JPH08186796A - Recording and reproducing device for digital video signal - Google Patents

Abstract

PURPOSE: To provide a digital VTR or a compression system which can perform the searching and editing operations in every frame through the common processing even in an SP made or a compression LP mode. CONSTITUTION: In an SP mode, the different subcode data are recorded between former 5 or 6 tracks and latter 5 or 6 tracks of a single frame. In a high compression LP mode, the subcode data are recorded with no distinction needed between those former and latter tracks of a single frame. Furthermore, in the high compression LP mode, a TTC pack, a VRD pack, a VRT or ARD pack, and an ART pack are recorded in the same way as the latter 5 or 6 tracks of a single frame of the SP record mode. As a result, the searching and editing operations can be carried out in every frame in both SP and high compression LP modes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital video signal recording apparatus and a reproducing apparatus suitable for use in an image compression recording type digital VTR, and more particularly to a normal recording mode (SP mode) and a long time recording mode. (High compression L
(P mode) and that which can be set.

[0002]

2. Description of the Related Art Development of a compression recording type digital VTR in which a digital video signal is compressed by a DCT and a variable length code and recorded on a magnetic tape by a rotary head is under way. Digital VTR of such compression system
Then, as shown in FIG. 16, ITI is added to the beginning of each track.
An area is provided, followed by an audio area, a video area, and a subcode area.
The ITI area is a timing block for surely performing post-recording, and is used for accurately performing positioning when post-recording and rewriting data written in subsequent areas. A digital audio signal is recorded in the audio area. A compressed digital video signal is recorded in the video area. In the sub code area, data for high speed search such as time code and track number is recorded. In the normal recording mode (SP mode), one frame of data is recorded on 10 tracks in the NTSC system and 12 tracks in the PAL system.

[0003]

As described above, in the conventional compression recording type digital VTR, a video signal for one frame is recorded on 10 tracks in the case of the NTSC system and 12 in the case of the PAL system. It is recorded on the track. In addition to such a recording mode (SP mode),
It has been proposed to provide a mode (hereinafter, referred to as a high compression LP mode) in which the compression rate of a video signal is increased and recording can be performed for a long time. In high compression LP mode,
A 1-frame video signal is recorded on 5 tracks in the case of the NTSC system and 6 tracks in the case of the PAL system. Therefore, a recording time twice as long as that in the SP mode can be obtained.

However, when such a high compression LP mode is provided, conventionally, when the high compression LP mode is set, it may not be possible to edit in one frame units using subcodes. In the prior art, as shown in FIG. 17, the data in the main area of the subcode is the first half of one frame, which is 5 tracks (in the case of the NTSC system) or 6 tracks.
This is because the tracks (in the case of the PAL system) and the latter half 5 tracks or 6 tracks are recorded differently. In the high compression LP mode, one frame is recorded on 5 tracks or 6 tracks, so that the data of the main area of the subcode is arranged so that it is different between the 5 tracks or 6 tracks in the first half and the 5 tracks or 6 tracks in the latter half. Then, editing can be performed only in units of two frames.

In particular, when the SP mode and the high compression LP mode are mixed and recorded, the SP mode portion can be searched and edited on a frame-by-frame basis, while the high compression LP mode portion can be edited. Editing can be performed only in units of two frames, which causes confusion to the user. Further, if the data arrangement in the main area of the subcode is completely different between the SP mode and the LP mode, the processing of the main area data cannot be performed by the common processing, and the SP mode and high compression It cannot support the case where the LP mode and the LP mode are recorded together.

Therefore, an object of the present invention is to provide a digital video signal recording apparatus and a reproducing apparatus capable of performing a search and an edit on a frame-by-frame basis by a common process in both the SP mode and the high compression LP mode. is there.

[0007]

The present invention comprises first compression means for compressing a digital video signal, and second compression means for compressing the digital video signal at a higher compression ratio than the first compression means. Switching means for switching between a standard recording mode for compressing and recording the digital video signal by the first compression means and a long-time recording mode for compressing and recording the digital video signal by the second compression means, and a high-speed search mode. Sub-code data generating means for generating sub-code data is provided. In the standard recording mode, different sub-code data is recorded in the first half and the second half of a track for one frame, and in the long-time recording mode, the first half and the second half are recorded. This is a digital video signal recording device that records similar subcode data without distinction.

According to the present invention, there is provided a first expanding means for expanding a digital video signal compressed in a standard recording mode, a second expanding means for expanding a digital video signal compressed in a long recording mode, and a first expanding means. Switching means for switching between expanding the digital video signal by the expanding means and expanding the digital video signal by the second expanding means, and subcode data detecting means for detecting subcode data for high speed search. In the standard recording mode, the subcode has different data in the first half and the latter half of the track for one frame, and in the long-time recording mode, the same data is used regardless of the first half and the latter half. It is a digital video signal reproducing device for detecting data and performing a search.

[0009]

In the SP mode, different subcode data is recorded in the first half and the latter half of the track for one frame, and in the high compression LP mode, the subcode data is similarly recorded without distinction between the first half and the second half. Therefore, even in the high compression LP mode, a search can be performed on a frame-by-frame basis according to the video recording time or the audio recording time. Furthermore, when recording in the high compression LP mode, as in the latter half 5 tracks or 6 tracks of one frame when recording in the SP mode,
Since TTC packs, VRD packs and VRT packs or ARD packs and ART packs are recorded, S
The same search and edit can be performed in both the P mode and the high compression LP mode.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the structure of a recording system of a digital VTR to which the present invention is applied. In this embodiment, in addition to the normal recording mode (SP mode), it is possible to set a recording mode (high compression LP mode) that enables long-time recording by increasing the compression rate. The mode settings are
It is performed by the input key 12.

In FIG. 1, reference numeral 1 is an input terminal for a digital video signal, and 2 is an input terminal for a digital audio signal. The digital video signal from the input terminal 1 is supplied to the switch circuit 3. A switch control signal is supplied from the controller 4 to the switch circuit 3. The switch circuit 3 is switched between the SP mode and the high compression LP mode by this switch control signal. Switch circuit 3
Is set to the terminal 3A side in SP mode, and high compression L
In the P mode, it is set on the terminal 3B side.

The output of the terminal 3A of the switch circuit 3 is supplied to the SP mode compression circuit 5. Terminal 3 of switch circuit 3
The output of B is supplied to the LP mode compression circuit 6. The SP mode compression circuit 5 and the LP mode compression circuit 6 are for highly efficient compression coding of a digital video signal by DCT and variable length coding.

That is, the SP mode compression circuit 5 and the LP
The mode compression circuit 6 is a blocking circuit that blocks the input video signal, a DCT conversion circuit that performs DCT conversion on the input video signal, a quantizer that quantizes the DCT-converted data, and a total code amount is estimated and optimized. It includes an estimator that determines a different quantizer and a variable-length coding circuit that performs variable-length coding using a two-dimensional Huffman code. The compressed video signal is arranged in a predetermined sync block and framed. When compressed by the SP mode compression circuit 5, one frame of video signal is recorded on 10 tracks or 12 tracks. When compressed by the LP mode compression circuit 6, a video signal of 1 frame has 5 tracks or 6 tracks.
Recorded on the track.

The output of the SP mode compression circuit 5 is supplied to the terminal 7A of the switch circuit 7. The output of the LP mode compression circuit 6 is supplied to the terminal 7B of the switch circuit 7. A switch control signal is supplied from the controller 4 to the switch circuit 7. The switch circuit 7 is switched between the SP mode and the high compression LP mode by this switch control signal. The switch circuit 7 is set to the terminal 7A side in the SP mode, and is set to the terminal 7B side in the high compression LP mode. The output of the switch circuit 7 is supplied to the multiplexer 8.

The digital audio signal from the input terminal 2 is supplied to the audio processing circuit 9. In the audio processing circuit 9, the audio signal is arranged in a predetermined sync block. The output of the audio processing circuit 9 is supplied to the multiplexer 8.

Subcode data is generated from the subcode generation circuit 10 based on a command from the controller 4. The subcode is used during high speed search. This subcode data is supplied to the multiplexer 8.

The multiplexer 8 switches between video data, audio data and subcode data. The output of the multiplexer 8 is supplied to the head 11. The head 11 records the digital video data, the digital audio data signal, and the subcode data on the magnetic tape.

FIG. 2 shows the structure of the subcode area. The subcode area is, as shown in FIG. 2A,
It is composed of 12 sync blocks. One sync block is composed of 12 bytes as shown in FIG. 2B.

As shown in FIG. 2B, a sync pattern of 2 bytes is provided at the head of one sync block. Following this, ID data consisting of ID0 and ID1,
Three bytes of IDP, which is a parity for ID0 and ID1, are added. Next, a 5-byte main data area is provided, and 2-byte parity is further added. One sync block in the subcode area is 12 bytes, which is shorter than the video area and audio area. This is to enable high speed search.

As shown in FIGS. 2C and 2D, ID0 is provided with an F / R flag for detecting an address during high speed search. Subsequently to this, as shown in FIG. 2C, in sync block numbers SB0 and SB6, an application ID (AP3) indicating the data structure of the subcode.
Is arranged, and the absolute track number is arranged so as to straddle the next ID1. For other sync block numbers,
As shown in FIG. 2D, an F / R flag is provided, followed by an index ID, a skip ID, and a photo picture ID, and an absolute track number is arranged so as to straddle ID1. The index ID is for index search. The skip ID is for cutting unnecessary scenes. The photo picture ID is for searching a still image. The absolute track number and sync number are recorded in ID0.

In the main data area of the subcode, as shown in FIG. 3, data is recorded in a pack structure based on 5 bytes. The pack is basically composed of 5 bytes (PC0 to PC4). The first 1 byte PC0 is a header, and the following 4 bytes PC1 to PC1
Data is arranged in the PC 4. The header is divided into upper 4 bits and lower 4 bits to form two layers.
It is possible to extend to the layer below by bit assignment of data. Due to this layering, the contents of the pack are clearly organized and the expansion is easy. Then, 256 spaces including the upper header and the lower header are prepared as a pack header table together with the contents of the pack. Each area is described using this. Since the data area of one sync block is 5 bytes, exactly one pack of data is recorded in one sync block.

The following packs are prepared as packs to be recorded in the main data area of the subcode.

Title Time Code Pack (hereinafter TT
C pack): Header PC0 is "13h" (h
Indicates a hexadecimal number) and indicates a time code of the elapsed time (FIGS. 4A and 4B).

Title binary group pack (hereinafter,
Called TBG pack): Header PC0 is "14h"
That is, the VTR for business use is prepared as a time code interpolation user unit (FIG. 5). In a normal consumer VTR, this title binary group pack is not used. In this case, the title time code pack shown in FIG. 4A is used.

Video recording time minutes seconds pack (hereinafter VRD
(It is called a pack): The header PC0 is "62h" and indicates the recording date of the video data. In addition, DS is summer time information, TM is GMT with 30 minutes as a unit.
It is a flag indicating the time difference from (FIG. 6).

Video recording time minute second pack (hereinafter VRT
(It is called a pack): The header PC0 is "63h" and indicates the recording time minute second of the video data (FIG. 7).

Audio recording hour minute second pack (hereinafter referred to as A
(Referred to as RD pack): The header PC0 is "52h" and indicates the recording date of audio data. Note that D
S is a summer time information, and TM is a flag indicating a time difference from GMT (Greenwich Mean Time) in which 30 minutes is a unit (FIG. 8).

Audio recording hour, minute, second pack (hereinafter referred to as A
(It is referred to as RT pack): The header PC0 is "53h" and indicates the recording time minute second of the video data (FIG. 9).

NO INFO pack (hereinafter referred to as NOI pack): A pack having no information.

In one embodiment of the present invention, when recording in the SP mode, the first half 5 tracks (NTS) of one frame are recorded.
The data is arranged so that the data in the main area of the subcode is different between the C system) or 6 tracks (PAL system) and the latter half 5 tracks or 6 tracks. That is, in the case of recording in the SP mode, the TTC pack, T
A BG pack is recorded, and a TTC pack, a VRD pack, and a V
RT pack or ARD pack and ART pack are recorded.

When recording in the high compression LP mode, data is similarly recorded without distinction between the first half 5 tracks or 6 tracks and the latter half 5 tracks or 6 tracks. That is, when recording in the high compression LP mode, the TTC pack, the VRD pack and the VR are the same as the latter half 5 tracks or 6 tracks of one frame when recording in the SP mode.
T pack or ARD pack and ART pack are recorded.

That is, FIG. 10 shows subcode data of each track when an NTSC system signal is recorded in the SP mode. As shown in FIG. 10, sync block numbers SB3 to SB5 and sync block numbers SB9 to
SB11 is a main area, and sync block number S
B0 to SB2 and sync block numbers SB6 to SB8 are optional areas. NTSC in SP mode
When recorded by the method, 1 of track numbers T0 to T9
0 track is for 1 frame. Track number T0
In the first half 5 tracks up to T4, the TTC pack is recorded in the sync block number SB3, and the TTC pack or the TBG pack or N is recorded in the sync block number SB4.
The OI pack is recorded, the TTC pack is recorded in the sync block number SB5, the TTC pack is recorded in the sync block number SB9, and the sync block number SB1 is recorded.
The TTC pack, the TBG pack, or the NOI pack is recorded in 0, and the TTC pack is recorded in the sync block number SB11. In the latter half 5 tracks of track numbers T5 to T9, the TTC pack is recorded in the sync block number SB3, the VRD pack or the ARD pack or the NOI pack is recorded in the sync block number SB4, and the VRT is recorded in the sync block number SB5. Pack, ART pack, or NOI pack is recorded, sync block number SB9 is recorded with TTC pack, sync block number SB10 is recorded with VRD pack, ARD pack, or NOI pack, and sync block number S is recorded.
A VRT pack, an ART pack, or a NOI pack is recorded in B11.

FIG. 11 shows a case where an NTSC system signal is recorded in the high compression LP mode. As shown in FIG. 11, sync block numbers SB3 to SB5 and sync block numbers SB9 to SB11 are main areas, and sync block numbers SB0 to SB2 and sync block numbers SB6 to SB8 are optional areas. In the high compression LP mode, when recorded by the NTSC system, 5 tracks of track numbers T0 to T4 and T5 to T9 correspond to one frame. As shown in FIG. 11, track numbers T0 to T0
In T4 and track numbers T5 to T9, a TTC pack is recorded in sync block number SB3, and a VRD pack, ARD pack, or NO is recorded in sync block number SB4.
I pack is recorded, and V is written in sync block number SB5.
RT pack, ART pack, or NOI pack is recorded, sync block number SB9 is recorded with TTC pack, sync block number SB10 is recorded with VRD pack, ARD pack, or NOI pack, and sync block number SB11 is recorded with VRT pack. Alternatively, an ART pack or a NOI pack is recorded.

It is recommended that the optional areas (sync block numbers SB0 to SB2, SB6 to SB8) have the same contents as the main area when the optional areas are not used.

FIG. 12 is a flowchart showing a process for recording data in the main area of the subcode. As shown in FIG. 12, is it recorded in SP mode?
It is determined whether or not recording is performed in the high compression LP mode (step S1). In SP mode, the first half of one frame (NTS
The first half 5 tracks for C system, the first 6 tracks for PAL system), TTC pack, TBG pack, or NOI
The pack is recorded (step S2). High compression LP mode, TTC pack, VR without distinction between the first half and the second half
D pack and VRT pack or ARD pack and A
The RT pack is recorded.

As described above, in one embodiment of the present invention, S
In the P mode, the subcode data is recorded in the main data area of the subcode in different formats in the first half and the latter half of one frame. In the high compression LP mode, the LP mode is recorded in the main data area of the subcode. In case of
The one corresponding to the subcode data in the latter half of the frame is
It is recorded without distinction between the first half track and the second half track. In this case, the TBG pack is not recorded in the high compression LP mode. This TBG pack is provided as time code interpolation user data in a commercial VTR and is not used in a consumer VTR. Further, in the high compression LP mode, it is difficult to obtain a good image quality that can be used for commercial use. Therefore, even if the TBG pack is not recorded in the high compression LP mode, no problem will occur.

FIG. 13 shows the structure of a reproducing system of a digital VTR to which the present invention is applied. In FIG. 13, the reproduction signal of the head 21 is supplied to the demultiplexer 22. The demultiplexer 22 separates the reproduction signal of the audio area, the reproduction signal of the video area, and the reproduction signal of the subcode area.

The reproduction signal of the audio area is supplied from the demultiplexer 22 to the audio processing circuit 23. The audio processing circuit 23 performs processing such as time axis conversion and interpolation. The output of the audio processing circuit 23 is output from the output terminal 26.

The reproduction signal of the video area is supplied from the demultiplexer 22 to the switch circuit 24. A switch control signal is supplied from the controller 29 to the switch circuit 24. The switch circuit 24 is switched between the SP mode and the high compression LP mode by this switch control signal. The switch circuit 24 is set to the terminal 24A side in the SP mode, and the terminal 24B in the high compression LP mode.
Set on the side. The output of the terminal 24A of the switch circuit 24 is supplied to the SP mode expansion circuit 25. The output of the terminal 24B of the switch circuit 24 is supplied to the LP mode expansion circuit 26.

The SP mode decompression circuit 25 and the LP mode decompression circuit 26 perform the decoding of the variable length code and the inverse DCT,
It expands a compressed video signal into an original video signal. That is, the SP mode decompression circuit 25 and the LP mode decompression circuit 26 perform the opposite processing to the SP mode compression circuit 5 and the LP mode compression circuit 6 on the recording side (FIG. 1). SP mode decompression circuit 25 and LP mode decompression circuit 2
6 is supplied to the terminals 27A and 27B of the switch circuit 27. A switch control signal is supplied from the controller 29 to the switch circuit 27. The switch circuit 27 is switched between the SP mode and the high compression LP mode by this switch control signal. The switch circuit 27 is set to the terminal 27A side in the SP mode, and is set to the terminal 27B side in the high compression LP mode. The output of the switch circuit 27 is output from the output terminal 28.

The reproduction signal of the subcode area is supplied from the demultiplexer 22 to the subcode detection circuit 30. The subcode detection circuit 30 decodes the subcode data. The output of the subcode detection circuit 30 is supplied to the controller 29. During high-speed reproduction, a subcode is detected by the subcode detection circuit 30, and this subcode is supplied to the controller 29. A search or edit process is performed based on this subcode.

As shown in FIG. 14, for example, in the case of a search by video recording time, a desired video recording time (hour / minute / second) is input (step S11). During high-speed reproduction (step S12), the VRT pack data is detected from the subcode data, and the recording hour / minute / second of this VRT pack is compared with the input hour / minute / second (step S1).
3). When the recorded hour / minute / second obtained from the VRT pack of the subcode and the input hour / minute / second match, the tape is stopped there and the cueing process is performed up to the first track where the hour / minute / second data is recorded ( In step S14), the search ends (step S15).

Even in the case of the video date, the search can be performed by the same processing as described above. It is also possible to carry out a search using both.

[0044]

According to the present invention, when recording in the high compression LP mode, data is recorded in the same manner without distinction between the first half and the second half. You can search by. Further, when recording in the high compression LP mode, the TTC pack, the VRD pack and the VR are the same as the latter half 5 tracks or 6 tracks of one frame when recording in the SP mode.
Since the T pack, the ARD pack, and the ART pack are recorded, the search and the editing can be performed by the same processing in both the SP mode and the high compression LP mode.

That is, conventionally, even when recording in the high compression LP mode, as in the case of the SP mode, the subcodes of the first half 5 tracks or 6 tracks and the second half 5 tracks or 6 tracks of the two frames are recorded. The data is recorded so that the data in the main area is different. in this case,
As shown in FIG. 15, the VRD pack and the VRT pack or the ARD pack and the ART pack can be obtained only every two frames. Therefore, it is impossible to search by the video recording time or the audio recording time on a frame-by-frame basis.

On the other hand, in the present invention, the high compression LP
When recording in the mode, as shown in FIG. 11, the same data is recorded regardless of the first half and the second half, so that the VRD pack and the VRT pack or the ARD pack and the ART pack are obtained for each frame. Therefore, it is possible to search by video recording time or audio recording time in units of one frame. Furthermore, when recording in the high compression LP mode, the TTC pack and VRD are the same as the latter half 5 tracks or 6 tracks of one frame when recording in the SP mode.
Pack and VRT pack or ARD pack and AR
Since the T pack is recorded, the same search and edit can be performed in both the SP mode and the high compression LP mode.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a recording system of a digital VTR to which the present invention is applied.

FIG. 2 is a schematic diagram used to describe subcode data.

FIG. 3 is a schematic diagram used to describe a pack structure.

FIG. 4 is a schematic diagram used to describe a TTC pack.

FIG. 5 is a schematic diagram used to describe an example of a TBG pack.

FIG. 6 is a schematic diagram used to describe an example of a VRD pack.

FIG. 7 is a schematic diagram used to describe an example of a VRT pack.

FIG. 8 is a schematic diagram used to describe an example of an ARD pack.

FIG. 9 is a schematic diagram used to describe an example of an ART pack.

FIG. 10 is a schematic diagram used to describe an embodiment of the present invention.

FIG. 11 is a schematic diagram used to describe an embodiment of the present invention.

FIG. 12 is a flow chart used for explaining one embodiment of the present invention.

FIG. 13 is a block diagram showing a configuration of a reproduction system of a digital VTR to which the present invention is applied.

FIG. 14 is a flow chart used for explaining one embodiment of the present invention.

FIG. 15 is a schematic diagram used to describe an embodiment of the present invention.

FIG. 16 is a schematic diagram used to describe a video track.

FIG. 17 is a schematic diagram used to describe subcode data.

[Explanation of symbols]

 5 SP mode compression circuit 6 LP mode compression circuit 10 Subcode detection circuit

Claims (5)

[Claims] 1. A first compression means for compressing a digital video signal, a second compression means for compressing the digital video signal at a compression ratio higher than that of the first compression means, and a first compression means. Switching means for switching between the standard recording mode for compressing and recording the digital video signal by means of the second compression means and the long-time recording mode for compressing and recording the digital video signal by means of the second compression means, and the subcode data for high speed search. In the standard recording mode, different subcode data is recorded in the first half and the second half of the track for one frame, and in the long-time recording mode, the first half and the second half are distinguished from each other. A digital video signal recording device adapted to record similar sub-code data. 2. In the standard recording mode, the subcode data recorded in the first half of the track for one frame includes a time code, and the subcode data recorded in the latter half track of the track for one frame is time. Subcode data including a code and a recording time, which is recorded without distinction between the first half and the latter half in the long-time recording mode, is recorded in the latter half track of the one frame track in the standard recording mode. The digital video signal recording device according to claim 1, which is similar to the code data. 3. The first compression means comprises (525-6).
The video signal of 0) system is compressed so that it is recorded on 10 tracks, and the second compression means compresses the video signal of (525-60) system on 5 tracks. When recording in the standard recording mode, different subcode data is recorded in the first half 5 tracks and the latter half 5 tracks, and in the long time recording mode, the first half 5 tracks and the latter half 5 tracks are not distinguished. 3. The digital video signal recording device according to claim 1, wherein the same subcode data is recorded. 4. The first compression means comprises (625-5).
The video signal of 0) system is compressed so that it is recorded on 12 tracks, and the second compression means compresses the video signal of (625-50) system on 6 tracks. When recording in the standard recording mode, different subcode data is recorded in the first 6 tracks and the latter 6 tracks. In the long-time recording mode, the first 6 tracks and the latter 6 tracks are not distinguished. 3. The digital video signal recording device according to claim 1, wherein the same subcode data is recorded. 5. A first decompression means for decompressing the digital video signal compressed in the standard recording mode, a second decompression means for decompressing the digital video signal compressed in the long-time recording mode, and the first decompression means. Switching means for switching between expanding the digital video signal by the expanding means and expanding the digital video signal by the second expanding means, and subcode data detecting means for detecting subcode data for high speed search. In the standard recording mode, the sub-code has different data in the first half and the latter half of the track for one frame, and in the long-time recording mode, the same data without distinction between the first half and the second half. And a digital video signal reproducing apparatus adapted to perform a search by detecting the subcode data.