JP2000041216A - Digital signal recorder and recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital signal recorder and a recording and reproducing device that apply compression coding to a television signal of the HDTV system and record/reproduce the signal with higher image quality than that of a home digital VTR. SOLUTION: In the case of recording 4050 macro blocks in total, since this recording and reproducing device can records/reproduce 5400 macro blocks at maximum, the remaining 1350 macro blocks are in idle state. Then a macro block processing circuit 14 processes the 1350 macro blocks in a way that dummy data of same values are recorded in an area for 1080 macro blocks in total at least each division area in the case that two macro block groups of an equal size to that of a maximum macro block group of one frame recordable according to the television signal standards of the HDTV system for an existing home use digital VTR are vertically divided into five divisions respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital signal recording apparatus and a recording / reproducing apparatus, and more particularly to a digital signal recording apparatus for recording a digital signal obtained by compression-encoding a video signal or the like on a recording medium and a recording / reproducing apparatus. It relates to a playback device.

[0002]

2. Description of the Related Art Two rotating heads having different azimuth angles are attached to a rotating surface of a rotating drum so as to face each other, and a magnetic tape wound obliquely over a range of about 180 degrees around an outer peripheral surface of the rotating drum in a predetermined direction. A helical scan type home which records a digital signal obtained by compression-encoding a video signal or the like on the magnetic tape while alternately using the two rotary heads to form an inclined track. Digital VTRs are known.

[0003] The standard "DV" of the above-mentioned home digital VTR formulated by the HD Digital VCR Council includes NT.
There is a specification to compress and encode an HDTV television signal, which is a television standard having a higher image quality than a standard television system such as the SC system, and record it on a magnetic tape (HD-Digital VCR Conference: Specification of Di
gital VCR for Consumer-use (Jul. 1993)).

An outline of the above standard "DV" will be described. One frame of the HDTV video signal is composed of two fields, a first field and a second field, which are interlaced, and has a number of scanning lines of 1125 and a field frequency of 60 Hz (hereinafter referred to as 1125/60 system). And a system in which the number of scanning lines is 1250 and the field frequency is 50 Hz (hereinafter referred to as 1250/50 system). In both cases, the video signal is a luminance signal (Y) and two types of color difference signals (CR and C).
B), the sampling frequency of the chrominance signal is 1/3 that of the luminance signal, and the chrominance signal is decimated in the vertical direction by 内 in the field.

For example, the sampling frequency of the luminance signal of the 1125 · 60 system is 40.5 MHz, and FIG.
The pixel arrangement is as shown in FIG.
And CB have a sampling frequency of 13.5 MHz, and as shown in FIG. 6B, have a relationship of being thinned out to 1/3 in the horizontal direction with respect to the luminance signal, and in the vertical direction even in the field. The color difference signals CR and CB are thinned out by half.
Are arranged line-sequentially.

As shown in FIG. 7, eight pixels in the vertical direction and eight pixels in the horizontal direction (that is, 8 × 8 pixels) of a luminance signal are unit blocks (DCT) of DCT (discrete cosine transform).
T block). The same applies to the color difference signals CR and CB. As a result, as shown in FIG.
In the 5.60 system, since the number of pixels in one frame in the horizontal direction is 1008, the number of DCT blocks in the horizontal direction is one.
Since 26 (= 1008/8) pixels and the 1250.50 system has 1080 horizontal pixels per frame, the horizontal DCT block is 135 (= 1080).
/ 8). As for the color difference signals of CR and CB, as shown in FIG.
-In the 60 system, the number of pixels in one frame in the horizontal direction is 3
Since there are 36 DCT blocks in the horizontal direction, 42
(= 336/8), 1 for 1250.50 system
Since the number of pixels in the horizontal direction of the frame is 360, the DCT block in the horizontal direction has 45 (= 360/8) D
A CT block is configured. The number of DCT blocks in the vertical direction of one frame of the luminance signal is 128 in the 1125 · 60 system, and that of the color difference signals of CR and CB is 64.
In a 1250/50 system, the number of DCT blocks in the vertical direction of one frame of the luminance signal is 144,
The number of each of the R and CB color difference signals is 72.

Further, as shown in FIG. 9, DCT blocks DCT0 to DCT0 of six luminance signals at the same position in the screen.
5 and a DCT block DCT6 of one color difference signal CR.
And a DCT block DCT7 of one color difference signal CB, a macroblock is composed of a total of eight DCT blocks. Then, as shown in FIG. 10, one superblock is formed by a total of 27 macroblocks, three in the vertical direction and nine in the horizontal direction.

[0008] The result of the DCT is requantized, variable-length coded, and recorded as a recording digital signal. The requantization is performed by using a variable length code in units of a video segment composed of a total of five macroblocks, one macroblock being extracted from a superblock in each divided block obtained by dividing one screen into five in the vertical direction. This is performed so that the code amount after the conversion is as close as possible to the code amount allocated to the video segment and does not exceed the allocated code amount. The code after the variable length coding is formatted into 77 bytes as shown in FIG. 11 together with parameters necessary for decoding (such as QNO which is the number of the selected quantization table and STA which is information of error and concealment information). And a sync word and I
After being converted into a data block (sync block) to which a D code and an error correction code are added, the data block is recorded on a magnetic tape by a rotating head. Note that the above concealment indicates that data is replaced by using data of the previous frame or the like when an error occurs.

[0009] Information of one video segment is stored in five sync blocks. FIG. 11 shows an arrangement of coded data in one sync block, Y0 to Y5 are data areas of DCT blocks of six luminance signals forming one macroblock, and CR and CB are chrominances each forming one macroblock. This is a data area of the DCT block of the signals CR and CB. DC indicates a DC component, and AC indicates an AC component. If the AC component of one DCT block has a code amount equal to or larger than the recording area allocated to it, a vacant AC component recording area in the same sync block is allocated. It is assigned to an empty AC component recording area of another sync block.

[0010]

As described above, in a home digital VTR, a television signal of the HDTV system is compression-encoded and recorded on a magnetic tape and reproduced. In addition, it is required to record and reproduce HDTV television signals with higher image quality than a home digital VTR. In this case, simply increasing the sampling frequency and increasing the number of pixels is not desirable because the price of the digital VTR for business is extremely high. It is desirable to reduce the compression ratio as much as possible from the viewpoint of reducing quantization noise.

The present invention has been made in view of the above points,
HDT with even higher image quality than home digital VTR
It is an object of the present invention to provide a digital signal recording device and a recording / reproducing device capable of recording / reproducing a V-system television signal by compression encoding.

Another object of the present invention is to provide a digital signal recording apparatus and a recording / reproducing apparatus capable of recording / reproducing an HDTV television signal by compressing and encoding it with an inexpensive configuration.

[0013]

In order to achieve the above object, a first aspect of the present invention is to provide a method for converting a luminance signal of an HDTV television signal into an HDTV television signal of an existing home digital VTR. For the two types of color difference signals of the HDTV television signal at the first sampling frequency higher than the predetermined sampling frequency in the application standard, the line-sequential color difference signals composed of these two types of color difference signals are converted to the first sampling frequency. At a second sampling frequency that is 1 / n (n is an integer of 2 or more) times the pixel obtained by sampling each pixel in the horizontal direction,
1 in k pixels in the vertical direction (j and k are each an integer of 2 or more)
A DCT block is composed of 2n DCT blocks for luminance signals and 1 DCT block for two types of color difference signals.
A single macroblock is composed of a plurality of HDTV television signals for one frame, and at least the data constituting the same DCT block is defined as a macroblock based on pixels of the same value of dummy data. A macroblock of the same size is formed, and has a size equivalent to the maximum recordable macroblock group of one frame in the HDTV television signal standard of the existing home digital VTR, and is formed by a luminance signal and a color difference signal. Macroblock generating means for creating a plurality of macroblock groups each including macroblocks including dummy data and dummy blocks, and extracting a plurality of macroblocks from the plurality of macroblock groups so as to include one macroblock using dummy data. Configure the video segment, which is the unit of control Then, a compression processing unit that performs compression processing in units of video segments, and coded data obtained by performing compression processing by the compression processing unit are converted into a DC component of a DCT block that constitutes a macroblock and at least a low-frequency AC component. And recording means for storing the components in one sync block and recording them on a recording medium.

According to the present invention, the existing home digital V
A plurality of macroblock groups consisting of macroblocks of luminance signals and color difference signals and macroblocks of dummy data are sequentially formed in a size equivalent to the maximum macroblock group of one recordable frame in the HDTV television signal standard of TR. Since the data is input to the compression processing section, the circuit for the compression processing section of the existing home digital VTR can be used, and the dummy data becomes a DC component by the compression processing by the compression processing section, so that the code amount does not increase.

Further, in order to achieve the above object, a second invention provides a method for converting a luminance signal of an HDTV television signal into an HDT signal at a predetermined first sampling frequency.
For the two types of color difference signals of the V-system television signal, the first line-sequential color difference signal composed of these two types of color difference signals is multiplied by 1 / n (n is an integer of 2 or more) times the first sampling frequency. At the second sampling frequency, each pixel obtained by sampling is 1 DCT in j pixels in the horizontal direction and k pixels in the vertical direction (j and k are each an integer of 2 or more).
It is assumed that one macro block is composed of 2n DCT blocks of luminance signals and one DCT block of two types of color difference signals, each of which constitutes one macro block.
This is performed on the television signal of the DTV system, and the decimated 2 which does not constitute the first line-sequential color difference signal is used.
Pixels obtained by sampling a second line-sequential color difference signal composed of different types of color difference signals at a second sampling frequency are j pixels in the horizontal direction and k pixels in the vertical direction (j and k are integers of 2 or more, respectively). 1 DCT block and its second
The construction of one macroblock of the same size as the macroblock of the luminance signal and the first line-sequential color difference signal from a plurality of DCT blocks using only the line-sequential color difference signal of A plurality of macroblocks including one macroblock based on a second line-sequential chrominance signal from a macroblock group created by the macroblocking means, and a unit of code amount control. And a compression processing unit for performing compression processing in units of the video segments, and coded data obtained by performing compression processing by the compression processing unit.
A recording means for storing a DC component of a DCT coefficient of a CT block and at least a low-frequency AC component in one sync block and recording the same on a recording medium. According to the present invention, the color difference signal can be recorded without thinning in the vertical direction.

According to a third aspect of the present invention, there is provided the macroblock forming means according to the second aspect, wherein at least the data constituting the same DCT block as the macroblock by the second line-sequential color difference signal is used. One or two DCT blocks with the same dummy data,
It is constituted by a plurality of DCT blocks based on a second line-sequential color difference signal.

According to the present invention, as in the second invention, the dummy data is converted into a DC component by the compression processing by the compression processing unit, so that the code amount does not increase, and each video segment is composed of one second line-sequential signal. D by color difference signal
A CT block can be included, and the compression ratio can be averaged.

According to a fourth aspect of the present invention, there is provided the macroblock forming means according to the first to the third aspects, wherein the two types of color difference signals are switched for each field and are combined in a time-sequential manner. It is characterized in that it is used in place of the line-sequential color difference signal.

The fifth invention is the second invention and the third invention.
Of the two types of color difference signals by sub-band division.
It is characterized in that the chrominance signal is divided and used in place of the first line-sequential chrominance signal in the low frequency side divided band, and the chrominance signal in the high frequency side divided band is used in place of the second line-sequential color difference signal.

Further, according to a sixth aspect of the present invention, at the time of variable speed reproduction of a recording medium, a pixel rearrangement process is performed on a macroblock other than the macroblock based on the second line-sequential color difference signal from a plurality of macroblock groups, and a luminance signal and Two types of color difference signals are reproduced, and line interpolation is performed on the two types of reproduced color difference signals. According to the present invention, it is possible to reproduce an image without a sense of incongruity during variable speed reproduction.

[0021]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a block diagram of a first embodiment of a digital signal recording device and a recording / reproducing device according to the present invention. In this embodiment, the recording rate of the HDTV television signal is set to the digital VTR standard D for home use.
V is set to 100 Mbps, which is twice that of 50 Mbps in the 1125 · 60 system, and the number of pixels per line of the luminance signal is set to 1440 and the number of effective lines per frame is set to 1080 (so-called 1440 pixels × 1080)
Pixel), the number of pixels 480 per line of each of the color difference signals CR and CB, and the number of effective lines per frame is 1
080 (so-called 480 pixels × 1080 pixels).

That is, in this embodiment, the luminance signal is recorded and reproduced in 24300 DCT blocks (= 4050 macroblocks), and the two types of color difference signals CR and CB are 8100 DCT blocks (= 8100 macroblocks). In the case of type 1 in which recording and reproduction of 4050 macroblocks are performed by thinning out every other line (so-called 3: 1: 0) and in the case of type 2 in which recording and reproduction of 8100 macroblocks are performed (so-called 3: 1: 1)
There is. In this embodiment, 5400 macroblocks can be recorded, which is twice the total of 2700 macroblocks of 45 macroblocks in the horizontal direction and 60 macroblocks in the vertical direction per frame in a 1125/60 system of the domestic digital VTR standard DV. Equipment.

FIG. 1 shows the case of the type 1 in which the luminance signal Y
The line-sequential color difference signals of the color difference signals CR and CB and the dummy data and the dummy data are supplied to the selection circuit 11 respectively.
The input is distributed to the block configuration circuits 12 and 13,
Each of them constitutes a DCT block of 8 × 8 pixels. The dummy data is distributed and input to the DCT block configuration circuits 12 and 13 by the selection circuit 11 as if they were a luminance signal and a color difference signal.

In this case, the selection circuit 11 outputs a vertical pixel every 16 pixels which is the number of vertical pixels of one macro block in the pixel group 33 of one frame of the luminance signal shown in FIG. Is divided, the odd-numbered vertical 16-pixel groups are allocated to one DCT block configuration circuit 12, and the even-numbered vertical 16-pixel groups are allocated to the other DCT block configuration circuit 13. Similarly, when the line-sequential color-difference signal is divided into every 16 pixels, which is the number of pixels in the vertical direction of one macroblock, and the frame is composed of 1080 lines for the line-sequential color difference signal, the odd-numbered vertical The 16 divided pixel groups in the direction are allocated to one DCT block configuration circuit 12, and the even-numbered 16 divided pixel groups in the vertical direction are allocated to the other DCT block configuration circuit 13. However, since the signal is a line-sequential color difference signal, the line-sequential color difference signal of a 16-pixel group divided in the vertical direction is input to the DCT block configuration circuit 12 (13), so that the color difference of eight lines every two pixels in the vertical direction is obtained. This means that the signal CR and the color difference signals CB for eight lines between them are input.

When one frame of the input signal is divided into 16 pixels in the vertical direction, the luminance signal and the line-sequential color difference signal are 1080 lines in total, and the fraction of 8 lines remains. A process is performed in which the data is divided into two for each line and distributed to the DCT block configuration circuits 12 and 13.

The DCT block configuration circuits 12 and 13 are:
The DCT block is configured in the same manner by the same configuration as the DCT block configuration circuit of the existing home digital VTR. The dummy data constitutes a DCT block without distinction between a luminance signal and a color difference signal. However, the same DCT block constitutes a DCT block having the same value (in other words, dummy data between different DCT blocks is different from each other). Value.)

The luminance signal, the chrominance signal, and the dummy data, which have been DCT-blocked by the DCT block forming circuits 12 and 13, respectively, are supplied to correspondingly provided macro-blocking circuits 14a and 14b, and are shown in FIG.
The macro blocks (M
B) That is, the macroblock conversion circuit 14
a and 14b are based on the DCT block data from the DCT block configuration circuits 12 and 13, and are 45 macroblocks (MB) in the horizontal direction and 60 macroblocks in the vertical direction, respectively, similarly to the macroblocking circuit of the existing home digital VTR.
A macroblock group indicated by 31 and 32 in FIG. 2 is created, which is composed of a total of 2700 macroblocks (MB) of macroblocks (MB).

That is, the macroblock forming circuit 14a outputs the luminance signals of the odd-numbered vertical division 16 pixel groups from the DCT block forming circuit 12 to the color difference signals CR and CB from the DCT block forming circuit 12 for every 6 DCT blocks.
One macro block group 31 is formed by repeating the synthesis of each DCT block to form a macro block, and the macro block forming circuit 14b is an even-numbered vertical division 16 pixel from the DCT block forming circuit 13. The group of luminance signals constitutes the other macroblock group 32 by repeating the synthesis of macroblocks by synthesizing the color difference signals CR and CB from the DCT block configuration circuit 13 with one DCT block every 6 DCT blocks.

In this manner, 5400 macroblocks (MB) recordable by the apparatus of this embodiment are arranged in the horizontal direction 45, as indicated by 31 and 32 in FIG.
2 for every 2700 macroblocks (MB) of macroblocks (MB) and vertical 60 macroblocks (MB)
Create by dividing.

In this way, a total of 4050 macroblocks are recorded. In this recording / reproducing apparatus,
As described above, since a maximum of 5400 macroblocks can be recorded and reproduced, the remaining 1350 (= 5400−40)
50) The macro block has an empty space. Therefore, in this embodiment, when the macroblock groups 31 and 32 in FIG. 2 are vertically divided into five out of the 1350 macroblocks, at least one of the divided regions 34 and 35 is provided.
In a total of 1080 macro blocks (MB).

As described above, the luminance signal and the two types of color difference signals CR and CB that have been formed into macroblocks are divided into video segments by the compression processing units 15a and 15b shown in FIG.
The same compression processing as the standard DV, such as discrete cosine transform (DCT), quantization, and variable length coding (VLC), is performed. That is, when the macroblock groups 31 and 32 of FIG. 2 are first divided into five vertical sections, the compression processing sections 15a and 15b extract one macroblock from each of the divided areas according to a predetermined rule, and At 1
A video segment is formed, and DCT is performed for each DCT block in the video segment. This is to average the deviation of the local information amount on the screen.

The one video segment is composed of four macroblocks composed of data of a luminance signal and a color difference signal and one macroblock of dummy data. Since the dummy data becomes a DC component when DCT is performed, the data amount by the DCT is usually reduced. Can be compressed to 4/5.

The compression processing units 15a, 15b
After the T operation result (DCT coefficient) is quantized, variable-length encoding is performed. This variable-length coding is Huffman coding, which is not the gist of the present invention, and its coding process is known, so that detailed description will be omitted. The variable-length coded data is temporarily stored in a buffer memory, and the quantization width at the time of the above-described quantization is controlled so that the code amount is constant for each video segment.

The data compression-encoded by the compression processing units 15a and 15b is added with an error correction code by an error correction encoding circuit 16, and a synchronization signal and an ID are added thereto. Is converted to Each sync block stores a DC component of a DCT coefficient of a DCT block constituting the macro block and at least a low-frequency AC component. Digital signal of the sync blocks is supplied to the modulation circuit 17 is modulated by a predetermined modulation method, after being amplified to a required level by the recording amplifier 18, a recording rotary head H _R through a rotary transformer (not shown) Supplied.

The recording rotary head H _R is composed of two pairs of opposing rotary heads having different azimuth angles attached to the rotary surface of a rotary drum (not shown). Two inclined tracks are simultaneously formed and recorded on the magnetic tape 19 which is wound in the inside and travels in a certain direction. Here, the home digital VT is sequentially applied to the macroblock groups 31 and 32 of FIG. 2 having the same size (size) as the maximum recording macroblock group of the home digital VTR standard DV.
The same processing as R standard DV is performed, and as a result,
bps, magnetic tape 1 at a recording rate of 100Mbps in total
At 9, a digital signal is recorded by forming 40 inclined tracks per frame.

Next, the operation at the time of reproduction will be described. At the time of reproduction, the magnetic tape 1 on which the above digital signal is recorded
9 is reproduced by the reproducing rotary head H _P. Rotation reproducing head H _P is normally recording rotary heads H _R described above is also used. The digital signal reproduced by the reproducing rotary head H _P is amplified and supplied to the playback amplifier 20 through a rotary transformer (not shown), further demodulation circuit 2
After being demodulated by 1, it is decoded by the error correction decoding circuit 22, and if there is an error, error correction is performed using an error correction code.

The signal extracted from the error correction decoding circuit 22 is supplied to decompression processing units 23a and 23b, where it is subjected to variable length decoding, inverse quantization and inverse DCT in the order of compression processing unit 1a.
After the signal processing reverse to 5a, 15b is performed, it is supplied to the pixel rearranging circuits 24a, 24b, where the processing reverse to the processing when the video segment was created at the time of recording is performed, and based on the pixel arrangement. Then, the selection circuit 25 performs pixel rearrangement of the data from the pixel rearrangement circuits 24a and 24b, and returns each macro block to luminance signal data and two types of color difference signal data.

As described above, in this embodiment, the compression processing section 15a is applied to each of the macroblock group 31 and the macroblock group 32 of FIG. 2 having the same size (size) as the home digital VTR standard DV. , 15b, error correction coding processing by the error correction coding circuit 16, modulation processing by the modulation circuit 17, demodulation circuit 2
1 is performed by the demodulation circuit, the error correction decoding circuit 22, and the decompression processing units 23a and 23b, so that the home digital VTR standard DV is used as the compression processing units 15a and 15b and the decompression processing units 23a and 23b. Large-scale semiconductor integration (LSI) currently used in Japan
Circuit can be used and the home digital VTR standard DV2
Even when recording and reproducing at a double recording rate, hardware design costs can be reduced, and the compression ratio is 4/5.
Therefore, the quantization noise associated with the compression can be reduced, and a higher quality image can be obtained than with the existing home digital VTR standard DV.

Next, a second embodiment of the present invention will be described. FIG. 3 is a block diagram showing a digital signal recording apparatus and a recording / reproducing apparatus according to a second embodiment of the present invention. In the figure, the same components as those in FIG.
The description is omitted. In this embodiment, the luminance signal is 2
4300 DCT blocks (= 4050 macro blocks)
And the two types of color difference signals CR and CB
Is a type 2 example (so-called 3:
1: 1). In this embodiment, 5400 macroblocks can be recorded, which is twice the total of 2700 macroblocks of 45 macroblocks in the horizontal direction and 60 macroblocks in the vertical direction per frame in a 1125/60 system of the domestic digital VTR standard DV. Equipment.

In FIG. 3, the color difference signals CR and CB are
The first color difference signals CR and CB which are supplied to the dividing circuit 41 are alternately thinned out every other line and synthesized in time series.
, And the thinned color difference signals CR and CB are alternately and time-sequentially synthesized every other line.
, And is input to the selection circuit 42.

The selecting circuit 42 supplies the luminance signal Y to the DCT block forming circuit 12, the first line-sequential color difference signal to the DCT block forming circuit 13, and inputs the luminance signal Y for 24300 DCT blocks for one screen. When the input of the color difference signals CR and CB for each of the 4050 DCT blocks is completed, the color difference signals CR and CB constituting the second line-sequential color difference signal are converted to the DCT block configuration circuit 12 respectively.
And 13 and input.

The luminance signal and the chrominance signals CR and CB which have been DCT-blocked by the DCT block forming circuits 12 and 13 are supplied to a macro-blocking circuit 43 to be divided into two macro-block groups 51 and 52 shown in FIG. (MB). That is, in this embodiment,
Recordable 5400 macroblocks (MB) are divided into 45 macroblocks (MB) in the horizontal direction and 60 macroblocks (MB) in the vertical direction, totaling 2700 macroblocks (M).
B) The macroblock groups 51 and 52, each of which is divided into two, are each divided into five in the vertical direction. Four regions each include six DCT blocks of the luminance signal Y and 480 pixels each represented by CR1 and CB1. × 40 consisting of 540 pixels
Each one of the color difference signals CR and CB in the 50 DCT block
The same as in the first embodiment is that one macro block composed of DCT blocks is arranged in a total of 4050 macro blocks (MB).

Further, in the second embodiment, the macroblocking circuit 43 is thinned out and discarded in the first embodiment.
A 4050 DCT block of the second line-sequential color difference signal composed of 0 pixels × 540 pixels is divided into a macro block group 51
And 52, each of the divided areas 53 and 54 in total 108
CR2 and CB2 in the area of 0 macroblock (MB)
Are extracted from each of the four DCT blocks to form one macroblock, and a total of 1012.5 (= (405
0 + 4050) / 8) A configuration in which macro blocks are arranged.

As described above, the luminance signal and the color difference signals CR and CB which have been macroblocked by the macroblocking circuit 43.
Is supplied to the compression processing unit 15 and the macro block group 51
And 52, a video segment is formed by extracting five macroblocks so as to include one macroblock of the divided areas 53 and 54, and after performing compression processing in units of the video segments, the first embodiment It is recorded on the magnetic tape 19 by the rotary head H _R by the the same manner as the embodiment.

Further, during reproduction, the digital signal reproduced by the first embodiment and the rotary head H _P in the same manner is supplied to a macro block recognition means 44 from the error correction decoding circuit 22 of FIG. 3, Here, whether or not the input digital signal is a macroblock of the divided areas 53 and 54 of the macroblock groups 51 and 52 in FIG. 4 is identified based on the reproduced signal, and if the input digital signal is not a macroblock of the divided areas 53 and 54 (including the luminance signal). (If it is a macroblock), it is input to the expansion processing unit 45, and if it is a macroblock of the divided areas 53 and 54, it is input to the expansion processing unit 46.

The signals extracted by the decompression processing sections 45 and 46 being subjected to signal processing reverse to that of the compression processing section 15 separately are sent to a first pixel rearrangement circuit 47 and a second pixel rearrangement circuit 48. In this case, a process reverse to the process performed when the video segment was created at the time of recording is performed to restore the pixel arrangement, and the first pixel rearrangement circuit 47 further divides each macro block into two types of luminance signal data and luminance signal data. , And the second pixel rearranging circuit 48 returns each macroblock to two types of color difference signal data.

The normal reproduction for reproducing a running speed of the magnetic tape 19 as a recording time of the same value, since the rotary head H _P is controlled so as to accurately scan the recording inclined track mark, recording the digital signal is a frame All macroblocks are played. Accordingly, the selection circuit 49 selects the luminance signal and the color difference signal extracted from the first pixel rearrangement circuit 47 and the second pixel rearrangement circuit 48,
A luminance signal and two types of color difference signals CR and CB which are not thinned out are output. That is, at the time of normal reproduction, reproduction of 3: 1: 1 can be performed, and the color reproducibility can be further improved as compared with the first embodiment.

On the other hand, during variable speed reproduction in which the running speed of the magnetic tape 19 is set to a value different from that during recording, the rotating head H
_{Since P} scans across the recording tilt track trace, the recorded digital signal cannot reproduce all macroblocks (sync blocks) of one frame. Therefore, in this embodiment, the selection circuit 49 includes only two types of luminance signals that have been thinned out only from the first pixel rearrangement circuit 47 that rearranges pixel data obtained by expanding a macroblock including a luminance signal. Color difference signals CR and CB are selectively output. That is, at the time of variable-speed reproduction, reproduction of 3: 1: 0 can be performed. At the time of the 3: 1: 0 reproduction, two types of color difference signals CR are used.
And CB interpolate the color difference signal every other line by applying a band limiting filter in the vertical direction at the subsequent stage of the selection circuit 49.

Next, a third embodiment of the present invention will be described. As described above, this recording / reproducing apparatus can record / reproduce a maximum of 5400 macroblocks, whereas a luminance signal and two kinds of color difference signals CR and CB are:
When recording and reproducing at 1: 0, 4050 macroblocks are recorded, so that the remaining 1350 (= 5400-
4050) The macro block has an empty recording capacity.

Therefore, in this embodiment, an empty 1
As in the second embodiment, the two types of color difference signals CR and CB, which are thinned out, are also recorded by using 350 macroblocks. However, in the second embodiment, the two types of color difference signals CR and CB, which are thinned out, are 101
Since the data is recorded in 2.5 macro blocks, 337.5 macro blocks including data (dummy data) other than the luminance signal and the color difference signal remain as empty macro blocks.

For this reason, one video segment has four macro blocks each including a DCT block of six luminance signals and one DCT block of one color difference signal, and a macro block including eight DCT blocks of color difference signals. Is 1
And one video segment is a DCT block of six luminance signals and a DCT block of one color difference signal.
In some cases, the macroblock is composed of four macroblocks composed of T blocks and one macroblock composed of data other than the luminance signal and the chrominance signal, and the compression ratio is greatly different between them. , The compression ratio is averaged.

That is, in this embodiment, recordable 5400 macroblocks (MB) are divided into 45 macroblocks in the horizontal direction (MB) and 60 macroblocks in the vertical direction (MB), as indicated by 61 and 62 in FIG. MB)
Divided into 2700 macroblocks (MB) each, a total of 1350 macroblocks consisting of the regions 63 and 65 and the regions 64 and 66, and one macroblock (MB)
Out of the eight DCT blocks 67, the two types of color difference signals CR, C
B is arranged, for example, by 3 DCT blocks, and the remaining 2 DCT blocks 68 are recorded as macroblocks by a macroblocking circuit so as to arrange macroblocks configured as dummy data.

The two types of color difference signals CR and C which have been thinned out
B has a total of 8050 DCT blocks, each having 4050 DCT blocks as described above.
Since T blocks are used for one macroblock, 805
The 0DCT block is recorded as a 1350 (= 8050/6) macroblock. And this third
In the embodiment of the present invention, there are two DCT blocks in one macroblock having the same value of dummy data. Therefore, when DCT operation is performed, the dummy data becomes a DC component.
The compression ratio can be improved as compared with the case where it is configured by blocks, so that the quantization noise accompanying code compression can be reduced.

In the above description, 2 DCT blocks in one macro block are described as dummy data. However, although the compression ratio is reduced, 1 DCT block may be used as dummy data. The block configuration in this case is the same as in FIG.

The present invention is not limited to the above embodiment, and various other modifications are possible. For example, two types of color difference signals recorded at the time of performing 3: 1: 0 recording are the same as those shown in FIG.
As shown in (B), two adjacent lines are thinned out alternately in one frame screen, and in each field, two types of color difference signals are alternately synthesized time-sequentially for each line. Although the line-sequential color difference signal is used, the present invention is not limited to this. One of the first and second fields is only one type of color difference signal, and the other field is only the other type of color difference signal. A so-called plane-sequential color difference signal may be used. Similarly, the two types of color difference signals may both be used as the color difference signals of one field. in this case,
Since the correlation between lines is high, the compression efficiency can be improved.

When 3: 1: 1 recording is performed as in the second and third embodiments, two types of color difference signals C are used.
R and CB are divided into two by sub-band division in the vertical direction in the field. Among them, a DCT block composed of a divided band signal on the low frequency side and a DCT block of six luminance signals constitute a macro block, DCT blocks composed of the divided frequency band signals of the high frequency divided band chrominance signal, and a macro block composed of only the DCT blocks of the high frequency divided frequency band color difference signal may be configured and recorded. Furthermore,
The second embodiment has been described as being applied to a VTR having a recording rate twice as high as that of an existing home digital VTR for an HDTV television signal. However, the present invention is not limited to this.

[0057]

As described above, according to the present invention,
A macro having a size equivalent to the largest recordable macroblock group of one frame in the HDTV television signal standard of the existing home digital VTR, and comprising a macroblock using a luminance signal and a color difference signal and a macroblock using dummy data. When a plurality of blocks are sequentially input to the compression processing section, the existing home digital V
In addition to using the circuit for the compression processing unit of the TR, the dummy data is converted into a DC component by the compression processing by the compression processing unit so that the code amount is not increased. Existing digital VT for home use
Signal recording can be performed so as to obtain an image with higher definition than the standard for the HDTV television signal of R.

Also, according to the present invention, since a macroblock is composed of a DCT block of a luminance signal and a DCT block of a chrominance signal thinned in the vertical direction in the same area in the screen, the code amount of the macroblock is reduced. While you can
As a result, the length of the sync block can be reduced.

Further, according to the present invention, since the color difference signal can be recorded without thinning out in the vertical direction, the luminance signal can be reproduced with high definition, and the color reproducibility is improved as compared with the existing home digital VTR. Signal recording is possible.

Further, according to the present invention, the two types of color difference signals are divided into two by sub-band division, and the color difference signals in the low frequency side divided band are used in place of the first line-sequential color difference signals, and the high frequency side divided band is used. By using the color difference signal of the band in place of the second line-sequential color difference signal, the DCT block of the color difference signal forming the macroblock together with the DCT block of the luminance signal is constituted by the color difference signal of the lower frequency side divided band. Even if an image is composed only of the sync block, aliasing can be prevented.

Further, according to the present invention, it is possible to reproduce an image without a sense of incongruity at the time of variable speed reproduction, so that it is possible to obtain good variable speed reproduction image quality.

[Brief description of the drawings]

FIG. 1 is a block diagram of a first embodiment of a digital signal recording device and a recording / reproducing device according to the present invention.

FIG. 2 is an explanatory diagram of macroblock formation in the device of FIG. 1;

FIG. 3 is a block diagram of a digital signal recording device and a recording / reproducing device according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram of macroblock formation in the device of FIG. 3;

FIG. 5 is an explanatory diagram of macroblock formation in a digital signal recording device and a recording / reproducing device according to a third embodiment of the present invention.

FIG. 6 is a diagram showing a pixel arrangement of a luminance signal and a color difference signal in a conventional device.

FIG. 7 is a diagram showing a DCT block and a pixel arrangement.

FIG. 8 is an explanatory diagram of a DCT block of a luminance signal and a color difference signal.

FIG. 9 is an explanatory diagram of an example of a macro block.

FIG. 10 is a diagram illustrating a relationship between a super block and a macro block.

FIG. 11 is a diagram showing an example of a format of data to be recorded.

[Explanation of symbols]

11, 42 Selection circuit (macroblocking means) 12, 13 DCT block configuration circuit (macroblocking means) 14a, 14b, 43 Macroblocking circuit (macroblocking means) 15a, 15b, 15 Compression processing section 16 Error correction Encoding circuit (recording means) 17 Modulation circuit (recording means) 19 Magnetic tape (recording medium) 21 Demodulation circuit 22 Error correction decoding circuit 23a, 23b Decompression processing section 24a, 24b Pixel rearrangement circuit 25, 49 Selection circuit 41 Division circuit (macro-block means) 44 macro block recognition means 45, 46 decompression processing unit 47 first pixel rearrangement circuit 48 the second pixel rearrangement circuit H _R recording rotary head (recording means) H _P reproducing rotary head

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C053 FA17 FA22 GA11 GA16 GB07 GB15 GB21 GB22 GB26 GB34 HA21 KA08 KA24 KA28 5C059 KK03 KK07 LB01 MA23 MC32 MC34 MC38 ME01 PP14 RC07 RF04 RF09 SS03 SS11 SS16 UA02 UA05

Claims (6)

[Claims] An HDTV of a conventional home digital VTR is used for a luminance signal of an HDTV television signal.
At a first sampling frequency higher than a predetermined sampling frequency in the TV signal standard of the TV system, two types of color difference signals of the HDTV system television signal are line-sequential color difference signals composed of these two types of color difference signals. The signal is 1 / n of the first sampling frequency.
(N is an integer of 2 or more) times the second sampling frequency, and a pixel obtained by sampling is a j-pixel in the horizontal direction and a k-pixel in the vertical direction (j and k are each an integer of 2 or more) to form one DCT block. And 2n DCT blocks of luminance signals and DCT blocks of the two types of color difference signals, respectively.
Constructing one macro block from each one block is performed for one frame of the HDTV television signal, and at least data constituting the same DCT block is based on pixels of dummy data having the same value. A macroblock having the same size as the macroblock, and having the same size as the largest macroblock group of one recordable frame in the HDTV television signal standard of the existing home digital VTR, and Macroblock generating means for creating a plurality of macroblock groups each including a macroblock based on a signal and a color difference signal and a macroblock based on the dummy data; and including one macroblock based on the dummy data from the plurality of macroblock groups. Extract multiple macroblocks and add A compression processing unit that forms a video segment that is a unit of volume control, and performs compression processing on a video segment basis; and a coded data obtained by the compression processing performed by the compression processing unit is converted into a DCT that forms the macroblock. A digital signal recording apparatus, comprising: recording means for storing a DC component of a DCT coefficient of a block and at least a low-frequency AC component in one sync block and recording the same on a recording medium. 2. For a luminance signal of an HDTV television signal, at a predetermined first sampling frequency,
Regarding the two kinds of color difference signals of the HDTV television signal, a first line-sequential color difference signal composed of these two kinds of color difference signals is divided by 1/1 of the first sampling frequency.
At a second sampling frequency of n (n is an integer of 2 or more) times, each pixel obtained by sampling is a j-pixel in the horizontal direction and a k-pixel in the vertical direction (j and k are each an integer of 2 or more) and 1 DCT block. And 2n DCT blocks of the luminance signal and the DCT blocks of the two types of color difference signals, respectively.
Constructing one macro block from each one of the blocks is performed on the HDTV television signal for one frame, and the thinned one that does not constitute the first line-sequential color difference signal is used. Pixels obtained by sampling a second line-sequential color difference signal composed of the two types of color difference signals at the second sampling frequency are j pixels in the horizontal direction and k pixels in the vertical direction (j and k are two or more, respectively). integer)
To form one DCT block, and to construct one macroblock of the same size as the macroblock of the luminance signal and the first line-sequential color-difference signal from a plurality of DCT blocks using only the second line-sequential color-difference signal. Macroblocking means for performing the HDTV television signal for a frame; and one macroblock based on the second line-sequential color difference signal from a macroblock group created by the macroblocking means. To extract a plurality of macroblocks to form a video segment that is a unit of code amount control,
A compression processing unit that performs compression processing on a video segment basis; and encodes the coded data obtained by performing the compression processing by the compression processing unit with at least a low-frequency AC component and a DC component of a DCT coefficient of a DCT block that forms the macroblock. Recording means for storing the components in one sync block and recording the components in a recording medium. 3. The method according to claim 2, wherein the macroblocking means comprises:
As one macro block based on the line-sequential color difference signal, at least one or two DCT blocks based on dummy data having the same value as the data constituting the same DCT block, and a plurality of DCT blocks based on the second line-sequential color difference signal. 3. The digital signal recording apparatus according to claim 2, wherein the apparatus is configured. 4. The macroblock converting means converts the two types of color difference signals, which are switched in a field-by-field manner and are combined in a time-sequential manner, to a line-sequential color difference signal or a color difference signal of the same field. 4. The digital signal recording device according to claim 1, wherein the digital signal recording device is used in place of the digital signal recording device. 5. The macroblock dividing means divides the two types of color difference signals into two by sub-band division, uses a color difference signal of a lower frequency side divided band in place of the first line-sequential color difference signal, The color difference signal of the frequency side divided band is
4. A digital signal recording apparatus according to claim 2, wherein said digital signal recording apparatus is used in place of said line sequential color difference signal. 6. A variable-rate reproduction of a recording medium recorded by the digital signal recording apparatus according to claim 2, wherein the plurality of macroblock groups are used for a macroblock other than a macroblock based on the second line-sequential color difference signal. A digital signal recording / reproducing apparatus, which performs pixel rearrangement processing to reproduce the luminance signal and two types of color difference signals, and performs line interpolation for the two types of reproduced color difference signals.