JP2950870B2 - Video information compression or decompression adapter - Google Patents

Description

The present invention relates to a video information compression or decompression adapter mounted on a video tape recorder.

(B) Conventional technology A stationary video tape recorder waits for recording in a recording pause state when recording, and releases the recording pause state when desired video information is monitored.

Some of the existing video tape recorders with an integrated camera have an interval recording function.

This interval recording has a normal recording cycle of 30 seconds, 1
Minutes and 3 minutes can be switched.
Continuous recording of continuous shooting is repeated every second, realizing simple low-speed shooting.

In addition, video tape recorders for long-time recording, which are awarded for monitoring, have recording tracks formed on a stationary tape with the tape intermittently moved, and run at normal speed during playback. The tape to be reproduced is reproduced and scanned in a direction different from the recording track to enable high-speed reproduction.

(C) Problems to be solved by the Invention However, it is quite difficult for the user to release the recording pause at a desired timing.

In addition, in the interval recording of the portable video tape recorder, the recording period is concentrated, and it is not possible to record a phenomenon that occurs intensively in a period other than the recording period.

Therefore, it is necessary to store video information intermittently and read it out continuously during recording.

(D) Means for Solving the Problems Therefore, in the present invention, video storage means for continuously reading out stored video information at the start of recording while storing input video information at a predetermined cycle before recording is arranged. A video storage unit that performs compression recording, stores compressed video information during playback, and repeatedly reads out stored video information, and a tape running pause that instructs a tape running pause during a period from completion of playback of compressed video information to completion of reading of stored video information. An instruction unit is provided to extend the time axis of the compressed video information.

(E) Action According to the present invention, the video information intermittently stored is compressed and recorded at the start of recording, and is expanded as necessary at the time of reproduction.

(F) Examples The present invention will be described below with reference to the illustrated examples.

First, in the embodiment shown in FIGS. 1 and 2, the video information previously intermittently stored before recording is continuously read out only once at the start of recording to form a video track. Then, a compressed audio track is formed, and at the time of reproduction, the compressed audio information and the compressed video information are reproduced, the tape running is paused, the time axis of the information is expanded, and then the tape running is restarted.

FIG. 1 is an explanatory diagram for explaining the recording / reproducing principle of the present embodiment. As shown in FIG. 1, in this embodiment, input video information is intermittently and cyclically stored in the video storage means for 16 fields in an N-field cycle before recording starts. As for audio information, input audio information for 16N fields or more is continuously and cyclically stored in the video storage means.

When the video tape recorder enters a recording start state in such a state, audio information and video information are compressed and recorded. FIG. 1A schematically shows the storage contents of the video storage means at the time of starting the recording. As is apparent from FIG. 1A, at the start of recording, the video information storage means stores video information for 16 fields from the field before the α field to the field before (15N + α) intermittently and cyclically at an N field cycle. Stored (however, α <N).

At the start of recording, first, audio information for 16N fields is compressed according to the audio compression format of the electronic still camera and recorded on the video track. The number of video (compressed audio) tracks for recording this compressed audio information is set. It is determined according to the set intermittent storage cycle and the set recording sound quality.

After the compressed audio information is recorded, the intermittently stored video information is sequentially read out from the video storage means for 16 fields to form 16 intermittent video (compressed video) tracks.

As soon as the formation of the intermittent video track is completed, the input video information and the input audio information are normally recorded, and the audio information is recorded on the Hi-Fi track formed before the video track.

Note that a first identification signal D1 and a second identification signal D2 are recorded on the formed compressed audio track and compressed video track for time axis compression multiplexing during the vertical blanking period.

On the other hand, in the playback mode, an identification signal multiplexed in the vertical blanking period of the playback video information is detected. Therefore, when the first identification signal D1 is detected, the compressed audio information is temporarily stored in the audio storage means, and when the second identification signal D2 is detected, the intermittent video information is stored in the video storage means. You. When playback of the compressed video track is completed,
The tape running is stopped.

The stored audio information is read out at a low speed after being expanded N times in time axis one field after the start of the storage. Also,
The stored intermittent video information is also repeatedly read out N times one field after the start of storage.

In the present embodiment, when all of the stored intermittent video information is read, the time axis expansion is terminated, the pause of the tape running is released, and normal reproduction is started.

In order to execute the above-described recording / reproducing operation, the video tape recorder 1 and the adapter 2 have functional blocks as shown in FIG.

First, the video tape recorder 1 uses the input video information and the input audio information obtained from the tuner 3 as one input of the EE switch 4 and uses the reproduced video information and the reproduced audio information obtained from the reproduction unit 5 as other inputs. Therefore, the reproduction information is derived from the EE switch 4 in the reproduction mode, and the input information is derived in the other modes. In the recording mode,
The input information of the EE switch 4 is supplied to the recording means 6 via the switching means 7 and recording is performed. The switching means 7 selects information of the adapter 2 mechanically in conjunction with the connection of the adapter 2. The output of the switching means 7 is supplied to an externally connected television receiver (not shown). Note that the adapter 2 feeds back the output of the EE switch 4 to the switching means 7 during a period other than the storage information reading period.

The video tape recorder 1 is provided with a system controller 8 for operation control, and is provided with connection terminals for a mode output of a recording mode and a reproduction mode, a recording start output, and a tape control input.

The video tape recorder 1 has an output terminal of the synchronizing signal generating means 9 and a power output terminal.

These terminals and information input / output terminals are
Are connected to each terminal.

Each functional block of the illustrated video tape recorder 1 is common to a normal video tape recorder except that connection terminals are provided and switching means is added.

On the other hand, the adapter 2 inputs the input video information to the identification signal detection means 25 and the first AD conversion compression means 13 constituting a part of the video storage means from before the start of recording. The video writing control means 16 generates a writing address signal and a timing pulse for each field period starting from a frequency division output obtained by dividing the vertical synchronizing component in the synchronizing signal by 1 / N by the variable frequency dividing means 26. I have.

As a result, the input video information is digitized and code-compressed by the AD conversion / compression means 13, and is stored in the video memory 14 in N-field cycles one by one. This storing operation is continued, and the video information for 16 fields is continuously updated and stored in the video memory 14 at all times.

The frequency dividing ratio of the variable frequency dividing means 26 is set by a cycle setting means 31 operable from outside the adapter 2. This cycle setting means 31 is a detent type switch, and if the user adjusts the rotation position of the detent switch to the display of the retroactive recording period before the release of the recording pause, the division ratio corresponding to the retroactive period can be set. Will be possible.

For example, when the retroactive period is set to 1 second, the intermittent storage period becomes slightly more than 2 seconds when the period required from the release of the recording pause to the start of the recording is slightly more than 1 second, and the intermittent storage period may be set to about 8 field periods. Also, if it is 2 seconds, it is 12 field cycle, if it is 3 seconds, it is 16 field cycle,
The division ratio may be set for each.

Further, the input voice information is input to the second AD conversion means 18 constituting a part of the voice storage means. Voice writing control means 23
Generates a timing pulse and a write address signal so that the input voice information is always stored in the voice memory 20. The voice information digitized by the AD conversion means 18 is always stored in the voice memory 20 in accordance with the write address signal. I remember it.

In this storage state, the recording is started about one second after the recording pause state is released, and when the recording start output is generated, the recording start output is sent to the audio reading control means 24 via the control signal generating means 11 and the audio reading control means 24. It is input to the means 29, the video storage means 28 and the identification signal adding means 30.

As a result, the audio reading means 24 is in a compression reading state, the audio output means 29 supplies the compressed audio information to the video output means 28, and the compressed audio information passed through the video output means 28 is transmitted to the identification signal adding means. Supply to 30. The identification signal adding means 30 multiplexes the first identification signal D1 on the sector portion of the compressed audio information and supplies the multiplexed audio signal to the video input terminal.

The compressed audio information derived through the above-described path is formed in accordance with the audio signal compression format of the electronic still camera. The compression control unit 27 includes information on the intermittent storage period of the video information and the sound quality setting outside the adapter 2. The compression setting and the compression ratio of the stored audio information are determined by inputting the setting information of the means. A timing pulse and a read address signal are generated to read information. The read compressed audio information is added with sector information by the sector adding means 21 and is converted into an analog signal by the second DA converting means 22. The sound quality setting means 32 can also switch and set the sound quality to three values using a detent switch.

When the reading of the compressed audio information is completed, the audio reading control unit 24 outputs the video reading control unit 17 and the video output unit.
The image read control unit 17 is supplied to the readout control unit 28 and the identification signal adding unit 30, and the readout control unit 17 enters a readout state, and generates a timing pulse and a readout address signal. Therefore, the video memory
14 sequentially reads out the intermittent video information in synchronization with the synchronization signal,
The first DA conversion / expansion means code-expands the read intermittent video information and converts it into an analog signal. The analogized intermittent video information passes through the video output unit 28 and the identification signal adding unit 30
And the second identification signal is added during the vertical blanking period and is derived.

When the reading of the 16 fields of the intermittently stored video information is completed, a video reading completion output EV is generated by the video reading control means 17, and the video reading completion output EV is output to the audio output means 29 via the control signal generating means 11. And the video output means 28 and the identification signal adding means 30. As a result, the audio output means 29 supplies the input audio information to the audio input terminal, and the video output means 28 supplies the input video information to the video input terminal via the inactive identification signal adding means 30. I do.

In this state, the video tape recorder 1 records the input information as it is.

When the video tape recorder 1 is set to the reproduction mode to reproduce the tape on which the above-mentioned recording has been performed, the identification signal detecting means
25 is activated.

When the compressed recording portion is reproduced in this state, first, the identification signal detecting means 25 detects the first identification signal D1,
The detection output K1 is generated.

This first detection output K1 is input to the signal switching means 10 and the voice writing control means 23 via the control signal generating means 11. As a result, the compressed audio information obtained from the video output terminal is supplied to the second AD conversion means 18 through the signal switching means 10,
The voice write control means 23 generates a timing pulse and a write address control signal. Therefore, the compressed audio information is
After being digitized by the second AD conversion means 16, the sector signal is removed by the sector removal means 19 and the audio memory 20 is removed.
Is stored at high speed. This storage is continued until the completion of the reproduction of the compressed video information.

Next, when the compressed video information is reproduced following the compressed recording portion, the identification signal detecting means 25 detects the second identification signal D2 and generates the second detection output K2.

This second detection output K2 is input to the signal switching means 10 and the video writing control means 16 via the control signal generating means 11. As a result, the compressed video information obtained from the video output terminal is supplied to the first AD conversion means 13 through the signal switching means 10,
The video write control means 16 generates a timing pulse and a write address control signal. Therefore, the compressed video information is
After being digitized by the first AD converter 13, they are sequentially stored in the video memory 14.

This storage is continued until the completion of the reproduction of the compressed video information. When the reproduction in the compression recording period ends and the second detection signal is deactivated, the control signal generation means 11 supplies a compression period reproduction end detection output SP to the tape running control means 12. As a result, the tape running pause output generated by the tape running control means 12 is input to the system controller 8 via the running control input terminal, and the tape running of the video tape recorder 1 is temporarily stopped.

Each reading of the audio information and the video information is started one field later than the start of each storage operation described above. That is, the control signal generating means 11 supplies the first delay output K1D to the audio output means 29 and the audio readout control means 24 one field later than the first detection output K1, and one field from the second detection output K2. The second delay output K2D is delayed by the video output means 28
Is supplied to the video reading control means 17.

Therefore, the audio readout control means 24 supplies the read address signal to the audio memory 20 and supplies the timing pulse to the second DA conversion means 22 one field after the start of the storage of the compressed audio information, and sequentially stores the stored audio information in a normal manner. Read and convert to analog at speed. The analogized audio information is supplied to an audio input terminal via an audio output unit 29.

Also, the video read control means 17 supplies a read address signal to the video memory 14 and a timing pulse to the first DA conversion / expansion means 15 one field after the start of storage of the compressed video information. As a result, the video memory 14 reads out the stored video information N times in field units, and the first DA conversion / expansion means 15 converts the read video information into an analog signal by code expansion. The analogized video information is supplied to the video input terminal via the video output means 28.

When the reading of the video information is completed, a video reading completion detection output EV is generated, the tape running control unit 12 deactivates the tape running pause output, and the video output unit 28 and the audio output unit 29.
Select and derive reproduction information.

As a result, the video tape recorder 1 returns to the normal playback state, and the adapter 2 feeds back the playback information.

In the above-described embodiment, the time axis compression function and the time axis expansion function are housed in a common adapter, but it goes without saying that only one function may be housed independently.

In the first embodiment described above, the video information before the start of recording is recorded by adopting an adapter to a stationary video tape recorder. For example, a video tape integrated with a camera that performs interval recording at a rate of 1 second to 30 seconds. If the present invention is adopted in a recorder, ideal intermittent recording without changing the direction of a recording track can be performed, and not only full-scale low-speed shooting can be performed but also a surveillance camera can be used.

In this embodiment, as shown in FIG. 3, an adapter (video storage means) 2 for intermittent storage, which stores video intermittently in a camera-integrated video tape recorder 1 'and reads it out continuously at recording timing, is attached and detached. It can be freely configured.
As shown in the figure, 15 fields of video information stored one field at a time in a 2-second cycle are read out four times at a time, and a video track of 60 fields is continuously formed.

In FIG. 3, a camera-integrated video tape recorder 1 'is connected to an electronic viewfinder 35 and an external monitor M via an EE switch 13 to output continuous video information continuously obtained from the camera 3' during an interval recording mode. To supply. When the adapter 2 is not mounted, the switching means 7 supplies the EE output to the recording means 6 to realize normal interval recording. Synchronously, recording video information obtained from the adapter 2 is selected and supplied to the recording means 6. The switching of the switching means 7 is performed mechanically in conjunction with the mounting operation of the adapter 2.

Further, the system controller 8 generates a timing signal which becomes high level during a 1 second recording timing period in the interval recording mode. The adapter 2 is supplied with power, continuous video information and its timing output via a connection terminal.

The playback video information obtained from the playback means 5 is the EE
The power is supplied to the electronic viewfinder 35 and the external monitor M via a switch.

In the adapter 2, the continuous video information is input to the synchronization separating means 9 'to obtain a synchronization signal, and the synchronization signal is further frequency-divided by 1/120 by the 1/120 frequency dividing means 26.

The write control means 16 generates a timing pulse and a write address signal for one field period starting from the divided output in synchronization with the synchronization signal.

In synchronization with this timing pulse, continuous video information is
It is digitized by the conversion means 13a and further encoded by the code compression means 1.
Code compression is performed in 3b. A write address signal is supplied to the video memory 14 via the memory access means 10 so as to sequentially store the compressed data as video information in the write address of the video memory 14 one field at a time.

When a timing signal is generated in such a state, read control means
Reference numeral 17 denotes a read control state, in which a timing pulse and a read address signal are generated to repeatedly read the same video information from the video memory 14 four times in field units.

This read address signal is supplied to the video memory 14 via the memory access means 10, and the same video information is read from the video memory 14 four times.

The read video information is code-expanded by code expansion means 15a in synchronization with the timing pulse, converted to analog by DA conversion means 15b, and recorded as video information by the adapter 2 from the camera-integrated video tape recorder 1 '. And is input to the switching means 7.

Accordingly, the recording means 6 continuously records the same video information while taking a total of 60 tracks of 4 tracks. FIG. 4 illustrates the relationship between the distribution of video information and the continuous recording of video information.

When the recording tape recorded as described above is played,
Video information having a period of 120 fields is continuously derived every four fields, and reproduction at substantially 30 times speed is performed.

In the present embodiment, the storage capacity of the video memory 14 is 6 Mbit, and the video information for 16 fields is stored. However, if the storage capacity is expanded to 24 Mbit, the intermittent storage period of the video memory 14 becomes 15 fields. Can be set finely.

Further, in the present embodiment, no particular consideration is given to recording and reproduction of audio information for the purpose of use. However, when used as a security device, it is necessary to record audio information in accordance with video information. In this case, if the audio information corresponding to each video is time-axis-compressed and multiplexed during the scanning period of the vertical blanking period, the audio information can be recorded in a limited band.

Further, in this embodiment, the interval recording cycle is described as 30 seconds. However, when the recording cycle is switched, the intermittent storage cycle may be switched in conjunction with the recording cycle.
Needless to say.

(G) Effects of the Invention According to the present invention, video information that is likely to be missed can be stored and reproduced reliably, and the effect is great.

[Brief description of the drawings]

FIG. 1 is an explanatory view of the operation principle of the first embodiment of the present invention, FIG. 2 is a functional block diagram thereof, FIG. 3 is a functional block diagram of the second embodiment of the present invention, and FIG. Are shown, respectively. DESCRIPTION OF SYMBOLS 1 ... Video tape recorder 1 '... Camera-integrated video tape recorder 2 ... Adapter (video storage means) 6 ... Recording means, 14 ... Video memory

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-243786 (JP, A) JP-A-3-88486 (JP, A) (58) Fields investigated (Int.Cl. ⁶ , DB name) H04N 5 / 91,5 / 92

Claims (2)

(57) [Claims] 1. Before starting recording of a video tape recorder, input video information obtained from the video tape recorder is intermittently stored in a predetermined cycle and on a field basis, and stored video information is recorded at the start of recording of the video tape recorder. A video information compression adapter for sequentially reading, outputting the stored video information as recorded video information of the video recorder, and outputting the input video information as the recorded video information after the reading is completed. 2. A video tape recorder for reproducing a video tape comprising a video track on which normal video information and compressed video information intermittently stored and continuously read are recorded. Video storage means for repeatedly reading out the stored video information by a predetermined number of times; and tape running for instructing a tape running stop of the video tape recorder during a period from completion of reproduction of the reproduced compressed video information to completion of reading of the stored video information. A video information decompression adapter for distributing pause instruction means;