JPH1118052A - Digital recording and reproducing device and its method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allown an identical hardware for processing video signals of different standards. SOLUTION: Timing generators 100-102 generate a clock signal with frequencies corresponding to the frequencies of video signals of different systems respectively up to an input side of an input filter 13 and an output side of an output filter 55 are operated at a clock f1 , and the output side of the input filter 13 and up to the input side of the output filter 55 are operated at a clock f2 . The timing generators 100-102 are switched depending on the system of the processed video signal, and the clock frequency is changed. A rotary speed of a rotary heat and a tape speed are changed. An audio signal is processed at a sampling rate of 48 kHz at all times. The number of bits for one sample of the audio signal is changed, depending on the system of the video signal to be processed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a digital recording / reproducing apparatus and method for recording / reproducing video signals of different systems with common hardware.

[0002]

2. Description of the Related Art A signal processing apparatus for processing a video signal in a digital manner, for example, a high definition (High Definition) apparatus.
n) In a signal processing device used for a digital video tape recorder (hereinafter abbreviated as HD-VTR) for recording and reproducing video signals, image compression encoding is performed on an input video signal. Then, the compression-encoded video signal is recorded on, for example, a video tape.
In order to record / play back high data rate recording data,
A helical scan type recording / reproducing apparatus in which a magnetic tape is obliquely wound around a rotating drum and a magnetic head is attached to the rotating drum is known. In this device, recording data is sequentially recorded so as to form oblique tracks on a magnetic tape.

In recording a signal on a video tape, an encoding process using a product code is often performed for error correction. In the coding by the product code, data arranged in a matrix in units of one symbol (for example, one byte) is respectively coded in a column direction by, for example, a Reed-Solomon code, and an outer code parity is set. Generated. Then, the data and the outer code parity are encoded in the row direction to generate an inner code parity. As described above, the outer code parity is generated in the column direction and the inner code parity is generated in the row direction, so that the error correction coding by the product code is performed. At this time, the time-series order of the data coincides with, for example, the row direction.

By the way, in such an HD-VTR, for example, in the NTSC area such as Japan and the United States, the field frequency is set to 60 Hz in consideration of compatibility with the conventional system. Similarly, in a PAL area such as European countries, the field frequency is 50 Hz. Also,
In consideration of application to movies, compatibility is easy if 24 frames per second used in movie film, that is, 24 frames / second in a video signal.

[0005] As described above, the requirements for the HD-VTR differ depending on the market. Providing hardware and formats that facilitate this is
This is important even considering the benefits and economics of the user.

[0006]

Conventionally, for example, PA
In the L zone, 1250 scanning lines and a field frequency of 5
Hardware that conforms to a standard of 0 Hz and that performs interlaced scanning has been considered. In the following, this "1250 scanning lines, 50 Hz field frequency,
Abbreviated as "interlaced scanning". The same applies to other similar notations. However, this 1250/5
0i system hardware is 1125/6 in the NTSC area.
By simply modifying the hardware that supports the 0i method,
There was a problem that it was difficult to realize. That is, the hardware corresponding to the 1250 / 50i system had to be independently developed separately from the hardware of the 1125 / 60i system.

In the 1250 / 50i system, 1
In obtaining compatibility with the 125 / 60i system, there are various differences based on the standards of both systems, such as a difference in field frequency and a difference in the number of scanning lines, which has been an obstacle. Therefore, conventionally, there has been a problem that a large-scale device is required for conversion between these formats.

Further, there is a problem in application to a movie of the 1125 / 60i system. For a movie with 24 frames / sec, the NTSC system has 30 frames / sec. Therefore, when recording video of a movie film with the 1125 / 60i HD-VTR, a method of inserting a black image at a rate of, for example, 6 frames per second has been adopted. However, this method has a problem that handling a black image when editing a tape is very troublesome. In addition, when recording a movie film, for example, a method of shortening the recording time and performing the recording has been adopted. This method also has a problem that inconvenience in time management occurs.

Further, 1125 / 60i system, 12
The amount of information differs between the 50 / 50i system and the 24 frame / second system for movies. Conventionally, there has been a problem that different hardware and formats are required for recording / reproducing signals having different amounts of information.

It is therefore an object of the present invention to provide a digital recording / reproducing apparatus and method for handling video signals of different systems with the same hardware.

[0011]

According to the present invention, there is provided a digital recording apparatus for recording and reproducing first and second video signals having different numbers of frames per second from each other. In the reproducing apparatus, the video signal processing means for processing the first and second video signals is common, and the processing of the first video signal is different from that of the first video signal in that the number of frames per second is different. A digital recording / reproducing apparatus characterized in that the clock frequency used for processing in the video signal processing means is changed between the case of processing the second video signal.

Further, in order to solve the above-mentioned problems, the present invention provides first and second video signals having different numbers of frames per second and first and second video signals corresponding to the first and second video signals, respectively. And a second audio signal recorded and reproduced by a digital recording / reproducing apparatus, wherein the audio signal processing means for processing the first and second audio signals is common, and the audio signal processing means comprises the first and second audio signals. A digital recording / reproducing apparatus for performing processing of a first audio signal and a second audio signal so that the second audio signal can be recorded in a recording area of the same size.

Further, according to the present invention, in order to solve the above-mentioned problem, first frames having different numbers of frames per second are used.
And a second recording / reproducing apparatus in which a second video signal is recorded and reproduced on a helical track by a rotating drum, when the first video signal is recorded and when the first video signal is transmitted per second. Wherein the rotation speed of the rotary drum and the running speed of the magnetic tape are changed so that the track pattern is substantially the same as when recording a second video signal having a different number of frames. It is a recording and reproducing device.

Further, according to the present invention, in order to solve the above-mentioned problem, first frames having different numbers of frames per second are used.
And a digital recording / reproducing method adapted to record and reproduce a second video signal, wherein the video signal processing steps for processing the first and second video signals are common and the first video signal is processed. And a case where a second video signal having a different number of frames per second from the first video signal is processed, wherein a clock frequency used for processing in the video signal processing step is changed. This is a digital recording / reproducing method.

Further, according to the present invention, in order to solve the above-described problems, first and second video signals having different numbers of frames per second and first and second video signals respectively corresponding to the first and second video signals are provided. And a second audio signal, wherein the step of processing the audio signal for processing the first and second audio signals is common, and the step of processing the audio signal is a second step. A digital recording / reproducing method characterized in that the first and second audio signals are processed so that the first and second audio signals can be recorded in a recording area of the same size.

Further, according to the present invention, in order to solve the above-mentioned problem, first frames having different numbers of frames per second are used.
And a digital recording / reproducing method in which the second video signal is recorded and reproduced on a helical track by a rotating drum, when the first video signal is recorded and when the first video signal is transmitted per second. Wherein the rotation speed of the rotary drum and the running speed of the magnetic tape are changed so that the track pattern is substantially the same as when recording a second video signal having a different number of frames. This is a recording / reproducing method.

As described above, in the present invention, the signal processing of the first video signal and the signal processing of the second video signal having a different number of frames per second from the first video signal are common. The processing means changes the clock frequency, the rotation speed of the rotating drum, and the running speed of the magnetic tape, and changes the first audio signal and the second audio signal accompanying the first and second video signals, respectively. Are processed by common processing means and are recorded in recording areas of the same size, so that processing of the first and second video signals having different numbers of frames per second by the same hardware is performed. Can be performed.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. According to the present invention, a video signal of a different system can be handled by the same hardware by switching a clock frequency and a rotation speed of a rotary drum in signal processing. In this embodiment, as a video signal, 1125 / 60i system, 1
125 / 50i system and 1125 / 48i system,
It is intended for signals of the 1125 / 24p system using progressive scan (abbreviated as "p") without interlacing. In addition, 1125 / 24p
In the scheme, “24 Hz” means a frame frequency.

FIG. 1 shows an example of the configuration of one frame according to this embodiment. In FIG. 1, the hatched portions represent vertical and horizontal blanking periods,
Other parts are effective pixel areas. The numbers in the horizontal direction are sample numbers corresponding to the pixels, and the numbers in the vertical direction are line numbers. 2200 pixels in the horizontal direction,
In the vertical direction, each is composed of 1125 lines.
Of these, 1920 pixels are regarded as effective pixels in the horizontal direction. In the vertical direction, the 21st to 560th lines (first field) and the 584th to 1123rd lines (second field) are effective lines.
That is, one field is composed of 1920 pixels × 540 lines. This frame structure is commonly applied to video signals according to the above-described four methods.

FIG. 2 shows a frame structure for one second when video signals of the above-described systems are handled in this embodiment. FIG. 2A shows a signal of the 1125 / 60i system. 1
There are 30 frames per second and the number of fields is doubled to 60 fields. If the video signal is a 4: 2: 2 component signal, the sampling rate of the luminance signal Y is 74.25 MHz, and the sampling rate of the color difference signals Pb / Pr is 37.125 MHz.

FIG. 2B shows a 1125 / 50i signal. There are 25 frames per second, and the number of fields is doubled to 50 fields. In the time of 6 frames of the 1125 / 60i system shown in FIG.
Five frames of the 5 / 50i system are configured. The sampling rate is 61.875 MHz for the luminance signal Y and 30.9375 MHz for the color difference signals Pb / Pr. That is, based on the rate of the 1125 / 60i system, 7
4.52 MHz × 5/6 = 61.875 MHz, 37.
125 MHz × 5/6 = 30.9375 MHz.

As described above, the number of scanning lines is 1250 in the PAL area system. However, the number of scanning lines is 1125 by omitting margin areas arranged above and below the effective pixel area. It can be. The conversion of the number of scanning lines may be performed by a predetermined interpolation process. It is also possible to combine these methods.

FIG. 2C shows a 1125 / 24p signal. There are 24 frames per second. This is a signal obtained when one image is taken in 1/24 second, for example, when shooting with a video camera. In the time of 5 frames of the 1125 / 60i system shown in FIG.
Four frames of the 125 / 24i system are configured. The sampling rate is 59.4 MHz for the luminance signal Y and 29.7 MHz for the color difference signals Pb / Pr. That is, 11
74.52M based on 25 / 60i system rate
Hz × 4/5 = 59.4 MHz, 37.125 MHz ×
4/5 = 29.7 MHz.

In this case, in order to convert a signal which is originally a progressive scan into a signal for performing interlaced expression, scanning line information of the first field and scanning line information of the second field are arranged alternately on the screen. You. That is, as shown in FIG.
The first line of the field is assigned to the 21st line, and the next line is assigned to the first line of the second field, the 584th line. The next line is assigned to line 22. Thus, lines are allocated on the comb teeth.

The 1125 / 24p system is suitable for use, for example, when a video output by this system is burned onto a film by some kind of conversion means to produce a movie or the like. It is also suitable for the purpose of enhancing the affinity with the image display in progressive scan, which is generally used as a display method on a CRT of a computer.

Although not shown in FIG.
In the 5 / 48i system, there are 24 frames per second as in the 1125 / 24i system, and the number of fields is twice as many. The sampling rate is
59.4 MHz for luminance signal Y and 2 for color difference signal Pb / Pr
9.7 MHz. Four frames of the 1125 / 24i system are constituted by five frames of the 1125 / 60i system.

As can be seen from FIGS. 2A to 2C, the respective methods can be associated with each other by expanding and contracting the time axis. For example, by extending the time axis of the 1125 / 60i system as appropriate, it is possible to cope with other systems. In the present invention, this is applied to video signal processing.

Next, a case where the present invention is applied to an HD-VTR will be described. Recording performed by the HD-VTR is performed by a helical scan method in which tracks are formed obliquely with respect to a magnetic tape by a magnetic head provided on a rotating drum, for example, and have different angles from each other. An azimuth method is used in which azimuths are recorded differently on adjacent tracks by one set of magnetic heads.

FIGS. 3 and 4 show an example of this recording method. As shown in an example in FIG.
Magnetic heads 2A, 2B, 2C, and 2D for recording
Is provided. The four magnetic heads 2A, 2B, 2C, and 2D are set as a set of two magnetic heads, and are disposed at positions facing each other. 180 ° opposed magnetic heads 2A, 2C
And the magnetic heads 2B and 2D have the same azimuth, and these sets have different azimuths.

A magnetic tape is wound around the rotary drum 1 at a winding angle of, for example, 180 °. Each time the rotating drum 1 rotates by 180 °, the signal to the magnetic head opposed thereto is switched. This switching point is called a switching point. Thus, when the channels corresponding to the respective heads are A, B, C, and D, these four magnetic heads 2A, 2B, 2C, and 2D
As shown in FIG. 4, tracks A and B are formed on the magnetic tape 4 by the magnetic heads 2A and 2B, and tracks C and D are formed by the magnetic heads 2C and 2D.

Of the tracks formed, A and C,
B and D are tracks with the same azimuth. At this time, a segment is composed of two adjacent tracks (A and B channels and C and D channels) having different azimuths. Also,
One frame of the video signal includes 12 tracks. Therefore, one frame of the video signal is composed of six segments. Each of these six segments is assigned a segment number from 0 to 5.

The audio data having four channels is arranged, for example, at the center of the track so as to be interposed between the video data. Audio data is recorded on 12 tracks that constitute one frame of a video signal.
Predetermined shuffling is performed between the four channels. This shuffling prevents errors from concentrating on a specific channel when a defect occurs in the longitudinal direction of the magnetic tape 4.

The rotary drum 1 is further provided with magnetic heads 3A, 3B, 3C and 3D for reproduction. The arrangement of these magnetic heads 3A, 3B, 3C, and 3D and the relationship of azimuth are the same as those of the above-described recording magnetic heads 2A, 2B, 2C, and 2D. When reproducing from a magnetic tape, these magnetic heads 3A, 3A
B, 3C, and 3D are used.

FIG. 5 shows an example of the configuration of the HD-VTR. The HD-VTR includes a plurality of timing generators 100 and 10 according to a format of a corresponding video signal.
1, and 102. Timing generator 1
00 is for the 1125 / 60i system and generates clocks f ₁ and f ₂ with frequencies of 74.25 MHz and 46.4 MHz, respectively. Further, a clock having a frequency of 48 KHz for sampling the audio signal and a clock having a frequency of 90 Hz for servo of the rotating drum 1 are generated.

Similarly, the timing generator 101 for the 1125 / 50i system has 61.875 MHz for clock f ₁ , clock f ₂ , for sampling the audio signal, and for servo of the rotating drum 1, respectively.
z, 38.67 MHz (= 46.4 MHz × 5/6),
A clock of 48 KHz and 75 Hz (= 90 Hz × 5/6) is generated.

Further, similarly, the timing generator 102 for the 1125 / 48i system and the 1125 / 24p system is used for sampling the clock f ₁ , the clock f ₂ , the audio signal, and the servo of the rotating drum 1, respectively. 4MHz, 37.12MHz
(= 46.4 MHz × 4/5), 48 KHz, and 7
A clock of 2 Hz (= 90 Hz × 4/5) is generated.

The timing generators 100, 1
The clocks generated in 01 and 102 are switched by a switch circuit (not shown) by a predetermined control signal, for example, and supplied to corresponding circuits described below.

Here, the timing generator 1
Although 00, 101, and 102 are provided corresponding to each system, it is needless to say that the clock frequency generated by one timing generator may be changed.

The input terminal 10 receives a serial digital A / V signal having a predetermined rate based on each system. This digital A / V signal corresponds to the configuration of one frame shown in FIG.
Data is transmitted serially for each line in the order of video sample numbers. One frame of image and sound is transmitted by 2200 samples in the horizontal direction and 1125 lines in the vertical direction. Auxiliary data such as a line number, check bits, and digital audio data are inserted at predetermined positions in the horizontal and vertical blanking periods.

The serial signal supplied to the S / P converter 11 is converted into a parallel signal and output. The parallel signal is a signal obtained by converting the supplied serial signal into a luminance signal Y and color difference signals Pr and Pb, for example, a 4: 2: 2 signal having a data width of 8 bits. The converted video data is supplied to the coprocessor 12. This coprocessor 12 has, for example, 1
ASICs (Application Specific Integrated Circuits)
it).

The coprocessor 12 is operated based on the clock f ₁ and performs processing on the supplied parallel signal. This treatment was fed 4: 2: with digital audio data and ancillary data contained in the second signal is taken out is separated and the rate at which data rate is based on the clock f _1. For example, when the clock of the timing generator 100 is selected,
The data rate is set to 74.25 MHz. 4: 2: 2 auxiliary data such as line numbers and check bits
It is added to the signal every horizontal period. The separated digital audio data is supplied to the audio processor 16. This audio processor 16
Is supplied with a clock having a frequency of 48 KHz from the timing generator 100, 101, or 102, and can perform signal processing bidirectionally.

The digital video data output from the coprocessor 12 is supplied to a frame / field converter 17. If the supplied digital video data is 112
In the case of the 5 / 24p system, the signal is converted from a progressive scan signal to an interlace signal. That is, as shown in FIG. 2C, conversion is performed such that odd-numbered line information of the progressive scan signal is collected into a first field, and even-numbered line information is collected into a second field. This conversion is performed using the memory 15 connected to the frame / field converter 17. If the supplied digital video data is a signal other than the 1125 / 24p system, this processing is not performed and the supplied signal is output as it is.

Of course, using a switch circuit or the like,
Only the signal of the 5 / 24p system may be supplied to the frame / field converter 17, and in the case of other signals, the frame / field converter 17 may be bypassed.

The output of the frame / field converter 17 is supplied to the input filter 13. The input filter 13 performs band compression on the supplied digital video data by using the connected memory 14, and includes, for example, one ASIC. Clocks f ₁ and f ₂ are supplied to the input filter 13.
Bandwidth compression signal is output dropped to a rate based on the clock f _2. In the case of the 1125 / 60i system, the rate of the supplied signal is 74.25 MHz.
It dropped into frequency 46.4MHz based on the clock f ₂ from. The input filter 13 performs an operation based on the check bit, and adds the check result to the signal.

The output BRR (B
it Rate Reduction) encoder 18. BR
The R encoder 18 is connected to a memory 20 and performs, for example, DCT (Discrete Cosine Transfo
rm) and performs quantization to perform signal compression encoding at a predetermined compression ratio. The processing in the BRR encoder 18 is made based on the supplied clock f _2.

The BRR encoder 18 extracts the line number from the supplied digital video data, and performs the compression encoding process by using the BRR encoder 18.
For example, shuffling is performed in units of a DCT block including 8 × 8 pixels. Each of the shuffled DCT blocks is written to a predetermined address in the memory 20. Since the writing control to the memory 20 is performed by the address control based on the line number, the position of the effective video area can be adjusted even if the line is discontinuous during the vertical blanking period, for example.

The digital video data compressed and encoded by the BRR encoder 18 is converted into an ECC (Error Corrected Coded).
ing) It is supplied to the encoder 22. At the same time, a digital audio recording signal that has been subjected to predetermined processing by the audio processor 16 and output is also supplied to the ECC encoder 22. The supplied digital video data and digital audio recording signal
The data is temporarily written to the memory 23 connected to the C encoder 22.

[0048] In the ECC encoder 22, based on the supplied clock f _2, using the memory 23, performs on the supplied signal an error correction encoding process such as by product code. That is, as described in the above-described related art, the outer code parity and the inner code parity are generated for the data written in the memory 23, and the error correction coding of the product code is performed. The size of the data in which the product code of the inner code and the outer code is completed is called an error correction block.

The memory 23 is divided into, for example, two areas, and the processing of the inner code and the outer code is performed in each area. Also, the processing of the inner code and the outer code can be performed by devising a data access method without dividing the area. Memory 23,
It may be configured with two memories that respectively perform the processing of the inner code and the outer code.

FIG. 6 schematically shows an example of the configuration of this error correction block. As already shown in FIGS. 3 and 4, in the HD-VTR shown in this example, the magnetic tape 4
The signal is recorded by a helical track. The error correction encoding process in the ECC encoder 22 is performed for each helical track.

FIG. 6A shows an example of video data. 12
One track in the frame is one error correction block shown in FIG. 6A. When all the 226 sync blocks of the data portion arrive at the ECC encoder 22, a data array of 217 bytes × 226 bytes as shown is formed. For this data, FIG.
From top to bottom, data in the section indicated by the ECC enable of each column is encoded by, for example, a (250, 226) Reed-Solomon code, and a 24-byte outer code parity is generated. In this embodiment, encoding is performed in units of one symbol consisting of one byte.

Further, with respect to the video data and the outer code parity, the data in the section indicated by the ECC enable of each row is encoded by, for example, a (229, 219) Reed-Solomon code from left to right in FIG. 6A. And a 12-byte inner code parity is generated. At this time, sync data and ID each having a size of 2 bytes are arranged at the head of each data row, and the inner code is calculated including this. In this embodiment, encoding is performed in units of one symbol consisting of one byte.

FIG. 6B shows an example of the configuration of an error correction block in audio data. The audio data forms one error correction block shown in FIG. 6B with six tracks out of twelve tracks for one frame.
For example, for audio data having a data array of 217 bytes × 12 bytes, data in a section indicated by the ECC enable of each column is, for example, a (24,12) Reed-Solomon code from top to bottom in FIG. 6B. To generate a 12-byte outer code parity.

Further, with respect to the video data and the outer code parity, the data in the section indicated by the ECC enable of each row is encoded by, for example, a (229, 219) Reed-Solomon code from left to right in FIG. 6B. And a 12-byte inner code parity is generated. At that time, sync data and ID are arranged at the head of each data row, and the inner code is calculated including the sync data and ID. For audio data, the encoding is
This is performed in units of one symbol consisting of one byte.

FIG. 7 schematically shows the structure of one sync block in these error correction blocks, taking video data as an example. The first two bytes are sync data. The next two bytes are an ID, which is ID0
And ID1. In ID0, a sync block number which is a number of one sync block in one track is described. ID1 describes more detailed information on this sync block. This ID is followed by 217 bytes of video data (or outer code parity) and inner code parity. The recording data on the magnetic tape 4 is a sequence of the sync blocks.

The digital video data which has been error-correction-coded by the ECC encoder 22 is replaced with the recording rate frequency on the magnetic tape 4 in error correction block units, and is divided into four channels A, B, C and D. The signals are divided into signals and output as two-system signals of channel A / C and channel B / D. These two signals of channel A / C and channel B / D are supplied to the recording drive circuit 24, respectively.
Then, the data is modulated and amplified so as to be recordable on the magnetic tape 4 and output. The output signal is supplied to the magnetic head 2A or 2C for the channel A / C and supplied to the magnetic head 2B or 2D for the channel 2B or 2D, and is recorded on the magnetic tape 4.

At this time, the rotation of the rotary drum 1 is controlled by a servo mechanism (not shown). The servo mechanism controls the rotation of the rotary drum 1 based on a clock selected from among the servo clocks generated by the timing generator 100, 101, or 102.

In FIG. 5, for the sake of simplicity, the magnetic heads 2A, 2B, 2C and 2D for recording are replaced by two magnetic heads 2A or 2C, 2B or 2D, and these four magnetic heads. Signal paths for each of the magnetic heads are omitted in two systems. Also,
The recording drive circuit 24 has a changeover switch corresponding to the rotation of the rotary drum 1, and can switch and output the channels A and C and the channels B and D with respect to the rotation of the rotary drum 1 by 180 °. it can.

FIG. 8 shows the format of one track formed on the magnetic tape 4. This track represents the data arrangement along the direction traced by the head.
One track is roughly divided into video sectors V1 and V2 and audio sectors A1 to A4. The product code is encoded in units of video data and audio data recorded in one track. OP1 and OP2 indicate the parity of the outer code generated when the video data is product-coded. The parity of the outer code generated when product coding the audio data is recorded in the audio sector. Each track is divided into 233 bytes at regular intervals, each of which is called a sync block.

FIG. 8 shows an example of the length of each data recorded in one track. In this example, within one track, 2
75 sync blocks + 124 bytes of data are recorded. The video sector is a 226 sync block. The time length of one track is about 5.6 ms. A non-recorded portion is interposed between the sectors. This gap is called an edit gap, and is provided so that adjacent sectors are not erased when recording is performed in sector units.

Next, processing on the reproduction side will be described. The signals recorded on the magnetic tape 4 are reproduced by the read magnetic heads 3A, 3B, 3C, and 3D. As described above, the magnetic heads 3A, 3B, 3C, and 3
D reproduces tracks A, B, C, and D, respectively. The reproduction signal is supplied to the equalizer 40.

In FIG. 5, in order to avoid complication, the magnetic heads 3A, 3B, 3C and 3D are
A or 3C, 3Bor3D, and 4
Signal paths for each of the two magnetic heads are omitted in two systems. Each of the equalizers 40 and 47 has a changeover switch corresponding to the rotation of the rotary drum 1 by 180 °. Thus, in the equalizer 40, the reproduction signals from the magnetic heads 3A and 3C or the magnetic heads 3B and 3D are alternately processed.

The equalizer 40 outputs the signal A / C and the signal B / D, and the reproduced clock generated by the rotation of the rotary head 1. These signals are
It is supplied to the CC decoder 41. This ECC decoder 4
1 is supplied with a clock f ₂ , and the memory 42 is connected. In the ECC decoder 41, using the memory 42,
The error correction decoding of the supplied channel signal A / C is performed.

That is, the signal A / C reproduced for each track and supplied in units of error correction blocks is subjected to error correction decoding by an inner code and an outer code. The digital video data obtained by the error correction decoding is a clock f ₂ (in the example of the 1125 / 60i system, the frequency 46.
(4 MHz clock), output in sync block units, and supplied to the next stage BRR decoder 43.
The digital audio reproduction data obtained by the decoding is supplied to the audio processor 16.

The clock f ₂ is supplied to the BRR decoder 43. The BRR decoder 43 can know the head of the frame based on, for example, ID0 and ID1 added to the head of the sync block. BRR decoder 4
In step 3, the supplied signal A / C is subjected to inverse DCT conversion and deshuffling using, for example, the memory 44 to decode a compression code. The decoded and decompressed digital video data is supplied to a concealing circuit 45 for correcting a video signal.

The concealing circuit 45 includes, for example, one AS
An error which exceeds the error correction capability of the ECC decoder 41 in the reproduced signal, for example, a long error due to a scratch on the magnetic tape 4 exists in the reproduction signal, and the ECC decoder 41 corrects the signal that could not be corrected. . This correction is performed, for example, by interpolating a part lost without error correction by a predetermined method.

The output of the concealing circuit 45 is supplied to the output filter 55. Output filter 55
Is composed of, for example, one ASIC, and both the clock f ₁ and the clock f ₂ are supplied. In the output filter 55, the supplied digital video data is converted into a 4: 2: 2 signal using the memory 56 based on the supplied clock. That is, the clock f ₂
In the supplied digital video data is is resampled with the clock f _1, bandwidth compression is released. The resampled data is temporarily written to the memory 56, for example. The output of the output filter 55 is supplied to the video processor 57.

The video processor 57 is supplied with the clock f _{1 and} performs predetermined processing such as gain and offset adjustment on the supplied digital video data. This process is performed using the memory 58.
The processed data is supplied to a field / frame converter 63.
Supplied to

If the supplied signal is based on the 1125 / 24p system, the field / frame converter 63
In, digital video data is returned from the interlaced signal to the original progressive scan signal. This is because, for example, the supplied data is temporarily stored in the memory 64.
And the written data is read out in a predetermined order. This field / frame converter 63, the clock f ₁ is supplied. If the supplied data is data other than the 1125 / 24p format, this processing is not performed and the supplied data is output as it is.

Of course, using a switch circuit or the like,
Only data of the 5 / 24p system may be supplied to the frame / field converter 63, and this circuit 63 may be bypassed for other data.

The digital audio reproduction data supplied to the audio processor 16 after being subjected to error correction decoding by the ECC decoder 41 is subjected to predetermined processing in the audio processor 16 and supplied to the coprocessor 60.

The output of the frame / field converter 63 is supplied to the coprocessor 60 together with the digital audio reproduction data described above. The co-processor 60, the clock f ₁ is supplied. Coprocessor 60, based on the clock f _1, the digital audio data while being inserted into the digital video data, a predetermined auxiliary data defined in the format are added. The output of the coprocessor 60 is supplied to a P / S converter 61. Then, the parallel signal is converted by the P / S converter 61 into a serial signal having a predetermined rate corresponding to each system, and is output to the output terminal 62.

As described above, according to the present invention, by selecting the clock supplied to each signal processing circuit and the servo mechanism of the rotary drum 1 based on each video signal system, the video signal processing by a plurality of systems is performed. Are realized by the same hardware. As mentioned above, 1125/6
This is possible because the form in which the time axis of the video signal in the 0i system is extended is compatible with other systems.

That is, in the above example, 1125/50
In the case of a video signal according to the i method, the rotation speed of the rotating drum 1 is increased from 90 Hz to 90 Hz × 5/6 = 75.
Hz, and although not shown in FIG. 5, the feed speed of the magnetic tape 4 is reduced at that ratio. At the same time, the recording frequency at the time of recording on the magnetic tape 4 is also reduced at that ratio. Similarly, the 1125 / 24p system and 1125 /
In the case of a video signal by the 48i system, the rotating drum 1
From 90Hz × 4/5 =
The frequency is reduced to 72 Hz, and the feed speed of the magnetic tape 4 and the recording frequency for recording on the magnetic tape 4 are reduced in that ratio. By doing so, 1125 /
The same track pattern as that by the 60i method can be formed.

As described above, similarly, in the signal processing, by selecting the processing frequency of another system based on the processing frequency in the 1125 / 60i system, for example, the same circuit configuration can cope with the processing of a plurality of systems. can do.

By the way, the video signal can be adapted to each system by changing the processing frequency in this way. However, for the audio signal, a sampling rate of, for example, 48 KHz must always be secured, and it is not possible to change the processing frequency. Next, processing of audio data performed by the audio processor 16 according to the present invention will be described.

In the present invention, the lack of the capacity of audio data due to the extension of the time axis is dealt with by reducing the number of bits of one sample of the audio data. That is, in the 1125 / 60i system, the number of bits, which is 24 bits per sample, is set to, for example, 20 bits per sample in other systems.

The number of audio data samples per second is as follows. First, in the case of the 1125 / 60i system, one sample is composed of 24 bits, that is, 3 bytes. As described above with reference to FIG. 6B, the error correction block of the audio data has 217 (bytes) × 12 per six tracks (one field).
(Sync block). Therefore, the number of data for each channel is {217 (bytes) / 3 (bytes)} × 12 (sync block / field) × 2 (field / frame) ×
30 (frames / second) = 52,080 (samples / second) That is, a sufficient number of samples at a sampling rate of 48 KHz is ensured.

In the case of the 1125 / 50i system, one sample is composed of 20 bits, that is, 2.5 bytes. The configuration of the error correction block is the same as that of the 1125 / 60i system. In this case, the number of data in each channel is {217 (bytes) /2.5 (bytes)} × 12 (sync block / field) × 2 (field / frame) × 25 (frame / sec) = 52,080 ( (Sample / sec) Even in this case, the number of samples at the sampling rate of 48 KHz is sufficiently ensured.

The 1125 / 24p system and the 1125/4
In the case of the 8i system, one sample is composed of 20 bits. The configuration of the error correction block is the same as in the other systems. In this case, the number of data of each channel is {217 (byte) /2.5 (byte)} × 12 (sync block / field) × 2 (field / frame) × 24 (frame / sec) = 49,996 ( (Sample / sec) Also in this case, it can be seen that the number of samples at the sampling rate of 48 KHz is secured.

As described above, error correction is performed by 1
This is performed in units of one symbol consisting of bytes. Therefore, when one sample is a 1125 / 60i system of 24 bits, one sample of audio data is composed of three symbols, which is convenient for error correction encoding. However, other systems, that is, 1125 / 50i system, 1125
In the / 24p system and the 1125 / 48i system, one sample is composed of 20 bits, and one sample of audio data is 2.5 symbols. Therefore, 0.5 bytes (4 bits) are wasted when performing error correction encoding.

In the present invention, this problem is solved by 1125/5
0i system, 1125 / 24p system, and 1125/4
The problem is solved by performing error correction encoding of audio data in the 8i system over adjacent samples. That is, out of one sample of 20 bits, 1
For 6 bits, error correction coding is performed by a normal method. The remaining 4 bits are subjected to error correction coding in combination with the 4 bits of the next sample. The remaining 16 bits of the next sample are subjected to error correction coding by a normal method. That is, error correction coding is performed by considering two samples as one set.

In the above description, the 1125 / 24p system and the 1125 / 48i system have been described as independent processes. However, the present invention is not limited to this example. For example, these processes can be used in combination. That is,
The video camera captures images at a rate of 24 frames per second and outputs them in the 1125 / 48i format. In the VTR, other 1125 / 60i systems and 1125/50
It is also possible to perform signal processing as an interlace similar to the i-type, and to convert from interlace to progressive scan when outputting a VTR.

Further, in the above description, the present invention is applied to 1125/6
The present invention is applied to an HD-VTR capable of supporting all of the 0i system, the 1125 / 50i system, the 1125 / 24p system, and the 1125 / 48i system, but this is not limited to this example. That is, the above-described configuration can be used alone or as an HD-VTR compatible with two or three systems by omitting a predetermined portion. this is,
For example, among the timing generators 100, 101, and 102, only those corresponding to a desired system are mounted.

When the 1125 / 24i system is not used, the frame / field converter 17 and the field / frame converter 63 and the memories 15 and 64 connected to them can be omitted.

In the case where a plurality of methods are supported, the switching is manually performed by, for example, a changeover switch. Switching can be performed using a coding hole provided in the video tape cassette.

Further, in the above description, the audio data is described so as to correspond to each system by changing the number of bits of one sample, but this is not limited to this example. For example, it is possible to provide a rate converter for audio data and change the sampling rate of the audio data to correspond to each system.

Further, in the above description, 1125 / 60i
The method has been described assuming that the field frequency is 60 Hz.
It is also easy to apply to the NTSC system of 9.94 Hz. In this case, each interface and clock frequency are set to 1.001 (= 60
/59.94).

In the above description, the number of scanning lines is 1125.
Although the system which is a book has been described, this is not limited to this example, and the present invention can be similarly applied to a system having another number of scanning lines.

[0090]

As described above, according to the present invention, the hardware of the 1125 / 60i system, 1125/2 can be obtained by only slightly modifying the hardware of the 1125 / 60i system.
There is an effect that it can correspond to the 4p system and the 1125 / 48i system.

According to the present invention, 1125/60
There is an effect that one hardware can easily cope with all of the i system, the 1125 / 50i system, the 1125 / 24p system, and the 1125 / 48i system, or a plurality of these systems.

Further, according to the present invention, 1125/6
In each of the 0i system, the 1125 / 50i system, the 1125 / 24p system, and the 1125 / 48i system, the position of the effective pixel area, the position of the effective scanning line, and the position of the blanking period are the same. There is an effect that conversion between formats is easy.

Furthermore, according to the present invention, 1125
/ 60i system, 1125 / 50i system, 1125/24
In each of the p system and the 1125 / 48i system, the recording wavelength, the number of rotations of the rotating drum, and the like are adaptively controlled so that the track pattern on the magnetic tape becomes the same. Therefore, there is an effect that an optimum tape can be selected. In addition, since the characteristics of the electromagnetic conversion system can be designed based on the same recording wavelength, the design becomes easy, and the cost of hardware can be reduced accordingly.

Since the track pattern on the magnetic tape is the same, the pattern read from the tape at the time of variable speed reproduction is the same between the respective systems. Therefore, the design of the servo system and the signal system for coping with the variable speed reproduction can be shared for each system. Therefore, the design is facilitated, and the cost of the hardware is suppressed accordingly.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an example of a configuration of one frame according to an embodiment;

FIG. 2 is a time chart showing a frame configuration for one second when a video signal of each system is handled in this embodiment.

FIG. 3 is a schematic diagram illustrating an example of a recording method used in the embodiment.

FIG. 4 is a schematic diagram illustrating an example of a recording method used in the embodiment.

FIG. 5 is an HD-VTR to which the present invention can be applied.
FIG. 3 is a block diagram showing an example of the configuration of FIG.

FIG. 6 is a schematic diagram schematically illustrating an example of a configuration of an error correction block.

FIG. 7 is a schematic diagram schematically illustrating an example of the configuration of one sync block in an error correction block.

FIG. 8 is a schematic diagram illustrating an example of a format of one track formed on a magnetic tape.

[Explanation of symbols]

4 ... magnetic tape, 13 ... input filter,
16 audio processor, 17 frame / field converter, 18 BRR encoder, 2
2 ... ECC encoder, 41 ... ECC decoder, 43 ... BRR decoder, 55 ... Output filter, 63 ... Field / frame converter,
Timing generator for 100 ... 1125 / 60i system, 101 ... 1125 / Timing generator for 50i system, 102 ... 1125 /
Timing generator for 48i and 1125 / 24p systems

Claims (11)

[Claims] 1. A digital recording / reproducing apparatus adapted to record and reproduce first and second video signals having different numbers of frames per second from each other, wherein a video for processing the first and second video signals is provided. The signal processing means is common, and the processing of the first video signal is different from the processing of the first video signal in the number of frames per second.
A digital recording / reproducing apparatus characterized in that a clock frequency used for processing in the video signal processing means is changed in the case where the video signal is processed. 2. The digital recording / reproducing apparatus according to claim 1, wherein said change of said clock frequency is performed by said first and second clocks.
A digital recording / reproducing apparatus which is performed in accordance with the ratio of the field or frame frequency of the video signal. 3. The digital recording / reproducing apparatus according to claim 1, wherein the first video signal and the second video signal are:
1125 scanning lines / field frequency 60 Hz / interlace video signal, 1125 scanning lines / field frequency 50 Hz / interlace video signal, 1125 scanning lines / frame frequency 24 Hz / video signal of progressive scan, and 1125 scanning lines / A digital recording / reproducing apparatus, which is two of a video signal having a field frequency of 48 Hz / interlace. 4. The digital recording / reproducing apparatus according to claim 1, wherein the video signal is interlaced and progressive.
A digital recording / reproducing apparatus, further comprising conversion means for performing conversion between scans. 5. Recording and reproduction of first and second video signals having different numbers of frames per second and first and second audio signals respectively corresponding to the first and second video signals. In the digital recording / reproducing apparatus, the audio signal processing means for processing the first and second audio signals is common, and the audio signal processing means makes the first and second audio signals the same size. A digital recording / reproducing apparatus which processes the first and second audio signals so that the signals can be recorded in the recording area. 6. The digital recording / reproducing apparatus according to claim 5, wherein said audio signal processing means makes the sampling rate of said first audio signal and the sampling rate of said second audio signal substantially the same. A digital recording / reproducing apparatus, wherein the number of bits of one sample of the first audio signal or the second audio signal is changed. 7. The digital recording / reproducing apparatus according to claim 5, wherein the audio signal processing means includes a bit number of one sample of the first audio signal and a bit number of one sample of the second audio signal. Wherein the sampling rate of the first audio signal or the second audio signal is changed so as to make the same. 8. A digital recording / reproducing apparatus in which first and second video signals having different numbers of frames per second are recorded and reproduced on a helical track by a rotating drum. The rotation speed of the rotating drum and the magnetic field are set so that the track pattern is substantially the same between when recording a signal and when recording a second video signal having a different number of frames per second from the first video signal. A digital recording / reproducing apparatus characterized by changing a running speed of a tape. 9. A digital recording / reproducing method adapted to record and reproduce first and second video signals having different numbers of frames per second from each other, wherein a video processing the first and second video signals. The signal processing steps are common, and the case of processing the first video signal is different from the case of processing the first video signal in the number of frames per second.
A digital recording / reproducing method, wherein the clock frequency used in the processing of the video signal processing is changed between the processing of the video signal and the processing of the video signal. 10. A method according to claim 1, wherein the number of frames per second is different.
And a second video signal, and a first and second audio signal corresponding to the first and second video signals, respectively, in the digital recording / reproducing method. The audio signal processing step for processing the second audio signal is common, and the audio signal processing step includes the first and second audio signals so that the first and second audio signals can be recorded in a recording area of the same size. A digital recording / reproducing method, wherein a second audio signal is processed. 11. A digital recording / reproducing method in which first and second video signals having different numbers of frames per second are recorded and reproduced on a helical track by a rotating drum. The rotation speed of the rotating drum and the magnetic field are set so that the track pattern is substantially the same between when recording a signal and when recording a second video signal having a different number of frames per second from the first video signal. A digital recording / reproducing method characterized by changing a running speed of a tape.