JP2000149455A - Data recorder and recording method, data recording and reproducing device and recording and reproducing method, and data recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable dealing with recording/reproducing of plural formats in which rates are different and to suppress increase of the redundancy, with hardware of a small scale. SOLUTION: Respective lengths of data packet of video data and data packet of audio data is made different and set to optimum for plural formats in which video rates are different. Thereby, a circuit for record processing with respect to plural formats can be used as a circuit for reproduction processing. Also, since audio does not depend on a video rate and a picture frame, a video rate can be adjusted without changing audio signal processing. Further, since two video data packets can be stored in one Sync block, the recording efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data recording apparatus and a recording method applied for recording / reproducing digital video signals and digital audio signals, a data recording / reproducing apparatus and a recording / reproducing method, and a data recording medium.

[0002]

2. Description of the Related Art Digital VTR (Video Tape Recorder)
As represented by r), a data recording / reproducing apparatus which records a digital image signal and a digital audio signal on a recording medium and reproduces the data from the recording medium is known. In a recording processing unit of a digital image recording device, video and audio digital data are stored in packets of a predetermined length, ID information indicating data contents and error correction codes are encoded in packet units, and the packetized data is encoded. , A sync pattern is formed by adding a synchronization pattern and an ID to the parity of the error correction code. The sync blocks are grouped according to the type of data into sectors, and serial data is recorded on a magnetic tape by a rotating head in sector units. Sync blocks within the same sector have the same length, and I
The D numbers are consecutive, and the ID information has the same value. A product code is used as the error correction code. That is, the outer code and the inner code are encoded in the vertical and horizontal directions of the two-dimensional array of data symbols, respectively, and each symbol is double encoded. 1 of encoding / decoding of this product code
The unit is called an ECC block.

On the reproducing side, the head position of each sync block is detected by a synchronization signal, and the packets in the block are rearranged according to the ID number and ID information. Since a unique synchronization pattern is added to the head position of the sync block, the bit sequence of the synchronization pattern, the pattern appearance cycle, and the fact that the ID information is continuous and the ID information is the same in the same sector are used. , The phase of the synchronization block can be specified. That is, when the bit sequence of the synchronization pattern matches the unique pattern, the same pattern is detected at a position delayed by the block length, and the content of the block ID is appropriate, the phase of the synchronization block is specified. In a conventional digital VTR format, the length of a synchronization block is determined to be the same (one type) regardless of the type of data in order to facilitate the synchronization detection process.

[0004] In order to record / reproduce the amount of image data, compression encoding is performed. For example, MPEG (Moving
In the case of Picture Experts Group, DCT (Discrete
Variable length coding of coefficient data generated by Cosine Transform). 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 coded data, that is, variable-length data is packed in data areas of a plurality of sync blocks prepared for a predetermined period.

In the case of digital audio signals, the amount of data is not so large, and in order to avoid quality degradation due to compression, and in the case of MPEG audio, the access unit does not match the video frame and switches between video and audio. For this reason, the processing is complicated, so that uncompressed audio data (linear PCM) is recorded / reproduced.

There are already 18 digital television broadcast formats in the United States. In such a situation, a digital VTR capable of recording / reproducing image data in a plurality of formats is desired. If the sync block length is one type regardless of the type of data as in a conventional digital VTR, synchronization detection is easy, but it becomes difficult to record data in various formats. This will be described below.

An example of a conventional digital VTR will be described. This VTR records video data and audio data on a tape in a tape format as shown in FIG. 22A. As shown in FIG. 22A, data per frame is recorded as six tracks. One segment is composed of two tracks having different azimuths. That is, six tracks are composed of three segments. Track number corresponding to azimuth for a set of tracks constituting a segment

[0] and a track number [1] are assigned. In each of the trucks
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.

In the track format shown in FIG. 22A, four channels of audio data can be handled. A1 to A4 indicate sectors of audio data 1 to 4 ch, respectively. The video data is shuffled (interleaved), and
Each sector is divided into er Side and Lower Side and recorded. In the lower sector video sector, a system area is provided at a predetermined position. In FIG. 22A, SAT1 (Tr) and SAT1 (Tr)
2 (Tm) is an area where a signal for servo lock is recorded. Also, gaps (Vg1, Sg1, Ag, Sg2, Sg3, and Vg2) of a predetermined size are provided between the recording areas.

As shown in FIG. 22B, the data recorded on the tape is composed of a plurality of equally-spaced blocks called sync blocks. FIG. 22C schematically shows a configuration of a sync block. The sync block includes a SYNC pattern for synchronous detection, 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. Data is recorded and reproduced in sync block units. A number of sync blocks are arranged to form, for example, a video sector.

[0010] The configuration of the sync block includes a synchronization signal and an ID.
Sync block: sync pattern + sync
Designated as id + data packet + inner parity, and design condition: Make the data packet length of video and audio the same. Next, the following is considered as an example of video data recording processing.

[0011] Video data (4: 2: 2) Design condition: Data amount after compression is 1/2 or more before compression Packing of 10 DCT blocks into 2 sync blocks 6 tracks per field [525 lines / 60 fields] video In case of signal Video data amount per field 512 × 720 × (8 + 4 + 4) bits / 8/2 = 368640 bytes Number of DCT blocks per field 512 × 720/8/8 = 5760 10 blocks / 2 sync → 1152 Sync block Data packet length> 368640 × (1/2) / 1152 = 160 (1) For a video signal of [625 lines / 60 fields] Video data amount per field 608 × 720 × (8 + 4 + 4) bits / 8/2 = 437760 bytes Number of DCT blocks per field 608 x 720/8/8 = 6840 10 blocks / 2 syncs → 1368 sync blocks Data packet length> 437760 x (1/2 ) / 13 68 = 160 (2) An example of the audio data recording process is shown below.

Audio data (24-bit 48 kHz sampling) Design condition: Uncompressed AUX data has 6 bytes per field [525/60]. The number of samples per field 48 k / 59.94 Hz × 24 bits / 8 = 2402.4 Byte (5 field sequence) AUX data is 12 bytes → 2415 bytes (total data amount) Number of samples per field when [625/50] is 48k / 50Hz × 24 bits / 8 = 2880 bytes AUX data is 12 bytes → 2892 bytes (total data amount).

In order to determine the optimum sync block length for audio data, the data packet length (16
2, 163) and the number of sync blocks, In a relationship.

Here, the video compression rate is defined as the ratio between the amount of data after video compression and the amount of original data.
Consider selecting a data packet length such that the video compression rate is more than 1/2. The data packet length at which the extra recording area is minimized in both [525] / [625] as audio is 161. Since the audio sample is a unit of 24 bits (3 bytes), the data packet length is 3 bytes. Must be a multiple.
Therefore, 162 is selected as the data packet length. After all, the format of the digital VTR has the following data amount.

[525/60] Video 162 × 1152 = 186624 bytes Audio 162 × 15 = 2430 bytes [625/50] Video 162 × 1368 = 221616 bytes Audio 162 × 18 = 2916 bytes.

[0016] Then, to video and audio data,
Attach outer code (Outer) parity data for error correction. The parity number of the outer code is 10 for data in video.
% And 100% for audio (that is, the number of audio symbols is equal to the number of parity). Further, since the circuit scale greatly depends on the number of parities, the upper limit of the number of parities is set to 14. Further, since the number of tracks per field is 6, the sum of the number of data blocks and the number of outer code parities must be divisible by 6. In the case of video data, two ECC blocks are formed on one track.

In the case of [525/60] video, 1152 = (96 × 2) × 6 → number of parities of outer code 10, 2 ECC blocks per track Number of data blocks per track + number of parity blocks of outer code = (96 +10) × 2 = 212 [625/50] Video 1368 = (114 × 2) × 6 → Number of outer code parity 12, 2 ECC blocks per track Number of data blocks per track + Number of outer code parity blocks = (114 +10) × 2 = 248.

Audio data is EC in one field.
15 = (5 × 3) → number of parities of outer code 5, 3 ECC blocks per field ECC block Number of data blocks per track + number of outer code parity blocks = (15 + 15) / 6 = 5 Number of unnecessary recording area bytes per CH 21 bytes /
In the case of the audio of the field [625/50] 18 = (9 × 2) → number of parities of outer code 9, 2 ECC blocks per field Number of data blocks per track + number of outer code parity blocks = (18 + 18) / 6 = 6 Number of unnecessary recording area bytes per CH 30 bytes
/ Field relationship.

An ID (2 bytes), a block synchronization signal (sync pattern) (2 bytes) and an inner code (Inner) parity (14 bytes) are added to these data packets.
A sync block (180 bytes) to be finally recorded is configured. The video and audio data composed in sync block units as described above is recorded on the tape. On the decoder side, the head of the sync block is detected from the synchronization signal (synchronization detection).
The video and audio signals are separated using the identification flags of the video and audio data recorded in the video and audio data, and the video and audio signals are separately decoded after the outer code error correction.

The reason why the video and audio sync blocks have the same length is to facilitate synchronization detection. FIGS. 23A and 23B show an ECC block configuration of a conventional digital VTR, and FIG. 23C shows a sync block configuration. FIG. 23A shows the configuration of a video ECC block, and FIG. 23B shows the configuration of an audio ECC block. As shown in FIG. 23C, the sync block length is equal between video and audio, and
It is 0 bytes. Video ECC block (FIG. 23)
A) In [625/50] and [525/60], 12 blocks / 1 field, 4 heads, 6 tracks / 1 field. In the audio ECC block (FIG. 23B), in [625/50],
2 blocks / 1 field, 4 heads, 6 tracks / 1
In [525/60], 3 blocks / 1 field, 4 heads, 6 tracks / 1 field.

FIGS. 24 and 25 show the relationship between audio ECC blocks and audio samples. FIG. 24 shows a sample arrangement when the field frequency is 50 Hz, and FIG. 25 shows a sample arrangement when the field frequency is 59.94 Hz. 24 and 25, the number of each audio sample indicates the order of the audio samples from the beginning of the field, and AUX is system data indicating the content of the audio data. [525
/ 60] (FIG. 24) and [625/50] (FIG. 25) are different from each other in the arrangement of the samples and the configuration of the ECC block. is there.

[0022]

Next, a multi-rate format will be considered. For example, a conventional VTR
Considering a format that reduces the video rate of the format of 1/3 to 1/3, 1 in formulas (1) and (2)
If / 2 is replaced by 1/3, the data packet length is 10
It becomes 7. On the other hand, if the length of the audio data packet is selected to be the same as the length of the video data packet, the data packet length must be a multiple of the audio sample (3 bytes).

On the other hand, the data amount per audio field is 2415 bytes in [525/60] and [6
[25/50] is the same as 2892 bytes, so [5
25/60], 108 × 23 = 2484 bytes,
In [625/50], it becomes 108 × 27 = 2916 bytes.

An example of the combination of the data packet length (108 bytes) and the number of sync blocks (the total data amount is the product of both) is 22 23 24 25 26 27 28 108: 2376 2484 2592 2700 2808 2916 3024.

Further, consider the ECC block configuration. In the case of video data, two ECC blocks are formed in one track. In the case of [525/60] video, 1152 = (96 × 3) × 4 → the number of parities of the outer code is 10, and 3 is stored in one track. ECC block Number of data blocks per track + number of outer code parity blocks = (96 + 10) x 3 = 318 [625/50] For video 1368 = (114 x 3) x 4 → number of parity of outer code 12, One track has 3 ECC blocks. The number of data blocks per track + the number of outer code parity blocks = (114 + 12) × 3 = 378.

It is assumed that one field of audio constitutes an ECC block. Here, since the number of tracks per field of this format is set to 4, in the case of [525/60] audio, 23 = 23 × 1 → the number of parities of the outer code 23, 1 ECC block per field, data per track Number of blocks + number of outer code parity blocks = (23 + 23) / 4 = 11.5 In the case of [625/50] audio 27 = (9 × 3) → number of parity of outer code 9 in 1 field
3 ECC block The number of data blocks per track + the number of outer code parity blocks = (27 + 27) /4=13.5.

In this case, the number of parities of the outer code is too large in NTSC. In both cases, since the number of blocks per track is not an integer, an ECC block cannot be formed. Therefore, in [525/60], 108 × 24
= 2592 bytes, [625/50], 108 x 28 = 30
24 bytes. Then, in the case of [525/60] audio, 24 = (8 × 3) → the number of parities of the outer code is 8, 1 field
3 ECC block Number of data blocks per track + number of outer code parity blocks = (24 + 24) / 4 = 12 Number of unnecessary recording area bytes per CH 183 bytes
/ Field [625/50] audio 28 = (7 × 4) → number of parities of outer code 7, one field
4 ECC block Number of data blocks per track + number of outer code parity blocks = (28 + 28) / 4 = 14 Number of unnecessary recording area bytes per CH 136 bytes
/ Field.

In this example, in the case of [525/60], 1
183 bytes x 4 ch per field (0.35
(Equivalent to M bps).
Recording efficiency deteriorates. Further, this useless area increases in proportion to the number of audio channels.

As described above, the video rate is increased from 1/2.
FIG. 26A shows the configuration of the video ECC block when the ratio is changed to 1/3, and FIG.
FIG. 26C shows the configuration of a sync block having the same length for video and audio as shown in FIG. The video ECC blocks (FIG. 26A) are [625/50] and [525 /
60], 18 blocks / 1 field, 4 heads, 4 tracks / 1 field. In the audio ECC block (FIG. 26B), [625/50]
In [525/60], there are 3 blocks / 1 field, 4 heads, 4 tracks / 1 field.

FIG. 27 shows the relationship between audio ECC blocks and audio samples. FIG.
This shows a sample arrangement for a field frequency of 50 Hz.
As can be seen from FIG. 27, the original format (FIG. 2)
4 and FIG. 25). In a multi-rate VTR,
Since the original format must also be able to be recorded and reproduced, all of these different arrangements must be processed. Therefore, in all formats having different video data rates and frame frequencies, individually corresponding signal processing circuits are required, and the circuit scale is increased (I
C cost increase).

Actually, as shown in FIG. 28, the video data rate (25 Mbps) is used as the video format.
~ 600M bps), video scan mode (interlaced, progressive), frame frequency (59.94, 50,
Fourteen types of formats are assumed by combinations of modes such as 29.97, 25, and 23.976 Hz. In FIG. 28,
The picture frame in the NTSC area is 720 × 480, and the picture frame in the PAL area is 720 × 576. In the video scan mode, interlace is described as i, and progressive is described as p.

It is necessary to determine the length of the sync block for all the formats shown in FIG. The length of the sync block depends on the frame frequency, the amount of video data,
Since it is closely related to the amount of audio data,
If the lengths of the video and audio sync blocks are to be the same, it is very difficult to select an optimal and common sync block length (data packet length) for each. Further, the configuration of the audio greatly depends on the video rate, and it is necessary to form a circuit corresponding to each of them. Also, considering signal processing in multi-rate format encoders and decoders,
If the processing in each format becomes completely different, the circuit scale becomes enormous and there is a problem that the cost of the IC increases.

Further, in the conventional digital VTR, 1
It is common to store data, for example, one packet of variable length data in a sync block. Therefore, in the case of the Macchi format, when the video rate is reduced, the length of one packet is reduced. Since the data lengths of the sync pattern, ID, and the like added to the sync block are set to predetermined lengths, the specific gravity other than the data packet in one sync block becomes large. That is, there is a problem that the redundancy is increased.

Accordingly, an object of the present invention is to provide a data recording apparatus, a recording method, and a data recording method capable of recording, recording and reproducing video and audio data in a plurality of formats by making the sync block length different between video and audio. An object of the present invention is to provide a recording / reproducing apparatus, a recording / reproducing method, and a data recording medium.

Another object of the present invention is to provide a data recording apparatus and a recording method capable of recording a plurality of data having different data rates without increasing redundancy.
An object of the present invention is to provide a data recording / reproducing device, a recording / reproducing method, and a data recording medium.

[0036]

In order to solve the above-mentioned problems, the invention according to claim 1 records image data and audio data on a recording medium, and a plurality of image data rates to be recorded exist. In a data recording device having a plurality of data amounts of audio data in edit units,
A first error correction unit that divides the image data into first data packets, forms a first error correction code block by the plurality of first data packets, and performs error correction coding in units of the first error correction code block; Correction encoding means,
Dividing the audio data into second data packets, forming a second error correction code block by the plurality of second data packets, and performing a second error correction coding in units of the second error correction code blocks Correction encoding means, means for adding a synchronization signal to each of the first and second data packets to form first and second sync blocks, and data comprising the first and second sync blocks. An image data recording apparatus, comprising: recording means for recording on a recording medium, wherein the first and second sync blocks have different lengths.

According to a twelfth aspect of the present invention, there is provided a data recording apparatus in which image data and audio data are recorded on a recording medium, wherein a plurality of rates of image data to be recorded exist, and a plurality of data amounts of audio data in edit units exist. In the recording method, image data is divided into first data packets, a first error correction code block is formed by a plurality of first data packets, and error correction coding is performed in units of the first error correction code blocks. A first error correction encoding step; dividing the audio data into second data packets; forming a second error correction code block by a plurality of second data packets; A second error correction coding step of performing error correction coding in the first and second data packets. Each adds a synchronizing signal, forming a first and second sync blocks, the first
And a recording step of recording data comprising the second sync block on a recording medium.
Are different in the length of the sync block.

According to a second aspect of the present invention, there is provided a data recording apparatus for recording image data and audio data on a recording medium, wherein there are a plurality of rates of image data to be recorded, and a plurality of data amounts of audio data in edit units. , The image data is divided into first data packets, a first error correction code block is configured by the plurality of first data packets, and error correction coding is performed in units of first error correction code blocks. Error correction encoding means, and divides audio data into second data packets, forms a second error correction code block by a plurality of second data packets, and performs error correction in units of second error correction code blocks. A second error correction coding means for coding, and a synchronization signal for each of the first and second data packets. In addition, it comprises means for forming first and second sync blocks, and recording means for recording data comprising the first and second sync blocks on a recording medium. An image data recording apparatus for storing an integer of 1 or more first data packets in accordance with a data rate of image data.

According to a thirteenth aspect of the present invention, there is provided a data recording method for recording image data and audio data on a recording medium, wherein a plurality of rates of image data to be recorded exist, and a plurality of data amounts of audio data in units of editing exist. , Image data is divided into first data packets, a first error correction code block is formed by a plurality of first data packets, and error correction coding is performed in units of first error correction code blocks. (C) dividing the audio data into second data packets, forming a second error correction code block by a plurality of second data packets, and performing error correction in units of second error correction code blocks. A second error correction coding step for performing correction coding, and a step for the first and second data packets. And a recording step of recording data comprising the first and second sync blocks on a recording medium, wherein the first and second sync blocks are recorded on a recording medium. A data recording method characterized by storing an integer of 1 or more first data packets in a sync block according to a data rate of image data.

According to a third aspect of the present invention, image data and audio data are recorded on a recording medium, and the image and audio data are reproduced from the recording medium. In a data recording / reproducing apparatus having a plurality of data amounts of audio data, image data is divided into first data packets, and a first error correction code block is formed by the plurality of first data packets. A first error correction coding unit for performing error correction coding in units of correction code blocks, and a second error correction code block composed of a plurality of second data packets by dividing audio data into second data packets A second error correction encoding unit for performing error correction encoding in units of a second error correction code block; Means for adding a synchronizing signal to each of the first and second data packets to form first and second sync blocks, and recording means for recording data comprising the first and second sync blocks on a recording medium A reproducing means for reproducing data comprising the first and second sync blocks from the recording medium; decoding the error correction code for the reproduced data in units of a first error correction code block; The first error correction decoding means that occurs and the error correction code are decoded for the reproduced data in units of second error correction code blocks.
An image data recording / reproducing apparatus comprising second error correction decoding means for generating reproduced audio data, wherein the first and second sync blocks have different lengths.

According to a fourteenth aspect of the present invention, image data and audio data are recorded on a recording medium, image and audio data are reproduced from the recording medium, and there are a plurality of image data rates to be recorded and reproduced. In a data recording / reproducing method in which a plurality of data amounts of audio data exist, image data is divided into first data packets, and a first error correction code block is formed by the plurality of first data packets. A first error correction coding step of performing error correction coding in units of correction code blocks, and dividing audio data into second data packets, and forming a second error correction code block by a plurality of second data packets. A second error correction coding unit configured to perform error correction coding in units of a second error correction code block A method, respectively a synchronization signal to the first and second data packets is added, forming a first and second sync blocks, the first
A recording step of recording the data composed of the first and second sync blocks from the recording medium, a recording step of recording the data composed of the first and second sync blocks from the recording medium, A first error correction decoding step of decoding the error correction code in units of error correction code blocks to generate reproduced image data; and applying an error correction code to the reproduced data in units of second error correction code blocks. A second error correction decoding step of performing decoding and generating reproduction audio data, wherein the lengths of the first and second sync blocks are different from each other. is there.

According to a fourth aspect of the present invention, image data and audio data are recorded on a recording medium, image and audio data are reproduced from the recording medium, and a plurality of image data rates to be recorded and reproduced exist. In a data recording / reproducing apparatus having a plurality of data amounts of audio data, image data is divided into first data packets, and a first error correction code block is formed by the plurality of first data packets. A first error correction coding unit for performing error correction coding in units of correction code blocks, and a second error correction code block composed of a plurality of second data packets by dividing audio data into second data packets A second error correction encoding means for performing error correction encoding in units of a second error correction code block; Means for adding a synchronizing signal to each of the first and second data packets to form first and second sync blocks, and recording means for recording data comprising the first and second sync blocks on a recording medium A reproducing means for reproducing data comprising the first and second sync blocks from the recording medium; decoding the error correction code for the reproduced data in units of a first error correction code block; The first error correction decoding means that occurs and the error correction code are decoded for the reproduced data in units of second error correction code blocks.
And a second error correction decoding means for generating reproduced audio data, wherein one or more first sync blocks have an integer equal to or greater than one in accordance with the data rate of the image data.
An image data recording / reproducing apparatus characterized by storing data packets of

According to a fifteenth aspect of the present invention, image data and audio data are recorded on a recording medium, image and audio data are reproduced from the recording medium, and there are a plurality of image data rates to be recorded and reproduced. In a data recording / reproducing method having a plurality of data amounts of audio data, image data is divided into first data packets, a first error correction code block is formed by the plurality of first data packets, and a first error correction code block is formed. A first error correction coding step of performing error correction coding in units of correction code blocks, and dividing audio data into second data packets, and forming a second error correction code block by a plurality of second data packets. A second error correction coding unit configured to perform error correction coding in units of a second error correction code block A method, respectively a synchronization signal to the first and second data packets is added, forming a first and second sync blocks, the first
A recording step of recording the data composed of the first and second sync blocks from the recording medium, a recording step of recording the data composed of the first and second sync blocks from the recording medium, A first error correction decoding step of decoding the error correction code in units of error correction code blocks to generate reproduced image data; and applying an error correction code to the reproduced data in units of second error correction code blocks. A second error correction decoding step of performing decoding and generating reproduced audio data. In one first sync block, one or more integer number of first data in accordance with the data rate of image data. A data recording / reproducing method characterized by storing a packet.

According to a fifth aspect of the present invention, the image data and the audio data are recorded, the rate of the recorded image data is one of a plurality of types, and the data amount of the recorded audio data in edit units. Is a data recording medium that is one of a plurality of types, in which an image data recording area and an audio data recording area are provided, and in the image data recording area, data including a first sync block is recorded; In the data recording medium, data comprising a second sync block is recorded in the audio data recording area, and the first and second sync blocks have different lengths.

According to a sixth aspect of the present invention, the image data and the audio data are recorded, the rate of the recorded image data is one of a plurality of types, and the data amount of the recorded audio data in edit units. Is a data recording medium that is one of a plurality of types, in which an image data recording area and an audio data recording area are provided, and in the image data recording area, data including a first sync block is recorded; Data composed of second sync blocks is recorded in the audio data recording area, and one or more integer data packets of one or more are stored in one first sync block according to the data rate of image data. It is a data recording medium characterized by being performed.

In the present invention, the sync block length of video data is different from the sync block length of audio data. Therefore, an optimum sync block length can be set according to each data. Therefore, data in many formats can be recorded / reproduced, and processing in each format can be shared, and the circuit scale can be reduced. Further, by storing a plurality of video data packets in one sync block, the present invention can avoid the problem of increasing redundancy when supporting multi-formats having different video rates.

[0047]

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 of video signals of a plurality of different formats /
It enables playback. For example, it is possible to record / reproduce data in the format described above and shown in FIG.

In this embodiment, the video signal can be recorded / reproduced both in a compressed state and in a non-compressed state. As the compression method, for example, the MPEG2 method is adopted. 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 includes a header section and one or more macro blocks. The picture layer includes a header section and one or more slices. A picture corresponds to one screen. The GOP layer is composed of a header section, I pictures that are pictures 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 includes 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.

For example, a recording area in which recording data for one frame 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 usually 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, V
When the MPEG elementary stream is recorded as it is by the TR, at the time of high-speed reproduction, the reproducible portion is concentrated on the left end of the screen 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 SDTI
(Serial Data Transport Interface) format data is input. This signal is transmitted to the SDTI receiving unit 10
In step 5, synchronization is detected. Then, the elementary stream is temporarily stored in the buffer, and the elementary stream is extracted. The extracted elementary stream is supplied to the other input terminal of the selector 103.

In one embodiment, in order to transmit, for example, an MPEG ES, an SDTI (Serial Data Transport Interface) is used.
rface) -CP (Content Package) is used. This ES is a 4: 2: 2 component, is a stream of all I pictures, and has a relationship of 1 GOP = 1 picture. In the SDTI-CP format, MPEG ES is separated into access units, and is packed into packets in frame units.
In the SDTI-CP, a sufficient transmission band (27 MHz or 36 MHz at a clock rate and 270 Mbps or 360 Mbps at a stream bit rate) is used.
It is possible to send an ES in bursts during the frame period. That is, EA starts after SAV of one frame period.
Up to V, system data, video stream, audio stream, and AUX data are arranged. There is no data in the entire one frame period, but data exists in a burst form for a predetermined period from the beginning. SDTI-CP streams (video and audio) can be switched in stream states at frame boundaries. SDTI-CP uses SMP as a clock reference.
In the case of the content using the TE time code, a mechanism for establishing synchronization between audio and video is provided. Further, the format is determined so that SDTI-CP and SDI can coexist.

The interface using the SDTI-CP described above does not require the encoder and decoder to pass through a VBV (Video Buffer Verifier) buffer and TBs (Transport Buffers) as in the case of transferring TS, and can reduce delay. . Also, SDTI-CP
The fact that it is capable of extremely high-speed transfer itself further reduces the delay. Therefore, it is effective to use SDTI-CP in an environment where synchronization exists for managing the entire broadcasting station.

The elementary stream selected and output by the selector 103 is supplied to the 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.

The 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 required) 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 unless otherwise required)
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 scramble processing may be performed on the recording data as needed. 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 the 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 outer code decoder 137 is supplied to deshuffling and depacking section 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 is restored. Further, in the deshuffling and depacking unit 138, the system data is separated,
It is 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 point onward, the macro block , DCT coefficients from DC and low-frequency components can be distributed evenly to each of the DCT blocks that constitute.

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.

Further, for the input and output of the stream converter 141, a sufficient transfer rate (bandwidth) is ensured 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 outer code decoder 152 is supplied to AUX separation section 153, and 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 entire operation of the recording / reproducing apparatus, and the like are provided. Have been.

FIG. 3A 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. 3B, 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.

In the stream converter 106, the DCT coefficients of the supplied signal are rearranged. 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. 4 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. 4A, 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.

In the stream converter 106, the variable-length coded and arranged DCT coefficients are once decoded by decoding the variable-length code to detect a break of each coefficient, and the frequency is spread over each DCT block constituting the macro block. Summarize by component. This is shown in FIG. 4B. 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.

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. 5 schematically shows a packing process of macroblocks in 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. 5, for simplicity,
Assume that one frame contains eight macroblocks.

As shown in an example in FIG. 5A, the lengths of the 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. 5B, 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. 5B, 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 variable-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. 6 shows a more specific configuration of the recording side according to the embodiment of the present invention. In FIG. 6, reference numeral 164 denotes an interface of the main memory 160 external to the IC. The main memory 160 is composed of an SDRAM. The interface 164 arbitrates an internal request for the main memory 160, and performs write / read processing on the main memory 160.
The packing unit 107a, the video shuffling unit 1
07b and the packing unit 107c constitute a packing and shuffling unit 107.

FIG. 7 shows an example of the address configuration of the main memory 160. The main memory 160 is, for example, 64M
It is composed of a bit SDRAM. Main memory 160
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.
5 shows a data portion of one sync block of a video signal. 1
Data of a different number of bytes is inserted into the sync block depending on the format. 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 output area 250B 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 unit 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 divided and the data is written to the first area 250A of the main memory 160 (first packing process), and the overflow data is packed in the memory to the outer code encoder 109. (The second packing process), generation of the outer code parity, and data and 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 included 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 provided with an ECC block for the difference in recording video signal format.
The configuration of the C block is made flexible.
The null sink is generated in the packing unit 107a of the packing and shuffling block 107, and written into the 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 different 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 picture data. Non-image data includes headers (PES header, sequence header, GOP header, and picture header) defined by the MPEG syntax, and ancillary data (Ancill data) included as user data in the picture header.
ary Data: closed caption, teletext, V
ITC etc.). 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. MPE
The G syntax allows more data per macroblock than the original data. For example, 1
Of all the macroblocks of the frame, the original image data is small, and most of it can be user data.

In one embodiment, non-image data is treated as equivalent to picture data.
Also supplies non-image data to the packing and shuffling unit 107, and packs them together with 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,
One GOP is composed of one I picture, one slice is composed of one macroblock, and picture data starts from slice 1. For convenience, non-image data is called slice 0, and picture data slices are collectively called Called slice X.

The extension and user data () includes a video index (coded information inserted in a specific line in a vertical blanking period), video ancillary data, closed caption, teletext,
Data such as VITC (time code recorded in the vertical blanking period) and LTC (time code recorded in the longitudinal direction of the tape) are stored.

In the embodiment described above, video and audio data in various formats (multi-format) can be recorded. Hereinafter, functions that can support the multi-format according to the embodiment will be described. FIG. 8 shows a list of compatible multi-formats. The Edit freq in FIG. 8 is for distinguishing an editing unit, for example, a frame frequency. As the value increases, the frequency increases to (23.976 Hz, 25 Hz, 29.9 Hz, 50 Hz, 59.9 Hz). The progressive frame period is the same as the interlace field period. Interlace frames and fields are simply expressed as Frame, Field, and progressive frames are expressed as Pframe.
Further, in FIG. 8, video data is divided according to the number of lines, a scanning method (interlace / progressive), and a video rate.

In the audio data, the number of bits of one sample (16 bits / 24 bits) and the number of channels are indicated. Further, the number of tracks per editing unit, the number of rotating heads used, and the mode (SD1 to SD4, HL
1 to HL4) are shown. SD mode is (standar
d level), the HL mode is (high level). These mainly indicate the level of the resolution. Further, those indicated by * mean data not compressed by MPEG or the like. As can be seen from FIG. 8, the present invention can support various formats based on a combination of SD / HL, compression / non-compression, and interlace / progressive. The following description mainly describes the SD mode.

FIG. 9 shows an ECC format for video data. FIG. 9A shows the SD1 mode, and FIG.
B is the SD2 mode, FIG. 9C is the SD3 mode, and FIG. 9D is the SD4 mode. These figures show 1E
Indicates a CC block. In FIG. 9, VLC data is data from the packing and shuffling unit 107. For each row of VLC data, a SYNC pattern,
The ID and DID are added, and the parity of the inner code is added to form one SYNC block. That is, a predetermined number of bytes of an outer code parity is generated from a predetermined number of symbols (bytes) aligned in the vertical direction of the array of VLC data, and aligned in the horizontal direction.
The parity of the inner code is generated from the ID, DID, and a predetermined number of bytes of the VLC data (or the parity of the outer code).

In FIG. 9A (SD1), the frame frequency
The sync block lengths are different from 171, 151, and 163 corresponding to 29.97 Hz, 25 Hz, and 23.976 Hz, respectively.
With the same relationship, the number of outer code parity and inner code parity can be changed. In FIG. 9B (SD2), similarly, the sync block length is different from 164, 168, and 172, and the number of parities is also changed corresponding to the frame frequencies of 29.97 Hz, 25 Hz, and 23.976 Hz, respectively. FIG. 9C (SD
In 3), the sync block length is made different from 165 and 139 corresponding to the frame frequencies of 59.94 Hz and 50 Hz, respectively. With the same relationship, the number of outer code parity and inner code parity can be changed. In FIG. 9D (SD4), similarly, the sync block lengths are changed to 145 and 126 and the number of parities is changed corresponding to the frame frequencies of 59.94 Hz and 50 Hz, respectively. As a specific error correction code, a Reed-Solomon code is used.

In the SD mode, as an example, the number of inner code parities can be selected from 10, 12, and 14, and the number of outer code parities is 10, 12, 13, 14, 1 or more.
It can be selected from 6, 18, and 20, and the audio outer code parity number can be selected from 10, 12.

FIG. 10 shows an EC for audio data.
4 shows a configuration example of a C block. In the case of audio data, a sampling frequency of 48 kHz is used, and one sample is 16 bits or 24 bits.
Is a case where 1 sample = 16 bits. FIG.
Shows the number of bytes, which is a unit of error correction coding. Two ECC blocks are constituted by one field of audio data / 1 channel. 1 ECC
The block includes one of the even-numbered and odd-numbered audio samples and the audio AUX as data.

FIG. 10A shows that the interlace frame frequency is 29.97 Hz or the progressive frame frequency is 29.97 Hz.
The ECC configuration for 59.94 Hz is shown. FIG. 10B shows a configuration of the ECC when the interlace frame frequency is 25 Hz or the progressive frame frequency is 50 Hz. FIG. 10C shows that the progressive frame frequency is 2
The configuration of the ECC at 3.976 Hz is shown. These ECC
Pattern, ID and D for one row of data
An ID is added, and an audio sync block is configured as shown in FIG. 10D. Audio data packet length (102/122/12 corresponding to each frame frequency)
5) is different from the video data packet length described above.

FIG. 11 shows the arrangement of audio ECC samples in detail. However, the inner code parity is omitted,
10 bytes (PV0 to PV9) of the outer code parity are shown. FIG. 11A shows an ECC block composed of even-numbered samples of audio data for one field, and FIG. 11B shows the odd-numbered samples.
1 shows an ECC block composed of the following. As shown in FIG. 11, the number of samples in one field differs depending on the frame frequency. As can be seen from FIGS. 10 and 11, in the ECC of the audio data, the parity number of the outer code (= 10) and the parity number of the inner code (= 12)
Does not change even if the frame frequency is different.

The format of the audio data will be described in more detail. Here, the audio data is uncompressed, 16 bits / sample, the sampling frequency is 48 kHz, and the AUX data is 12 bytes / 1 field. The ECC configuration for each frame frequency will be described below.

[59.94Hz]: 48k / 59.94Hz x 16 bits / 8 = 1602 bytes + Aux data 12 bytes → 1614 bytes: 2 ECC block 102 x 8 x 2 = 1632 bytes [50Hz]: 48k / 50Hz x 16 Bit / 8 = 1920 bytes + Aux data 12 bytes → 1932 bytes: 2 ECC blocks 122 x 8 x 2 = 1952 bytes [29.97Hz]: [59.94Hz] twice → 3228 bytes: 4 ECC blocks 102 x 8 x 4 = 3264 bytes [25Hz]: [50Hz] twice → 3864 bytes: 4 ECC blocks 102 x 8 x 4 = 3904 bytes [23.976Hz]: 48k / 23.976Hz x 16 bits / 8 = 4004 bytes + Aux data 12 Byte x 2 → 4028 bytes: 4 ECC blocks 126 x 8 x 4 = 4032 bytes.

Further, the configuration of the sync block will be described with reference to FIG. 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 depends on the format of the video signal handled. Length is changed. As shown in FIG.
The sync block includes a 2-byte SYNC pattern, a 2-byte ID, and a 1-byte DID, for example, 11 bytes from the beginning.
It consists of a data area variably defined between 2 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 used for synchronization detection and have a predetermined bit pattern. Synchronization detection is performed by detecting a SYNC pattern that matches the unique pattern.

FIG. 13A shows an example of the bit assignment of ID0 and ID1. The ID has important information unique to the sync block, and has 2 bytes (I
D0 and ID1). ID0 is
The identification information (SYNC ID) for identifying each of the sync blocks in one track is stored. SYN
The C 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.

[0125] 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. 13B 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. 13C shows an example of bit assignment of DID in the case of audio. Bits 7 to 4 are
Reserved. Whether the data stored in the payload in bit 3 is audio data,
Indicates whether the data is 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 correspond to 5 in the NTSC system.
Field sequence information is stored. That is,
In the NTSC system, the sampling frequency of an audio signal for one field of a video signal is 48 k.
In the case of Hz, it is either 800 samples or 801 samples, and this sequence is prepared every 5 fields.
Bit 2 to bit 0 indicate where in the sequence it is located.

Returning to FIG. 12, FIGS. 12B to 12E show examples of the above-mentioned payload. FIGS. 12B and 12C show examples in which video data (variable length data) of 1 and 2 macroblocks is stored in the payload, respectively. In the example shown in FIG. 12B where one macroblock is stored, a data length indicator LT indicating the length of the variable 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. In the example shown in FIG. 12C where two macroblocks are stored because the data rate is low, the data length indicator LT of the first macroblock is arranged at the beginning, and the first macroblock is arranged subsequently. Is done. Then, the data length indicator LT indicating the length of the second macroblock is arranged following the first macroblock, and the second macroblock is arranged subsequently. The data length indicator LT is information necessary for depacking.

FIG. 12D shows an example in which video AUX (auxiliary) data is stored in the payload.
The first data length indicator LT describes the length of the video AUX data. Subsequent to the data length indicator LT, 5 bytes of system information, 12 bytes of PICT information, and 92 bytes of user information are stored. The remaining portion of the payload length is reserved.

FIG. 12E 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. The data length indicator LT is not inserted for audio data.

In this embodiment, the length of the payload, which is the storage area for the data of each sync block, is not optimally set for each of the video sync block and the audio sync block. . 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, multi-format can be handled uniformly.

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.

FIGS. 14 to 17 show the track format of the SD mode, and FIGS. 18 and 19 show the HL track format. In the SD mode, two video sectors, eight audio sectors, and S
Two ATs are arranged. In these figures, SAT1
(Tr) and SAT2 (Tm) are areas where servo lock signals are recorded. A gap of a predetermined size (Vg1, Sg1, Ag) is provided between the recording areas.
g, Sg2, Sg3 and Vg2).

FIG. 14 shows a track format corresponding to the SD1 mode, and FIGS. 15, 16 and 17 show formats corresponding to the SD2 mode, SD3 mode and SD4 mode, respectively. In SD1 mode,
The number of audio channels is set to four, and otherwise, the number of audio channels is set to eight. In the SD1 mode, as shown in FIG. 8, video data and audio data per frame are recorded as four tracks. In the SD2 mode, video data and audio data per frame are recorded as eight tracks. In the SD3 mode, video data and audio data per frame (progressive frame) are recorded as four tracks. In the SD4 mode, video data and audio data per frame (progressive frame) are recorded as six tracks.

In the SD2 mode, for example, an interlace signal (480i signal) and an audio signal having a frame frequency of 29.97 Hz, a rate of 50 Mbps, the number of effective lines of 480, and the number of effective horizontal pixels of 720 are recorded. Also, the frame frequency is 25Hz and the rate is 50Mbp
s, effective line number is 576, effective horizontal pixel number is 720
Pixel interlace signals (576i signals) and audio signals can also be recorded in the SD2 mode.

One segment is composed of two tracks having different azimuths. That is, in the example of the SD2 mode (FIG. 15), eight tracks are composed of four segments. For a set of tracks that make up a segment,
Azimuth and corresponding track number

[0] and a track number [1] are assigned. In the example shown in FIG.
The track numbers are exchanged between the track and the latter eight tracks, and a different track sequence is 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 these track formats, 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. SD2
In the mode, eight channels of audio data can be handled, and A1 to A8 indicate sectors 1 to 8 of the audio data, respectively. The audio data is recorded with its arrangement changed in segment units. In the 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 the SD2 mode, one field of audio data is recorded on four tracks, and thus two ECC blocks per channel of audio data are recorded on four tracks. Data of two ECC blocks (including outer code parity) is divided into four sectors, and as shown in FIG. 15, recorded in a distributed manner over four tracks. A plurality of sync blocks included in the two ECC blocks are shuffled. For example, four ECCs of channel 1 are provided by four sectors with reference numbers of A1.
A block is configured.

In this example, the video data is shuffled (interleaved) for four ECC blocks for one track, divided into upper sectors and lower sides, and recorded. In the lower sector video sector, a system area is provided at a predetermined position. In the SD4 mode, one frame has a format of six tracks.
In this example, the track sequence is

Only [0] is set.

FIG. 18 shows track formats in the HL1 mode and the HL2 mode. In HL1 mode,
1 video and audio data per frame
It is recorded as two tracks. In the HL2 mode, video and audio data per progressive frame are recorded as 12 tracks. Further, FIG.
Reference numeral 9 denotes a track format of the HL3 mode and the HL4 mode. In the HL3 mode, video and audio data per frame are recorded as 20 tracks. In the HL4 mode, video and audio data per progressive frame are recorded as 20 tracks.

According to the present invention, as described above, in order to cope with the multi-format, the video and audio data packet lengths are not set to be the same, but are respectively set to optimal ones. It is determined only by the frequency. Also, as shown in FIG. 11, the configuration of the ECC block and the audio sample is also the same, except that the data packet length changes only depending on the frame frequency, and the arrangement of the samples is the same. As described above, the length of the audio sync block is determined independently of the video, and the relationship between the ECC block and the audio sample is made common, so that a common signal processing circuit is used when encoding and decoding various formats having different video rates. Can be used, so that the circuit scale can be significantly reduced.

As shown in FIG. 12C, it is possible to store VLC data packets for two macroblocks in one sync block. By applying this format to the recording / reproduction of video data with a low data rate, it is possible to prevent an increase in redundancy.

Next, the video data will be described. In this embodiment, MPEG2 is used as a video compression method. A macroblock is a unit in which eight 8 × 8 DCT blocks are collected. The number of syncs means the number of sync blocks in which the corresponding data is stored. The following symbols are used for explanation.

Fq: 59.94 / 50 / 29.97 / 25 / 23.976 Hz Video MB: Number of video macroblocks [625/50] 720 x 608 → 1710 macroblock [525/60] 720x512 → 1440 macroblock Ecc nb: 1 Number of ECC blocks interleaved in track SYS SYNCnb: Number of SYNC (system sync) in which system data is stored per edit unit packet length: Data packet length Tr nb: Number of tracks per edit unit VLC SYNCnb: Edit unit Number of SYNCs that store VLC packets per unit VSYNCnb: Total number of video sync blocks per editing unit Heade SYNCnb: Number of SYNC blocks that store Picture header and User data Null SYNCnb: Null sync (VLC sync, Header The number of SYNCs other than sync and system sync.

In the MPEG2 compression system, if data at least in units of macroblocks are not available, decoding as image data is not possible. At the time of shuttle reproduction, data is updated only in sync block units. Therefore, in order to improve the image update rate, it is necessary that macroblock data be stored in the same sync block as the corresponding macroblock information. Therefore, as described above, DC
The rearrangement of the T coefficients has been performed. A block in which the one piece of macroblock information and its data are stored in the order of data importance is defined as a VLC packet. When one VLC packet is updated, the image of the macroblock is updated from the DC component to the frequency component stored in the packet. Further, as described above, packing processing is performed, and Null sync is used for packing out-of-range data. The total amount of video data is rate-controlled so that the packing process can always be accommodated. One sync block is formed by adding a synchronization pattern, a block ID, and an error correction parity to this packet.

Here, as an example, Header SYNCnb = 1,
If Ecc nb = 4, SYS SYNCnb = Tr nb and VLC SYNCnb = Video MB (3), the number of syncs Vd of video data of one ECC block is Vd = (int) ((VLC SYNCnb + SYS SYNCnb + Header SYNCnb) / Ecc nb / Tr nb +1) (4) The total number of SYNC blocks of Video per editing unit is as follows: VSYNBnb = Vd × Ecc nb × Tr nb (5) Among them, the number of null syncs is Null SYNCnb = VSYNCnb-VLC SYNCnb-SYS SYNCnb-Header SYNCnb (6). Null sync is generated as a result of adjusting the total number of SYNC blocks to a clear value in terms of the number of tracks and the configuration of the ECC block. On the other hand, the average bit rate of video has the following relationship.

Avr bit rate = (VLC SYNCnb + Null SYNCnb + Header SYNCnb) × Fq × 8 bits × packet length (7) From this equation (7), the average video bit rate is packe
It can be seen that it is proportional to t length (data packet length). In other words, in order to obtain the target video bit rate, the video data packet length, that is, the video sync block length may be adjusted. In this example, since the length of the audio data packet can be made independent, the bit rate of the video can be adjusted without changing the audio signal processing.

Incidentally, the average bit rate of video is
Since the bit rate is proportional to the data packet length,
As the data packet length is reduced to 1/2 or 1/3, the data packet length must be shortened accordingly. FIG. 20 shows the relationship between data packets and sync blocks. Here, the redundancy is sync block length / packet length × 100%.

FIG. 20A shows the structure of a sync block when the average bit rate of video is a basic value. Data packet length is 180 bytes, sync block length is 197
Bytes. The redundancy at this time is (197/180)
× 100 = 109%. If the average bit rate is reduced to 1/2 with respect to FIG. 20A, the sync block shown in FIG. 20B is formed. Since the sync pattern, ID, DID, etc. added to the sync block have a fixed length, there is a problem that the redundancy increases to 118%. Thus, as shown in FIG. 20C, it is conceivable to reduce the number of error correction parities of the inner code according to the length of the data packet.

However, reducing the number of parities lowers the error correction capability. The inner code is encoded for data obtained by removing two bytes of the SYNC pattern from the sync block. FIG. 21 shows the correction capability. The horizontal axis represents the sample error rate before correction, and the vertical axis represents the error rate after correction. As described above, when the number of parities is halved, the error correction capability shown by the solid line is reduced to that shown by the broken line.

In this embodiment, in order to solve this problem, as described above, VP num: the number of VLC packets per SYNC is newly defined so that a plurality of VLC packets can be stored in one sync block. I have to. FIG. 20D shows an example in which two VLC packets are stored in one sync block. In this case, the redundancy is 109%. In this embodiment, as described with reference to FIG. 12, the upper limit of VP num is 2, and the DID records data indicating the number of packets per sync block. Since a plurality of VLC packets are stored in one sync block, equation (3) is replaced by VLC SYNCnb = Video MB / VP num (8). By allowing a plurality of VLC packets to be stored in one sync block in this way, it is possible to reduce redundancy and improve recording efficiency.

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

[0153]

According to the present invention, since the sync block length of video data and the sync block length of audio data are different from each other, the respective lengths can be set optimally. Therefore, a common signal processing circuit can be used at the time of encoding and decoding for various formats having different video rates, and the circuit scale can be significantly reduced.
Cost reduction of C can be realized. In addition, since the audio does not depend on the video rate or the picture frame, it is possible to adjust the bit rate of the video without changing the audio signal processing.

Further, according to the present invention, by selecting an optimal value for the number of data packets stored in one sync block according to the video bit rate, the redundancy can be reduced and the recording efficiency can be improved. it can.

[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 for explaining an output method of a video encoder and variable-length encoding.

FIG. 4 is a schematic diagram for explaining rearrangement of an output order of a video encoder.

FIG. 5 is a schematic diagram for explaining a process of packing data whose order is rearranged into a sync block;

FIG. 6 is a more specific block diagram of a recording signal processing unit.

FIG. 7 is a schematic diagram illustrating a memory space of a memory to be used.

FIG. 8 is a schematic diagram showing a list of formats to be recorded and reproduced.

FIG. 9 is a schematic diagram illustrating a plurality of examples of ECC blocks of video data.

FIG. 10 is a schematic diagram illustrating a plurality of examples of ECC blocks of audio data.

FIG. 11 is a schematic diagram illustrating an arrangement of audio samples in an ECC block.

FIG. 12 is a schematic diagram illustrating a plurality of examples of a configuration of a sync block.

FIG. 13 shows ID and DI added to a sync block.
It is a schematic diagram which shows the content of D.

FIG. 14 is a schematic diagram illustrating a first example of a format on a tape.

FIG. 15 is a schematic diagram illustrating a second example of a format on a tape.

FIG. 16 is a schematic diagram illustrating a third example of a format on a tape.

FIG. 17 is a schematic diagram illustrating a fourth example of a format on a tape.

FIG. 18 is a schematic diagram illustrating a fifth example of a format on a tape.

FIG. 19 is a schematic diagram illustrating a sixth example of a format on a tape.

FIG. 20 is a schematic diagram for explaining a method of configuring a sync block.

FIG. 21 is a schematic diagram for explaining a correction capability of an error correction code.

FIG. 22 is a schematic diagram showing a tape format of an existing digital VTR to which the present invention is referred.

FIG. 23 is a schematic diagram illustrating a configuration of an ECC block of an existing digital VTR.

FIG. 24 is a schematic diagram showing an arrangement of audio samples of an existing digital VTR.

FIG. 25 is a schematic diagram showing an arrangement of audio samples of an existing digital VTR.

FIG. 26 is a schematic diagram illustrating a configuration of an ECC block obtained by modifying an ECC block of an existing digital VTR.

FIG. 27 is a schematic diagram showing an arrangement of audio samples when an ECC block of an existing digital VTR is modified.

FIG. 28 is a schematic diagram illustrating an example of a plurality of formats.

[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

Claims (15)

[Claims] 1. A data recording apparatus which records image data and audio data on a recording medium and has a plurality of rates of image data to be recorded and a plurality of data amounts of audio data in edit units. A first error correction code block that is divided into a first data packet, a first error correction code block is configured by the plurality of first data packets, and error correction coding is performed in units of the first error correction code block; Encoding means; dividing the audio data into second data packets, forming a second error correction code block by a plurality of the second data packets, and performing error correction code in units of the second error correction code blocks. Second error correction coding means for performing coding, and synchronizing signals for the first and second data packets, respectively. And a recording means for recording data comprising the first and second sync blocks on a recording medium, wherein the first and second sync blocks are recorded on a recording medium. An image data recording device, wherein the lengths of the sync blocks are different. 2. A data recording apparatus which records image data and audio data on a recording medium and has a plurality of rates of image data to be recorded and a plurality of data amounts of audio data in edit units. A first error correction code block that is divided into a first data packet, a first error correction code block is configured by the plurality of first data packets, and error correction coding is performed in units of the first error correction code block; Encoding means; dividing the audio data into second data packets, forming a second error correction code block by a plurality of the second data packets, and performing error correction code in units of the second error correction code blocks. Second error correction coding means for performing coding, and synchronizing signals for the first and second data packets, respectively. And first and second sync blocks, and recording means for recording data comprising the first and second sync blocks on a recording medium. An image data recording device, wherein one or more integer number of the first data packets are stored in a block according to a data rate of the image data. 3. The image data and the audio data are recorded on a recording medium, the image and the audio data are reproduced from the recording medium, and there are a plurality of rates of the image data to be recorded and reproduced. Wherein the image data is divided into first data packets, a first error correction code block is formed by the plurality of first data packets, and the first error correction code block is First error correction coding means for performing error correction coding in units, audio data is divided into second data packets, and a plurality of second data packets constitute a second error correction code block; A second error correction encoding unit that performs error correction encoding in units of the second error correction code block; Means for adding a synchronization signal to each of the first and second data packets to form first and second sync blocks; and recording data comprising the first and second sync blocks on a recording medium. Recording means for reproducing the data comprising the first and second sync blocks from the recording medium; and decoding the error correction code for the reproduced data in units of the first error correction code block. A first error correction decoding means for generating reproduction image data, and a second error correction code for decoding the reproduction data in units of the second error correction code block to generate reproduction audio data. Image data recording means comprising error correction decoding means, wherein the first and second sync blocks have different lengths. Raw devices. 4. The image data and audio data are recorded on a recording medium, the image and the audio data are reproduced from the recording medium, and there are a plurality of rates of the image data to be recorded and reproduced, and the data amount of the audio data in an editing unit. Wherein the image data is divided into first data packets, a first error correction code block is formed by the plurality of first data packets, and the first error correction code block is First error correction coding means for performing error correction coding in units, audio data is divided into second data packets, and a plurality of second data packets constitute a second error correction code block; A second error correction encoding unit that performs error correction encoding in units of the second error correction code block; Means for adding a synchronization signal to each of the first and second data packets to form first and second sync blocks; and recording data comprising the first and second sync blocks on a recording medium. Recording means for reproducing the data comprising the first and second sync blocks from the recording medium; and decoding the error correction code for the reproduced data in units of the first error correction code block. A first error correction decoding means for generating reproduction image data, and a second error correction code for decoding the reproduction data in units of the second error correction code block to generate reproduction audio data. Error correction decoding means, wherein one or more integer number of the first sync blocks are one or more in accordance with a data rate of image data. Image data recording and reproducing apparatus characterized by storing data packets. 5. The image data and the audio data are recorded, the rate of the recorded image data is one of a plurality of types, and the data amount of the recorded audio data in an editing unit is the number of types. A data recording medium provided with an image data recording area and an audio data recording area, wherein the image data recording area records data comprising a first sync block; A data recording medium, characterized in that data comprising a second sync block is recorded in an area, and the first and second sync blocks have different lengths. 6. The image data and the audio data are recorded, and the rate of the recorded image data is one of a plurality of types, and the data amount of the recorded audio data in the editing unit is one of the plurality of types. A data recording medium provided with an image data recording area and an audio data recording area, wherein the image data recording area records data comprising a first sync block; In the area, data composed of a second sync block is recorded, and one or more integer data of the first data packets is stored in one of the first sync blocks according to the data rate of image data. A data recording medium characterized by the following. 7. The apparatus according to claim 1, wherein a length of the second data packet is determined only by a frequency of an editing unit of the image data. 8. The method according to claim 1, wherein in the second error correction code block composed of the second data packet, a plurality of samples numbered in an editing unit are included. An apparatus characterized in that the arrangement is the same even when the frequency of the editing unit is different or different. 9. The method according to claim 1, wherein each of the first and second error correction encoding means encodes an outer code in a vertical direction of a two-dimensional array of data. An apparatus for encoding an inner code in a horizontal direction. 10. The image data according to claim 1, wherein the image data is generated by performing variable-length encoding on encoded data generated by compression encoding. And equipment. 11. The apparatus according to claim 10, wherein said compression coding is a combination of DCT and variable length coding. 12. A data recording method in which image data and audio data are recorded on a recording medium, and there are a plurality of rates of image data to be recorded and a plurality of data amounts of audio data in edit units. A first error correction code block that is divided into a first data packet, a first error correction code block is configured by the plurality of first data packets, and error correction coding is performed in units of the first error correction code block; Encoding, dividing the audio data into second data packets, forming a second error correction code block by the plurality of second data packets, and performing error correction in units of the second error correction code blocks. A second error correction coding step of performing coding; and Respectively comprising a step of adding a synchronization signal to form first and second sync blocks; and a step of recording data comprising the first and second sync blocks on a recording medium. An image data recording method, wherein the lengths of the second sync blocks are different. 13. A data recording method in which image data and audio data are recorded on a recording medium, and a plurality of rates of image data to be recorded exist and a plurality of data amounts of audio data in units of editing exist. A first error correction code block that is divided into a first data packet, a first error correction code block is configured by the plurality of first data packets, and error correction coding is performed in units of the first error correction code block; Encoding, dividing the audio data into second data packets, forming a second error correction code block by the plurality of second data packets, and performing error correction in units of the second error correction code blocks. A second error correction coding step of performing coding; and Each of adding a synchronization signal to form first and second sync blocks; and recording the data comprising the first and second sync blocks on a recording medium. A data recording method, wherein one or more integer number of the first data packets are stored in one sync block according to a data rate of image data. 14. Recording of image data and audio data on a recording medium, reproduction of the image and audio data from the recording medium, a plurality of rates of image data to be recorded and reproduced, and a data amount of audio data in edit units. Wherein the image data is divided into a first data packet, a first error correction code block is formed by the plurality of first data packets, and the first error correction code block is A first error correction coding step of performing error correction coding on a unit basis, dividing audio data into second data packets, and forming a second error correction code block by a plurality of the second data packets. Error correction coding for performing error correction coding in units of the second error correction code block. Adding a synchronization signal to each of the first and second data packets to form first and second sync blocks; and recording data comprising the first and second sync blocks. A recording step for recording on a medium; a reproducing step for reproducing the data comprising the first and second sync blocks from the recording medium; and an error for the reproduced data in units of the first error correction code block. A first error correction decoding step of decoding the correction code to generate reproduced image data; and decoding the error correction code of the reproduced data in units of the second error correction code block. And a second error correction decoding step of generating the first and second sync blocks having different lengths. Image data recording and reproducing method characterized in that it is as. 15. The image data and audio data are recorded on a recording medium, the image and audio data are reproduced from the recording medium, and there are a plurality of rates of image data to be recorded and reproduced, and the data amount of the audio data in edit units. Wherein the image data is divided into a first data packet, a first error correction code block is formed by the plurality of first data packets, and the first error correction code block is A first error correction coding step of performing error correction coding on a unit basis, dividing audio data into second data packets, and forming a second error correction code block by a plurality of the second data packets. Error correction coding for performing error correction coding in units of the second error correction code block. Adding a synchronization signal to each of the first and second data packets to form first and second sync blocks; and recording data comprising the first and second sync blocks. A recording step for recording on a medium; a reproducing step for reproducing the data comprising the first and second sync blocks from the recording medium; and an error for the reproduced data in units of the first error correction code block. A first error correction decoding step of decoding the correction code to generate reproduced image data; and decoding the error correction code of the reproduced data in units of the second error correction code block. And a second error correction decoding step of generating image data. Data recording and reproducing method characterized by storing an integer of 1 or more pieces of the first data packet in accordance with the Tareto.