inserted to the eliminated part to form an omitted sound waveform 24. In listening to the sound by a monitor speaker 14, the sound is listened to by the original pitch as a fast talking of just double speed. A video image software 11 is picked up by a video generation device 15 such as a video camera and its output signal and an output signal of a pitch processing unit 13 are recorded on a video floppy 19 by using a video floppy recorder 18.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is a recording method that removes the redundancy of audio, records n times the amount of audio on a recording medium in 1/n time, and reproduces it. The present invention relates to a playback device.

(Prior art) Generally, audio has a structure in which similar waveforms are repeated, and this can be played back using a tape recorder at, for example, twice the speed, and the frequency components that have doubled have been halved. The male voice, which now sounds like a female voice at twice the pitch, is returned to its original pitch, which is a male voice, making it easier to hear, and the voice content is doubled at twice the speed. It is quite possible to understand. This reproduced voice is spoken at twice the speed, but the frequency components are processed to return to the original pitch, so in principle they are the same as the original components. Therefore, in this state, even if the recording device is capable of recording only the frequency components of the original audio, it is possible to record exactly twice as much audio information in terms of time.

In particular, a track on a video floppy disk that can record one field of television still images rotates once every 1760 seconds, and as it is, only 1/60 seconds of audio can be stored. However, if the audio time axis is compressed by a factor of 640, approximately 10 seconds of audio can be compressed by 1/60 seconds. However, for this reason, the 5KHz audio signal is approximately 3.2
M1 (Z signal), but a video floppy originally intended for recording video signals has a sufficient recording range of l. The audio is played back at double speed and the apparent resolution is converted to a video signal of 10KT (z), so it cannot be recorded on a video floppy as it is.

For example, when audio with a band of 5 KHz is compressed for about 10 seconds, the time axis is compressed by 640 times, and recorded as a 3.2 MIk video area signal on one track of a video floppy.

The usual means of recording 20 seconds of audio is to record it on two tracks of a video floppy, or to reduce the bandwidth to 2.5K.
Hz, compress the time axis by 1280 times, and
, 2 MHz video area signal on one track of a video floppy. However, the former consumes twice the memory area, and the latter degrades the quality of the audio.

On the other hand, there is a technique for changing the playback speed of a tape recorder, for example, in a device that performs fast-forward playback, to restore the raised pitch of the audio to its original level and make it easier to hear.

(Problems to be Solved by the Invention) The present invention solves the problem of the storage capacity of a storage medium, for example, 1 track per track.
If you record, for example, 20 seconds of audio that exceeds the recording time capacity of the track, without changing the original sound frequency band (for example, 5KIIz), on a video recording track of a video floppy whose capacity is to record only 0 seconds of original sound. The purpose is to enable recording and playback.

(Means for Solving the Problems) The recording and reproducing apparatus of the present invention includes an audio reproducing means for reproducing audio information at n times higher speed, and a pitch of the output audio of the audio reproducing means which is n times higher. pitch processing means for returning the output signal to /n, means for recording and reproducing the output signal of the pitch processing means, and repeating the reproduction signal of the recording and reproducing means n times at predetermined time intervals to extend the reproduction time by n times. The apparatus is characterized in that it is equipped with a means for recording and reproducing audio for n times as long.

(Embodiment) FIG. 1 is a diagram showing the configuration of a recording system in an embodiment of the present invention. In the figure, audio software 1 to (10) and video software h (11) are related to each other, as if they were a combination of audio and pictures. This audio software (10) is recorded on an audio cassette, and is played back at double speed, for example, with a variable speed cassette player (1z). Pitch processing bag for elevated pitch audio for this! (13) returns to the original pitch. If you listen to this state through the monitor speaker (14), you can hear the speech at exactly twice the speed and at the original pitch. On the other hand, video software (11) consisting of paintings, photographs, etc. can be photographed by a video generator (15) such as a video camera, and viewed on a monitor or television (16). With this output signal.

Pitch processing bag! The output signal of (13) is connected to the input key (1
7), the video floppy recorder (18) records on the video floppy (19). What is important here is that when recording on the video floppy (19), the video floppy recorder (18) sends timing commands for recording in a predetermined arrangement and position on the tracks of the video floppy (19). (1
8) to the pitch processing device 1 (13) via a timing command path (20) so as not to overflow the track on the video floppy (19).

The video floppy (19) is also the video generator (15).
) is rotated synchronously in relation to horizontal and vertical synchronization signals included in the timing command path (20
) is input to the pitch processing device (13).

FIG. 2 shows the concept of discarding the redundancy of the sound and returning the sound, which has been played back at twice the speed and whose pitch has doubled, to its original pitch. In the figure, for example, the original sound for 20 seconds (21
) is reproduced at double speed to obtain a waveform (22) similar to the original sound (21) in which the time axis is multiplied by 1f2 in 10 seconds.

This signal waveform (22) reproduces 20 seconds of audio in 10 seconds, but the frequency band is doubled. Of this waveform (22), a discarded waveform portion (23) is designated for each cycle of the audio waveform, and this portion is removed. In general speech, successive waveforms are extremely similar.

This is the redundancy of speech. In this removed part,
The time axis of the previous one cycle is expanded twice to obtain an abbreviated audio waveform (24). The waveform obtained in this way is the 20 seconds of speech spoken by the original sound (21), which is spoken in 10 seconds, but the pitch (higher pitch) and frequency band are the original sound (21).
) is almost the same as This is a conceptual diagram, and a complicated processing device is required to obtain the waveform (24) as shown.

FIG. 3 shows a block diagram of the reproduction system in the embodiment of the present invention. With the configuration shown in FIG. 1, audio and video processed based on the concept shown in FIG. 2 are recorded on a video floppy (20). In FIG. 3, an audio signal and a video signal are obtained from the audio recording track and video recording track of this video floppy (20), respectively, and the former is processed by the audio processing bag @ (31).
The audio with a band of 5 KHz and a duration of 20 seconds is played back, while the video is played back and reproduced by the video processing device (32), respectively.
Speakers for viewers (33) and TV for viewers (34)
is output to. In addition, here, the video floppy player (
30) operates synchronously with a television synchronization signal source (35). Note that the recorder (18) and the player (30) can be a common player/recorder (36), and a changeover switch (37) distinguishes between recording and reproduction.

In FIG. 1, the video floppy recorder (18) is synchronized by the synchronization signal of the video generator (15) shown in the figure, so the same applies when the recording mode is set by the changeover switch (37).

Next, a specific example of the pitch processing device (13) shown in FIG. 1 will be explained. FIG. 4 shows its basic configuration. As shown in the conceptual diagram in Figure 2, if half of the audio waveform is removed, the original audio (21) is processed into an abbreviated audio waveform (
24) is obtained. However, in the conceptual diagram Figure 2, the audio waveform 1
Although the processing is performed for each cycle, in the embodiment shown below, processing is performed for each cycle of the vertical synchronization signal of the television video signal. Since audio signals have the characteristic of repeating the same waveform, it is most desirable to process them one cycle at a time as shown in Figure 2, but it is best to process them one cycle at a time as shown in Figure 2. We conducted an experimental study to find out that the original sound would not be significantly affected by the noise.

In FIG. 4, the output signal of the speed changer/player (12) input to the input terminal (40) is transmitted to the switch A (4).
1) and then input to the signal memory (42). The signal memory (42) is, for example, a BBD (charge transfer device) or an AD.
A converter is used to store the data in RAM (Random Access Memory), and a DA converter is used to convert it back to an analog signal.In both cases, the compression ratio is changed by changing the transfer lock frequency. Now, when the audio (22) reproduced at double speed is input to the input terminal (40), the switch A (41) closes its contact for 1760 seconds, and the clock pulse generator (43) generates 2f, =24KHz pulse train was driven through switch B (44) to a signal memory (hereinafter referred to as BBD) (42) consisting of 400 stages of BBD, and was stored as an amplitude modulated pulse train. When all 400 stages were completed, that is, 1760 seconds had elapsed. Time switch A (41
) is turned to a to open it, switch B (44) is closed to a, and the second clock pulse generator (45) outputs the first clock pulse.
72 clock frequency f, = 12KI (z pulse train is passed through switch B (44) to 400 stages B B D (
42), output for 1730 seconds, and take this envelope, the output terminal 100 obtains a signal in which the time axis has been compressed twice and the signal has been returned to the original time axis. In the case of NTSC, a 60KHz vertical synchronization signal is input to the synchronization signal input terminal (46), and in the case of PAL, a 50KIIz vertical synchronization signal is input directly from the video generator (15) or via the video floppy recorder (18). reactor. Control A (48) of the output of the clock pulse control device (47)
Switching control is applied to switch A (41) and switch B (44) by the two lines of control 1 and control B (49). FIG. 5 shows pulse waveforms at various parts of the apparatus shown in FIG. 4. In Figure 5,
Switch B (44) is shown in the switch model of the goo 1-circuit; during period a (50), pulse train (53) of 2 f, (e.g. 24Kl(z)), period b (5
During 1), f. (for example, 12K) lz) pulse train (
54) and f during one period c (52). Mo2i
This is a prohibited section where even 1o is not allowed to pass. This period (50)
What exists in (51) and B B D (42) is an amplitude modulated waveform (55) imitating the waveform of signal (22).
and (56). Waveforms (55) and (56) have a 1:2 relationship when the time axis is zero. The phase relationship with the television synchronization pulse train (57) input to the vertical synchronization signal input terminal (46) is determined as shown in Fig. 5, and if the video floppy is also NTSC, this pulse train (57)
The disk rotates at 3,600 revolutions per minute in synchronization with the

Figure 6 shows two configurations of the basic configuration shown in Figure 4, with C and D in the figure corresponding to A and B in Figure 4, and component switch C.
(61), switch D (64) is switch A (41)
), corresponds to switch B (44). Further, control A (48) and control B (49) correspond to control C (68) and control D (69). That is, the C10 series is simply in reverse phase with the A and B series, and the operations of C and D are basically the same as the operations of A and B, so the explanation will be omitted. B B D (42)
, (62) are alternately combined by a combiner (63) and output to an output terminal (65). This output signal and B
FIG. 7 shows the recording/reading timing relationship of B D (42) and (62).

In the figure, clock pulses 2 f, (43) , f, (45) applied to the second B B D (62)
) is the period d for 2 f, (43)
(70), period e(71) is made to correspond to fO(45). Here, period a (50) and d (70) and period b (51) and e (71) are given a phase shift of exactly 180', and audio b (56) read out in period b (51) and period e Voice e read out in (71)
(76) are made to be continuous. This continuous audio signal has the audio information removed from each field of the television image, and is spoken at twice the speed, but the pitch has been returned to its original pitch, which is what is called the original frequency band component. ing.

In the present invention, if the time axis compression of this pitched voice is 640 times, the highest frequency component of the original sound, 5KHz, is reduced to 3.
2M) Iz video domain signal, which can be fully recorded on a video floppy, and as described at the beginning of the detailed description of the invention, it is possible to record 20 seconds of audio instead of recording 10 seconds of audio on one track of a video floppy. is possible. This relationship is shown in FIG.

In the figure, approximately 20 seconds of original sound (21) is converted into approximately 10 seconds of double compressed sound (22), and this is converted into a 10 second sound signal (56) and a vertical synchronization pulse (56) using the method described so far.
7), compressed the time axis to 1/640, and recorded it in one TV field period. Signal (56), (76
) may be realized by using a memory device and switching the repetition frequency of this clock pulse to 640 times during recording and reading. Since there are various known methods for doing this, the explanation thereof will be omitted. Note that the output audio signal (56) in FIG.

(76) compresses the time axis by 1/640 times every 1760 seconds and records every 1/640 of one floppy track.
The output audio signals (56) and (76) for 1760 seconds may be recorded sequentially on the same head twice, or for each period of 160 times the period b (51) (=2.67 seconds). If you record 4 times, you will get 1 floppy field (1
/60 seconds) can record 20 seconds of audio. The explanation is n=2
However, the gist of the present invention does not change whether n=1.5 or n=3.

Next, a system for reproducing the audio signals recorded in this way will be explained.

The recorded audio signal passes through a head amplifier, an FM demodulator, etc., and is reproduced as an audio signal compressed 640 times, as in conventional FM recording. This is the terminal (90
) and converted into an 8-bit DCM signal by the AD converter (91) and recorded in the memory (92). A.D.
The sampling clock of the converter (91) is approximately 7.6
Assuming 8MHz, one rotation of 1760 seconds is 7.68
10'÷60×8≠10F', and 1 megabit memory is required. By reading the audio stored in the memory (92) in this manner at a frequency of 12 KHz (1/640), the original 10 seconds worth of audio can be reproduced. This 10 seconds of audio was originally 20 seconds of audio at 176
It is made by discarding half of every 0 seconds to make 10 seconds, and this is 2
An example in which audio is played back for 0 seconds will be described. The number of samples per disc track is 1.28
10', which is 1 unit for rounding down, 17
The number of samples in 60 seconds is 7.68 x 106/
(60X 640) = 200. Therefore 2
By repeatedly playing back the 00 samples twice each time, 10 seconds of audio becomes 20 seconds of audio without changing the pitch.

The memory 92 has approximately 128 bytes and is divided into areas M1 to M640, each unit having 200 bytes.

First, 200 bytes of area M1 are read out, converted into an analog signal by a D-A converter (93), the clock is removed by a filter (94), and after being amplified by an amplifier (95), a speaker (9
6). This 200 byte read is about 1/
By sequentially reading out these 200 bytes again, the 1760 seconds of audio becomes 1730 seconds of audio in total, which can be expanded twice. Memory dM1 is followed by Ml2
The 00 byte is played back twice, and the same process is repeated sequentially up to M640. Give an address to the memory (92), control the memory, or use the A-D converter (91) or D-
A control unit (97) controls the A converter (93), and a PG indicating one rotation of the disk.
The signal is input from the double signal terminal (98), and a predetermined signal is created based on this signal.

(Effect of the invention) As explained above, one aspect of the present invention is, for example, 5KTTy,
By eliminating sound redundancy on a medium that has a capacity to record 10 seconds of audio, the amount of sound can be doubled without significantly reducing the clarity.
It is possible to record and play back 0 seconds of audio.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of a recording system in an embodiment of the present invention. FIG. 2 is a diagram for explaining a method of eliminating redundancy in speech. FIG. 3 is a diagram showing the configuration of the reproduction system in the embodiment of the present invention. FIG. 4 is a diagram showing the configuration of a specific example of the pit treatment device in FIG. 1. FIG. 5 is a pulse timing waveform diagram showing operation waveforms of each part in FIG. 4. FIG. 6 is a diagram showing the structure of another specific example of the pit processing device, which has two structures of No. 4121. FIG. 7 is a pulse timing waveform diagram showing operation waveforms of each part in FIG. 6. FIG. 8 is a diagram for explaining the operating principle of this embodiment in which a 20 second original sound is recorded and reproduced on a 10 second track. FIG. 9 is a diagram showing the configuration of an apparatus for reproducing recorded audio signals by a recording apparatus using the apparatus shown in FIG. 6. 10...Audio software, 11...Video software, 1
2... Variable speed cassette player, 13... Pitch processing device, 14... Monitor speaker, 15... Video camera, 16... Monitor television, 17...
Input key-118...Video floppy recorder, 19,
20... Video floppy, 30... Video floppy player, 31... Audio processing device, 32... Video processing device, 33... Speaker, 34... Monitor television, 35... Television synchronous signal source, 37
...Selector switch. Patent applicant: Matsushita Electric Industrial Co., Ltd. Figure 1 Figure 19, Pir'kai Broppi Figure 2 Figure 3 Figure 4 Figure 5 Figure 7 Figure 8

Claims (3)

[Claims] (1) audio reproduction means for reproducing audio information at n times higher speed; pitch processing means for returning the pitch of the output audio of the audio reproduction means which has become n times higher to 1/n; and an output of the pitch processing means. a means for recording and reproducing a signal, and a reproduction signal of the recording and reproducing means at a predetermined time interval.
1. A recording and reproducing device characterized in that the recording and reproducing device is equipped with a means for extending the reproduction time by a factor of n by repeating the method twice, and is capable of recording and reproducing audio for an n-fold longer period of time. (2) The recording and reproducing means is configured as a video floppy device for recording and reproducing audiovisual information consisting of related video information in addition to the audio information, and the means for generating the video information and the The video floppy device includes recording processing means for the video floppy device, and means for reproducing the video recorded on the video floppy device, and the audio information is 1/1/1
The recording and reproducing apparatus according to claim 1, wherein recording is performed in association with the video information on a video floppy for n hours, and the audio recording time on the video floppy is expanded by n times. . (3) The n-times higher output audio is removed from the n-times portion of the audio output signal for each video unit length of the video floppy, and the audio signal is compressed to 1/n in the free time. The recording/reproducing apparatus according to claim (2), wherein the pitch is returned to the original pitch by repeating the steps n times.