JP2001338467A - Device and method for signal recording, device and method for signal reproducing and device and method for signal recording and reproducing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain continuous reproduced sound while conducting an n-fold speed reproducing of digital audio signals recorded in a helical track in frame synchronized with digital video signals using a DT head. SOLUTION: During recording, a CH1 records digital audio signals that are delayed equivalent to one frame on a CH5 that is made a pair with the CH1. When a two-fold speed reproducing is conducted, traces are conducted by the DT head for every other track. Thus, at the CH1 and the CH5 that are made into a pair during a recording, frames F1, F3, F5, etc., and F0, F2, F4, etc., are respectively reproduced. During each frame interval, signals equivalent to two frames of the CH1 and the CH5 are thinned in a prescribed manner, for example to make the signals having the number of samples equivalent to one frame and outputted as the signals of the CH1. Thus, the signals of the CH1 during a recording are reproduced with a two-fold speed and pitch and sound feeling, in which audio signals recorded in a longitudinal track with an analog system are reproduced with a two-fold speed, is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal recording apparatus and method for reproducing a digital audio signal synchronized with a video signal so that a reproduced sound reproduced at a speed different from that at the time of recording does not feel uncomfortable. And a signal reproducing apparatus and method, and a signal recording and reproducing apparatus and method.

[0002]

2. Description of the Related Art Digital VTR (Video Tape Recorder)
r) a digital video signal and a digital audio signal are recorded on a recording medium as represented by
2. Description of the Related Art A data recording / reproducing apparatus that reproduces data from a recording medium is known. Since a digital video signal has a huge data capacity, it is generally compressed and encoded by a predetermined method and recorded on a recording medium. In recent years, MPEG2 (M
The oving Picture Experts Group 2) method is known as a standard method of compression encoding. In MPEG2, DC
The compression coding of the digital video signal is performed using T (Discrete Cosine Transform) and motion compensation, and the data compression rate is increased using a variable length code.

[0003] These digital video signals and digital audio signals are recorded on a magnetic tape by helical tracks, which form tracks diagonally by a rotary head provided on a rotating drum. A digital video signal that has been compression-encoded using a variable length code is made equal length in edit units such as one frame, and is recorded using a predetermined number of tracks, for example, eight tracks for each edit unit. Hereinafter, a plurality of tracks in which one frame is an editing unit and one frame of a video signal is recorded are referred to as a track set.

On the other hand, a digital audio signal is recorded in frame synchronization with a digital video signal. For example, a video area in which a digital video signal is recorded and an audio area in which a digital audio signal is recorded are provided for one track, and a digital audio signal corresponding to a frame of the digital video signal recorded in the video area is provided. Recorded in the audio area of the track.

[0005] The digital audio signal can be handled simultaneously by synchronizing a signal of a plurality of channels such as eight channels with the same frame. As described above, the digital audio signals of a plurality of channels are respectively recorded in the audio areas of the corresponding track sets.

FIG. 21 shows an example of the configuration of a digital VTR according to the prior art as described above. The video data is supplied to the video encoder 300, subjected to a compression encoding process by MPEG2, etc., and converted into an MPEG2 data stream. The video data output from the video encoder 300 is supplied to a packing / reordering circuit 301, packed in packet units, and reordered so that an outer code parity can be added. The rearranged video packets are output to the outer code encoder 302.
The data is rearranged in the order to be recorded by the rearrangement circuit 303 and supplied to the mixing circuit 304.

On the other hand, in the audio data, the input delay amount is adjusted by the delay circuit 305, and the data is arranged by the rearrangement circuit 306 so that an outer code parity can be added to each error correction block in which the error correction code is completed. Can be replaced. The sorted audio data is
An outer code parity is added by an outer code encoder 307,
The data is rearranged in the order of recording by the rearrangement circuit 308 and supplied to the mixing circuit 304.

[0008] The video data and audio data output from the rearranging circuits 303 and 308 are rearranged in the order of recording by the mixing circuit 304 and supplied to the block ID adding circuit 309. Block ID
In the addition circuit 309, the block ID is used for each data packet.
Information is added so that the data packets can be distinguished from each other. For the video data to which the block ID has been added, an inner code parity is added by the inner code encoder 310 for each data packet, and a sync pattern is added by the sync pattern adding circuit 311 to form a sync block.

The sync block is converted from serial data into serial data and output from the synchronous pattern adding circuit 311. The serial data output from the synchronization pattern adding circuit 311 is supplied to a recording head (not shown) via a recording amplifier 312, and is recorded on a magnetic tape 313 by a helical track.

[0010] The data sequence recorded on the magnetic tape 313 is read by a reproducing head (not shown) and supplied to a synchronous pattern detecting circuit 321 via a reproducing amplifier 320. In the synchronization pattern detection circuit 321, a synchronization pattern is detected from the supplied reproduced data sequence, and the phase of the sync block is restored based on the detected phase of the synchronization pattern. The sync pattern detection circuit 321 outputs a sync block. For the sync block, the inner code parity is decoded by the inner code decoder 322 and error correction is performed. If an error exists beyond the error correction capability of the error correction code, error correction is not performed and an error flag indicating that an error has occurred is set. The error-corrected sync block is supplied to the block ID error interpolation circuit 323, and the block ID of the sync block having an error is interpolated and restored based on, for example, the IDs of the preceding and succeeding sync blocks.

The data packet output from the block ID error interpolation circuit 323 is supplied to a separation circuit 324. The supplied data packet is separated by a separation circuit 324 into a video packet in which video data is stored and an audio packet in which audio data is stored, based on the ID information of the block ID.

[0012] The video packet is reordered by the rearrangement circuit 325.
Thus, the data is rearranged into an order that can be supplied to the outer code decoder 326. In the rearranged video packets, the outer code parity is decoded by the outer code decoder 326 and error correction is performed. When there are more errors than the error correction capability of the error correction code, an error flag indicating that an error exists is set and error correction is not performed. The error-corrected video packet is supplied to the depacking circuit 3
27, the packets are rearranged in the output order, and the packing is released.

The unpacked video data is
The data is supplied to the interpolation circuit 328, and the data is modified by interpolation or the like based on the error flag.
9. The video data is transmitted to the video decoder 32
At 9, the compression encoding is decoded and output.

On the other hand, the audio packets are rearranged by the rearrangement circuit 330 so that they can be input to the outer code decoder 331. In the rearranged audio packets, the outer code parity is decoded by the outer code decoder 331 and error correction is performed. If an error exists beyond the error correction capability of the error correction code, an error flag indicating that fact is set and error correction is not performed.

The audio packets output from the outer code decoder 331 are supplied to a rearrangement circuit 332, where auxiliary data (AUX data) is extracted and output, and the audio packets are rearranged in the output order. Decryption is performed. The decoded audio data is supplied to the correction circuit 333, and the data is interpolated and corrected by, for example, previous and subsequent samples based on the error flag. The audio data output from the modifying circuit 333 is supplied to a mute processing / delay circuit 334, where the output delay amount of the audio data is adjusted, and the audio data is muted and output as necessary.

[0016]

Here, the magnetic tape on which the digital video signal and the digital audio signal are recorded as described above is adjusted to a variable tape speed of about 1 to 2 to several times that of recording. Jog (JO)
G) Consider processing of a digital audio signal when reproduced by reproduction. Note that reproduction is performed in a VTR having a dynamic tracking head (DT head). The minimum editing unit is one frame. In the following, reproducing at a tape speed of n times speed during recording is referred to as n times speed reproduction.

If the tape speed at the time of reproduction is different from the speed at the time of recording, the tracing angle of the reproduction head changes. Cannot be read. Therefore, using the DT head described above, the height of the head is dynamically changed according to the tape speed,
The data of one frame unit can be traced.

FIG. 22 shows a case where a DT head is used.
The relation between frames of data reproduced at the time of double speed reproduction is shown. FIG. 22A shows the recording data. Digital audio signals are recorded in frame units in order from the first frame. It should be noted that each frame corresponds to channel CH1.
8 audio data for 8 channels. FIG.
2B shows reproduction data in the case of normal reproduction, that is, reproduction at the same tape speed as the tape speed at the time of recording. The digital audio signal is reproduced for each frame in the same order as the frame at the time of recording.

FIG. 22C shows reproduction data at the time of double speed reproduction using the DT head. The third frame is reproduced after the first frame, and subsequently, the fifth frame, the seventh frame,... Are reproduced every other frame. As described above, in the case of the double speed reproduction, the head is dynamically changed by the DT head and the track is traced. Therefore, the track is traced one frame at a time. Therefore, the digital audio data is jumped every frame, and the reproduced sound is a skipping sound every frame.

However, in a conventional analog VTR, a video signal is recorded on a helical track, and an audio signal is recorded in a longitudinal direction of a magnetic tape. In this case, the reproduced sound at the time of double speed reproduction is continuously reproduced without skipping every frame. Therefore, the audio signal is compressed by a factor of two in the time axis direction, resulting in a sound whose speed is doubled and whose pitch is doubled. Conventional users who are accustomed to editing using such analog audio signals recorded in the longitudinal direction often feel uncomfortable with the playback sound that jumps from frame to frame as described above. However, there were many requests for improvement.

Therefore, an object of the present invention is to obtain a continuous reproduced sound when a digital audio signal recorded by a helical track in frame synchronization with a digital video signal is reproduced at n times speed using a DT head. An object of the present invention is to provide a signal recording device and method, a signal reproducing device and method, and a signal recording and reproducing device and method.

[0022]

According to the present invention, there is provided a signal recording apparatus capable of recording a plurality of digital audio signals on a magnetic tape in a predetermined unit in order to solve the above-mentioned problems. Possible input means, delay means for giving a delay of one unit in a predetermined unit to each of a plurality of digital audio signals inputted by the input means, and each of the plurality of digital audio signals inputted by the input means And a recording unit for recording each of the digital audio signals delayed by the delay unit on a magnetic tape in a predetermined unit.

According to the present invention, in a signal recording method capable of recording a plurality of systems of digital audio signals on a magnetic tape in predetermined units, an input step capable of inputting a plurality of systems of audio signals and an input step are provided. A delay step of giving a delay amount of one unit in a predetermined unit to each of the plurality of audio signals, a plurality of audio signals input in the input step, and an audio signal delayed in the delay step And a recording step of recording each of these in a predetermined unit on a magnetic tape.

Further, according to the present invention, a digital audio signal is reproduced by using a dynamic tracking head from a magnetic tape on which a plurality of digital audio signals are recorded in a predetermined unit by a helical track, and the tape speed n ( n> 1) In a signal reproducing apparatus capable of reproducing at double speed, a reproducing means for reproducing, using a dynamic tracking head, a plurality of digital audio signals recorded on a magnetic tape by a helical track in a predetermined unit, and a reproducing means. Storage means for storing each of the reproduced digital audio signals of a plurality of systems; and a digital audio signal stored in the storage means in a predetermined unit such that the number of audio samples corresponds to the predetermined unit in accordance with the reproduction speed. Read over multiple lines each time And to reading means, a signal reproducing apparatus characterized by an output means for outputting the digital audio signal read out over multiple systems within a predetermined unit of 1 line per predetermined unit by the reading means.

Further, according to the present invention, a digital audio signal is reproduced by using a dynamic tracking head from a magnetic tape in which a plurality of systems of digital audio signals are recorded in helical tracks in a predetermined unit, and the tape speed n ( n> 1) In a signal reproducing method capable of reproducing at a double speed, a reproducing step of reproducing, using a dynamic tracking head, a plurality of systems of digital audio signals recorded on a magnetic tape by helical tracks in a predetermined unit; Storing each of the digital audio signals of the plurality of systems reproduced by the step in the storage means, and converting the digital audio signals stored in the storage means to the number of audio samples corresponding to a predetermined unit according to the reproduction speed. And for each predetermined unit A signal reproducing method comprising: a reading step of reading over several systems; and an output step of outputting, within a predetermined unit of one system, digital audio signals read over a plurality of systems in predetermined units by the reading step. Is the way.

According to the present invention, digital audio signals of a plurality of systems can be recorded on a magnetic tape by a helical track in a predetermined unit. The digital audio signals are reproduced from the magnetic tape using a dynamic tracking head, and the tape speed at the time of recording is reproduced. In a signal recording / reproducing apparatus capable of reproducing at n (n> 1) times speed, input means capable of inputting a plurality of systems of audio signals, and a plurality of digital audio signals inputted by the input means, each having a predetermined unit A delay unit for giving a delay amount of one unit, a plurality of digital audio signals of a plurality of systems input by the input unit, and a digital audio signal delayed by the delay unit in predetermined units. Recording means for recording in
Playback means for playing back a plurality of digital audio signals recorded on a magnetic tape by using a dynamic tracking head; storage means for storing each of the plurality of digital audio signals played back by the playback means; storage in the storage means Reading means for reading out the digital audio signal over a plurality of systems for each predetermined unit according to the reproduction speed so as to have the number of audio samples corresponding to the predetermined unit, and reading over a plurality of systems for each predetermined unit by the reading means Output means for outputting the digital audio signal within a predetermined unit of one system.

According to the present invention, a digital audio signal of a plurality of systems can be recorded on a magnetic tape by a helical track in a predetermined unit. The digital audio signal is reproduced from the magnetic tape using a dynamic tracking head, and the tape speed at the time of recording is reproduced. In the signal recording / reproducing method capable of reproducing at n (n> 1) times speed, an input step capable of inputting a plurality of audio signals, and a plurality of digital audio signals input at the input step, A delay step of providing a delay amount of one unit in a predetermined unit, each of a plurality of digital audio signals input in the input step, and each of the digital audio signals delayed in the delay step in a predetermined unit; Recording on magnetic tape by helical track A recording step, a reproducing step of reproducing a plurality of digital audio signals recorded on the magnetic tape using a dynamic tracking head, and storing the plurality of digital audio signals reproduced in the reproducing step in storage means. A reading step of reading the digital audio signal stored in the storage means over a plurality of systems for each predetermined unit according to the reproduction speed so that the number of audio samples corresponds to the predetermined unit; and An output step of outputting a digital audio signal read out over a plurality of systems for each predetermined unit by the step within a predetermined unit of one system.

As described above, according to the first and third aspects of the present invention, a plurality of systems of audio signals can be inputted, and each of the inputted plurality of systems of digital audio signals is delayed by one unit in a predetermined unit. Since each of the input digital audio signals and the signals obtained by delaying the input digital audio signal by one unit are recorded on the magnetic tape in a predetermined unit, the amount of the input digital audio signal is delayed during reproduction. By combining the recorded digital audio signal with the corresponding digital audio signal recorded without delay, a plurality of digital audio signals can be output within a predetermined unit.

The invention according to claims 4 and 6 provides:
A plurality of systems of digital audio signals recorded on a magnetic tape by a helical track in predetermined units are reproduced using a dynamic tracking head, and the reproduced plural systems of digital audio signals are stored and correspond to the predetermined units. Number of audio samples,
According to the reproduction speed, a plurality of systems are read out for each predetermined unit, and the read digital audio signal is output within a predetermined unit of one system. Minute digital audio signals can be output.

The invention according to claims 7 and 9 is
A predetermined unit of delay is given to each of the plurality of input digital audio signals in a predetermined unit, and each of the input plurality of digital audio signals and each of the delayed digital audio signals are input in a predetermined unit. A plurality of digital audio signals recorded on the magnetic tape by a helical track, reproduced using a dynamic tracking head, and each of the reproduced digital audio signals is stored and stored. A plurality of audio samples corresponding to a predetermined unit of the read digital audio signal are read out in a plurality of systems for each predetermined unit according to the reproduction speed, and the read digital audio signal is output within one system of the predetermined unit. Depending on the playback speed, In a unit, and the digital audio signal recorded is delayed, it is possible to output the digital audio signals of a plurality of unit of a combination of a digital audio signal recorded without being corresponding delay.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below. According to the present invention, a digital VTR capable of simultaneously handling audio data of a plurality of channels and performing reproduction by tracing a helical track formed on a magnetic tape using a DT head is used.
At the time of recording, audio data is recorded on a first channel, and audio data of the first channel delayed by one frame is recorded on a second channel paired with the first channel. At the time of reproduction, when performing jog reproduction at a speed higher than the tape speed at the time of recording, for example, at twice the speed, the audio data of the original frame recorded on the first channel and the original frame recorded on the second channel are compared. And the audio data delayed by one frame as the reproduced audio data of the output frame. At this time, samples of audio data for two frames are appropriately thinned out and output so that the number of samples becomes one frame.

FIG. 1 shows an example of the audio data processing at the time of jog reproduction according to the present invention described above in more detail. For example, assume a VTR capable of processing 8-channel audio data. Channel 1 (CH
1), the fifth channel (CH5), and the second channel (C
H2) and the sixth channel (CH6), the third channel (CH3) and the seventh channel (CH7), and the fourth channel (CH4) and the eighth channel (CH8) are used as pairs of channels. Accordingly, audio data for substantially four channels can be recorded. In FIG. 1, in order to avoid complexity, CH1
And CH5 are shown as representatives.

At the time of recording, as shown in FIG. 1A, the recording of the input audio data is performed in units of frames in CH1 to CH4. On the other hand, CH1
CH5 to CH8 each forming a pair with
The audio data of H1 to CH4 are each recorded with a delay of one frame. In addition, a flag indicating that the channel is used and recorded as a pair is recorded together with the audio data as auxiliary data (AUX data).

At the time of normal reproduction in which reproduction is performed at a tape speed equal to the tape speed at the time of recording, as shown in an example in FIG. 1B, audio data of CH1 to CH4 is output as it is. The data of CH5 to CH8 are, for example, muted and not output.

On the other hand, in the case of, for example, double speed reproduction in the jog reproduction mode, the track is traced by the DT head by skipping one frame at a time, and data is reproduced, as already described with reference to FIG. You. Therefore, as shown in FIG. 1C, reproduced audio data is obtained every other frame in each of CH1 and CH5. As shown in FIG. 1D, data of two channels obtained every other frame in this manner is divided into two frames corresponding to CH1 and CH5.
The audio data for the frame is appropriately thinned out, arranged in the order of the time axis, and output during one frame period.

For example, in the case of a VTR corresponding to a system in which the sampling frequency of audio data is 48 kHz and 625 lines / 50 Hz, 19 frames per frame are used.
The data amount is 20 samples. Therefore, in the output data, the number of samples of audio data output in one frame period is set to 1920 so that the number of samples becomes 1920 samples.
Decimates audio data for frames.

FIG. 2 shows an example of a method of outputting paired two-channel data in one frame period. Each circle represents an audio sample. In the example of FIG. 2, for the sake of explanation, it is assumed that one frame of audio data consists of 20 samples. FIG. 2A shows reproduced audio data of the third frame of CH1, and FIG. 2B shows C data in which the data of CH1 is delayed by one frame.
14 shows audio data of H5. That is, the audio data of the second frame of CH5 corresponds to the third frame of CH1.

When outputting the audio data for these two frames, as shown in an example in FIG. 2C, first, the data of CH5, which is the temporally previous data, is thinned out every other sample and CH1 is output. Output as
Next, the data of CH1, which is the later data, is set to 1
It thins out every other sample and outputs it as CH1 data. By doing so, audio data for two frames is output in one frame period.

At this time, the pitch of the reproduced audio data is also doubled, so that the reproduced sound obtained is similar in tone to that obtained when the audio signal recorded in the longitudinal direction of the magnetic tape in the analog system is reproduced at double speed. Is obtained.

Next, an embodiment in which the present invention is applied to a digital VTR will be described. This embodiment is suitable for use in the environment of a broadcasting station, and enables recording and reproduction of video signals of a plurality of different formats. For example, in an interlaced scan based on the NTSC system, a signal (4
80i signal) and a signal with 576 effective lines (576i signal) in interlaced scanning based on the PAL system
Can be recorded / reproduced almost without changing hardware. Further, a signal having 1080 lines (1080i signal) in interlaced scanning, and a signal having 480 lines, 720 lines, and 1080 lines (480p signal, 720p signal, 1080p signal) in progressive scanning (non-interlace), respectively. Recording / reproduction such as can be performed.

Further, in this embodiment, the video signal is compression-coded based on the MPEG2 system, and the audio signal is treated uncompressed. As is well known, MPEG
No. 2 is a combination of motion compensation predictive coding and compression coding by DCT. The data structure of MPEG2 has a hierarchical structure, and includes a block layer, a macroblock layer, a slice layer, a picture layer, a GOP layer, and a sequence layer from the lowest level.

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

When an I-picture (Intra-coded picture) is encoded, closed information is used only in one of the pictures, and at the time of decoding, it can be decoded only with the information of the I-picture itself. . P picture (Predictive-
A coded picture: a forward predictive coded picture) and a B picture (Bidirectionally predictive-coded picture: a bidirectional predictive coded picture) cannot be decoded alone because a temporally preceding or preceding or succeeding picture is used as a predicted picture.

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

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

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

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

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, as described above, the P picture and the B picture require a temporally preceding picture or a preceding or 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.

FIG. 3 shows an example of the configuration on the recording side of the recording / reproducing apparatus 100 according to this embodiment. This recording / reproducing apparatus 100 uses a magnetic tape as a recording medium, and a jog reproduction mode in which a tape speed at the time of reproduction can be varied from one to several times the tape speed at the time of recording as a reproduction mode of the recording medium. Have.

At the time of recording, a digital video signal is input from a terminal 101 via a receiving unit of a predetermined interface, for example, SDI (Serial Data Interface). SD
I is an interface defined by SMPTE for transmitting (4: 2: 2) component video signals, digital audio signals and additional data.

The input video signal is supplied to the video encoder 10.
In step 2, the data undergoes DCT (Discrete Cosine Transform) processing, is converted into coefficient data, and the coefficient data is subjected to variable length coding. The variable length coded (VLC) data from the video encoder 102 is an elementary stream compliant with MPEG2. This output is supplied to one input terminal of the selector 103.

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

The elementary stream selected and output by the selector 103 is supplied to a stream converter 106. In the stream converter 106, the MPE
The DCT coefficients arranged for each DCT block based on the G2 rule are replaced with a plurality of DCTs constituting one macroblock.
Through the T block, frequency components are grouped, and the grouped frequency components are rearranged. The rearranged converted elementary stream is stored in the packing and shuffling unit 1.
07.

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 portion that protrudes from the fixed frame is sequentially packed into a surplus portion with respect to the size of the fixed frame. Also, system data such as time code is input to the input terminal 108.
Is supplied to the packing and shuffling unit 107, and the system data is subjected to a recording process similarly to the picture data. 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 section 107 (hereinafter, also referred to as video data even when system data is included unless otherwise necessary) are supplied to the outer code encoder 109. A product code is used as an error correction code for video data and audio data. The product code encodes an outer code in a vertical direction of a two-dimensional array of video data or audio data, encodes an inner code in a horizontal direction thereof, and encodes data symbols doubly. As the outer code and the inner code, a Reed-Solomon code can be used.

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

Audio data is supplied from an input terminal denoted by reference numeral 112. In this embodiment, uncompressed digital audio signals are handled, and multiple channels,
For example, eight channels of audio data of channels CH1 to CH8 can be handled simultaneously. The digital audio signal is a signal separated by an SDI receiving unit (not shown) or an SDTI receiving unit 105 on the input side, or a signal input via an audio interface. The input digital audio signal is supplied to the delay unit 11
3 to the AUX adding unit 114.

In this embodiment, the uncompressed digital audio data is AES / EBU (Audio Eng
It is input as serial data based on the standards of the ineering Society / European Broadcasting Union. Data having a bit width of up to 24 bits can be transmitted for one frame sequence. Two channels of audio data can be transmitted by one system of serial data, and the channel is switched every time the frame sequence is inverted. For example, one input system is assigned to each of a set of CH1 and CH2, a set of CH3 and CH4, a set of CH5 and CH6, and a set of CH7 and CH8. The 16-bit audio data is chronologically preceding the LSB side and following the MSB side, and the data is stuffed from the LSB side to the MSB side with respect to the frame sequence.

The delay section 113 is for adjusting the time between the audio signal and the video signal. When the recording mode is a mode corresponding to jog reproduction, the delay unit 11
3, the audio data of the predetermined input channel is delayed by one frame, and the audio data delayed by one frame is used as the audio data of another input channel paired with the predetermined input channel. In this embodiment, CH1 and CH5, CH2 and CH6, CH
3 and CH7 and CH4 and CH8 are fixedly paired, respectively.

FIG. 4 shows an example of the configuration of the delay unit 113. Note that, in FIG.
Only the configurations for 1 and CH5 are shown. The input audio data of CH1 is supplied to one input terminal of the switch circuit 200 and is also supplied to a delay circuit 201 for adjusting a delay amount between the audio data and the video data. On the other hand, the input audio data of CH5 is supplied to the other input terminal of the switch circuit 200. The output of the switch circuit 200 is supplied to the delay circuit 202.

The switch circuit 200 has one input terminal and the other input terminal switched according to the recording mode.
02, which audio data of CH1 and CH5 is input is selected. If the recording mode is a mode corresponding to the jog reproduction, the switch circuit is switched so that the input audio data of CH1 is supplied to the delay circuit 202, and if the recording mode is a mode corresponding to the jog reproduction, The input audio data of CH5 is selected so as to be supplied to the delay circuit 202.

When the recording mode is a mode corresponding to the jog reproduction, the delay circuit 202 adjusts the delay amount between the input audio data and the video data, and adjusts the delay amount of the input audio data by one. A frame delay is provided. If the recording mode is not a mode corresponding to jog reproduction, a delay is provided to the input audio data to adjust the amount of delay between the audio data and the video data.

Therefore, if the recording mode is a mode corresponding to jog reproduction, the delay circuit 201
1 is output and the delay circuit 2
01 is delayed by one frame with respect to the audio data output from
5 is output from the delay circuit 202 as audio data. In this case, since CH5 is treated as a channel paired with CH1, recordable audio data is limited to four channels.

On the other hand, if the recording mode is not jog reproduction, delay circuits 201 and 202 output C
The audio data of H1 and CH5 are output respectively. In this case, CH5 is treated as an independent channel.

The audio data output from delay section 113 is supplied to AUX adding section 114.

The audio AUX supplied from the input terminal 115 is auxiliary data, and the sampling frequency of the audio data and whether the data supplied from the input terminal 112 is audio data or non-audio data such as compressed audio data. Such as whether it is audio data,
This is data having information related to audio data. Also, information as to whether the recording mode is a mode corresponding to jog reproduction is supplied as an audio AUX. The audio AUX is added to the audio data by the AUX adding unit 114, and is treated the same as the audio data.

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

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

The 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.

In the configuration on the reproducing side of the recording / reproducing apparatus 100 shown in FIG.
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, and 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. The ID interpolation unit 134 extracts a DID (to be described later), which is information of data stored in the sync block.

The output of the ID interpolation unit 134 is supplied to the separation unit 135, and the video data and the audio data are separated. The separation is performed, for example, by separating data reproduced from the corresponding areas from each other. As described above, video data means DCT coefficient data and system data generated by MPEG intra coding, and audio data is PCM (Pulse Code Modu).
lation) means data and AUX.

The video data from the separation unit 135 is supplied to the deshuffling unit 136, and the processing opposite to the shuffling is performed. 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 13
6 is supplied to the outer code decoder 137, and error correction by the outer code is performed. When an error that cannot be corrected occurs, an error flag indicating the presence or absence of the error is set to indicate the presence of the error.

The output of the outer code decoder 137 is supplied to a deshuffling and depacking unit 138. The deshuffling and depacking unit 138 performs processing for restoring shuffling in macroblock units performed by the packing and shuffling unit 107 on the recording side. In the deshuffling and depacking unit 138,
Disassemble the packing applied during recording. That is, the length of the data is returned in units of macroblocks, and the original variable length code 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 section 140 performs processing for recovering the header (sequence header, GOP header, picture header, user data, etc.) when the header added to the head of the video data is an error.

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 constituting.

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

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

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

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

The output of the outer code decoder 152 is supplied to an AUX separation section 153, where the audio AUX is separated.
Although details will be described later, AUX data is AUX0, AUX
1 and AUX2. Audio AU isolated
X is taken out to the output terminal 154. AUX0 is supplied to the output unit 156 and the jog audio processing unit 160. Further, 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 section 155 is supplied to the output section 156. The output unit 156 controls a method of outputting the supplied data. For example, the output unit 156 performs a mute process for preventing the output of a predetermined channel from being output for a predetermined period, and a delay amount adjustment process for time alignment with video data. Error due to mute processing,
Output of audio data that cannot be interpolated can be prohibited.

The output unit 156 has an AUX separation unit 1
Based on AUX0 supplied from 53, it is determined whether or not the reproduction data corresponds to the jog reproduction mode. If it is determined that they correspond, CH5 to CH8 are
Since these are used in pairs with CH1 to CH4, these C
Outputs of H5 to CH8 are muted at the output unit 156.

The audio data output from the output unit 156 is supplied to the jog audio processing unit 160.
From the jog audio processing unit 160 to the output terminal 157,
Playback audio data is extracted.

In the jog audio processing section 160, the AU
AUX0 of AUX data extracted by X separation unit 153
, It is determined whether or not the current playback audio data corresponds to jog playback. If the playback mode corresponds to jog playback and the playback mode is the jog playback mode, the audio data whose channels have been paired at the time of recording as described above is output as one-channel audio data. At this time, as described above with reference to FIGS. 1 and 2, two frames of audio data composed of corresponding frames of two channels of the pair are appropriately thinned out and output in one frame period.

An example of a method of outputting audio data for two channels / 2 frames as data for one channel / 1 frame will be described with reference to FIG.
In FIG. 6, CH1 and CH1 are used for explanation.
Only the part related to CH5 paired with is shown. The playback audio data of each channel is stored in memory 2
11 is temporarily stored. For example, CH1 and CH5 input from the input terminals 210A and 210B, respectively.
Are stored in areas 211A and 211B defined by addresses on the memory 210, respectively.

The reading of the memory 211 is controlled in accordance with, for example, a read address supplied from a system controller described later. When the playback mode is normal playback,
Based on the read address, the area 211A of the memory 211
And the audio data of CH1 and CH5 stored in the memory 211B respectively, ie, 1
The data is read out so as to be output with the number of samples for one frame in the frame period.

On the other hand, if the playback mode is jog playback,
For example, in the case of 2 × speed reproduction, the areas 211A and 21A
In each of 1B, data is decimated and read out in a predetermined manner so as to output the number of samples of １ ／ frame in one frame period. That is, in this case, as shown in FIG. 2 described above, the data of two frames CH1 and CH5 are combined and one frame period is used.
It is read out so as to be output with the number of samples for the frame.

The data read from the area 211A of the memory 211 is supplied to the input terminal 212A of the switch circuit 212. The data read from the area 211B is supplied to the input terminal 212B of the switch circuit 212, is also led to the output terminal 213B, and is output as the output data of CH5. The output of the switch circuit 212 is led out to the output terminal 213A.

The switch circuit 212 is supplied with reproduction speed information from, for example, a system controller described later, and switching is controlled based on the supplied reproduction speed information. When the reproduction speed is the normal speed, the input terminal 212A is fixedly selected in the switch circuit 212.
As a result, the audio data of CH1 and CH5 output from the areas 211A and 211B are output from the output terminal 2
13A and 213B.

On the other hand, when the input audio data corresponds to the jog playback mode, and the playback speed is twice as fast as the recording speed by the jog playback, the switch circuit 212 is turned on. The input terminals 212A and 212B are alternately switched at a half frame period. Switching of the switch circuit 212 in a half frame cycle and reading from the areas 211A and 211B of the memory 211 described above are performed in synchronization with each other, and in a half frame cycle in which data is read from the area 211A, the input terminal is switched. In the half frame period in which data is read from the area 211B, the input terminal 211A is selected.
B is selected. At this time, the output from the output terminal 213B is muted.

As described above, when the input audio data corresponds to the jog reproduction, the data of CH5 is obtained by delaying the data of CH1 by one frame. Therefore, audio data in which data for two frames is thinned out to the number of samples for one frame is derived to the output terminal 213A.

By doing so, the tape speed at the time of recording can be reduced to 2
Even when double-speed playback is performed at double tape speed, audio data for two frames during double-speed playback is played back during the time for one frame during normal playback, and recorded on the longitudinal track of the magnetic tape. It is possible to obtain a sense of sound close to a reproduced sound when the reproduced audio data is reproduced at double speed.

Although not shown in FIGS. 3 and 5, a timing generator for generating a timing signal synchronized with the input data, and a system controller (microcomputer) for controlling the entire operation of the recording / reproducing apparatus
Etc. are provided.

In the above description, the access control of the memory 211 is performed by the system controller.
This is not limited to this example. For example, a DSP (Digital Signal Processor) may be provided in the jog audio processing unit 160, and access control of the memory 211 may be performed by the DSP. By giving a predetermined command to this DSP from the system controller, the DSP
Performs access control of the memory 211.

The jog audio processing section 160
By providing an SP and performing a predetermined operation in the DSP and controlling access to the memory 211 based on the operation result, it is possible to easily cope with not only the double speed but also the 1.5 times speed and other speeds. Will be able to

In this embodiment, recording of a signal on a magnetic tape is performed by a helical scan method in which a diagonal track is formed by a magnetic head provided on a 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 °, the rotation of the rotary head 1
By the rotation of 80 °, a plurality of tracks can be formed at the same time. The magnetic heads are formed as a set of two magnetic heads having different azimuths. The plurality of magnetic heads
The azimuths of adjacent tracks are arranged to be different from each other.

FIG. 7 shows an example of a track format formed on a magnetic tape by the rotary head described above. This is an example in which video and audio data per frame are recorded on eight tracks. For example, the frame frequency is 29.97 Hz, and the rate is 50 Mbp
s, the number of effective lines is 480, and the number of effective horizontal pixels is 720
A pixel interlace signal (480i signal) and an audio signal are recorded. When the frame frequency is 25H
z, the rate is 50 Mbps, the number of effective lines is 576, and the number of effective horizontal pixels is 720.
6i signal) and the audio signal can also be recorded in the same tape format as in FIG.

As shown in FIG. 7A, one segment is composed of two tracks having different azimuths. That is, eight tracks are composed of four segments.
Track number corresponding to azimuth for a set of tracks constituting a segment

[0] and track number [1]
Is appended. In each of the tracks, a video sector in which video data is recorded is arranged on both ends, and an audio sector in which audio data is recorded is arranged between the video sectors. FIG. 7A mainly shows the arrangement of audio sectors on the tape.

In the track format shown in FIG. 7A, audio data of eight channels can be handled. A1 to A8 indicate sectors of channels 1 to 8 of the audio data, respectively. The audio data is recorded with its arrangement changed in segment units. The audio data is an audio sample generated in one field period (for example, the field frequency is 29.97 Hz,
When the sampling frequency is 48 kHz, 800 samples or 801 samples) are divided into even-numbered samples and odd-numbered samples.
X forms one error correction block of the product code.

In FIG. 7A, data for one field is 4
Since the error correction blocks are recorded on the tracks, two error correction blocks per channel of the audio data are recorded on four tracks. The data (including the outer code parity) of the two error correction blocks is divided into four sectors, and FIG.
As shown in FIG. 2A, the data is dispersedly recorded on four tracks.
A plurality of sync blocks included in the two error correction blocks are shuffled. For example, two error correction blocks of channel 1 are constituted by four sectors to which reference numbers A1 are assigned.

In this example, as for video data, data for four error correction blocks is shuffled (interleaved) for one track, and the upper side
The data is divided into sectors by e and Lower Side and recorded. Although not shown, a system area is provided at a predetermined position in the video sector of the lower side.
Further, in FIG. 7A, between the video sector and the audio sector of the lower side, as well as the low side.
er Side audio sector and Upper Si
An area for recording a servo lock signal is provided between the audio sector de. Also,
A gap having a predetermined size is provided between the recording areas.

As shown in FIG. 7B, the data recorded on the tape is composed of a plurality of equally-spaced blocks called sync blocks. FIG. 7C schematically shows a configuration of the sync block. As will be described later in detail, the sync block is composed of a SYNC pattern for detecting synchronization, an ID for identifying each sync block, a DID indicating the content of subsequent data, a data packet, and an inner code parity for error correction. Is done. Data is,
It is treated as a packet in sync block units. That is, the smallest data unit to be recorded or reproduced is one sync block. A number of sync blocks are arranged (FIG. 7B) to form, for example, a video sector (FIG. 7A).

In the example of FIG. 7, the audio sector is composed of nine sync blocks. Each sync block in the same sector is of the same length and, as shown in FIG.
D numbers (SYNC IDs described later) are continuously assigned. The ID numbers are [FF] to [F7], [7F] to [71], [3F] to [FF] to [F7] in the head trace direction, for example, as shown in FIG.
[31] and [1F] to [11] (in hexadecimal notation) are continuously applied to each sector for each sync block. Lower Side and Upe
The same value is used for r Side. The ID information (ID1 described later) in the same sector takes the same value.

FIG. 8 more specifically shows the data structure of a sync block of video data, which is the minimum unit of recording / reproduction. In this embodiment, one or two macroblocks of data (VLC data) are stored for one sync block according to the format of video data to be recorded, and the size of one sync block is reduced. The length is changed according to the format of the video signal to be handled. As shown in FIG. 8A, one sync block includes:
From the beginning, a 2-byte SYNC pattern, a 2-byte I
D, a 1-byte DID, for example, a data area variably defined between 112 bytes and 206 bytes, and a 12-byte parity (inner code parity).

As shown in FIG. 9, an inner code parity is generated for an ID, a DID, and a data area, and the inner code is completed from the ID to the 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. 10A 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) are assigned. 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.

[0112] 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. 11 shows an example of the relationship between each data of ID1 and the track on the magnetic tape. In this example, one frame is recorded using eight tracks, and 16 tracks for two frames are shown. The track in one frame data is specified by the segment number of bits 5 to 2 and the track number of bit 1 (SG and TR in FIG. 11). Bits 1 and 7 specify from which sector in one track the data is reproduced from, for example, which audio sector of Upper Side and Lower Side is the data reproduced from (in FIG. 11). VA and UL). further,
In the case of an audio sector, it is specified which sector has been reproduced based on the SYNCID. Furthermore, the channel of the reproduced audio data is specified from the sector and track information.

FIG. 10B shows an example of DID bit assignment 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. 10C 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 (non-audio data). When, for example, compression-encoded audio data is stored in the payload, bit 3 has a value indicating general data. Bit 2 to bit 0 store information of a 5-field sequence in the NTSC system. That is, in the NTSC system, when the sampling frequency is 48 kHz, the audio signal for one field of the video signal is 80 bits.
Either 0 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.

Referring back to FIG. 8, FIGS. 8B to 8E
Shows an example of the above-mentioned payload. 8B and 8C
Shows an example in which video data (variable-length coded data) of 1 and 2 macroblocks is stored for the payload, respectively. In the example shown in FIG. 8B in which one macroblock is stored, length information LT indicating the length of the following macroblock is arranged in the first three bytes.
The length information LT may or may not include its own length. Also, as shown in FIG.
In the example in which the macroblock is stored, the length information LT of the first macroblock is arranged at the head, and the first macroblock is arranged subsequently. Then, length information L indicating the length of the second macroblock following the first macroblock
T is arranged, followed by a second macroblock.
The length information LT is information necessary for depacking.

FIG. 8D shows video A for the payload.
An example in which UX (auxiliary) data is stored will be described. The head length information LT describes the length of the video AUX data. Subsequent to the length information LT, 5-byte system information, 12-byte PICT information, and 92-byte user information are stored. The remaining portion of the payload length is reserved.

FIG. 8E 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. However, the present invention is not limited to this, and it is also possible to handle non-audio data, for example, audio data compressed and encoded by a predetermined method.

In this embodiment, the length of the payload, which is the data storage area of each sync block, is not optimally set for 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, a plurality of different signal formats can be handled uniformly.

FIG. 12A shows the DCT of the MPEG encoder.
4 shows the order of DCT coefficients in video data output from the circuit. Starting from the upper left DC component in the DCT block, DCT coefficients are output in a zigzag scan in the direction in which the horizontal and vertical spatial frequencies increase. As a result, as shown in an example in FIG. 12B, a total of 64 (8 pixels × 8 lines) DCT coefficients are obtained by being arranged in the order of frequency components.

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

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

FIG. 13 shows the stream converter 10.
6 schematically shows the rearrangement of DCT coefficients in FIG.
In the case of a (4: 2: 2) component signal, one macroblock is composed of four DCT blocks (Y ₁ , Y ₂ , Y ₃ and Y ₄ ) based on a luminance signal Y and chromaticity signals Cb and C.
r, two DCT blocks (C
b ₁ , Cb 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. 13A, DCT coefficients are arranged in order of frequency components from DC components and low frequency components to high frequency components for each DCT block. When scanning of one DCT block is completed, scanning of the next DCT block is performed, and similarly, DCT coefficients are arranged.

That is, a DCT block is included in a macroblock.
Lock Y₁, Y_Two, Y_ThreeAnd Y_Four, DCT block C
b₁, Cb_Two, Cr₁And Cr_TwoAbout each of
The DCT coefficient is changed from the DC component and the low-frequency component to the high-frequency component.
Are arranged in order of frequency. And a continuous run
[DC, AC]₁, AC
_Two, AC_Three,...]
Variable-length coding.

The stream converter 106 decodes the variable-length coded and arranged DCT coefficients once by decoding the variable-length code to detect a break of each coefficient, and extends the frequency over each DCT block constituting the macro block. Summarize by component. This is shown in FIG. 13B. 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
(Y₁), DC (Y_Two), DC (Y_Three), DC
(Y_Four), DC (Cb₁), DC (Cr₁), DC (C
b_Two), DC (Cr _Two), AC₁(Y₁), AC₁(Y
_Two), AC₁(Y_Three), AC₁(Y_Four), AC₁(Cb
₁), AC₁(Cr₁), AC₁(Cb_Two), AC
₁(Cr_Two), ... Where DC, AC₁,
AC_Two,... Are described with reference to FIG.
Assigned to a set of runs and subsequent levels
Of the variable length codes obtained.

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. 14 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 is matched with the sync block length, 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. 14, for simplicity, it is assumed that one frame includes eight macroblocks.

As shown in FIG. 14A, the lengths of eight macroblocks are different from each other due to the variable length coding. In this example, as compared with the length of one sync block, which is a fixed frame, the data of macro block # 1, the data of # 3 and the data of # 6 are each longer, and the data of macro block # 2, the data of # 5, # 7 data and #
8 are short. Also, 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. 14B, a macroblock longer than one sync block is divided at a position corresponding to the sync block length. Of the divided macroblocks, the portion (overflow portion) that protrudes from the sync block length is packed in an area that is vacant in order from the beginning, that is, after the macroblock whose length is less than the sync block length.

In the example of FIG. 14B, macro block # 1
The portion that protrudes from 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, a portion of the macro block # 6 that protrudes from the sync block length is packed behind the macro block # 7, and a portion that protrudes further from the macro block # 7.
Stuffed behind 8. Thus, each macroblock is packed in a fixed frame of the sync block length.

The length of each macro block 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. 15 shows an example of an error correction code used in one embodiment, FIG. 15A shows one error correction block of an error correction code for video data, and FIG. 15B shows an error correction code for audio data. 3 shows one error correction block. In FIG. 15A, VL
The C data is data from the packing and shuffling unit 107. SYN for each row of VLC data
By adding the C pattern, ID, and DID, and further adding the parity of the inner code, one SYNC block is formed.

That is, a 10-byte parity of the outer code is generated from a predetermined number of symbols (bytes) aligned in the vertical direction of the array of VLC data, and the ID, DID and VLC data (or external data) aligned in the horizontal direction are generated. Parity of the inner code is generated from a predetermined number of symbols (bytes) of the code parity. In the example of FIG. 11A, 10 outer code parity symbols and 12 inner code parity symbols are added. As a specific error correction code, a Reed-Solomon code is used. FIG.
In 5A, the lengths of VLC data in one SYNC block differ from each other in 59.94 Hz, 25 Hz, 23.
This is because the frame frequency of video data is different, such as 976 Hz.

As shown in FIG. 15B, the product code for audio data is the same as that for video data.
The parity of the 10-symbol outer code and the parity of the 12-symbol inner code are generated. In the case of audio data, the sampling frequency is, for example, 48 kHz.
And one sample is quantized to 16 bits. One sample may be converted into another bit number, for example, 24 bits. According to the difference in the frame frequency described above, 1SYN
The amount of audio data in the C block is different.
As described above, one field of audio data /
One channel forms two error correction blocks. One error correction block includes one of the even-numbered and odd-numbered audio samples and the audio AUX as data.

In the recording / reproducing apparatus 100 described above, the audio data has a bit width of one sample of 16 bits (2 bits).
Bytes). Next, with this device 100,
A method of handling audio data and non-audio data in common will be described. First, the recording format of audio data will be described in more detail.

In the following description, audio data having a bit width of 16 bits per sample is assumed to be 1 bit.
Briefly described as 6-bit audio data.

FIG. 16 shows the outer code encoder 11 described above.
6 shows an example of audio data to which an outer code parity is added. This is an example in which the sampling frequency is audio data of 48 KHz and the field period of the video data is 50 Hz. The 960 samples of audio data correspond to one video period. In each channel of the audio data, two error correction blocks in which the outer code parity of 10 sync blocks is added to the audio data of 8 sync blocks are formed in one field period. That is,
The audio data for one field period includes 36 sync blocks including the outer code parity.

In the audio data of each channel, even-numbered samples and odd-numbered samples in one field period constitute one error correction block. In FIG. 16, each frame in one error correction block represents one sample of data. In this example, since one sample is 16 bits (2 bytes), each frame is data of 16 bits. One row in the horizontal direction corresponds to one sync block. The number added to the head of each row is called an outer code number, and is an identification number of a sync block within one field period.

In each of the first three sync blocks of each error correction block, AU is added to the first sample.
X data is stored. FIG. 17 shows an example of the content of each AUX data. FIG. 17A shows the bit assignment of AUX data, and FIG. 17B shows the meaning of each data.

AUX0 is 2 representing an audio edit point.
Bit data EF, 1 indicating whether the quantization bit number of the audio sample is 16 bits or 24 bits
Bit length data B, 1-bit data D indicating whether or not the data is uncompressed audio data, 2-bit audio mode Amd for determining whether this channel is a paired channel with another channel, and a sampling frequency of 48KHz, 44.1KHz, 32KH
It consists of 2-bit data FS indicating which of z and 96 Hz. The next 8 bits and one sample are 24
If it is a bit, 8 more bits are reserved.
ed (reserved).

As can be seen from FIG. 17B, the audio mode Amd has a value

A value other than [00] indicates that the channel of the audio data forms a pair with another channel. That is, if the value is

In [00], it is indicated that the audio data is data of an independent channel, and when the values are [01] and [10], the data amount per unit exceeds the original data amount. It is shown that one audio data is formed in combination with another channel.

On the other hand, when the value of the audio mode Amd is [1
In [1], at the time of the above-described jog reproduction, the audio data is paired with the original frame to generate one frame of audio data using the audio data of the original frame and the audio data of one frame before. This indicates that the audio data is audio data.

AUX1 is entirely reserved.
(Reserved). The data AUX2 has the format mode in the first 8 bits. If the subsequent 8 bits and one sample are 24 bits, another 8 bits are reserved. The format mode is a 2-bit [Line mod].
e], 2-bit [Rate], 1-bit [Sca
n] and 3 bits [Freq]. These [Li
The video format can be known from [ne mode], [Rate], [Scan], and [Freq].

As described above, the information indicating whether or not the recording corresponding to the jog reproduction has been performed is the audio AU.
Since the audio mode Amd in X is recorded on the magnetic tape, the processing can be automatically changed on the reproducing device side. An example of an operation mode of the digital VTR 100 according to the embodiment will be described with reference to FIGS.

The two digital VTRs 400 and 401 exemplified in FIGS. 18A and 18B respectively correspond to the above-described digital VTR 100, have substantially the same internal configuration, and have eight channels of audio. It is possible to record data simultaneously. However, the digital VTR 400 has only four input / output channels. Digital VTR
401 has input / output of 8 channels. Consider a case where tape 402 is exchanged between digital VTRs 400 and 401.

In this example, the digital VTR 401
The input audio data for eight channels is recorded. FIG. 19B shows an example of a recording format of audio data in the digital VTR 401. In this way, audio data of CH1 to CH8 is recorded in a predetermined manner for each of the four systems. At this time, CH1
The values of Amd in AUX0 of 4 and CH5-8 are both

[00].

On the other hand, in the digital VTR 400, recording is performed in a jog reproduction compatible mode. That is, the input audio data for the four channels is recorded as CH1 to CH4. At the same time, audio data with a delay of one frame given to each of the input four-channel audio data is recorded as CH5 to CH8.

FIG. 19A shows an example of a recording format of audio data in the digital VTR 400. Of the four systems, the two systems in which CH1 / 2 and CH3 / 4 are to be recorded include the input CH1 / 2 and C
H3 / 4 audio data is recorded. Since these two systems have no difference from normal recording, the value of Amd in AUX0 is

[00].

On the other hand, CH5 / 6 and CH7 /
8 is to be recorded, the input CH1 / 2
And CH3 / 4 audio data are recorded after being delayed by one frame. These two systems correspond to the above-described CH1 / 2.
And CH3 / 4 audio data are used as a pair for two systems, so that A in AUX0 is used as a pair.
The value of md is [11], which indicates that recording is being performed in a mode corresponding to jog reproduction.

For example, when audio data of channels 1 to 8 are recorded on the tape 402 by the digital VTR 401, the digital VTR 400 determines the recording mode of the audio data based on the audio mode Amd, and reproduces only the channels 1 to 4. And CHs 5 to 8 are muted. When only the audio data of CH1 to CH4 is recorded on the tape 402 by the digital VTR 400, the digital VTR 401 determines the recording mode of the audio data based on the audio mode Amd, and reproduces the audio data of CH1 to CH4. CH5 to CH8 are muted.

A digital VTR 4 for the tape 402
Even when the recording areas of 00 and 401 are mixed,
By referring to the audio mode Amd at the time of reproduction, processing can be automatically switched on the device side. FIG.
A is an example in which audio data in a mode corresponding to jog playback is recorded and inserted into a predetermined section of a tape on which audio data is recorded on eight channels. Tape 402
Has previously recorded audio data of eight channels. In the digital VTR 400, the tape 40
No. 2 is reproduced by muting the channels 5 to 8 in the digital VTR 400, and in the section 404 as an insertion point, CH1
To 4 record input audio data, and CH 5 to 8
Records data obtained by delaying the input audio data recorded in CH1 to CH4 by one frame. CH5-8
Of the audio mode Amd in the sections 403 and 404
And 403 '

[00], [11] and

[00]
And change. At the time of reproduction, the reproduction mode is automatically set based on the audio mode, and the reproduction mode is switched.

FIG. 20B shows a state where a predetermined section of a tape on which audio data is recorded in a mode corresponding to jog reproduction is recorded.
This is an example of recording and inserting audio data of eight channels. Audio data is recorded on the tape 402 in advance in a mode corresponding to jog reproduction. Therefore, the audio data of CH1 to CH4 delayed by one frame is recorded at the position where CH5 to CH8 is to be recorded. In the digital VTR 401, CH5
8 is muted and played back, and the section 40 as the insertion point is
At 6, audio data of CHs 1 to 8 is recorded. C
The value of the audio mode Amd for H5 to H8 is in the section 40.
5, 406 and 405 ', [11],

[00] and [11]. At the time of reproduction, the reproduction mode is automatically set based on the audio mode, and the reproduction mode is switched.

As described above, even when the mode corresponding to the jog reproduction and the normal recording mode are mixed on one tape 402, the reproduction side refers to the audio mode Amd on the CH5-8 side to reproduce the data. The mode can be switched automatically.

[0156]

As described above, according to the present invention, a digital audio signal is recorded as a signal of one channel each as a pair of signals delayed by one frame. Therefore, when performing double-speed playback using a dynamic tracking head, the signals of the paired channels are combined and thinned out in a predetermined manner to output a signal of one channel. There is an effect that an audio signal recorded on a longitudinal track in the analog system can be made close to the sound sensation at the time of double speed reproduction.

Further, according to the embodiment of the present invention, the sound pitch of the reproduced sound at the time of the double speed reproduction is close to the sound pitch at the time of the double speed reproduction of the audio signal recorded on the longitudinal track in the analog system. Since the functions that can be performed and the number of channels that can be recorded on the magnetic tape can be selected in a trade-off, there is an effect that it is possible to respond to a wider range of user requests.

Furthermore, according to one embodiment of the present invention,
Since the fact that the digital audio signal is recorded as a pair with the signal delayed by one frame is recorded on the magnetic tape as the flag Amd, an area where the channel is recorded as a pair in one magnetic tape Even if there are areas in which channels and channels are independently recorded, these recording modes can be automatically determined during reproduction.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of audio data processing during jog reproduction according to the present invention.

FIG. 2 is a schematic diagram illustrating an example of a method of outputting paired two-channel data in one frame period.

FIG. 3 is a block diagram illustrating an example of a configuration on a recording side of the recording / reproducing apparatus according to the embodiment of the present invention.

FIG. 4 is a block diagram illustrating a configuration example of a delay unit;

FIG. 5 is a block diagram illustrating an example of a configuration on a reproducing side of the recording / reproducing apparatus according to the embodiment of the present invention.

FIG. 6 is a block diagram showing an example of a configuration for outputting audio data for two channels / one frame as data for one channel / one frame.

FIG. 7 is a schematic diagram illustrating an example of a track format formed on a magnetic tape by a rotating head.

FIG. 8 is a schematic diagram more specifically showing a data configuration of a sync block of video data.

FIG. 9 is a schematic diagram illustrating an example of an inner code parity in the case of audio data.

FIG. 10 shows an ID and DI added to a sync block.
It is a schematic diagram which shows the content of D.

FIG. 11 is a schematic diagram illustrating an example of a relationship between each data of ID1 and a track on a magnetic tape.

FIG. 12 is a schematic diagram for explaining an output method of a video encoder and variable-length encoding.

FIG. 13 is a schematic diagram for explaining rearrangement of an output order of a video encoder.

FIG. 14 is a schematic diagram for explaining a process of packing data whose order is rearranged into a sync block.

FIG. 15 is a schematic diagram for explaining an error correction code for video data and audio data.

FIG. 16 is a schematic diagram illustrating an example of audio data to which an outer code parity has been added;

FIG. 17 is a schematic diagram illustrating an example of the content of each AUX data.

FIG. 18 is a diagram for describing an example of an operation mode of the digital VTR according to the embodiment.

FIG. 19 is a diagram illustrating an example of an operation mode of the digital VTR according to the embodiment.

FIG. 20 is a schematic diagram illustrating an example in which audio data in a mode corresponding to jog reproduction is recorded and inserted into a predetermined section of a tape on which audio data is recorded on eight channels.

FIG. 21 is a block diagram showing a configuration of an example of a digital VTR according to the related art.

FIG. 22 is a schematic diagram showing a relationship between frames of data reproduced at 2 × speed reproduction when a DT head is used.

[Explanation of symbols]

100: recording / reproducing device, 113: delay unit, 11
4: AUX addition circuit, 116: outer code encoder, 117: shuffling, 118: ID addition circuit, 119: inner code encoder, 120: S
YNC additional circuit, 123 ... magnetic tape, 132 ...
SYNC detection circuit, 133... Inner code decoder, 1
34 ... ID interpolation circuit, 151 ... Deshuffling circuit, 152 ... Outer code decoder, 153 ... AU
X separation circuit, 155: interpolation circuit, 156: output unit, 160: jog audio circuit, 201, 20
2 ... delay circuit, 211 ... memory

Claims (9)

[Claims] 1. A signal recording apparatus capable of recording a plurality of systems of digital audio signals on a magnetic tape in predetermined units, comprising: input means capable of inputting a plurality of systems of audio signals; Delay means for giving a delay amount of one unit in predetermined units to each of the digital audio signals; each of the plurality of digital audio signals input by the input means; and the digital audio signal delayed by the delay means And a recording means for recording each of these on a magnetic tape in the predetermined unit. 2. The signal recording apparatus according to claim 1, wherein the digital audio signal input by the input unit and the digital audio signal whose digital audio signal is delayed by the delay unit are paired. A signal indicating the flag is recorded on the magnetic tape. 3. A signal recording method capable of recording a plurality of systems of digital audio signals on a magnetic tape in a predetermined unit, comprising: an input step capable of inputting a plurality of systems of audio signals; A delay step of giving a delay amount of one unit in a predetermined unit to each of the audio signals of the systems, each of the audio signals of the plurality of systems input by the inputting step, and the delaying by the delaying step A step of recording each of the audio signals on a magnetic tape in the predetermined unit. 4. A digital audio signal is reproduced using a dynamic tracking head from a magnetic tape in which a plurality of systems of digital audio signals are recorded in helical tracks in a predetermined unit, and a tape speed n (n> 1) at the time of recording is reproduced. A signal reproducing apparatus capable of reproducing at a double tape speed, a reproducing means for reproducing, using a dynamic tracking head, a plurality of digital audio signals recorded in a predetermined unit on a magnetic tape by a helical track; Storage means for storing each of the reproduced digital audio signals of the plurality of systems; and converting the digital audio signals stored in the storage means to the number of audio samples corresponding to the predetermined unit in accordance with a reproduction speed. In addition, a plurality of A signal reproducing apparatus comprising: a readout unit that reads out a plurality of systems; and an output unit that outputs the digital audio signal read out over a plurality of systems for each of the predetermined units by the readout unit within one system of a predetermined unit. . 5. The signal reproducing apparatus according to claim 4, wherein, based on a flag recorded on a magnetic tape, of the plurality of digital audio signals reproduced by the reproducing means, the plurality of digital audio signals are read by the reading means. A set of digital audio signals to be read over the digital audio signal. 6. A digital audio signal is reproduced using a dynamic tracking head from a magnetic tape in which a plurality of systems of digital audio signals are recorded in helical tracks in predetermined units, and a tape speed n (n> 1) at the time of recording is reproduced. In a signal reproducing method capable of reproducing at a double tape speed, a reproducing step of reproducing, using a dynamic tracking head, digital audio signals of a plurality of systems recorded on a magnetic tape by a helical track in a predetermined unit; Storing each of the digital audio signals of the plurality of systems reproduced by the step in a storage means; and converting the digital audio signals stored in the storage means into audio samples corresponding to the predetermined unit in accordance with a reproduction speed. To be a number A reading step of reading over a plurality of systems for each of the predetermined units; and an output step of outputting the digital audio signal read over a plurality of systems for each of the predetermined units by the reading step within one system of a predetermined unit. A signal reproducing method comprising: 7. A digital audio signal of a plurality of systems can be recorded on a magnetic tape by a helical track in a predetermined unit, a digital audio signal is reproduced from the magnetic tape using a dynamic tracking head, and a tape speed n (n) at the time of recording is reproduced. > 1) In a signal recording / reproducing apparatus capable of reproducing at a double tape speed, an input means capable of inputting a plurality of audio signals, and a plurality of digital audio signals input by the input means, Delay means for giving a delay amount of one unit per unit; each of the plurality of digital audio signals input by the input means; and each of the digital audio signals delayed by the delay means in the predetermined unit , A recording hand that records on magnetic tape by helical tracks A stage, reproducing means for reproducing the plurality of digital audio signals recorded on the magnetic tape using a dynamic tracking head, and storage for storing each of the plurality of digital audio signals reproduced by the reproducing means. Means for reading out the digital audio signal stored in the storage means over a plurality of systems for each predetermined unit so as to have the number of audio samples corresponding to the predetermined unit in accordance with a reproduction speed; An output unit for outputting the digital audio signal read by the reading unit over a plurality of systems for each of the predetermined units within a predetermined unit of one system. 8. The signal recording / reproducing apparatus according to claim 7, wherein the digital audio signal input by the input means and the digital audio signal obtained by delaying the digital audio signal by the delay means form a pair. A flag indicating that the digital audio signal is read out by the reading unit over the plurality of systems out of the digital audio signals of the plurality of systems reproduced by the reproducing unit based on the flag recorded on the magnetic tape. A signal recording / reproducing apparatus, wherein a set of the digital audio signals is determined. 9. A digital audio signal of a plurality of systems can be recorded on a magnetic tape by a helical track in a predetermined unit, a digital audio signal is reproduced from the magnetic tape using a dynamic tracking head, and a tape speed n (n) at the time of recording is reproduced. > 1) In a signal recording / reproducing method capable of reproducing at a double tape speed, an input step capable of inputting a plurality of systems of audio signals; and a digital audio signal of the plurality of systems input by the input step. A delay step of providing a delay amount of one unit in a predetermined unit; each of the plurality of digital audio signals input in the input step; and each of the digital audio signals delayed in the delay step. The helical truck Recording on a magnetic tape, reproducing the digital audio signals of a plurality of systems recorded on the magnetic tape using a dynamic tracking head, and reproducing the plurality of digital audio signals on the magnetic tape. Storing each of the digital audio signals of the system in storage means; and converting the digital audio signals stored in the storage means to the number of audio samples corresponding to the predetermined unit according to a reproduction speed. A step of reading out a plurality of systems for each predetermined unit; and an output step of outputting the digital audio signal read out for a plurality of systems in the predetermined unit by the reading step in one system of a predetermined unit. Signal recording characterized by the following: Playback method.