JPH03136486A - Recording or reproducing device for video and sound - Google Patents

Abstract

PURPOSE:To record video information and sound information while backing to a recording starting time point by a limited memory by compressing the time base of a video, retroactively executing recording and similarly executing compressed recording and extended reproducing even concerning a correspondent sound. CONSTITUTION:A video storing means 3 is provided to read out the video information with a cycle shorter than a storing cycle after recording is started while intermittently storing the input video information, and a sound storing means 4 is provided to lead out input sound information corresponding to the video information stored in the video storing means 3 while compressing the time base of the input sound information. After the outputs of the both storing means 3 and 4 are recorded, the information before the start of recording are recorded by recording means 7 and 8 to record the both input information. At the time of reproducing, the both compressed information are led out while extending the time base. Thus, the video information and sound information before the start of recording can be recorded by using the small capacity of the memory and at the time of reproducing, the sound in the correspondent cycle can be reproduced together with the stroboscopic reproducing.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a video and audio recording or reproducing device that records video information and video information retroactively from the start of recording.

(B) #, Next Technique When recording an audio signal before the recording start time, a configuration is used in which the audio signal is stored via a delay means.

(c) Problems to be solved by the invention However, when recording a video signal, a huge amount of memory is required to delay the video signal for several seconds, making it difficult to implement it in products due to cost. be.

Therefore, it is necessary to skillfully utilize the limited memory capacity to retroactively record the video, and to similarly compress and record the audio corresponding to the video and decompress and play it back.

(d) Means for Solving the Problems The present invention provides a video storage means for intermittently storing input video information and reading out the video information in a cycle shorter than the storage cycle after the start of recording; The information before the start of recording is recorded by the audio storage means that compresses and derives the input video information corresponding to the video information obtained by compressing the time axis, and the recording means that records the backward input information that records the outputs of both storage means. The second feature is that both compressed information is derived by expanding the time axis during playback.

(e) According to the present invention, video information corresponding to stored video information is recorded in time-axis compression at the beginning of recording, and is expanded in time-axis during playback.

(f) Example The present invention will be described below with reference to illustrative embodiments.

First, in the first embodiment, input video information is stored in a video memory having a storage capacity of 16 fields at a cycle of 0.5 seconds, and each video information is repeated six times from the video memory at the start of recording. The same video information is read out sequentially and recorded in 6 fields at a time on a high-fidelity video recorder, and about 20 fields of intermittent video information for about 10 seconds are recorded in 6 tracks at a time of about 2 seconds at high speed with time axis compression. .

Further, in this embodiment, the video information corresponding to this video information is time-axis compressed to 115 and recorded in the high fight rank.

Furthermore, in this embodiment, an identification signal is recorded during this time axis compression recording period, and while performing intermittent slow playback at 1/5 times speed during the period in which the identification signal is detected during playback, the audio signal is 5f of playback video information in field units
In this case, the time axis is extended.

FIG. 1 is an explanatory diagram showing the relationship between recording and reproduction of the above-mentioned video information, and A in the diagram schematically shows the information stored in the video memory at the time of recording start, and 2 fields from 482 fields ago.
This indicates that the input video information up to the field is stored for 16 fields at a period of 30 fields.

When starting recording, reading is started from the oldest video information 482 fields ago. This reading is performed six times for each field of each video information. Therefore, video information from 482 fields before the start of recording will be recorded on the 6 trunks, and video information from 452 fields before will be recorded on the next 6 tracks.As a result, the video tracks recorded will be in units of 6. The video information is updated. Therefore, in this embodiment, past video information is compressed and recorded on a total of 114 video tracks.

On the other hand, the video information recorded together with the video information is compressed and recorded on a high-fidelity track that is formed prior to the video track. This compressed recording is formed by compressing the video information stored in the audio storage means five times in time. That is, 10 seconds worth of video information is compressed and recorded from 8 seconds before the start of recording until just before the end of compression recording.

B in FIG. 1 shows the information stored in the video memory at the time when 114 tracks have been recorded since the start of recording. At this point, the reading of the latest updated video information (88th field from the recording start point) is completed. When the end of this reading is detected, the input video signal is normally recorded thereafter.

In the compressed recording portion recorded in this manner, the video tape recorder is controlled to the intermittent slow playback state 115 by a detection means to be described later. As a result, each track is scanned five times, and video information for approximately 10 seconds (114×5 fields) corresponding to real time is reproduced as strobe video information, resulting in time axis expansion. When this intermittent slow playback state is completed, the normal playback state is entered.

Regarding the video information, each time the playback trunk is updated during the intermittent slow playback period, one field of new time axis compressed video information is stored in the audio storage means, and the time axis is expanded five times, so that the original continuous It is converted and formed into video information. The video information recorded on the high-fidelity track during periods other than this compressed recording period is reproduced and derived as usual.

The recording circuit for carrying out the above-mentioned operation will be explained below with reference to FIG.

First, input video information and input video information are generated from a video information source 1 and a video information source 2 that constitute an information source such as a tuner or a video camera.

In this state, the input video information continues to be cyclically and intermittently stored in the video memory 18 at a period of 30 fields, and the input video information continues to be cyclically and continuously stored in the audio memory 26 for approximately 8 seconds.

The video storage means 3' including the video memory 18 digitizes the input video information using the AD converter means 16, and then compresses the data using the encoder means 17.

This data compression reduces the capacity of the video memory 18, which used to be 16 Mbit, to 6 Mb1t. The storage of this input video information must be done in synchronization with the synchronization signal of the input video information, and the synchronization signal obtained from the synchronization separation circuit 10 that inputs the input video information is transmitted to the first write control means 2.
1, and from this write control means 2] 3079f-
Timing pulses for AD conversion and code compression for each field and a write address signal are derived in each field period. The first memory access means 22 continues to supply the write address signal to the video memory 18 and continues to constantly store input video information intermittently.

Further, the audio storage means 4 including the audio memory 26 supplies AD conversion pulses to the second AD conversion means 25 while changing the write address cyclically so as to function as a video information compression means. Therefore, the input video information is digitized in synchronization with the fixed clock and continues to be stored in the corresponding write addresses of the audio memory 26 in sequence.

When a recording operation is performed in the above-mentioned circular memory state,
The video tape recorder is activated and the servo circuit 1 of the cylinder cab stan is synchronized with the synchronous separation output.
1 is activated.

When the servo circuit 11 enters the synchronization pull-in state, a phase lock detection output is generated and a recording start state is entered.

At the start of recording, the video storage means 3 sends a write address signal to specify the video information to start reading, and a phase start/tick detection output synchronization signal to specify the read timing of the video information to start reading. 1
It is supplied to the continuous output control means 23. Therefore, the readout control means 23 derives a readout address signal synchronized with the rotation of the video head 7 after generation of the phase lock detection signal and a timing pulse for processing the readout data. The data read from the video memory 18 is expanded into the original data by the code expansion means 19, and
The conversion means 20 converts it into analog video information.

Further, the video information storage means 4 inputs a write address signal to the second readout control means 30 in order to specify the readout start address. Therefore, the second reading control means 3
0 generates a read address signal and a timing pulse five times as large as that for storage in synchronization with the phase lock detection output. According to this read address, the data read from the audio memory 26 in the order of oldest data is converted into analog compressed video information by the second DA converting means 27 and derived.

In this state, the video selection switch 14 and the audio selection switch 15 are both set to the storage means side, and the video information is input to the well-known video recording processing means 5, converted to recorded video information, and transferred to the rotating video 7. The video track is recorded.

Further, the compressed video information is inputted to a well-known audio recording processing means 6, converted into recorded video information, and is converted into a rotary audio head 8.
A high-fidelity track is recorded that precedes the video track.

This recording state is ended when the read video information catches up with the written video information in the video storage means 3.

Therefore, when the write address and the read address match, the comparison means 24 generates a match output as a compression recording mode end detection signal, and from now on, both selection switches 14 and 15
is switched to the input information side and enters the normal recording mode.

On the other hand, control signal generation means 1 for inputting a synchronization signal
Reference numeral 2 inputs a control signal to a pulse width modulation means 13, which maintains a pulse width modulation state from when a phase lock detection output is generated until when a coincidence output is generated. Therefore, the compression recording mode control head 9 records all of the narrow pulse width control signals.

In this embodiment, the control signal is pulse width modulated as the identification signal, but it goes without saying that the identification signal may be multiplexed and recorded during the blanking period of the video information.

Further, it is also possible to configure the video storage means so that the fields of video information read out from the video storage means are alternately combined with odd fields and even fields, if necessary.

A third step for playing back the videotape recorded as described above.
In the reproducing circuit shown in the figure, the narrow pulse width control signal reproduced by the control head 9 is transmitted to the recording start edge detecting means 3.
4, and the detection output is manually input to the system control circuit 35. As a result, the system controller circuit 35 performs a 115 intermittent slow playback function on the video tape recorder during the detection output generation period.

The reproduced video information is processed by the reproduced video processing means 31,
It is derived as is as video information.

Furthermore, the reproduced voice information is processed by the reproduced voice processing means 32 and inputted to the voice storage means 4 which functions as one stage of voice expansion. In order to store the compressed video information in the audio memory 26 intermittently at a five-field period, the second write control means 28
inputs the head switching pulse of the rotating audio head and the tape drive pulse of 5 field cycles generated by the system control circuit 35. Therefore, the second write control means 28 generates a timing pulse and a write address signal for AD converting and storing compressed video information for one field immediately after the tape drive fI 71 in the second AD conversion means 25. Occur. As a result, the audio memory 26 stores video information for five fields in one field. Second
The read control means 30 inputs a write address signal in order to specify the address where the video information is written,
Immediately after writing is completed, a read address signal and timing pulse corresponding to the stored address are generated.

As a result, the compressed video information stored in the audio memory 26 is read out after being expanded in time by a factor of five by the second readout control means 30, converted into analog information by the second DA conversion means 27, and derived.

The video information derived from this audio storage means 4 is selectively derived via the audio selection switch 33 set on the side of the intermittent slow playback means, and after the intermittent slow playback ends, the reproduced audio processing means 32 Video information that is more directly derived is selectively derived.

Therefore, during reproduction, intermittent slow reproduction is performed for 10 seconds during the M period during which the pulse width modulated control signal is reproduced at the start of recording, and normal reproduction is then allowed.

It goes without saying that if an identification signal is multiplexed in the video information, it is sufficient to detect the identification signal and perform intermittent slow playback.

Furthermore, instead of recording intermittent storage information in long cycles as in this embodiment, the video is compressed and intermittent storage information of short 1M periods is recorded, and the monitor is displayed while performing intermittent slow playback. It goes without saying that compressed small-screen images may be displayed as smoother continuous images.

In the first embodiment described above, in addition to the inconvenience that the start of normal recording is delayed because compressed recording is performed for 2 seconds from the start of recording, intermittent slow playback must be performed during playback, and the intermittent slow playback function is not effective. It is difficult to expand the time axis with a video tape recorder that does not have a

Therefore, in the second embodiment, the compressed video information is recorded one track at a time, and the compressed video information is also recorded on the video track, and during playback, the green part of the compressed record is played back at once and compressed once in the storage means. The tape running is stopped when the information is stored, the tape running is stopped when the storage is completed, the video information and the time axis of the video information are expanded during the pause period, and the tape running is resumed and normal playback is performed after the time axis expansion is completed. , each is characterized in that the configuration to be added in order to realize the above-mentioned functions is made detachable from the video tape recorder as an adapter.

In the present embodiment described below, the compressed video information is recorded in one track following the compressed video information, but it is also possible to record the compressed video information in a plurality of tracks, or to record the compressed video information in advance. Not until now.

FIG. 1 is an explanatory diagram of the recording/reproducing principle of this embodiment, and C in the figure exemplifies the recorded contents of the video memory at the start of recording. In this video memory, video information is cyclically and intermittently stored at a cycle of 37 fields before the start of recording, and video information up to about 9.5 seconds before the start of recording is intermittently stored. Immediately after the start of recording, the video memory enters the read state and 16
Compressed video information for one field is read out, and this compressed video information is recorded one field at a time in 16 video trunks.

In this embodiment, 10 seconds worth of retrospective video information is compressed and recorded on the 17th video track in accordance with the 7-ohm recording format of the electronic still camera, and then video information and video information are normally recorded from the 18th video track. ing. In this normal recording state, a video track and a high-fidelity track are formed on the videotape.

In this embodiment, the first identification signal is multiplexed on 16 video tracks for recording compressed video information, and the second identification signal is multiplexed on 17 compressed video information recording tracks, so that the It is used to identify compressed information.

Therefore, during playback, when the first identification signal is detected, the playback video information is stored in the video memory.

Therefore, in the compressed video recording portion, the first identification signal is detected 16 times, and compressed video information for 16 fields is stored in the video memory at once. When the compressed video information of the first track is recorded in the video memory, repeated reading of the video information is started from the video memory, and the same compressed video information is sequentially read out 37 times in field units.

On the other hand, when the second identification signal is detected following the compressed video information, the reproduced compressed video information is stored in the audio memory. Immediately after this storage is completed, the stored compressed video information is time-axis expanded and read out continuously for 10 seconds.

As soon as the detection of both discrimination signals is interrupted, the video tape recorder stops tape running. This tape running pause state is canceled when the time axis expansion of the video information and the repeated reading of the video information are completed.

By canceling this tape running pause, the video tape recorder enters a normal playback state, and thereafter derives the playback video information of the video track and the video information of the high-fidelity track as they are.

FIG. 5 shows a functional block diagram of the device of this embodiment, 60
indicates a monitor TV.

The video tape recorder 40 derives the video information from the tuner 41 as a signal source and the video information via the switching means 45 during recording, and derives the video information and the video information obtained from the playback means 47 during playback. A video output terminal T3 and an audio output terminal T4 for deriving the signal are arranged. Although not shown, the video tape recorder is capable of inputting the output of an externally connected video camera instead of the output of the tuner. Further, the synchronization separation means 42, which inputs the video information supplied to the video output terminal T3, supplies the separated synchronization signal to the synchronization output terminal T2. During recording, the servo means 43, which controls the rotational phase of the rotary cylinder and the rotation of the capstan, inputs the synchronization signal as a reference signal and outputs a signal to the phase lock detection terminal T1 at the timing to enter a recordable phase lock state and start recording. Generating phase lock detection output. Further, the system control means 44 supplies a system control output indicating the mode setting state of the video tape recorder to the system control output terminal T7, and receives a tape drive control output obtained from the adapter 50 from the control input terminal T8 to control the video tape recorder. It controls the pause and cancellation of tape running. Further, the switching means 45 inputs the video information obtained from the adapter 50 and the video information from the video input terminal T5 and the audio input terminal T6 i) to the recording means 46 during recording and to the television receiver 60 during reproduction. They supply each. Note that the adapter 50 has a power terminal T9.
It is driven by the power supply voltage given by j).

FI! can be selectively connected to the terminals mentioned above! 4, the adapter 50 is connected to the switching means 5 in the pre-recording state.
The input video information obtained from 1 is intermittently stored in the video storage means 53 for 16 fields in 37 fields for compressed recording, while the switching means 51 and 1
2. Voice storage means 541: cyclically stores 10 seconds of input a-side information obtained for compressed recording.

In this state, the 0 operation is performed, and about 1.5 seconds later, the phase lock detection output is generated and the recording start timing is reached.
First, the video storage means 53 generates video information for 16 fields in synchronization with a synchronization signal and supplies it to the switch 1 means 51.

Next, when the derivation of video information for 16 fields is completed,
The video information for 10 seconds is compressed on the time axis in one field period according to the 7-orbit audio signal of the electronic still camera, and is derived from the video storage means 53 as the video information of the 17th field.

The switching means 51 causes the compressed information for 17 fields to be derived as the video output information of the adapter 50. The switching means 51 is controlled by the switching control means 52, which generates the switching control means during the period (17 fields) from the generation of the phase lock detection output to the generation of the timing output of the end of time axis compression readout. Information from the image storage means 53 is selectively derived.

In order to enable the above-mentioned time axis compression during recording, the video storage means and the audio storage means are FI! 4
It employs a sword.

First, in order to store video information in 37 fields in the video storage means 53, the synchronization signal is transmitted to the 1/37 frequency dividing means 71.
The signal is frequency-divided by 5 and input to the write control means 67 via the recording/reproducing switch 0. The write control means 67 supplies timing pulses to the first AD conversion means 61 and the code compression means 62 in order to intermittently store video information in the video memory G3 at 37 field cycles before starting recording. At the same time, a write address signal is supplied to the video memory 63 via the memory access means 68. Therefore, the input video information is
The data is AD-converted and code-compressed for one field period at a period of 37 fields, and is stored in the video memory 63 in a circular manner. Incidentally, if a variable frequency dividing means is adopted in place of the l/'37 frequency dividing means 71 and the frequency division value can be freely set by an operating means external to the adapter 50, intermittent storage can be performed at a cycle of short intervals. become.

When a phase lock detection output is generated in this state and recording is started, the succession control means 69 generates a read address signal and a timing pulse in synchronization with the synchronization signal. Note that the read address signal is formed with reference to the write address signal,
The order of address formation is set so that all of the video information for 16 fields is sequentially read out from the previously stored video information.

Therefore, the read video information is expanded by the code expansion means 64, converted into analog by the first DA conversion means 65, and inputted to the recording information switching means 73. This recording information switching means 73 uses compressed video information as an independent source, and is configured to temporarily select compressed video information in synchronization with the matching output when the reading of the compressed video information is completed.

Incidentally, the scattering output is generated by the comparing means 72 when the write address matches the read address. This -spread output is also input to the timing pulse generating means 75, and a timing output delayed by one field from the -spread output is formed and derived.

The identification signal adding means 71 inputting the switching output multiplexes the first identification signal during the vertical ranking period of the compressed video information for 16 fields in synchronization with the synchronization signal, and also adds the first identification signal to the subsequent compressed video information. A second identification signal is added at the same timing as the identification signal.

This identification signal additional output is derived via the second recording/reproducing switch 66.

The compressed video information mentioned above is derived from the audio storage means 54. This audio storage means 54 stores the input video information in a third
The signal is input to the second AD conversion means 77 via the recording/reproducing switch 76. The recording memory control means 82 constantly generates timing pulses and write address signals in order to store input video information before recording. Therefore, the audio memory 78 always stores 10 seconds of AD-converted audio data.

The video information stored in the audio memory 78 is read out at high speed when a coincidence output is input to the recording memory control means 82. The read compressed video information is input to the sector signal adding means 80 and converted into compressed video information for one field of the electronic still camera, and then sent to the second DA converting means 81 via the fourth recording/playback switch 79. The information is inputted, converted into analog data, and used as an independent control of the recording information switching means 73.

Therefore, from the start of recording, compressed video information is continuously derived from 16 fields and compressed video information from 1 field as output video information.

On the other hand, during reproduction, the reproduced video information is input to the identification signal detection means 55, and when the 19th separate signal is detected, the first identification signal detection output is immediately generated, and the video storage means 53
The write control means 67 inside becomes in a write control state. In this write state, the write control means 67 derives a timing pulse and a write address signal in synchronization with the synchronization signal, and the compressed video information for 16 fields is sequentially transmitted from the first address of the video memory 63. be remembered.

On the other hand, stored compressed video information must begin one field later than the start of storage. Therefore, when the write address reaches a predetermined address, the read υ1 output means 69 enters a read control state and reads the same video information 37 times in field units.

The repeatedly read video information is code-expanded by the code expansion means 64, converted into analog by the first DA conversion means 65, and outputted as output video information via the second recording/reproduction switch 66.

Next, when the identification signal detection means 55 generates a second identification signal detection output, the reproduction memory controller stage 84 enters the high-speed write state. In this high-speed writing state, the compressed video information input from the input video information side via the third recording/reproducing switch 76 is
The data is digitized at high speed by the AD conversion means 77, the sector signal is detected by the sector removal means 83, and only the compressed video information is stored at high speed in the audio memory 78.

When this high-speed storage is completed, the reproduction memory control means 84 enters a reading state, and the video information in the audio memory 78 is read out at the original speed and time axis expansion is performed. The video information that has been time-axis expanded as before is input to the second DA converter 8I via the fourth recording/reproducing switch 79 and converted into analog data.

Analogized video information is derived as output video information5
It will be done.

On the other hand, the reproduction memory control means 84 generates an expansion end detection output in synchronization with the end of reading.

The tape running control means 56, which inputs the second identification signal detection output and the expansion end detection output described above, outputs a control output to the video tape recorder 40 during the period from the end of the compressed information reproduction period to the completion of time axis expansion. The signal is supplied to the system controller circuit 44, and the tape running of the video tape recorder is interrupted until the time axis expansion is completed, and the playback is stopped.

Further, the switching control means 52 inputting the 19th separate signal detection output and the extension end detection output generates a switching control signal during the time axis extension period, and the switching means 51
The memory output is selectively derived with priority over the input signal.

(G) According to the present invention, video information before the start of recording and video information can be recorded using a small memory capacity, and during playback, the strobe playback screen and the audio of the corresponding period can be recorded. can be reproduced, and the effect is great.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a moving object according to a first embodiment of the present invention, FIG. 2 is a block diagram of its recording circuit, FIG. 3 is a block diagram of its reproducing circuit, and FIG. 4 is a diagram of a moving object according to a second embodiment of the present invention. Operation diagram,
FIG. 5 shows its overall functional block diagram, and FIG. 6 shows a functional block diagram of the main part of FIG. 5, respectively.

Claims (2)

[Claims] (1) a video storage means that stores input video information field by field for a plurality of fields in a predetermined cycle, and sequentially reads out compressed video information at a cycle shorter than the predetermined cycle from the video information stored first at the start of recording; an audio compression unit that continuously stores input audio information for a period corresponding to the video information stored in the video storage unit, and continuously reads out a time-axis compressed audio signal after starting recording; and the compressed video information and the compressed audio information. A video and audio recording device comprising recording means for first recording the input video information and the input audio information at a constant speed together with an identification signal, and then recording the input video information and the input audio information at a constant speed. (2) A playback device that plays back a videotape that records intermittent video information before the start of recording, compressed audio information that corresponds to the intermittent video information, and an identification signal that corresponds to the intermittent video information recording period. During the identification signal detection period, video decompression means repeatedly derives the intermittent video information and expands the time axis; A video and audio playback device comprising: an audio expansion means for expanding the time axis of the video and audio.