JP2000152174A - Image data processor its method and image data recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To process image data with common hardware without making the processing complicated even when a data quantity of non-image data relating to image data varies with an image format. SOLUTION: A stream converter 106 generates image data resulting from discrete cosine transform DCT and variable length coding processing and non- image data such as a header and user data relating to the image data. The image data are variable length data for each macro block and the non-image data are outputted as data corresponding to one macro block. A packing and shuffling section 107 packs the image data and the non-image data. Fixed frames whose number is incremented by one with respect to number of macro blocks for one image are prepared and the non-image data and the image data are respectively packed in each fixed frame. One fixed frame is assigned to the non-image data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image data processing apparatus and method applied to record variable-length non-image data together with variable-length image data, and an image data recording apparatus.

[0002]

2. Description of the Related Art Digital VTR (Video Tape Recorder)
As represented by r), there is known a data recording / reproducing apparatus for recording a digital image signal on a recording medium and reproducing the digital image signal from the recording medium. In a recording processing unit of a digital image recording device, video and audio digital data are stored in packets of a predetermined length, information indicating data contents, an error correction code is encoded in packet units, and packetized data is stored. A sync block and an ID are added to the parity of the error correction code to form a sync block, converted into serial data in sync block units, and recorded on a magnetic tape by a rotating head. The process of packing data into the data area of the sync block on the recording side is called packing, and the process of extracting data from the data area of the sync block on the reproduction side is called depacking. When a product code is used, the product code ECC (E
(rror Correctig Code) Data is packed to the length of one line of the block.

In order to compress the amount of image data,
Compression encoding is performed. For example, MPEG (Moving Pictur
e Experts Group), DCT (Discrete Cosine)
Transform) performs variable-length coding on the coefficient data. When the amount of data that can be recorded per track or a predetermined number of tracks is fixed, as in a helical scan type VTR, the data length is set so that the data amount of the variable-length code generated in a predetermined period is equal to or less than a target value. The amount is controlled. Then, variable-length encoded data is stored in a data area of a plurality of sync blocks prepared for a predetermined period,
That is, unequal length data is packed.

[0004] In MPEG, image data has a six-layer hierarchical structure of a sequence, a GOP (Group Of Picture), a picture, a slice, a macroblock, and a block, and multiplexing processing of each layer is performed. The multiplexing process is defined as a syntax in MPEG, and includes PES (Packetize) in addition to picture data.
dElementary Stream) header, sequence header, GO
Header information such as a P header and a slice header is multiplexed. The header information is necessary for processing such as decoding of picture data. When recording / reproducing an MPEG elementary stream, it is necessary to record / reproduce the header information together with the picture data. As one method of recording / reproducing the header information, it is conceivable to record / reproduce the minimum amount of data necessary for reproduction as fixed length data in the entire header information or in the header information.

[0005]

However, it may be difficult to handle the data amount of the header information as fixed-length data. For one, there are various image data formats, and the data amount of header information varies. For example, there are 18 image formats for digital television broadcasting in the United States. Second, video index data or ancillary data multiplexed on a specific line (closed caption, teletext, time code (VIT
C)) is transmitted as a video elementary stream and inserted into user data in a picture header, the data amount of the user data fluctuates.

As described above, although data is not original image data, its data length is variable (header information, video index, ancillary data, etc., and these are collectively referred to as data other than picture data. In order to record non-image data), it is necessary to allocate a recording area in consideration of each image format to be recorded, and secure a recording area capable of recording the maximum amount of data that can occur. There is a need to.

When there are only one or two types of image formats, the fluctuation range of the data amount is relatively small, and it is not possible to set a recording area of non-image data on a tape corresponding to each image format. Not so difficult. However, if there are many types of image formats, the fluctuation range of the data amount of non-image data becomes large or unpredictable, and it becomes difficult to set a recording area for non-image data. Further, if an area in which the maximum amount of data that can occur can be recorded is set, when the data amount is not large, a useless area not used for recording occurs on the tape, and the recording capacity of the tape cannot be used effectively.

Accordingly, it is an object of the present invention to provide an image data processing apparatus and method, and an image data recording apparatus which can record non-image data of variable length without causing these problems. is there.

[0009]

In order to solve the above-mentioned problems, the invention according to claim 1 comprises a plurality of variable-length image data generated corresponding to a plurality of predetermined ranges of image areas, respectively. Data including non-image data related to the image data is input, the image data and the non-image data are arranged in a plurality of fixed frames, and overflow data protruding from the fixed frame is packed into an empty area generated in another fixed frame. Is an image data processing device.

According to a second aspect of the present invention, in a recording apparatus for recording image data on a recording medium, a plurality of variable-length image data generated corresponding to a plurality of predetermined ranges of image areas, respectively, and the image data are related. A packing unit to which data consisting of non-image data is input, arranging image data and non-image data in a plurality of fixed frames, and packing overflow data protruding from the fixed frames into an empty area generated in another fixed frame; and a packing unit. A processing unit for performing an error correction coding process on the output of the data, a process of adding a synchronization signal for each data packed in the fixed frame, and a recording unit for recording the output of the processing unit on a recording medium. An image data recording apparatus characterized by the following.

According to a ninth aspect of the present invention, there is provided a step of inputting data comprising a plurality of variable-length image data generated respectively corresponding to a plurality of predetermined image areas and non-image data related to the image data. And arranging image data and non-image data in a plurality of fixed frames, and filling overflow data that overflows the fixed frame into a free area generated in another fixed frame. .

The image data consists of unequal length data generated corresponding to a predetermined range, for example, a macroblock. Also,
Information necessary for restoring image data and non-image data such as user data are also generated. Non-image data is treated in the same manner as image data and packed in a fixed frame. By performing the packing process on the non-image data in the same manner as the image data, it is not necessary to set a recording area dedicated to the non-image data on the recording medium. Even if the data amount fluctuates, processing can be performed by common hardware without complicating the processing.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to a digital VT.
An embodiment applied to R will be described. This embodiment is suitable for use in a broadcast station environment,
Recording and recording of video signals of multiple different formats
It enables playback. For example, a signal (480i signal) having 480 effective lines in the interlaced scanning based on the NTSC system and a signal (576 signals) having 576 effective lines in the interlaced scanning based on the PAL system.
i) are recorded with almost no hardware changes.
It is possible to reproduce. Furthermore, a signal having 1080 lines (1080i signal) in interlaced scanning,
In progressive scanning (non-interlace), the number of lines is 480, 720, and 1080, respectively.
Recording / reproduction such as 0p signal, 720p signal, and 1080p signal) can also be performed.

In this embodiment, the video signal is compression-coded based on the MPEG2 system. As is well known, MPEG2 uses motion compensated predictive coding and DCT.
This is a combination of compression encoding by MPE
The data structure of G2 has a hierarchical structure, and includes, from the bottom, a block layer, a macroblock layer, a slice layer, a picture layer, a GOP layer, and a sequence layer.

The block layer is a unit for performing DCT, D
It consists of a CT block. The macroblock layer includes a plurality of D
It is composed of CT blocks. The slice layer is composed of a header section and any number of macroblocks that do not extend between rows. The picture layer includes a header section and a plurality of slices. A picture corresponds to one screen. G
The OP layer includes a header portion, an I picture that is a picture based on intra-frame coding, and P and B pictures that are pictures based on predictive coding.

An I-picture (Intra-coded picture) uses information that is closed only in one picture when it is coded. Therefore, at the time of decoding, decoding can be performed using only the information of the I picture itself. A P-picture (Predictive-coded picture: a forward predictive coded picture) uses a previously decoded I-picture or P-picture which is temporally previous as a predicted picture (a reference picture for taking a difference). . Whether to encode the difference from the motion-compensated predicted image, to encode without taking the difference,
The more efficient one is selected for each macroblock. A B picture (Bidirectionally predictive-coded picture) is a temporally previous I-picture or P-picture which is temporally preceding, and a temporally backward I-picture, We use three types of I-pictures or P-pictures already decoded, as well as interpolated pictures made from both. Among the three types of difference coding after motion compensation and intra coding, the most efficient one is selected for each macroblock.

Therefore, as the macroblock type,
Intra-frame coding (Intra) macroblock, forward (Fward) inter-frame prediction macroblock predicting the future from the past, and backward (Backward) interframe prediction macroblock predicting the future from the future, There is a bidirectional macroblock to be predicted. All macroblocks in an I picture are intra-coded macroblocks. The P picture includes an intra-frame coded macro block and a forward inter-frame predicted macro block. The B picture includes all four types of macroblocks described above.

A GOP contains at least one I picture, and P and B pictures are allowed even if they do not exist. The top sequence layer is composed of a header section and multiple GOPs.
It is composed of

In the MPEG format, a slice is one variable-length code sequence. A variable-length code sequence is a sequence in which a data boundary cannot be detected unless a variable-length code is decoded.

At the head of the sequence layer, GOP layer, picture layer, slice layer, and macroblock layer, an identification code (referred to as a start code) having a predetermined bit pattern arranged in byte units is provided. Be placed. Note that the header section of each layer described above collectively describes a header, extension data, or user data. In the header of the sequence layer, the size of the image (picture) (the number of vertical and horizontal pixels) and the like are described. The time code, the number of pictures constituting the GOP, and the like are described in the header of the GOP layer.

The macro blocks included in the slice layer are:
It is a set of a plurality of DCT blocks, and the encoded sequence of the DCT block is a variable of a sequence of quantized DCT coefficients, with the number of consecutive 0 coefficients (run) and a non-zero sequence (level) immediately after it as one unit. It is a long code. The macroblock and the DCT block in the macroblock are not provided with the identification codes arranged in byte units.

The macro block is composed of one screen (picture).
It is divided into a grid of 6 pixels × 16 lines. A slice is formed by connecting these macroblocks in the horizontal direction, for example. The last macroblock of the previous slice of a continuous slice and the first macroblock of the next slice are continuous, and it is not allowed to form a macroblock overlap between slices. When the size of the screen is determined, the number of macroblocks per screen is uniquely determined.

On the other hand, in order to avoid signal deterioration due to decoding and encoding, it is desirable to edit the encoded data. At this time, the P picture and the B picture require a temporally preceding picture or a preceding and succeeding picture for decoding. Therefore, the editing unit cannot be set to one frame unit. In consideration of this point, in this embodiment, one GOP is made up of one I picture.

A recording area in which, for example, one frame of recording data is recorded is a predetermined area. MPEG2
Since the variable length coding is used, the amount of generated data for one frame is controlled so that data generated during one frame period can be recorded in a predetermined recording area. Further, in this embodiment, one slice is composed of one macroblock so as to be suitable for recording on a magnetic tape, and one macroblock is applied to a fixed frame having a predetermined length. In MPEG, one slice is generally composed of one stripe (16 lines), and variable-length coding starts from the left end of the screen and ends at the right end. Therefore, when the MPEG elementary stream is recorded as it is by the VTR, the portion that can be reproduced is concentrated at the left end of the screen during high-speed reproduction, and cannot be uniformly updated. Further, since the arrangement of the data on the tape cannot be predicted, if the tape pattern is traced at a constant interval, the screen cannot be uniformly updated. Furthermore, if an error occurs even at one location, it affects the right edge of the screen and cannot return until the next slice header is detected. For this purpose, one slice is composed of one macroblock.

FIG. 1 shows an example of the configuration of the recording side of the recording / reproducing apparatus according to this embodiment. At the time of recording, a predetermined interface, for example, SDI (Serial Data Interface)
The digital video signal is input from the terminal 101 via the receiving unit of the above. SDI is an interface defined by SMPTE for transmitting (4: 2: 2) component video signals, digital audio signals, and additional data. An input video signal is converted by a video encoder 102 into a DCT (Discrete Cosine Transform).
form), is converted into coefficient data, and the coefficient data is subjected to variable length coding. The variable length coded (VLC) data from the video encoder 102 is an elementary stream compliant with MPEG2. This output is supplied to one input terminal of the selector 103.

On the other hand, through the input terminal 104, the ANSI
SDTI (Serial Data Transport Inter), which is an interface defined by / SMPTE 305M
face) format data is input. This signal is synchronously detected by SDTI receiving section 105. And
Once stored in the buffer, the elementary stream is extracted. The extracted elementary stream is supplied to the other input terminal of the selector 103.

The elementary stream selected and output by the selector 103 is supplied to a stream converter 106. In the stream converter 106, the MPE
The DCT coefficients arranged for each DCT block based on the G2 rule are replaced with a plurality of DCTs constituting one macroblock.
Through the T block, frequency components are grouped, and the grouped frequency components are rearranged. Further, when one slice of the elementary stream is one stripe, the stream converter 106 converts one slice to one macroblock. Further, the stream converter 10
No. 6 limits the maximum length of variable length data generated in one macroblock to a predetermined length. This reduces the higher order DCT coefficients to 0
Can be done by The rearranged converted elementary stream is stored in the packing and shuffling unit 10.
7 is supplied.

Since the video data of the elementary stream is variable-length coded, the data length of each macroblock is not uniform. In the packing and shuffling unit 107, macro blocks are packed in a fixed frame. At this time, the overflow portion that protrudes from the fixed frame is sequentially packed in an area vacant with respect to the size of the fixed frame. In addition, system data having information such as an image format and a version of a shuffling pattern is supplied from the input terminal 108 to the packing and shuffling unit 107, and the system data is subjected to a recording process similarly to the picture data. System data is video A
Recorded as UX. Also, shuffling is performed in which the macroblocks of one frame generated in the scanning order are rearranged and the recording positions of the macroblocks on the tape are dispersed. Shuffling can improve the image update rate even when data is reproduced in pieces during variable speed reproduction.

Video data and system data from the packing and shuffling unit 107 (hereinafter, also referred to as video data even when system data is included unless otherwise necessary) are supplied to the outer code encoder 109. A product code is used as an error correction code for video data and audio data. The product code encodes an outer code in a vertical direction of a two-dimensional array of video data or audio data, encodes an inner code in a horizontal direction thereof, and encodes data symbols doubly. As the outer code and the inner code, a Reed-Solomon code can be used.

The output of the outer code encoder 109 is supplied to a shuffling unit 110, and shuffling is performed so that the order is changed over a plurality of ECC blocks in sync block units. The shuffling in sync block units prevents errors from concentrating on a specific ECC block. Shuffling performed by the shuffling unit 110 may be referred to as interleaving. The output of the shuffling unit 110 is supplied to the mixing unit 111 and mixed with the audio data. The mixing unit 111 is configured by a main memory, as described later.

Audio data is supplied from an input terminal denoted by reference numeral 112. In this embodiment, an uncompressed digital audio signal is handled. The digital audio signal is supplied to an input SDI receiver (not shown)
These are separated by the DTI receiving unit 105 or input through an audio interface. The input digital audio signal is supplied to A
It is supplied to the UX adding unit 114. The delay unit 113 is for time alignment of the audio signal and the video signal.
The audio AUX supplied from the input terminal 115 is auxiliary data, and is data having information related to audio data such as the sampling frequency of audio data. The audio AUX is added to the audio data by the AUX adding unit 114, and is treated the same as the audio data.

The audio data and AUX from the AUX adding unit 114 (hereinafter, AUX except when necessary)
Is also simply referred to as audio data. ) Is supplied to the outer code encoder 116. Outer code encoder 11
No. 6 encodes an outer code for audio data. The output of the outer code encoder 116 is the shuffling unit 1
17 and undergoes a shuffling process. As audio shuffling, shuffling in sync block units and shuffling in channel units are performed.

The output of the shuffling unit 117 is
1 and the video data and the audio data are converted into data of one channel. The output of the mixing unit 111 is ID
The adding unit 118 is supplied, and the ID adding unit 118 adds an ID including information indicating a sync block number. The output of the ID addition unit 118 is the inner code encoder 119
, And the inner code is encoded. Further, the output of the inner code encoder 119 is supplied to the synchronization adding section 120, and a synchronization signal for each sync block is added. By adding the synchronization signal, recording data in which the sync blocks are continuous is configured. This recording data is supplied to the rotary head 122 via the recording amplifier 121, and is recorded on the magnetic tape 123. In practice, the rotary head 122 is configured such that a plurality of magnetic heads having different azimuths of heads forming adjacent tracks are attached to the rotary drum.

The recording data may be subjected to a scrambling process as required. Further, digital modulation may be performed at the time of recording, and a partial response class 4 and Viterbi code may be used.

FIG. 2 shows an example of the configuration on the reproducing side according to an embodiment of the present invention. Rotating head 1 from magnetic tape 123
The reproduction signal reproduced at 22 is supplied to the synchronization detection unit 132 via the reproduction amplifier 131. Equalization and waveform shaping are performed on the reproduced signal. Further, demodulation of digital modulation, Viterbi decoding, and the like are performed as necessary. The synchronization detection unit 132 detects a synchronization signal added to the head of the sync block. The sync block is cut out by the synchronization detection.

The output of the synchronization detection block 132 is supplied to the inner code encoder 133, where the error of the inner code is corrected. The output of the inner code encoder 133 is the ID interpolation unit 13
The ID of the sync block, which has been supplied to the block No. 4 and made an error by the inner code, for example, a sync block number is interpolated. I
The output of the D interpolation unit 134 is supplied to a separation unit 135, where the video data and the audio data are separated. As described above, video data means DCT coefficient data and system data generated by MPEG intra coding, and audio data is PCM (Pulse Code Modulati
on) means data and AUX.

The video data from the separation unit 135 is subjected to a process reverse to shuffling in a deshuffling unit 136. The deshuffling unit 136 performs a process of restoring the shuffling in sync block units performed by the shuffling unit 110 on the recording side. Deshuffling part 136
Is supplied to the outer code decoder 137, and error correction by the outer code is performed. When an error that cannot be corrected occurs, an error flag indicating the presence or absence of the error is set to indicate the presence of the error.

The output of the outer code decoder 137 is supplied to a deshuffling and depacking unit 138. The deshuffling and depacking unit 138 performs processing for restoring shuffling in macroblock units performed by the packing and shuffling unit 107 on the recording side. In the deshuffling and depacking unit 138,
Disassemble the packing applied during recording. That is, the length of the data is returned in units of macroblocks, and the original variable length code (unequal length data) is restored. Further, in the deshuffling and depacking section 138, the system data is separated and taken out to the output terminal 139.

Deshuffling and depacking unit 13
The output of No. 8 is supplied to the interpolation unit 140, and the data for which the error flag is set (that is, there is an error) is corrected. That is, if it is determined that there is an error in the macroblock data before the conversion, the DCT coefficients of the frequency components after the error location cannot be restored. Therefore, for example, the data at the error location is replaced with a block end code (EOB), and the DCT coefficients of the subsequent frequency components are set to zero. Similarly, at the time of high-speed reproduction, only DCT coefficients up to the length corresponding to the sync block length are restored, and the coefficients thereafter are replaced with zero data. Further, the interpolation unit 1
In 40, when the header added to the head of the video data is an error, the header (sequence header, GOP
Header, picture header, user data, etc.) are also recovered.

Since the DCT coefficients are arranged from the DC component and the low-frequency component to the high-frequency component over the DCT block, even if the DCT coefficients are ignored from a certain position onward, the macro block , DCT coefficients from DC and low-frequency components can be distributed evenly to each of the DCT blocks constituting.

The output of the interpolation section 140 is supplied to the stream converter 141. In the stream converter 141, the reverse process to that of the stream converter 106 on the recording side is performed. That is, the DCT coefficients arranged for each frequency component across the DCT blocks are rearranged for each DCT block. Thereby, the reproduced signal is converted into an elementary stream conforming to MPEG2.

As for the input / output of the stream converter 141, a sufficient transfer rate (bandwidth) is secured in accordance with the maximum length of the macroblock, as in the recording side. If the length of the macroblock (slice) is not limited, it is preferable to secure a bandwidth three times the pixel rate.

The output of the stream converter 141 is supplied to the video decoder 142. Video decoder 142
Decodes the elementary stream and outputs video data. That is, the video decoder 142 performs an inverse quantization process and an inverse DCT process. The decoded video data is taken out to the output terminal 143. For the interface with the outside, for example, SDI is used. In addition, the elementary stream from the stream converter 141 is supplied to the SDTI transmitting unit 144. Although illustration of the path is omitted, the SDTI transmission unit 144 is also supplied with system data, reproduced audio data, and AUX, and
It is converted into a stream having a data structure of the TI format. The stream from the SDTI transmission unit 144 is output to the outside through the output terminal 145.

The audio data separated by the separation unit 135 is supplied to the deshuffling unit 151. The deshuffling unit 151 performs a process opposite to the shuffling performed by the shuffling unit 117 on the recording side. The output of the deshuffling unit 117 is supplied to the outer code decoder 152, and error correction by the outer code is performed. Outer code decoder 152
Output the error-corrected audio data. An error flag is set for data having an uncorrectable error.

The output of the outer code decoder 152 is supplied to an AUX separation section 153, where the audio AUX is separated.
The separated audio AUX is taken out to the output terminal 154. The audio data is supplied to the interpolation unit 155. The interpolating unit 155 interpolates a sample having an error. As the interpolation method, it is possible to use an average value interpolation for interpolating with the average value of correct data before and after in time, a previous value hold for holding a previous correct sample value, and the like. The output of the interpolation unit 155 is supplied to the output unit 156. The output unit 156 performs a mute process for inhibiting the output of an audio signal that is in error and cannot be interpolated, and performs a delay amount adjustment process for time alignment with a video signal. The reproduced audio signal is extracted from the output unit 156 to the output terminal 157.

Although not shown in FIGS. 1 and 2, a timing generator for generating a timing signal synchronized with input data, a system controller (microcomputer) for controlling the overall operation of the recording / reproducing apparatus, and the like are provided. Have been.

In this embodiment, recording of a signal on a magnetic tape is performed by a helical scan method in which an oblique track is formed by a magnetic head provided on a rotating rotary head. A plurality of magnetic heads are provided on the rotating drum at positions facing each other. That is, when the magnetic tape is wound around the rotary head at a winding angle of about 180 °, a plurality of tracks can be simultaneously formed by rotating the rotary head by 180 °. The magnetic heads are formed as a set of two magnetic heads having different azimuths. The plurality of magnetic heads are arranged such that azimuths of adjacent tracks are different from each other.

FIG. 3 shows an example of a track format formed on a magnetic tape by the rotary head described above. This is an example in which video and audio data per frame are recorded on eight tracks. For example, the frame frequency is 29.97 Hz, and the rate is 50 Mbp
s, the number of effective lines is 480, and the number of effective horizontal pixels is 720
A pixel interlace signal (480i signal) and an audio signal are recorded. When the frame frequency is 25H
z, the rate is 50 Mbps, the number of effective lines is 576, and the number of effective horizontal pixels is 720.
6i signal) and audio signal can also be recorded in the same tape format as in FIG.

One segment is composed of two tracks having different azimuths. That is, eight tracks are composed of four segments. Track number corresponding to azimuth for a set of tracks constituting a segment

[0] and a track number [1] are assigned. In the example shown in FIG. 3, track numbers are exchanged between the first eight tracks and the second eight tracks, and different track sequences are assigned to each frame. Thus, even if one of the set of magnetic heads having different azimuths becomes unreadable due to clogging or the like, the influence of an error can be reduced by using the data of the previous frame.

In each of the tracks, a video sector in which video data is recorded is arranged at both ends, and an audio sector in which audio data is recorded is arranged between the video sectors. 3 and FIG. 4, which will be described later, show the arrangement of audio sectors on the tape.

In the track format shown in FIG. 3, eight channels of audio data can be handled. A1 to A8 indicate sectors of channels 1 to 8 of the audio data, respectively. The audio data is recorded with its arrangement changed in segment units. For audio data, audio samples generated in one field period (for example, when the field frequency is 29.97 Hz and the sampling frequency is 48 kHz, 800 or 801 samples) are divided into even-numbered samples and odd-numbered samples. Each sample group and AUX form one ECC block of a product code.

In FIG. 3, since one field of audio data is recorded on four tracks, two ECC blocks per channel of audio data are recorded on four tracks. The data (including the outer code parity) of the two ECC blocks is divided into four sectors.
As shown in (1), the data is recorded separately on four tracks. 2
A plurality of sync blocks included in the ECC blocks are shuffled. For example, two ECC blocks of channel 1 are constituted by four sectors to which reference numbers A1 are assigned.

In this example, video data of 4 ECC blocks is shuffled (interleaved) with respect to one track, and is divided into upper sectors and lower sides for each sector and recorded. In the lower sector video sector, a system area is provided at a predetermined position.

In FIG. 3, SAT1 (Tr) and SAT2 (Tm) are areas where servo lock signals are recorded. In addition, a gap of a predetermined size (Vg1, Sg1, Ag, Sg) is provided between the recording areas.
2, Sg3 and Vg2).

FIG. 3 shows an example in which data per frame is recorded on eight tracks. However, depending on the format of data to be recorded and reproduced, data per frame is recorded in four tracks.
Recording can be performed on tracks, six tracks, and the like.
FIG. 4A shows a format in which one frame has six tracks. In this example, the track sequence is

Only [0] is set.

As shown in FIG. 4B, the data recorded on the tape is composed of a plurality of equally-spaced blocks called sync blocks. FIG. 4C schematically shows a configuration of the sync block. As will be described later in detail, the sync block is composed of a SYNC pattern for detecting synchronization, an ID for identifying each sync block, a DID indicating the content of subsequent data, a data packet, and an inner code parity for error correction. Is done. Data is,
It is treated as a packet in sync block units. That is, the smallest data unit to be recorded or reproduced is one sync block. A number of sync blocks are arranged (FIG. 4B) to form, for example, a video sector (FIG. 4A).

FIG. 5 more specifically shows the data structure of a sync block of video data, which is the minimum unit of recording / reproduction. In this embodiment, one or two macroblocks of data (VLC data) are stored for one sync block according to the format of video data to be recorded, and the size of one sync block is reduced. The length is changed according to the format of the video signal to be handled. As shown in FIG. 5A, one sync block is
From the beginning, a 2-byte SYNC pattern, a 2-byte I
D, a 1-byte DID, for example, a data area variably defined between 112 bytes and 206 bytes, and a 12-byte parity (inner code parity). Note that the data area is also called a payload.

The first two bytes of the SYNC pattern are for synchronization detection and have a predetermined bit pattern. Synchronization detection is performed by detecting a SYNC pattern that matches the unique pattern.

FIG. 6A shows an example of the bit assignment of ID0 and ID1. The ID has important information inherent to the sync block, and each ID has 2 bytes (ID
0 and ID1). ID0 is 1
The identification information (SYNC ID) for identifying each of the sync blocks in the track is stored. SYNC
The ID is, for example, a serial number assigned to a sync block in each sector. The SYNC ID is represented by 8 bits. SYNC IDs are separately assigned to video sync blocks and audio sync blocks.

ID1 stores information on the track of the sync block. When the MSB side is bit 7 and the LSB side is bit 0, with respect to this sync block,
Bit 7 indicates whether the track is above (upper) or below (Lo)
wer), and bits 5 to 2 indicate the segment of the track. Bit 1 indicates the track number corresponding to the azimuth of the track.
Are bits for distinguishing video data and audio data by this sync block.

FIG. 6B shows an example of bit assignment of DID in the case of video. The DID stores information related to the payload. The content of DID differs between video and audio based on the value of bit 0 of ID1 described above. Bits 7 to 4 are undefined (Reserve
d). Bits 3 and 2 are the mode of the payload, for example, indicating the type of the payload.
Bits 3 and 2 are auxiliary. Bit 1 indicates that one or two macroblocks are stored in the payload. Bit 0 indicates whether the video data stored in the payload is an outer code parity.

FIG. 6C shows an example of DID bit assignment in the case of audio. Bits 7-4 are R
Eserved. Bit 3 indicates whether the data stored in the payload is audio data or general data. If compression-encoded audio data is stored in the payload, bit 3 is a value indicating the data.
Bit 2 to bit 0 store information of a 5-field sequence in the NTSC system. That is, NT
In the SC system, the sampling frequency of an audio signal for one field of a video signal is 48 kHz.
Is either 800 samples or 801 samples, and this sequence is aligned every five fields. Bit 2 to bit 0 indicate where in the sequence it is located.

Referring back to FIG. 5, FIGS. 5B to 5E
Shows an example of the above-mentioned payload. 5B and 5C
Shows an example where video data (unequal length data) of 1 and 2 macroblocks is stored for the payload, respectively. In the example shown in FIG. 5B in which one macroblock is stored, a data length indicator LT indicating the length of unequal length data corresponding to the macroblock is arranged in the first three bytes. The data length indicator LT may or may not include its own length. Also,
In the example shown in FIG. 5C in which two macroblocks are stored, the data length indicator LT of the first macroblock is arranged at the beginning, and the first macroblock is arranged subsequently. Then, the data length indicator LT indicating the length of the second macroblock is arranged following the first macroblock, and
Are arranged. The data length indicator LT is information necessary for depacking.

FIG. 5D shows video A for the payload.
An example in which UX (auxiliary) data is stored will be described. The first data length indicator LT describes the length of the video AUX data. Following this data length indicator LT, 5 bytes of system information, 12 bytes of PICT information, and 9 bytes
Two bytes of user information are stored. The remaining portion of the payload length is reserved.

FIG. 5E shows an example in which audio data is stored in the payload. Audio data can be packed over the entire length of the payload. The audio signal is not subjected to compression processing or the like, and is handled in, for example, a PCM format. The present invention is not limited to this, and audio data compressed and encoded by a predetermined method can be handled.

In this embodiment, the length of the payload, which is the data storage area of each sync block, is set optimally for the video sync block and the audio sync block, and is not equal to each other. . In addition, the length of a sync block for recording video data and the length of a sync block for recording audio data are set to optimal lengths according to the signal format. Thereby, a plurality of different signal formats can be handled uniformly.

FIG. 7A shows the order of DCT coefficients in video data output from the DCT circuit of the MPEG encoder. Starting from the DC component at the upper left in the DCT block, in the direction where the horizontal and vertical spatial frequencies increase,
DCT coefficients are output by zigzag scan. As a result, as shown in an example in FIG. 7B, a total of 64 (8
DCT coefficients of (pixel × 8 lines) are obtained by being arranged in the order of frequency components.

This DCT coefficient is equal to the V of the MPEG encoder.
Variable length coding is performed by the LC unit. That is, the first coefficient is fixed as a DC component, and the next component (AC
From the component), codes are assigned corresponding to the run of zero and the subsequent level. Therefore, the variable-length coded output for the coefficient data of the AC component is converted from the low (low-order) coefficient of the frequency component to the high (high-order) coefficient of AC ₁ ,
AC ₂ , AC ₃ ,... The elementary stream includes DCT coefficients subjected to variable length coding.

The stream converter 106 rearranges the DCT coefficients of the supplied signal. That is, in each macroblock, DCT coefficients arranged in order of frequency components for each DCT block by zigzag scan are rearranged in order of frequency components over each DCT block constituting the macroblock.

FIG. 8 shows this stream converter 106.
2 schematically shows the rearrangement of the DCT coefficients in. (4:
2: 2) In the case of a component signal, one macroblock is composed of four DCT blocks (Y ₁ ,
Y _2, and Y ₃ and Y _4), chroma signal Cb, DCT blocks (Cb ₁ of every two according to each of Cr, C
b ₂ , Cr ₁ and Cr ₂ ).

As described above, the video encoder 102
Then, a zigzag scan is performed in accordance with the rules of MPEG2, and as shown in FIG. 8A, for each DCT block,
DCT coefficient is changed from DC component and low frequency component to high frequency component,
The frequency components are arranged in order. When scanning of one DCT block is completed, scanning of the next DCT block is performed, and similarly, DCT coefficients are arranged.

That is, in the macro block, DCT blocks Y ₁ , Y ₂ , Y ₃ and Y ₄ , DCT block C
For each of b ₁ , Cb ₂ , Cr ₁ and Cr ₂ , the DCT coefficients are arranged in order of frequency from the DC component and the low-frequency component to the high-frequency component. Then, [DC, AC ₁ , AC
_2, AC _3, and..], So that codes are assigned, it is variable length coded.

The stream converter 106 decodes the variable-length coded and arranged DCT coefficients once by decoding the variable-length code to detect a break of each coefficient, and extends the frequency over each DCT block constituting the macro block. Summarize by component. This is shown in FIG. 8B. First, the DC components of the eight DCT blocks in the macroblock are summarized, the AC coefficient components of the eight DCT blocks having the lowest frequency components are summarized, and the AC coefficients of the same order are grouped in order. The coefficient data is rearranged across the DCT blocks.

The rearranged coefficient data is DC
(Y ₁ ), DC (Y ₂ ), DC (Y ₃ ), DC
(Y ₄ ), DC (Cb ₁ ), DC (Cb ₂ ), DC (C
r ₁ ), DC (Cr ₂ ), AC ₁ (Y ₁ ), AC ₁ (Y
₂ ), AC ₁ (Y ₃ ), AC ₁ (Y ₄ ), AC ₁ (Cb
₁ ), AC ₁ (Cb ₂ ), AC ₁ (Cr ₁ ), AC
₁ (Cr ₂ ),. Where DC, AC ₁ ,
AC ₂ ,... Are, as described with reference to FIG. 7, each of the variable-length codes assigned to the set consisting of the run and the subsequent level.

The converted elementary stream in which the order of the coefficient data is rearranged by the stream converter 106 is supplied to the packing and shuffling unit 107. The data length of the macroblock is the same for the converted elementary stream and the elementary stream before conversion. In the video encoder 102, even if the length is fixed in GOP (one frame) units by bit rate control, the length varies in macroblock units. The packing and shuffling unit 107 applies the data of the macroblock to the fixed frame.

FIG. 9 schematically shows the processing of packing a macroblock in the packing and shuffling section 107. The macro block is applied to a fixed frame having a predetermined data length and is packed. The data length of the fixed frame used at this time matches the data length of the sync block, which is the minimum unit of data during recording and reproduction. This is to simplify the processing of shuffling and error correction coding. In FIG. 9, for simplicity,
Assume that one frame contains eight macroblocks.

As shown in an example in FIG. 9A, the lengths of eight macroblocks are different from each other due to the variable length coding. In this example, compared to the length of the data area of one sync block, which is a fixed frame, the data of the macro blocks # 1, # 3 and # 6 are each longer,
The data of the macro blocks # 2, # 5, # 7 and # 8 are short. The data of the macro block # 4 has a length substantially equal to one sync block.

By the packing process, macro blocks are packed into a fixed-length frame having a length of one sync block. Data can be packed without excess or shortage because the amount of data generated in one frame period is controlled to a fixed amount. As shown in an example in FIG. 9B, a macroblock longer than one sync block is divided at a position corresponding to the sync block length. Of the divided macroblocks, the part (overflow part) that protrudes from the sync block length is placed in an area that is vacant in order from the top,
That is, it is packed after a macroblock whose length is less than the sync block length.

In the example of FIG. 9B, the macro block # 1
The portion that exceeds the sync block length is first packed after the macro block # 2, and when it reaches the length of the sync block, it is packed after the macro block # 5. Next, the portion of the macro block # 3 that is outside the sync block length is packed behind the macro block # 7. Further, the part of the macro block # 6 that protrudes from the sync block length is packed after the macro block # 7, and the part that protrudes further is packed after the macro block # 8. Thus, each macroblock is packed in a fixed frame of the sync block length.

The length of the unequal-length data corresponding to each macroblock can be checked in advance by the stream converter 106. As a result, the packing unit 107 can know the end of the data of the macro block without decoding the VLC data and checking the contents.

FIG. 10 shows an example of an error correction code used in one embodiment. FIG. 10A shows one ECC block of an error correction code for video data.
B is 1E of an error correction code for audio data.
Indicates a CC block. In FIG. 10A, VLC data is data from the packing and shuffling unit 107. A SYNC pattern, ID, and DID are added to each row of the VLC data, and a parity of an inner code is added to form one SYNC block.

That is, a 10-byte outer code parity is generated from a predetermined number of symbols (bytes) aligned in the vertical direction of the array of VLC data, and the ID, DID, and VLC data (or external data) aligned in the horizontal direction are generated. Parity of the inner code is generated from a predetermined number of symbols (bytes) of the code parity. In the example of FIG. 10A, 10 outer code parity symbols and 12 inner code parity symbols are added. As a specific error correction code, a Reed-Solomon code is used. FIG.
At 0A, the difference between the lengths of VLC data in one SYNC block is 59.94 Hz, 25 Hz, and 23.97.
This is because the frame frequency of video data is different, such as 6 Hz.

As shown in FIG. 10B, the product code for audio data is the same as that for video data.
The parity of the 10-symbol outer code and the parity of the 12-symbol inner code are generated. In the case of audio data, the sampling frequency is, for example, 48 kHz, and one sample is quantized to 24 bits. One sample may be converted to another number of bits, for example, 16 bits. According to the difference in the frame frequency described above, 1SYN
The amount of audio data in the C block is different.
As described above, one field of audio data /
One channel forms two ECC blocks.
One ECC block includes one of even-numbered and odd-numbered audio samples and audio AUX as data.

FIG. 11 shows a more specific configuration of the recording side configuration according to an embodiment of the present invention. In FIG. 11, 16
Reference numeral 4 denotes an interface of the main memory 160 external to the IC. The main memory 160 is an SDRAM
It is composed of With the interface 164,
Arbitrates internal requests for main memory 160,
Write / read processing is performed on the main memory 160. The packing and shuffling unit 107 is constituted by the packing unit 107a, the video shuffling unit 107b, and the packing unit 107c.

FIG. 12 shows an example of the address configuration of the main memory 160. The main memory 160 is, for example, 64
It is composed of an M-bit SDRAM. Main memory 16
0 has a video area 250, an overflow area 251 and an audio area 252. Video area 250
Are four banks (vbank # 0, vbank # 1,
vbank # 2 and vbank # 3). Each of the four banks can store digital video signals of one equal length unit. One equalization unit is a unit for controlling the amount of generated data to a substantially target value, for example, one unit of a video signal.
This is a picture (I picture). Part A in FIG.
Indicates a data portion of one sync block of the video signal. Data of a different number of bytes is inserted into one sync block depending on the format (see FIG. 5A). In order to support a plurality of formats, the data size of one sync block is equal to or more than the maximum number of bytes and is a number of bytes convenient for processing, for example, 256 bytes.

Each bank in the video area is further divided into a packing area 250A and an area 250B for output to the inner encoding encoder. Overflow area 251
Consists of four banks, corresponding to the video area described above. Further, the main memory 160 has an area 252 for audio data processing.

In this embodiment, by referring to the data length indicator LT of each macroblock, the packing unit 107a separates the fixed frame length data and the overflow data that is beyond the fixed frame into separate data in the main memory 160. The data is divided and stored. The fixed frame length data is data shorter than the length of the data area of the sync block, and is hereinafter referred to as block length data. The area for storing the block length data is the packing processing area 250 of each bank.
A. If the data length is shorter than the block length, an empty area is created in the corresponding area of the main memory 160.
The video shuffling unit 107b performs shuffling by controlling the write address. Here, the video shuffling unit 107b shuffles only the block length data, and the overflow portion is written to the area assigned to the overflow data without shuffling.

Next, the packing section 107c performs processing of packing and reading the overflow portion into the memory for the outer code encoder 109. That is, 1 is prepared from the main memory 160 to the outer code encoder 109.
The data of the block length is read into the memory of the ECC block, and if there is an empty area in the data of the block length, an overflow portion is read there to block the data to the block length. When the data for one ECC block is read, the reading process is temporarily suspended, and the outer code encoder 109 generates the parity of the outer code. The outer code parity is the outer code encoder 10
9 is stored in the memory. When the processing of the outer code encoder 109 is completed for one ECC block, the outer code encoder 1
From 09, the data and the outer code parity are rearranged in the order of performing the inner code, and are written back to the packing processing area 250A of the main memory 160 and another output area 250B.
The video shuffling unit 110 performs shuffling on a sync block basis by controlling an address at the time of writing back the data on which the encoding of the outer code has been completed to the main memory 160.

As described above, the block length data and the overflow data are separated and the data is written into the first area 250A of the main memory 160 (first packing process), and the overflow data is packed into the memory of the outer code encoder 109. (The second packing process), the generation of the outer code parity, and the data and the outer code parity in the second area 250 of the main memory 160.
The process of writing back to B is performed in units of one ECC block.
Since the outer code encoder 109 includes the memory having the size of the ECC block, the frequency of access to the main memory 160 can be reduced.

A predetermined number of Es contained in one picture
When the processing of the CC block (for example, 32 ECC blocks) is completed, the packing of one picture and the encoding of the outer code are completed. The data read from the area 250B of the main memory 160 via the interface 164 is processed by the ID addition unit 118, the inner code encoder 119, and the synchronization addition unit 120, and the output data of the synchronization addition unit 120 is output by the parallel / serial conversion unit 124. Is converted to bit serial data. The output serial data is processed by the partial response class 4 precoder 125. This output is digitally modulated as necessary, and supplied to the rotary head via the recording amplifier 121.

It is to be noted that a sync block called null sync, in which valid data is not arranged, is introduced into the ECC block, and the ECC block is used to control the difference in the format of the recording video signal.
The flexibility of the configuration of the C block may be provided. The null sink is generated in the packing unit 107a of the packing and shuffling block 107,
Written to main memory 160. Therefore, since the null sync has a data recording area, it can be used as a recording sync for the overflow portion.

In the case of audio data, even-numbered samples and odd-numbered samples of one-field audio data form separate ECC blocks. Since the ECC outer code sequence is composed of audio samples in the input order, the outer code encoder 116 generates an outer code parity each time an outer code sequence audio sample is input. The address control when writing the output of the outer code encoder 116 to the area 252 of the main memory 160 causes the shuffling unit 117 to perform the shuffling (channel unit and sync block unit).

Further, a CPU interface indicated by 126 is provided, receives data from an external CPU 127 functioning as a system controller, and sets parameters for internal blocks. In order to support a plurality of formats, it is possible to set many parameters including a sync block length and a parity length. Shuffling table data as one of the parameters is stored in a video shuffling table (RAM) 128v and an audio shuffling table (RAM) 128a. The shuffling table 128v performs an address conversion for shuffling the video shuffling units 107b and 110. The shuffling table 128a performs an address conversion for the audio shuffling 117.

As described above, the stream converter 1
From 06, video data (picture data) rearranged so that the same frequency components of the coefficient data (variable length code) in the macroblock are collected is generated. For example, when the stream converter 106 issues a read request to the SDTI receiving unit 105, the stream stored in the buffer of the SDTI receiving unit 105 is read. The packing and shuffling unit 107 may issue this REIT request. The stream converter 106 also generates non-image data such as header information other than the picture data. Non-image data has a header (PE
S header, sequence header, GOP header, picture header) and ancillary data (closed caption, teletext, VITC, etc.) included as user data in the picture header. Non-image data is variable-length data whose data amount varies depending on the image format, the amount of user data, and the like. Moreover, it is difficult to estimate the maximum length of non-image data per frame. Even in the case of a video elementary stream, it is difficult to estimate the maximum length of data per macroblock. The MPEG syntax allows data per macroblock to be larger than the original data. For example, the original image data is small in all the macroblocks in one frame, and most of the image data can be used as user data.

In the present invention, since non-image data is handled in the same manner as picture data, non-image data is also supplied from the stream converter 106 to the packing and shuffling unit 107, and is packed together with the picture data. One fixed frame is allocated to the non-image data, as in the case of the picture data of one macroblock, and a length indicator is added to the head thereof. Therefore, when the amount of data generated in one editing unit, for example, one frame period is controlled to a predetermined value, the data amount including non-image data is controlled to a predetermined value, and 1 is set to the number of all macroblocks in one frame. Picture data and non-image data are packed in the added number of fixed frames. In this embodiment, 1
A GOP is composed of one I picture, and one slice is one
Since the picture data is composed of macroblocks and picture data starts from slice 1, in the following description, non-image data is referred to as slice 0 for convenience, and slices of picture data are collectively referred to as slice X.

Referring to FIGS. 13 and 14, a data interface between stream converter 106 and packing and shuffling unit 107 will be described. FIG. 13 shows the interface of slice X. In synchronization with the sync pulse shown in FIG.
As shown in the figure, the data of slice X (byte serial)
Is transferred. The transfer rate varies depending on the format of the input image data, but is, for example, 50 Mbps, which is the upper limit specified by MPEG. A baseband clock having a frequency equal to this transfer rate is used.

In the case of slice X, the sync pulse is 544
Generated at the clock cycle, and a maximum of 51 out of 544 clocks
Data is transferred in a period of two clocks (512 bytes). In each cycle, one slice of picture data is transferred. As described above, it is difficult to estimate the maximum length of picture data generated in one macroblock. In this embodiment, for example, in the stream converter 106, one byte of the slice X does not exceed 512 bytes. Has restricted. FIG.
As shown in C, from the stream converter 106,
A period corresponding to the length of the slice transferred in each cycle,
A high-level enable signal is generated in synchronization with data.

Packing and shuffling unit 107
The (packing unit 107a) can detect the data length of the slice transferred in each cycle by measuring the high-level period of the enable signal after being reset by the sync pulse as shown in FIG. 13D. . Instead of sending an enable signal, the packing and shuffling unit 107 may count the data received.
Since the stream 6 knows the stream, it is not necessary to analyze the stream again in the packing and shuffling unit 107, so that an enable signal is sent.

FIG. 14 shows that the slice 0 is transferred from the stream converter 106 to the packing and shuffling unit 107.
This is an explanation of the interface for transferring data to. As shown in FIG. 14B, the slice 0 is transferred using a section of a maximum of 512 clocks out of the 544 clocks, similarly to the slice X described above. However, as shown in FIG. 14A, no sync pulse is generated until the transfer of slice 0 is completed, thereby indicating that slice 0 is one slice. As shown in FIG. 14C, in each cycle, an enable signal that goes high in accordance with the data period is also transferred. As shown in FIG. 14D, the packing and shuffling unit 107 (packing unit 107a) can detect the data length of slice 0 by measuring the period of the high level of the enable signal after being reset by the sync pulse. it can.

The slice X has a fixed 3-byte start code (000001) as shown in FIG. 13E.
H (H means hexadecimal) is followed by slice start codes (01) H to (AF) H. On the other hand, in the case of slice 0, as shown in FIG. 14E, after a fixed 3-byte start code,
ce header code (B3) H follows. Therefore, slice 0
In the case of slice 0, the start code is changed to (000000) H in order to identify slice X and slice X.
Alternatively, the start code can be set to (00000
1) As H, then check whether (B3) H or not,
Slice 0 and slice X may be identified.

In summary, in the above-described interface, the interval of the sync pulse of slice X is fixed at 544 clocks, the valid data section is indicated by an enable signal, the maximum length is 512 clocks, and the enable is enabled within the interval of the sync pulse. The signal rises and falls once each. For slice 0, the rise and fall of the enable signal may occur a plurality of times within one sync interval. Further, as indicated by hatching in FIGS. 13B and 14B, in any of the slices 0 and X, the period of valid data is shorter than the interval of the sync pulse, so that a period in which data is not transferred occurs. By providing a period during which this data cannot be transferred for both slice 0 and slice X, the transfer rate of main memory 160, which is required instantaneously, can be reduced, and power consumption can be reduced and internal memory can be eliminated. Become.

The sync pulse is supplied to the stream converter 1
06 are generated from the video elementary stream in the following order.

If (if there is a PES header) one clock before the first 00 of the PES header Else if (if there is a Sequence header) one clock before the first 00 of the Sequence header Else if (if there is a GOP header) GOP One clock before the first 00 of the header The sync pulse is set high one clock before the first 00 of the Else Picture header. After that, slice header
Leave low until (MB data). Therefore, user data
No sync pulse is added to the start code or the like.

Further, as described above, the interface for transferring data will be described in more detail with reference to FIG. FIG. 15A shows a sync pulse, and FIG.
Indicates a video elementary stream from the stream converter 106. In the example of FIG. 15B, the data of slice 0 is intermittently transferred using four sync pulse intervals (544 clocks), and thereafter, the data is sequentially transferred from slice 1.

When the sequence header of slice 0 starts, the content of the data of slice 0 is, for example, as shown in FIG.
It is shown in FIG. Slice 0 is the first data portion,
It consists of a second data part and a third data part. The first data part is sequence header (), sequence extensi
It consists of on () and extension and user data (0). Second
Data part of group of pictures header () and ex
Consists of tension and user data (1). The third data part consists of picture header (), picture coding extension (), and extension and user data (2). In this embodiment, sequence header (), group of
Pictures header () and picture header () are always attached as slice 0. Furthermore, slice X
(Slice 1, slice 2, ...)
This is the data that macro () follows ice (). extens
ion and user data () include video index (coded information inserted in a specific line in the vertical blanking period), video ancillary data, closed caption, teletext, and VITC (vertical blanking period). Time code recorded in a), LTC
(Time code recorded in the longitudinal direction of the tape).

The contents of each data and the multiplexing method are described in MP.
It is specified in EG syntax (ISO / IEC 13818-2). FIG. 16 shows the definition of the start code value. The start code has a unique bit pattern in the video elementary stream. Each start code has a 2-bit predetermined bit string (0
000 0000 0000 0000) followed by a start code value. For example, the slice start code is defined as (01 to AF), and the sequence header code is defined as (B3).

FIG. 17 shows the MPEG syntax (video sequence). The data shown in FIG. 17 and described above, ie, the sequence heade
r (), sequence extension (), extension and user dat
a (), group of pictures header (), picture heade
r () and picture coding extension () are treated as slice 0 (non-image data).

FIG. 18 shows the contents of the Sequence header. For example, the horizontal size value (12 bits) indicates the number of horizontal pixels of the image, and the bit rate value indicates the bit rate. FIG. 19 shows the Group of pictures header
Represents the contents of For example, time code indicates the time from the beginning of the sequence, and closed gop indicates that the images in the GOP can be reproduced independently of other GOPs. FIG.
Shows the contents of Picture header. For example, picture coding t
ype indicates picture type, full pel forward vecto
r indicates whether the accuracy of the motion vector is an integer pixel or a half pixel unit.

In the above-described embodiment, the data width of the interface is 8 bits. However, another bit width may be used. Further, the position and the polarity of the sync pulse data are not limited to those of the embodiment. further,
The present invention can be applied not only to the MPEG2 stream but also to the MPEG1 stream.
In addition to the EG, the present invention can be applied to a video stream in which a header portion exists in the stream. further,
The method for calculating the slice length information is not limited to the method of one embodiment. Still further, the sync pulse is not limited to being generated by the stream converter, but can be generated by analyzing the stream by the packing and shuffling unit.

The present invention is applicable to a case where a recording medium such as an optical tape other than a magnetic tape, an optical disk (a magneto-optical disk, a phase-change disk) or the like is used, and a case where data is transmitted via a transmission line. Can be applied.

[0111]

According to the present invention, even non-image data such as a header is handled in the same manner as variable-length image data, so that even if the data amount of the non-image data varies depending on the image format, processing becomes complicated. Without the need to use common hardware. Further, since there is no need to provide a recording area dedicated to non-image data on a recording medium such as a tape, there is no useless area on the recording medium, and the capacity of the recording medium can be effectively used. Further, by controlling the total data amount of the non-image data and the image data in a predetermined period (for example, one frame) to be equal to or less than a certain value, various data will be included in the future as user data of the non-image data,
It can easily cope with a large amount of data and has excellent scalability.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration on a recording side according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a reproducing side according to an embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating an example of a track format.

FIG. 4 is a schematic diagram illustrating another example of a track format.

FIG. 5 is a schematic diagram illustrating a plurality of examples of a configuration of a sync block.

FIG. 6 shows an ID and a DID added to a sync block.
FIG.

FIG. 7 is a schematic diagram for explaining an output method of a video encoder and variable-length encoding.

FIG. 8 is a schematic diagram for explaining rearrangement of an output order of a video encoder.

FIG. 9 is a schematic diagram for explaining a process of packing data rearranged in order into a sync block.

FIG. 10 is a schematic diagram for explaining an error correction code for video data and audio data.

FIG. 11 is a more specific block diagram of a recording signal processing unit.

FIG. 12 is a schematic diagram illustrating a memory space of a memory to be used.

FIG. 13 is a timing chart for explaining a method of transferring image data.

FIG. 14 is a timing chart for explaining a method of transferring non-image data.

FIG. 15 is a timing chart for explaining a video stream transfer method.

FIG. 16 is a schematic diagram illustrating the definition of a start code value of MPEG syntax.

FIG. 17 is a schematic diagram illustrating MPEG syntax.

FIG. 18 is a schematic diagram illustrating MPEG syntax.

FIG. 19 is a schematic diagram illustrating MPEG syntax.

FIG. 20 is a schematic diagram illustrating MPEG syntax.

[Explanation of symbols]

106: stream converter, 107: packing and shuffling unit, 109, 116: outer code encoder, 110, 117: shuffling unit, 118: ID adding unit, 120: synchronization Additional unit, 160: main memory

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C053 FA20 FA21 GA11 GB15 GB22 GB26 GB30 GB38 JA01 LA01 5C059 MA00 MA23 ME01 PP04 RB02 RB19 RC02 RF04 RF21 SS11 SS30 TA73 TC18 TD11 UA02 UA05

Claims (9)

[Claims] 1. A method comprising the steps of: inputting data including a plurality of variable-length image data generated respectively corresponding to a plurality of predetermined ranges of image areas and non-image data related to the image data; An image data processing apparatus, wherein non-image data is arranged in a plurality of fixed frames, and overflow data that overflows the fixed frame is packed into a free area generated in another fixed frame. 2. A recording apparatus for recording image data on a recording medium, comprising: a plurality of variable-length image data generated respectively corresponding to a plurality of predetermined image areas; and non-image data related to the image data. A packing unit for inputting the data consisting of: A processing unit that performs error correction encoding processing on the output, and adds a synchronization signal to each of the data packed in the fixed frame; and a recording unit that records the output of the processing unit on a recording medium. An image data recording device, characterized in that: 3. The apparatus according to claim 1, wherein a data length indicator indicating a length of each of the image data and the non-image data is inserted into the fixed frame. 4. The image data according to claim 1, wherein the image data is generated for each two-dimensional area obtained by dividing one screen, and a total data amount of the image data and the non-image data generated in one screen is substantially equal to a target. An apparatus for packing the image data into a fixed number of fixed frames whose number is an integral multiple of the number of the two-dimensional areas on one screen, and packing the non-image data into one fixed frame. 5. The apparatus according to claim 1, wherein the image data is generated by performing variable length encoding on encoded data generated by compression encoding. 6. The apparatus according to claim 5, wherein the compression coding is a combination of DCT and variable length coding. 7. The apparatus according to claim 1, wherein the non-image data includes information necessary for restoring the image data. 8. The apparatus according to claim 1, wherein the non-image data includes user data. 9. A step of inputting data including a plurality of variable-length image data generated corresponding to a plurality of predetermined ranges of image areas and non-image data related to the image data, respectively. Arranging the data and the non-image data in a plurality of fixed frames, and packing overflow data that protrudes from the fixed frames into an empty area generated in another fixed frame.