JP2003134466A - Device for recording and reproducing digital signal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that an unused recording area exists so that the recording area of a recording medium cannot be effectively utilized in the conventional recording system. SOLUTION: In recording an image signal, a line data inserting part 4 stores 7.5 lines of line signals outputted from an additional information superimposing part 3 other than prescribed lines in areas V1 to V4 and areas E1 to E4 within a basic unit outputted from a compressing part 2 and outputs the line signals. In reproducing the image signal, a line data extracting part 10 extracts the line signals from the areas V1 to V4 and the areas E1 to E4, subsequently adds an EOB code to the areas E1 to E4 and outputs the resultant E1 to E4 to an expanding part 11. Consequently, it is made possible to record and reproduce all of effective scanning lines.

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 / reproducing apparatus for recording on a recording medium a digital signal obtained by compression-encoding a video signal or the like.

[0002]

2. Description of the Related Art A standard called "DVC" (hereinafter referred to as "DVC standard") has been proposed as a standard of a digital VTR (video tape recorder) for recording image data by compressing image data (for example, National Technical R).
eport Vol. 41 No.2 Apr. 1995 Page 48 to 55
page). The DVC standard defines a standard (hereinafter referred to as "SD-DVC standard") for recording an image signal (SD signal) having a normal resolution at the current broadcast level.

According to this SD-DVC standard, the so-called 52
Image signals of the 5/60 system (NTSC system and the like correspond) are luminance (Y) signals and color differences (Cr, C).
b) The signal is sampled at a sampling frequency with a ratio of 4: 1: 1, and the luminance (Y) signal has 720 pixels in the horizontal direction and 480 lines in the vertical direction in the frame, Regarding the color difference (Cr, Cb) signals, the number of pixels in the horizontal direction is 180 pixels and the number of lines in the vertical direction is 480 in each frame.

[0004] Here, FIG. 4A illustrates a luminance (Y) signal and a color difference (C) that are formatted according to the SD-DVC standard.
It is a figure which shows the macroblock structure (of the image signal of a 525/60 system) of r, Cb) signal. SD-DV
In the C standard, as shown in the figure, one pixel block is 8 × 8 pixels composed of luminance (Y) signals or color difference (Cr, Cb) signals that are adjacent in the horizontal and vertical directions in a frame, and are arranged in the horizontal direction. Pixel blocks DCT0 to DCT3 composed of four luminance (Y) signals, and these four pixel blocks DC
One pixel block DCT4 composed of color difference (Cr) signals which are at the same position as T0 to DCT3 and a color difference (Cb)
A macro block is composed of a total of six pixel blocks including one pixel block DCT5 composed of a signal.

[0005] Then, the luminance (Y) signal data and the color difference (Cr, Cb) signal data in this macroblock are subjected to DCT in each pixel block unit, and further subjected to requantization, variable length coding, etc. Through the process, these pixel data are stored in the basic unit of the SD-DVC standard shown in FIG. Here, the basic unit shown in FIG.
It is composed of four blocks Y0 to Y3 for luminance signals and two blocks Cr and Cb for color difference signals, and in principle, a pixel block DCT for four luminance (Y) signals.
The pixel data in 0 to DCT3 is the block Y
0 to Y3, the pixel data in the pixel block DCT4 of the color difference (Cr) signal is stored in the block Cr, and the pixel data in the pixel block DCT5 of the color difference (Cb) signal is stored in the block Cb.

[0006] Note that regions D0 to D5 illustrated in FIG. 5A are in the pixel blocks DCT0 to DCT3 of the luminance (Y) signal, the pixel block DCT4 of the color difference (Cr) signal, and the pixel block DCT5 of the color difference (Cb) signal. Areas A0 to A5 are areas where DC components and information to be referred to at the time of encoding and decoding are stored, and areas A0 to A5 are pixel blocks DCT0 to DCT3 for luminance (Y) signals, pixel blocks DCT4 for color difference (Cr) signals, This is an area in which the AC component of the pixel block DCT5 of the color difference (Cb) signal is stored.

[0007] Further, the areas A0 to A5 are not necessarily used individually. For example, even if the AC component of the pixel block DCT0 of the brightness (Y) signal is stored in the area A0, there is a space, but the brightness ( When all the AC components of the pixel block DCT2 of the Y) signal cannot be stored in the area A2, the remaining AC components of the pixel block DCT2 of the luminance (Y) signal are stored in the empty area of the area A0.

[0008] Then, by providing two signal processing systems of the SD-DVC standard in parallel, a standard for recording / reproducing an image signal of 4: 2: 2 at 50 Mbps which is twice the SD-DVC standard (hereinafter referred to as "DIGITAL"). -S standard ") has already been proposed. FIG. 4B is a macroblock structure (525/6) of a luminance (Y) signal and a color difference (Cr, Cb) signal that are formatted according to the DIGITAL-S standard.
The image signal of the 0 system) is shown in FIG.
(B) shows a basic unit of the DIGITAL-S standard.

According to the DIGITAL-S standard, so-called 5
In the image signal of the 25/60 system, the luminance (Y) signal and the color difference (Cr, Cb) signals are sampled at a sampling frequency with a ratio of 4: 2: 2, and the luminance (Y) signal is horizontal in the frame. The number of pixels in the vertical direction is 720, and the number of lines in the vertical direction is 480. Color difference (Cr, Cb)
Regarding the signals, the number of pixels in the horizontal direction is 360 pixels and the number of lines in the vertical direction is 480 in each frame.

[0010] As shown in FIG. 4B, the macroblock includes pixel blocks DCT0 to DCT3 each composed of four luminance (Y) signals arranged in the horizontal direction, and two macroblocks arranged in the same horizontal direction as the screen. Pixel blocks DCT4 and DCT5 composed of two color difference (Cr) signals and two color difference (C
b) It is composed of a total of eight pixel blocks including pixel blocks DCT6 and DCT7 each consisting of a signal, and the pixel data of this macroblock is processed into processes such as DCT, requantization, and variable length coding in a basic unit as described later. Is stored.

[0011] In the DIGITAL-S standard, SD-D
Similar to the VC standard, pixel data in a macroblock is subjected to DCT in each pixel block unit, and variable length coding processing is performed only to the AC component obtained by DCT. Further, in the requantization processing in the DIGITAL-S standard, five macroblocks shown in FIG. 4B are collected into one video segment, and the code amount after the variable length coding is controlled in units of this video segment. Then, the pixel data of one video segment (five macroblocks) is assigned to the five basic units shown in FIG. That is, the pixel data of the five macro blocks is shown in FIG.
The quantization step in the requantization processing is determined so that the number of basic units shown in FIG.

[0012] In the areas D0 to D7 illustrated in FIG. 5B, pixel blocks DCT0 to DCT of luminance (Y) signals are included.
3. Color difference (Cr) signal pixel blocks DCT4 and DC
T5, color difference (Cb) signal pixel blocks DCT6 and D
The DC component in CT7 and information to be referred to in encoding and decoding are stored, and pixel blocks DCT0 to DCT3 for luminance (Y) signals and pixel blocks DCT4 and DCT5 for color difference (Cr) signals are stored in areas A0 to A11. , AC components in the pixel blocks DCT6 and DCT7 of the color difference (Cb) signal are stored.

[0013] Note that invalid data is stored in the areas V1 to V4, and zero run length encoding in the variable length encoding process is performed in the areas E1 to E4 corresponding to the head portion in the areas A1, A3, A7, and A9. , 4-bit EOB codes obtained as a result of the modified two-dimensional Huffman coding are stored.

[0014]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
According to the ITAL-S standard, the number of recording pixels of the color difference (Cr, Cb) signal is doubled as compared with the SD-DVC standard, and the quantization step at the time of requantization of the luminance (Y) signal is significantly increased. However, since there is an unused area, there is a problem that the recording area of the recording medium cannot be effectively used.

Further, as described above, the SD-DVC standard or DI
According to the GITAL-S standard, only 480 image signals of the image signal of the 525/60 system are recorded and reproduced, but the number of effective scanning lines in the image signal of the 525/60 system is the number of effective scanning lines in each frame according to the SMPTE125M standard. There are a total of 487 lines from the 20th line to the 263rd line and from the 283rd line to the 525th line, and there is a problem that all of these effective scanning lines cannot be recorded and reproduced. Furthermore, there has been a demand for recording and reproducing additional information such as metadata, but this has not been dealt with.

[0016] The present invention has been made in view of such problems, and a digital signal that can effectively use the recording area of a recording medium and can record and reproduce line signals of all effective scanning lines and additional information. It is an object of the present invention to provide a recording / reproducing device.

[0017]

To achieve the above object, the present invention comprises a luminance signal and two color difference signals, wherein the ratio of the number of pixels of the luminance signal and the number of pixels of each of the two color difference signals is m: 1 (m is an integer of 2 or more)
Two signal processing circuits for recording and reproducing the first image signal for a predetermined line are provided in parallel, and the ratio of the number of pixels of the luminance signal to the number of pixels of each of the two color difference signals is m:
In the digital signal recording / reproducing apparatus for recording and reproducing the second image signal of 2 on the recording medium for the line larger than the predetermined line, the luminance signal and the color difference signal of the predetermined line in the second image signal are recorded. A pixel block composed of a predetermined number of pixels is divided, and DCT and AC component data are generated by subjecting the divided luminance signal and color difference signal to DCT in the pixel block unit.
C component data is further subjected to zero run length encoding, and D
The DC component data and the AC component data after the zero run length encoding are stored in a plurality of pairs of storage blocks having a first area for storing C component data and a second area for storing AC component data as a pair. When storing, the DC
For the first storage block storing the component data in the first area, the AC component data after the zero run length encoding is stored in the second area, and the DC component data is stored in the first storage block. For the second storage block that is not stored in the area of E, the E obtained by the zero run length encoding is added to the third area provided in the head portion of the second area.
A compression unit (2) for storing an OB code and a region other than the predetermined line of the second image signal in the first region and the third region in the second storage block output by the compression unit. A line signal inserting section (4) for inserting the line signal, the first storage block output by the compression section, and the second storage block in which the line signal is inserted are recorded and reproduced on a recording medium. Recording / playback section (6, 8)
And extracting the line signal inserted in the second storage block reproduced by the recording / reproducing unit and storing the EOB code in the third area in which the line signal was inserted. Stored in the line signal extraction unit (10) that outputs three storage blocks, the first storage block reproduced by the recording and reproduction unit, and the third storage block output by the line signal extraction unit. By performing zero run length decoding on the AC component data, and performing inverse DCT on the AC component data after the zero run length decoding and the DC component data stored in the first and third storage blocks, A decompression unit (11) for obtaining a luminance signal and a color difference signal of the predetermined line in the second image signal is provided.

[0018] Further, the compression section in the digital signal recording / reproducing apparatus according to the present invention performs re-quantization on the DCT-applied AC component data and then performs the zero run length encoding to obtain the DC component data. The quantization step in the requantization is set so that the AC component data after the zero run length encoding and the AC component data after the zero run length encoding can be stored in the plurality of pairs of storage blocks.

[0019] Further, the digital signal recording / reproducing apparatus according to the present invention is characterized in that the line signal inserting section inserts line signals other than the predetermined line of the second image signal without compression. It is a thing.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to preferred examples. FIG. 1 is a diagram for explaining a digital image signal recording / reproducing apparatus according to an embodiment of the present invention, where 1 is the 23rd to 262nd lines in each frame while counting the number of lines of an incoming line signal. From line 285 to line 52
The line signals for a total of 480 lines up to 4 lines are output to the compression unit 2, while the 3 lines from the 20th line to the 22nd line, the 263rd line, and the 2nd line from the latter half of the 282nd line to the 284th line. .5 line and the fifth
It is a line identification unit that outputs a total of 7.5 line signals of 25 lines to the additional information superimposing unit 3.

[0021] Further, 2 is a line signal output from the line identification unit 1, that is, the number of horizontal pixels in the frame is 720.
The number of pixels is a luminance (Y) signal sampled to have 480 lines in the vertical direction, and the number of pixels in the horizontal direction in the frame is 36.
DIG consisting of DCT, requantization, variable length coding, etc. for a line signal consisting of 0 pixels and color difference (Cr, Cb) signals sampled to 480 lines in the vertical direction
A compression unit 3 for performing compression processing according to the ITAL-S standard, and an additional information superimposing unit 3 which superimposes additional information such as metadata on the line signals for 7.5 lines output from the line identification unit 1 as necessary. It is a department.

[0022] Reference numeral 4 denotes a line data insertion unit that inserts 7.5 line signals output from the additional information superposition unit 3 into a predetermined area of the output data output from the compression unit 2, as described later. Is an error correction code addition unit for adding an error correction code to the output data output by the line data insertion unit 4 and outputting the data.
6 is DI in the output data output by the error correction code addition unit 5.
This is a recording unit that performs GITAL-S standard format processing and records this on the recording medium 7.

[0023] On the other hand, 8 is a reproducing unit for performing a DIGITAL-S standard deformatting process on the reproduced signal reproduced from the recording medium 7 and outputting the same, and 9 is an error correction process for the output data output by the reproducing unit 8. The error correction processing unit 10 to apply extracts 7.5 line signals from the output data output from the error correction processing unit 9 and outputs pixel data of 480 line signals to the decompression unit 11, while This is a line data extraction unit that outputs line signals for five lines to the additional information extraction unit 12.

[0024] Further, 11 is a decompression unit that performs decompression processing of DIGITAL-S standard on the pixel data output from the line data extraction unit 10, and 12 is a line signal for 7.5 lines output from the line data extraction unit 10. An additional information extraction unit that extracts the additional information when the additional information is superimposed on the
Is a line signal output from the decompression unit 11 and the additional information extraction unit 1
2 is a line synthesizing unit for synthesizing and outputting the line signals for 7.5 lines output by 2.

The operation of the digital image signal recording / reproducing apparatus according to the embodiment of the present invention will be described below. First, when an image signal for each frame is input to the line identification unit 1, the line identification unit 1 counts the line number in the image signal, and as described above, the 23rd line to the 262th line in each frame. , Line 285 to line 524
1. A total of 480 line signals up to the line is output to the compression unit 2, while the third line from the 20th line to the 22nd line, the 263rd line, and the second half of the 282nd line to the 284th line. A total of 7.5 line signals of 5 lines and 525th line are output to the additional information superimposing unit 3.

[0026] Here, when the incoming image signal is already in a digital signal form, as described above, the predetermined line signal is distributed to the compression unit 2 and the additional information superimposing unit 3 and output. However, when the incoming image signal has an analog signal form, the luminance (Y) signal and the color difference (C
It goes without saying that an A / D converter for sampling the r, Cb) signal at a ratio of 4: 2: 2 is additionally required.

[0027] The compression unit 2 then adds D to the luminance (Y) signal and color difference (Cr, Cb) signal output from the line identification unit 1.
The compression process of the IGITAL-S standard is performed. This compression processing mainly includes processing such as DCT, requantization, and variable length coding. The variable length coding referred to here is the zero run length coding and the modified 2 coding as described above.
This means a combination with two-dimensional Huffman coding, and only AC components obtained by DCT are subjected to processing such as requantization, zero run length coding, and modified two-dimensional Huffman coding.

[0028] In the DIGITAL-S standard, as described above, five macroblocks shown in Fig. 4B are collected into one video segment, and a quantization step in requantization is set in units of this video segment. The pixel amount of one video segment (five macroblocks) is controlled by controlling the code amount after the variable length coding according to FIG.
Allocate to five basic units shown in (b).

[0029] Here, FIG. 2 illustrates pixel data in pixel block units generated by the compression unit 2, and FIG. 2A illustrates the eight pixel blocks illustrated in FIG. 4B. As described above, A including the DC component and the EOB code from each pixel block
C component, respectively, and pixel data of each of these pixel blocks is converted into four blocks Y0 to Y3 for luminance signals and four blocks Cr0 and Cb0, Cr1 for color difference signals.
And Cb1. And the areas A1, A3, A
These pixel data are also stored in the areas other than the areas E1 to E4 of the respective leading portions of A7 and A9.

In addition to the pixel data of these eight pixel blocks, the compression unit 2 also generates four pieces of pixel data including invalid data and EOB code, as shown in FIG. 2B, and the areas V1 and E1 are generated. , Regions V2 and E2, regions V3 and E
3, and stores in areas V4 and E4, respectively.

Regions D0 to D7 in each block include pixel blocks DCT0 to DCT3 for luminance (Y) signals, pixel blocks DCT4 and DCT5 for color difference (Cr) signals, and pixel blocks DCT6 and DCT7 for color difference (Cb) signals. A DC component and information to be referred to at the time of encoding and decoding are stored, and pixel blocks DCT0 to DCT3 for luminance (Y) signals, pixel blocks DCT4 and DCT5 for color difference (Cr) signals, and color differences are stored in areas A0 to A11. (Cb)
AC in signal pixel blocks DCT6 and DCT7
The component is stored.

On the other hand, the additional information superimposing unit 3 superimposes additional information such as metadata on the 7.5 line signals output from the line identifying unit 1 and outputs the signal. When the additional information is not superimposed, the line signals for 7.5 lines are output to the line data insertion unit 4 as they are.

[0033] For 7.5 line signals, the number of quantization bits per pixel is 8, the number of pixels of a luminance signal per line is 720, and the number of pixels of a color difference (Cr, Cb) signal per line Each has 360, and the number of frames per second is 3
Since it is 0, 2.592 Mbps (= 8 bits x 14)
The data rate is 40 pixels × 7.5 lines × 30 frames).

[0034] The line data insertion unit 4 stores the line signals for 7.5 lines output from the additional information superimposing unit 3 in an empty area in the basic unit output from the compression unit 2, The data capacity of the areas V1 to V4 is 12 bits each (48 bits in total in one basic unit), the number of basic units in one video segment is 5, the number of video segments in one frame is 270, and the number of frames per second is Since it is 30, when only the areas V1 to V4 are used, the recordable data rate is 1.944 Mb.
ps (= 48 bits x 5 units x 270 segments x
30 frames), and it is not possible to store all 7.5 line signals.

Therefore, in the digital signal recording / reproducing apparatus according to the present invention, in addition to the areas V1 to V4, areas A1, A3, A
7, areas E1 to E4 corresponding to the beginning of A9 are set to 7.5
It will be assigned to the line signal for this line. in this case,
Since the data capacity of the areas E1 to E4 is 4 bits each (16 bits in total in one basic unit), the areas V1 to V4
The data rate that can be recorded by using the areas E1 to E4 is 2.592 Mbps (= 64 bits × 5 units ×).
(270 segments × 30 frames), all line signals for 7.5 lines can be stored.

The line data insertion unit 4 analyzes the pixel data in units of basic units output from the compression unit 2, and detects regions V1 to V4 in which invalid data is stored and regions E1 to E4 in which EOB code is stored. To do. Since the invalid data is stored in the areas V1 to V4, which are fixed positions, the invalid data can be easily detected by counting the number of bits from the head of each unit. In addition, regarding the areas E1 to E4 in which the EOB code is stored, each 4 following the areas V1 to V4
Bits are assigned and a fixed logical code such as "0110" is assigned as the EOB code, so that it can be easily detected.

Then, the line data insertion unit 4 detects the areas V1 to V4 and the areas E1 to E4 as described above, and divides the line signal for 7.5 lines into 16-bit units to obtain 64-bit ( = 16 bits x 4) line signals are stored in each basic unit.

[0038] In this way, the pixel data in which the line signal from the additional information superimposing unit 3 is inserted is converted into the line data inserting unit 4
Is output from the DIGI
An error correction code based on the TAL-S standard is added, and the recording unit 6 performs format processing of the DIGITAL-S standard on this and records it on the recording medium 7.

On the other hand, when reproducing from the recording medium 7, the reproducing unit 8
Performs deformat processing of the DIGITAL-S standard on the reproduced signal, and the error correction processing unit 9 performs error correction processing based on the error correction code added at the time of recording. Then, the pixel data that has undergone the error correction processing is output to the line data extraction unit 10. Then, the line data extraction unit 10 analyzes the structure of the basic unit in the pixel data from the error correction processing unit 9, and determines the regions V1 to V4 and the region E.
The line signals for 7.5 lines stored in 1 to E4 are extracted and output to the additional information extraction unit 12.

[0040] For the basic unit from which 7.5 line signals stored in the areas V1 to V4 and the areas E1 to E4 are extracted, the areas E1 to E4 are EOB code "01".
The 4-bit logical code “10” is stored and output to the decompression unit 11. That is, the line data extraction unit 10
EO in the areas E1 to E4 overwritten and erased by the line data insertion unit 4 to store the line signal of 7.5 lines
After the B code is restored, the pixel data for each basic unit is output to the decompression unit 11.

Then, the decompression unit 11 uses the DI in the compression unit 2.
Modified 2D Huffman decoding, zero run length decoding, which is complementary to the compression processing of the GITAL-S standard,
Decompression processing of the DIGITAL-S standard including inverse requantization and inverse DCT is performed, and 480 line signals are output to the line synthesizing unit 13.

[0042] On the other hand, the additional information extraction unit 12 extracts the additional information if it is superimposed on the 7.5 line signals output from the line data extraction unit 10. Then, the line synthesizing unit 13 synthesizes the line signal output from the decompressing unit 11 and the line signal output from the additional information extracting unit 12, and outputs the synthesized line signal for 487.5 lines.

As described above, in the digital image signal recording / reproducing apparatus according to the present invention, the SD-DVC standard signal processing system is used.
When recording and reproducing image signals by using them in parallel,
Areas V1 to V4 and area E1 in the basic unit are used as areas for recording line signals for 7.5 lines exceeding 480 lines.
Since ~ E4 are assigned, it becomes possible to record and reproduce all effective scanning lines. Further, it becomes possible to record and reproduce these 7.5 line signals without being compressed. For example, even when additional information such as metadata is superposed on this line signal, this is restored on the reproducing side. It has become possible.

In the above embodiments, the case of recording and reproducing the image signal of the 525/60 system has been described.
For example, when recording / reproducing an image signal of the 625/50 system, the procedure is as follows.

According to the SD-DVC standard, an image signal of a 625/50 system is sampled at a sampling frequency with a ratio of 4: 2: 0 for a luminance (Y) signal and a color difference (Cr, Cb) signal, and a luminance (Y) signal is sampled. ) Regarding the signal, the number of pixels in the horizontal direction in the frame is 720, and the number of lines in the vertical direction is 57.
The number of color difference (Cr, Cb) signals is 6, and the number of pixels in the horizontal direction is 360 pixels and the number of lines in the vertical direction is 288 in each frame. Here, 4:
2: 0 means that the ratio of the sampling frequency of the luminance (Y) signal and the color difference (Cr, Cb) signal is 4: 2, and only one of the color difference (Cr) signal or the color difference (Cb) signal is used depending on the line. Is sampled.

[0046] On the other hand, in the DIGITAL-S standard, 6
The image signal of the 25/50 system is such that the luminance (Y) signal and the color difference (Cr, Cb) signals are sampled at a sampling frequency with a ratio of 4: 2: 2, and the luminance (Y) signal is horizontal in the frame. The number of pixels in the vertical direction is 720, and the number of lines in the vertical direction is 576. Color difference (Cr, Cb)
Regarding signals, the number of pixels in the horizontal direction is 360 pixels and the number of lines in the vertical direction is 576 in each frame.

[0047] FIG. 3 shows the SD-DVC standard and DIGITAL-
FIG. 3A is a diagram showing a macroblock structure of a luminance (Y) signal and a (Cr, Cb) signal of a 625/50 system formatted by the S standard, and FIG. 3A is an SD-DV.
Macroblock structure in C standard, FIG. 3B shows D
3 shows a macroblock structure in the IGITAL-S standard.

[0048] According to the SD-DVC standard or DIGITAL-S standard, a total of 576 lines from the 23rd line to the 310th line and from the 335th line to the 622nd line in each frame of the image signal of the 625/60 system. The line signal is recorded and reproduced, but the number of effective scanning lines of the image signal of the 625/60 system is ITU BT Rec.
According to the 656 standard, a total of 576 lines from the 23rd line to the 310th line and from the 336th line to the 623nd line in each frame are defined, and the 623rd line cannot be recorded and reproduced.

[0049] However, in the digital signal recording / reproducing apparatus according to the present invention, from the 23rd line to the 310th line in each frame of the image signal of the 625/60 system,
In addition to a total of 576 lines from the 335th line to the 622th line, nine line signals can be recorded / reproduced as follows, so that the ITU BT Rec. It becomes possible to record and reproduce all the effective scanning lines defined by the 656 standard.

As with the case of the 525/60 system, when the image signal of the 625/50 system is recorded and reproduced by the digital signal recording / reproducing apparatus according to the present invention, as shown in FIG.
In the regions D0 to D7 shown in (b), the DC components in the pixel blocks DCT0 to DCT3 of the luminance (Y) signal, the pixel blocks DCT4 and DCT5 of the color difference (Cr) signal, the DC components in the pixel blocks DCT6 and DCT7 of the color difference (Cb) signal, and Information to be referred to at the time of encoding and decoding is stored, and the pixel blocks DC of the luminance (Y) signal are stored in the areas A0 to A11.
T0 to DCT3, color difference (Cr) signal pixel block DC
T4 and DCT5, color difference (Cb) signal pixel block D
The AC component in CT6 and DCT7 is stored. Also, 9.5 line signals are inserted in the areas V1 to V4 and the areas E1 to E4.

[0051] At that time, the line identification unit 1 outputs a total of 576 line signals from the 23rd line to the 310th line and the 335th line to the 622nd line in each frame to the compression unit 2, and the 19th line signal is output. A total of 9 line signals of 4 lines from line 22 to line 4, 4 lines from line 331 to line 334, and line 623 are output to the additional information superimposing unit 3. Then, the additional information superimposing unit 3 superimposes additional information on the nine line signals and outputs the superposed additional information to the line data inserting unit 4.

[0052] Note that the number of quantization signals per pixel is 8, the number of pixels of the luminance signal per line is 720, and the color difference per line (Cr, C
b) Since the number of pixels of the signal is 360 and the number of frames per second is 25, the data rate is 2.592 Mbps (= 8 bits × 1440 pixels × 9 lines × 25 frames).

[0053] On the other hand, the data capacity of the areas V1 to V4 and the areas E1 to E4 is 64 bits per basic unit, the number of basic units in one video segment is 5, the number of video segments in one frame is 324, and 1 second. Since the number of frames per frame is 25, the data rate that can be recorded using the areas V1 to V4 and the areas E1 to E4 is 2.
It becomes 592 Mbps (= 64 bits × 5 units × 324 segments × 25 frames), and all nine line signals can be stored.

As described above, in the digital image signal recording / reproducing apparatus according to the present invention, not only the image signal of the 525/60 system but also the image signal of the 625/50 system, the line signals of all effective scanning lines. It is possible to record / reproduce additional information such as or metadata. Also, 5
The same method can be applied not only to standard definition image signals such as 25/60 systems and 625/50 systems but also to high definition image signals such as 1125/60 systems and 1250/50 systems. it can.

[0055] In this case, a part of the DVC standard, which is a standard for recording image signals of these systems, "HD-D"
By using four signal processing systems based on the "VC standard" in parallel, an image signal of 12: 4: 4 can be converted into an HD-DV image signal with respect to an image signal of 12: 4: 0 in the HD-DVC standard.
It is possible to record at 100 Mbps, which is four times the C standard,
It is possible to record / reproduce additional information such as line signals and metadata of all effective scanning lines.

[0056] As described above, in the digital image signal recording / reproducing apparatus according to the present invention, an image in which the ratio of the number of pixels of the luminance signal and the two color difference signals in the frame is m: 1 (m is an integer of 2 or more). An apparatus for recording / reproducing an image signal in which a ratio of the number of pixels of a luminance signal and two color difference signals is m: 2 by using two signal processing systems for recording / reproducing a signal for a predetermined line in parallel, DC component storage areas V1 to V4 in which invalid data is stored and the following EOB
Line signals other than a predetermined line are stored in areas E1 to E4 in which codes are stored, and areas V1 to V4 are reproduced at the time of reproduction.
Further, since the line signals other than the predetermined line are extracted from the areas E1 to E4 subsequent thereto and the EOB code is stored in the areas E1 to E4, all line signals in the effective scanning line are recorded / reproduced or added. It has become possible to record and reproduce information.

[0057]

According to the invention of claim 1, since the line signals other than the predetermined line are recorded and reproduced by using the first area and the second area in the second storage block, Not only the recording area of the medium can be effectively used, but also all line signals in the effective scanning line can be recorded and reproduced.

[0058] According to the second aspect of the invention, since the quantization step is set in units of a plurality of pairs of storage blocks and the code amount control is performed, in addition to the above effects, the DC component data and the AC component are added. The effect that the data can be efficiently stored in the storage block is achieved.

[0059] According to the third aspect of the invention, since line signals other than the predetermined line are stored in the second storage block without being compressed, in addition to the above effects, the line signal includes metadata and metadata. Even if the additional information such as the character information is superimposed, it is possible to reliably reproduce this.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining a digital signal recording / reproducing apparatus according to the present invention.

FIG. 2 is a diagram for explaining pixel data generated by a compression unit.

FIG. 3 is a diagram showing a macroblock structure in an image signal of a 625/50 system.

FIG. 4 is a diagram showing a macroblock structure in an image signal of a 525/60 system.

FIG. 5 is a diagram showing a basic unit of the SD-DVC standard and the DIGITAL-S standard.

[Explanation of symbols]

1 ... Line identification section 2 ... Compressor 3 ... Additional information superimposing section 4 ... Line data insertion part 5 ... Error correction code addition unit 6 ... Recording section 7 ... Recording medium 8 ... Playback section 9 ... Error correction processing unit 10 ... Line data extraction unit 11 ... Extension part 12 ... Additional information extraction unit 13 ... Line composition section

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5C053 FA03 FA17 FA22 GB05 GB23                       GB26                 5C055 AA01 BA01 DA01 DA02 EA02                       EA04 EA16 FA22 GA07 HA18                 5C057 AA08 BA02 BA03 CC04 EA02                       EA06 EA07 EM09 EM12 EM13                       GF00                 5C059 MA23 MC11 MC32 MC34 MC38                       ME06 ME08 PP04 PP16 RC00                       RC07 RC24 RF04 SS14 TA46                       TB04 TC18 TC38 TD11 UA02

Claims (3)

[Claims] 1. A luminance signal and two color difference signals, wherein the ratio of the number of pixels of the luminance signal to the number of pixels of each of the two color difference signals is m: 1 (where m is an integer of 2 or more). ) Two signal processing circuits for recording and reproducing the first image signal for a predetermined line are provided in parallel, and the ratio of the number of pixels of the luminance signal to the number of pixels of each of the two color difference signals is m: 2. In a digital signal recording / reproducing apparatus for recording and reproducing a second image signal, which is a line larger than the predetermined line, on a recording medium, a luminance signal and a color difference signal of the predetermined line in the second image signal are predetermined. DC component data and A are obtained by dividing each pixel block consisting of several pixels and subjecting the divided luminance signal and color difference signal to DCT in the pixel block unit.
A plurality of pairs having a first area for storing DC component data and a second area for storing AC component data as a pair. When storing the DC component data and the AC component data after the zero run length encoding in the storage block of
For the first storage block stored in the first area, the AC component data after the zero run length encoding is stored in the second area, and the DC component data is not stored in the first area. For the second storage block, the second
In a third area provided in the head portion of the area, the compression unit that stores the EOB code obtained by the zero run length encoding, and the first area in the second storage block that is output by the compression unit And a line signal insertion unit that inserts a line signal other than the predetermined line of the second image signal into the third area, and the first storage block and the line signal output from the compression unit. A recording / reproducing unit for recording and reproducing the reproduced second storage block on a recording medium, and extracting the line signal inserted in the second storage block reproduced by the recording / reproducing unit,
A line signal extraction unit that outputs a third storage block that stores the EOB code in the third area where the line signal was inserted; a first storage block that is reproduced by the recording and reproduction unit; The AC component data stored in the third storage block output from the line signal extraction unit is subjected to zero run length decoding, and the AC component data after zero run length decoding and the first and third Digital signal recording / reproducing, comprising: a decompression unit for obtaining a luminance signal and a color difference signal of the predetermined line in the second image signal by performing inverse DCT on the DC component data stored in the storage block. apparatus. 2. The compression unit requantizes the DCT-processed AC component data, performs the zero run length encoding, and then performs the DC component data and the AC after the zero run length encoding. 2. The digital signal recording / reproducing apparatus according to claim 1, wherein the quantization step in the requantization is set so that the component data and the plurality of pairs of storage blocks fit in the storage blocks. 3. The digital signal recording device according to claim 1, wherein the line signal inserting section inserts line signals other than the predetermined line of the second image signal without compression. Playback device.