JP4099570B2 - Digital recording / reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a device dealing with different field frequencies based on a digital recording and reproducing device which is a fundamental device if such device exists. SOLUTION: The input section 3 of the digital recording and reproducing device has an intrinsic field frequency, accepts the audio data based on an intrinsic format and performs the base band processing thereof. A processing section 4 has a fundamental field frequency, is designed to process the audio data based on the fundamental format and operates on the clock meeting the sampling frequency, thereby performing encoding processing for error correction of the audio data adapted to the fundamental format. A conversion section 9 is disposed between both and converts the sampling frequency of the audio data according to the ratio between the intrinsic field frequency and the fundamental field frequency while adapting the intrinsic format to the fundamental format. The processing section 4 operates on the clock meeting the converted sampling frequency and performs the encoding processing for error correction.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for simplifying a recording / reproducing apparatus corresponding to a different field frequency on the basis of the system when there is an audio data or video data recording / reproducing apparatus corresponding to a certain field frequency. For example, the present invention relates to a method for simplifying an audio part and a video part of a VTR recording / reproducing apparatus. However, the present invention is not limited to the VTR.
[0002]
[Prior art]
The VTR recording / reproducing apparatus needs a digital magnetic recording / reproducing apparatus that can support, for example, each of the HDTV systems in Japan, the United States, and Europe in order to record and reproduce signals of a plurality of different television standards. HDTV, which provides higher-definition images than the current television, was developed by Japan ahead of the world. The Japanese HDTV system is called high-definition, and has 1125 scanning lines and a field frequency of 60 Hz. On the other hand, in Europe and the United States, the HDTV system is different from the Japanese system. For example, the European system has a field frequency of 50 Hz.
[0003]
In this way, if the television system is different and the equipment for producing and transmitting the program is different, the individual equipment has to be developed and manufactured for each, which increases the cost. Also, in order to screen software produced by other methods, it is necessary to prepare a VTR suitable for each method, convert the signal with a separate format converter, and then re-record it. Costs too much.
[0004]
In the first place, a VTR is one of the main equipment for production and transmission, and generally a VTR for broadcasting is expensive. Therefore, a common tape transport, signal processing circuit, cassette and tape are used in different HDTV systems. If it can be used, the equipment cost and running cost will be reduced, which will greatly benefit the user. In addition, there is an advantage that program conversion between countries can be easily performed at a low cost if it is possible to reproduce a tape recorded by another method using the same VTR.
[0005]
[Problems to be solved by the invention]
However, in the conventional magnetic recording / reproducing apparatus, there is no apparatus that can record and reproduce sound together with high-definition images using different HDTV systems by a common mechanism. When considering a device corresponding to a different frequency, a format is required for each different frequency, and a processing device corresponding to each field frequency is required. For example, if the audio input / output sampling frequency is 48 KHz and the number of bits per sample is 24 bits in both 60 Field / s and 50 Field / s devices, the audio format must be considered at 800 samples / field × 24 bits / sample at 60 Field / s. In 50 Field / s, the audio format must be considered as 960 sample / field × 24 bit / sample. The total number of bits per field is greatly different between 800 × 24 = 19200 bits / field and 960 × 24 = 223040 bits / field. Therefore, devices corresponding to different field frequencies have to have completely different formats and completely different devices.
[0006]
Also, the video frame is different at each field frequency. Therefore, devices corresponding to different field frequencies have to have completely different formats and completely different devices.
[0007]
Therefore, the present invention converts the audio data of a different field frequency so that it conforms to the format of the basic device and changes it to an appropriate processing rate when there is a digital audio recording / playback device that is a basic device corresponding to a certain field frequency. Thus, an object of the present invention is to realize a device corresponding to a different field frequency based on the basic device.
[0008]
In the present invention, when there is a digital video recording / playback device that is a basic device corresponding to a certain field frequency, video data of a different field frequency is converted to match the format of the basic device and changed to an appropriate processing rate. Thus, an object of the present invention is to realize a device corresponding to a different field frequency based on the basic device.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problems of the prior art and achieve the object of the present invention, the following measures were taken. That is, according to the first aspect of the present invention, audio data based on a specific format having a predetermined sampling frequency and a specific field frequency and defining a specific data arrangement and a bit arrangement in a field unit is received, and at least the audio Designed to process audio data based on a basic format that has a predetermined sampling frequency and a basic field frequency and defines a basic data array and a bit array in units of fields, and an input unit that performs baseband processing of data A processing unit that operates with a clock according to the sampling frequency and performs encoding processing for error correction of audio data conforming to the basic format, and an output unit that writes the audio data output from the processing unit to a recording medium Digital voice recording The conversion unit is disposed between the input unit and the processing unit. When the specific field frequency of the audio data is different from the basic field frequency and the specific format is different from the basic format, the conversion unit is While adapting the format to the basic format, the sampling frequency is converted in accordance with the ratio between the natural field frequency and the basic field frequency and audio data is passed to the processing unit, and the processing unit converts the sampling frequency to the converted sampling frequency. It operates with a corresponding clock, and performs encoding processing for error correction of audio data conforming to the basic format. Specifically, the conversion unit maintains the total number of bits per field determined by the product of the number of samples per field and the number of bits of one sample, while maintaining the number of samples per field and the bits of one sample. The sampling frequency is converted by changing the number of samples to adapt the specific format to the basic format and changing the number of samples per field. Further, when the total number of bits per field determined by the product of the number of samples per field and the number of bits of one sample differs between the specific format and the reference format, the conversion unit sets the sampling frequency of the input audio data. Convert to correct the number of samples per field, so that the corrected total number of bits per field, determined by the product of the corrected number of samples per field and the number of bits per sample, Match the total number of bits per field determined by. Alternatively, when the total number of bits per field determined by the product of the number of samples per field and the number of bits of one sample differs between the specific format and the reference format, the conversion unit sets dummy data that matches the number of bits that are insufficient. May be added to the specific format to correct the total number of bits per field, and thus the total number of bits on the specific format side may be matched with the total number of bits on the reference format side. Preferably, the conversion unit writes audio data including a bit stream of serially arranged samples to the FIFO in units of bits on the native format side, and reads out in units of bits on the basic format side, so that the number of samples per field The number of bits of one sample is rearranged and the specific format is adapted to the basic format. In this case, the conversion unit controls writing and reading of audio data to and from the FIFO in synchronization with the specific field frequency, and thereby adapts the specific format to the basic format.
[0010]
In one aspect, the processing unit includes the conversion unit as a conversion unit, and includes an encoding unit that performs encoding processing for error correction of audio data, and the inherent field frequency of the audio data is a basic field frequency. When the unique format is different from the basic format, the converting means converts the unique format and adapts it to the basic format and then passes the audio data to the encoding means. The encoding means has a predetermined sampling frequency. In addition, the encoding processing for error correction of the audio data adapted to the basic format is performed while pausing as needed at a rate corresponding to the ratio between the natural field frequency and the basic field frequency. Specifically, the conversion means maintains the total number of bits per field determined by the product of the number of samples per field and the number of bits per sample, while maintaining the total number of samples per field and per sample. Change the number of bits to convert the native format to the basic format. More specifically, the conversion means includes a register having a bit number corresponding to the number of bits per sample on the basic format side, and cyclically converts audio data in a specific format consisting of a bit stream of serially arranged samples. On the other hand, the audio data is cyclically read from the register while pausing as needed at a ratio corresponding to the ratio of the number of bits per sample of the native format side to the number of bits per sample of the basic format side. The number of samples per field and the number of bits of one sample are rearranged to convert the unique format into the basic format.
[0011]
According to the second aspect of the present invention, an input unit which reads audio data from a recording medium having a certain sampling frequency and a specific field frequency and conforming to a basic format which defines a basic data arrangement and a bit arrangement in a field unit. And is designed to process audio data based on the basic format and having a predetermined sampling frequency and basic field frequency, and operates at a clock according to the sampling frequency and at least error correction of audio data conforming to the basic format In a digital audio reproducing apparatus comprising: a processing unit that performs a decoding process for an image; and an output unit that performs at least baseband processing of audio data output from the processing unit and supplies the audio data to a reproduction device. The processing unit It is operable with a clock according to the sampling frequency of the read audio data, performs decoding processing for error correction of audio data conforming to the basic format, and converts between the processing unit and the output unit When the unique field frequency of the read audio data is different from the basic field frequency and the unique format is different from the basic format, the conversion unit converts the audio data that conforms to the basic format into the unique format. In addition, the sampling frequency of the read audio data is converted into a predetermined sampling frequency in accordance with the ratio between the natural field frequency and the basic field frequency, and the audio data is passed to the output unit. Specifically, the conversion unit maintains the total number of bits per field determined by the product of the number of samples per field and the number of bits of one sample, while maintaining the number of samples per field and the bits of one sample. The sampling frequency is converted by changing the number to return the audio data from the basic format to the native format and changing the number of samples per field. When the total number of bits per field determined by the product of the number of samples per field and the number of bits of one sample differs between the specific format and the standard format, the conversion unit temporarily approximates the basic format. The sampling frequency of the audio data returned to the format is converted to correct the number of samples per field, so that the audio data is finally converted into a specific format. Alternatively, when the total number of bits per field determined by the product of the number of samples per field and the number of bits of one sample differs between the specific format and the reference format, the conversion unit temporarily converts the audio data that conforms to the basic format. After adding extra dummy data to approximately return to the native format, the dummy data may be deleted, and the audio data may be finally converted to the native format. Preferably, the conversion unit writes audio data including a bit stream of serially arranged samples to the FIFO in units of the number of bits on the basic format side, and reads out the data in units of the number of bits on the specific format side, thereby obtaining the number of samples per field The number of bits of one sample is rearranged to return the basic format to the native format. In this case, the conversion unit controls writing and reading of audio data to and from the FIFO in synchronization with the specific field frequency, thereby returning the basic format to the specific format.
[0012]
In one aspect, the processing unit includes the conversion unit as a conversion unit, and includes a decoding unit that performs a decoding process for error correction of audio data. The decoding unit includes a predetermined sampling frequency. The audio data is decoded for error correction conforming to the basic format while paused at any time according to the ratio between the natural field frequency and the basic field frequency while operating with a clock according to the When the read field data has a unique field frequency different from the basic field frequency and the unique format is different from the basic format, the audio data conforming to the basic format is returned to the native format, and the audio data is converted. Pass to the output. Specifically, the converting means maintains the total number of bits per field determined by the product of the number of samples per field and the number of bits of one sample, while maintaining the number of samples per field and the bits of one sample. The number is rearranged to return the audio data from the basic format to the native format. More specifically, the converting means includes a register having a number of bits corresponding to the number of bits per sample in the basic format side, and the number of bits per sample in the specific format side and the number of bits per sample in the basic format side. The audio data of the basic format consisting of the bit stream of serially arranged samples is cyclically written to the register while pausing at a rate according to the ratio of the ratio, while being delimited by the number of bits per sample of the specific format side However, the audio data is cyclically read from the register, the number of samples per field and the number of bits of one sample are rearranged, and the basic format is returned to the inherent format. When switching between forward reproduction and reverse reproduction of audio data, the conversion means writes the MSB of the bit string on the one hand and LSB on the other hand when writing and reading audio data to and from the register. To the top.
[0013]
In another aspect, the conversion unit maintains the total number of bits per field determined by the product of the number of samples per field and the number of bits per sample, while maintaining the number of samples per field and the bits per sample. Change the number and return the audio data from the basic format to the native format The In this case, a shuttle reproduction control unit is further provided. When shuttle reproduction is performed by mixing audio data belonging to different fields, only valid samples including a correct bit string among samples returned to the unique format by the conversion unit are obtained. The data is passed to the output unit. Preferably, the shuttle reproduction control unit passes an alternative sample obtained by interpolating a valid sample to the output unit in place of an invalid sample that does not have a correct bit string among samples returned to the inherent format. The shuttle playback control unit replaces the incorrect bit string with 0 for at least a part of the invalid samples including the correct bit string and the incorrect bit string among the samples returned to the inherent format, and converts the invalid bit string into a valid sample. You may make it pass to an output part.
[0014]
According to the third aspect of the present invention, an input unit that accepts video data having a predetermined sampling frequency and a specific field frequency and is based on a specific format related to an image frame, and at least performs baseband processing of the video data; It is designed to process video data based on the basic format related to the image frame with the sampling frequency and the basic field frequency, and operates with a clock according to the sampling frequency, and the video data compression processing and error conforming to the basic format. In a digital video recording apparatus including a processing unit that performs a correction encoding process and an output unit that writes video data output from the processing unit to a recording medium, a conversion unit is provided between the input unit and the processing unit. And the natural field frequency of the video data is the basic field. When different from the wave number, the conversion unit converts the sampling frequency according to the ratio of the natural field frequency and the basic field frequency while adapting the specific format to the basic format, and passes the video data to the processing unit, The processing unit operates with a clock corresponding to the converted sampling frequency, and performs a compression process of video data conforming to the basic format and an encoding process for error correction. Specifically, when the specific format matches the basic format, the conversion unit converts the sampling frequency according to the ratio between the specific field frequency and the basic field frequency while maintaining the specific format, and converts the video data. Pass to the processing unit. More specifically, when the unique format matches the basic format, the conversion unit preserves the valid data entering the image frame as it is and maintains the unique format while adjusting invalid data that does not enter the image frame. Then, the sampling frequency is converted. In addition, when the specific format is different from the basic format, the conversion unit converts the specific format into the basic format, and then converts the sampling frequency in accordance with the ratio between the specific field frequency and the basic field frequency to convert video data. To the processing unit. Specifically, when the number of data lines included in the image frame of the specific format is different from the number of data lines included in the image frame of the basic format, the conversion unit calculates the number of data lines included in the image frame. Adjust to convert the native format to the basic format.
[0015]
According to the fourth aspect of the present invention, there is provided an input unit for reading video data having a certain sampling frequency and a specific field frequency and adapted to a basic format related to a picture frame from a recording medium, and having a predetermined sampling frequency and a basic field frequency. And a processing unit that is designed to process video data based on the basic format, operates with a clock according to the sampling frequency, and performs decoding processing and decompression processing for error correction of video data conforming to the basic format; In the digital video reproduction apparatus including an output unit that performs at least baseband processing of the video data output from the processing unit and supplies the video data to a reproduction device, the processing unit includes the read video data It can be operated with a clock according to the sampling frequency of Decoding and decompression processing for error correction of video data conforming to the basic format is performed, a conversion unit is disposed between the processing unit and the output unit, and a natural field frequency of the read video data is When different from the basic field frequency, the conversion unit returns the video data conforming to the basic format to the specific format, and the sampling frequency of the read video data according to the ratio between the specific field frequency and the basic field frequency. Is converted to a predetermined sampling frequency and the video data is passed to the output unit. Specifically, when the specific format is the same as the basic format, the conversion unit converts the sampling frequency according to the ratio between the specific field frequency and the basic field frequency while maintaining the specific format, and converts the video data. Pass to the output. More specifically, when the specific format is the same as the basic format, the conversion unit adjusts invalid data that does not enter the image frame while maintaining the specific format while leaving the valid data that enters the image frame as it is. To change the sampling frequency. In addition, when the inherent format is different from the basic format, the conversion unit returns the video data conforming to the basic format to the inherent format, and then changes the sampling frequency according to the ratio between the intrinsic field frequency and the fundamental field frequency. And the video data is passed to the output unit. For example, when the number of data lines included in the image frame of the specific format is different from the number of data lines included in the image frame of the basic format, the conversion unit adjusts the number of data lines included in the image frame. Return the video data to the native format.
[0016]
On the recording side of this apparatus regarding audio, the clock of the audio processing section that becomes a block close to the recording / reproducing medium from the audio data conversion section is input as the field frequency ratio clock of the base apparatus and the target apparatus. For example, assuming a VTR with a field frequency of 50 Field / s and a VTR with a field frequency of 60 Field / s and an audio processing clock frequency of 48 KHz as a base device, the audio processing clock frequency is 48 KHz × 50/60 = 40 KHz.
[0017]
The audio processing clock of the block close to the input unit of the device from the audio data conversion unit (distant from the medium) is set as the input clock frequency of the device. For example, when the base device is 60 Field / s and the audio data is 800 Sample / field × 24 bits / Sample (sampling frequency 48 KHz) per field, the device of 50 Field / s based on the device is 960 Sample / field × 20 bits per field. When recording at / Sample (sampling frequency 48 KHz), both blocks from the audio data converter to the input unit of the apparatus (distant from the medium) are processed with a 48 KHz clock. Therefore, the baseband processing is 48 KHz for both devices, and the same circuit can be used for both.
[0018]
The side near the device input unit of the audio data converter (the side far from the medium) is the number of samples per field and the number of bits per sample so that the total number of bits per field of audio data is the same as the device of the base field frequency To. For example, if audio is recorded at 800 Sample / Field × 24 bits / Sample per field with a device having a base field frequency of 60 Field / s, recording at 960 Sample / Field × 20 bits / Sample with a device having a field frequency of 50 Field / s. To do. In both cases, the total number of bits per field is 19200 bits / s. By changing the number of bits per sample from the base device as in this example, the input sampling frequency of both devices can be made the same. In the above example, the sampling frequency is 48 KHz for both field frequency devices.
[0019]
As described above, the number of samples per field and the number of bits per sample on the side closer to the device input unit of the audio data conversion unit are determined. If this is the same as the number of samples per field and the number of bits per sample of the device input unit, Processing is simplified. However, there may be no convenient number of samples per field and number of bits per sample depending on the target field frequency. Further, there are cases where it is desired to arbitrarily set the number of samples per field and the number of bits per sample of the device input unit depending on the convenience of the target device. In this case, the number of samples per field of the device input unit, the number of samples per field that is close to the total number of bits of the base device close to the number of bits per sample (influencing the sampling frequency), and the number of bits per sample are determined. An audio sampling rate converter is provided between the input unit of the apparatus and the audio data conversion unit so as to obtain the sampling frequency. For example, suppose that the apparatus is based on 60 Field / s and the audio can be recorded at 800 Sample / field × 24 bits / Sample per field, and based on this, the audio input unit is set to 48 KHz with the 48 field / s apparatus. In a 48 field / s device, the audio is 1000 samples / field. If simply converted, 800 sample / field × 24 bits / sample = 19200 bits / field, so 1000 samples / field × 19.2 bits / sample. Since 19.2 bits per sample is not an integer number of bits, it cannot be realized. Therefore, the number of samples per field that is close and convenient is used. For example, 960 samples / field × 20 bits / sample is set. However, with this number of samples per field, the sampling frequency is 960 sample / field × 48 field / s = 46080 sample / s. Therefore, a sampling rate converter of 46.08 KHz <-> 48 KHz is provided between the input unit of the apparatus and the audio data conversion unit so that the input unit has a desired 48 KHz sampling rate. In this case, the sampling rate is converted to 46.08 KHz, but since the human audible range is generally 20 KHz, the sampling frequency only needs to exceed 40 KHz even if applied to the sampling theorem, and the performance of D / A, A / D, etc. In view of this, it is considered that a sampling frequency of 46.08 KHz is sufficient.
[0020]
If the number of samples per field and the number of bits per sample are not convenient for the same reason as above, add stuffing (insignificant data) without using the sampling rate converter, and use the same total bits per field as the underlying device. It may be a number. For example, when a field frequency of 48 Field / s is considered, 200 samples of stuffing (insignificant data) is added to 1000 samples / field × 19 bits / sample and converted to 800 samples / field × 24 bits / sample = 19200 bits / field.
[0021]
In the audio recording apparatus according to the present invention, audio data format conversion processing can also be performed in an ECC encoding processing circuit. Audio data format conversion is performed by the ECC encoding processing circuit, and only the audio clock used for the baseband side is input to the ECC encoding processing circuit. For example, even when a VTR with a field frequency of 50 Field / s and a baseband side audio processing clock of 48 KHz is created based on a VTR with a field frequency of 60 Field / s and a baseband side audio processing clock of 48 KHz, only 48 KHz is input as the audio clock. To do. 48 KHz × 50/60 = 40 KHz is not necessary.
[0022]
Audio data format conversion is performed immediately after input to the ECC encoding processing circuit. Audio data conversion is performed by providing a register for the number of bits per audio baseband sample of the base recording device, and cyclically writing to and reading from the register using LSB fast or MSB fast. Perform conversion. Also, the read side puts a read break in order to match the data rate on the write side. For example, when a device having a field frequency of 50 Field / s and 960 samples / field × 20 bits / sample is made for a device based on a field frequency of 60 Field / s and 800 samples / field × 24 bits / sample, the ECC encoding processing circuit uses 24. The number of registers (for 24 bits) is provided, where the LSB fast is cyclically written to the register at 20 bits / sample, the LSB fast is read from the register at 24 bits / sample, and the format conversion of the audio data is realized. The reading side rests reading once every 6 samples.
[0023]
The control to the circuit after the audio data format conversion is extended in response to the audio data format conversion register read. That is, the internal counter operation for the control signal is rested according to the rest of the audio data format conversion register reading. For example, when a device having a field frequency of 50 Field / s is made for a device based on a field frequency of 60 Field / s, reading of the format conversion register of 1 sample audio data is taken off every 6 samples. At the same time, the control signal internal counter is also closed. Therefore, the cycle of the control signal is 6/5 of 60 Field / s, and the processing performed at 800 fields / s and 800 samples (1 field) takes 960 samples (1 field) at 50 Field / s and the same processing is performed. become.
[0024]
On the other hand, on the playback side of this apparatus, the audio frequency conversion unit clock of the block close to the recording / reproducing medium from the audio data conversion unit inputs the field frequency ratio clock of the base device and the target device. For example, assuming a VTR with a field frequency of 50 Field / s and a VTR with a field frequency of 60 Field / s and an audio processing clock frequency of 48 KHz as a base device, the audio processing clock frequency is 48 KHz × 50/60 = 40 KHz.
[0025]
The audio processing clock of the block close to the output unit of the apparatus from the audio data conversion unit (distant from the medium) is set as the output clock frequency of the apparatus. For example, the base device is 60 Field / s and the audio is 800 Sample / field × 24 bits / Sample (sampling frequency 48 KHz) per field, and the device of 50 Field / s based on it is 960 Sample / field × 20 bits / field. Assuming that recording is performed at Sample (sampling frequency 48 KHz), blocks close to the output unit of the apparatus from the audio data conversion unit (distant from the medium) are processed with a clock of 48 KHz. Therefore, the baseband processing is 48 KHz for both devices, and the same circuit can be used for both.
[0026]
The side near the device output unit of the audio data converter (the side far from the medium) is set to the number of samples per field and the number of bits per sample so that the total number of bits per field of the audio data is the same as that of the underlying field frequency device. To do. For example, if audio is recorded at 800 Sample / field × 24 bits / Sample per field with a device having a base field frequency of 60 Field / s, 960 Sample / field × 20 bits / Sample is recorded with a device having a field frequency of 50 Field / s. . In both cases, the total number of bits per field is 19200 bits / s. By changing the number of bits per sample from the original device as in this example, the output sampling frequency of both devices can be made the same. In the above example, the sampling frequency is 48 KHz for both field frequency devices.
[0027]
As described above, the number of samples per field and the number of bits per sample on the side closer to the device output unit of the audio data conversion unit are determined. If this is the same as the number of samples per field and the number of bits per sample of the device output unit, Processing is simplified. However, there may be no convenient number of samples per field and number of bits per sample depending on the target field frequency. Also, depending on the convenience of the target device, it may be desired to arbitrarily set the number of samples per field and the number of bits per sample in the device output unit. In this case, the number of samples per field of the device output unit, the number of samples per field that is close to the total number of bits of the base device close to the number of bits per sample (influencing the sampling frequency), and the number of bits per sample are determined. An audio sampling rate converter is provided between the output unit of the apparatus and the audio data conversion unit so as to obtain the sampling frequency. For example, suppose that the apparatus is based on 60 Field / s and the audio can be recorded at 800 Sample / field × 24 bits / Sample per field, and based on that, the 48-field / s apparatus uses an audio output unit of 48 KHz. In a 48 field / s device, the audio is 1000 samples / field. If simply converted, 800 sample / field × 24 bits / sample = 19200 bits / field, so 1000 samples / field × 19.2 bits / sample. Since 19.2 bits per sample is not an integer number of bits, it cannot be realized. Therefore, the number of samples per field that is close and convenient is used. For example, 960 samples / field × 20 bits / sample is set. However, with this number of samples per field, the sampling frequency is 960 sample / field × 48 field / s = 46080 sample / s. Therefore, a sampling rate converter of 46.08 KHz <-> 48 KHz is provided between the output unit of the apparatus and the audio data conversion unit so that the output unit has a desired 48 KHz sampling rate. In this case, the sampling rate is converted to 46.08 KHz, but since the human audible range is generally 20 KHz, the sampling frequency only needs to exceed 40 KHz even if applied to the sampling theorem, and the performance of D / A, A / D, etc. In view of this, it is considered that a sampling frequency of 46.08 KHz is sufficient.
[0028]
If the number of samples per field and the number of bits per sample are not convenient for the same reason as above, add the stuffing (insignificant data) without using the above sampling rate converter, and add the total per field as the underlying device. The number of bits may be used. For example, when a field frequency of 48 Field / s is considered, 200 samples of stuffing (insignificant data) is added to 1000 samples / field × 19 bits / sample and converted to 800 samples / field × 24 bits / sample = 19200 bits / field.
[0029]
When encoding in data recording, the audio data of the target device is converted by the audio data conversion unit, and converted to the same number of samples per field and bits per sample as the baseband of the base field frequency device, and at the same time the sampling rate is set to the field Change to frequency ratio double. Specifically, a FIFO can be used for data conversion, and sampling frequency conversion is also performed by the FIFO. For example, when the base device is 60 Field / s and the audio data is 800 samples / field × 24 bits / Sample per field, the 50 Field / s device based on it records 960 samples / field × 20 bits / Sample per field. Think of a device. On a 50 Field / s device, 6 samples × 20 bits / sample (48 KHz) is written in the FIFO of the audio data conversion unit at 48 KHz with 6 samples as one processing unit, and data is rearranged on the FIFO to 5 samples × 24 bits / sample, and 40 KHz ( = 48KHz × 50/60). In this way, the 960 sample / field × 20 bit / sample (48 KHz) can be converted to 800 sample / field × 24 bit / sample (40 KHz) by the audio data conversion unit.
[0030]
At the time of decoding in data reproduction, data conversion is performed by the audio data conversion unit to convert the number of samples per field and the number of bits per sample suitable for the target field frequency device, and at the same time, the sampling rate is converted back to the original field frequency ratio. Specifically, a FIFO can be used for data conversion, and sampling frequency conversion is also performed by the FIFO. For example, in the case where the base device is 60 Field / s and the audio data is 800 Sample / field × 24 bits / Sample per field, and the 960 Sample / field × 20 bits / Sample is recorded per field in the 50 Field / s device. Think. On the medium, 6 samples × 20 bits / sample (48 KHz) is converted to 5 samples × 24 bits / sample (40 KHz) and recorded. The reproduced 5 sample × 24 bit / sample (40 KHz) is written into the FIFO of the audio data conversion unit at 40 KHz, the data is rearranged into 6 sample × 20 bit / sample on the FIFO, and read out at 48 KHz. In this way, the 800 data / field × 24 bits / sample (40 KHz) can be converted to 960 samples / field × 20 bits / sample (48 KHz) by the audio data conversion unit.
[0031]
The audio data conversion sequence starts from the first sample in the first field. For example, in the above example, 6 samples × 20 bits / sample from the first sample of the first field at the time of encoding is converted to 5 samples × 24 bits / sample by the conversion process, and 5 samples × 24 bits / sample from the first sample of the field at the time of decoding is converted. In the conversion process, it is converted to 6 samples × 20 bits / sample.
[0032]
The audio recording format on the medium is the same as that of the underlying device, and processing such as error correction coding is performed in exactly the same way as the underlying device. For example, when the base device is 60 Field / s and the audio data is 800 Sample / field × 24 bits / Sample per field, and the 50 Field / s device based on it records 960 Sample / field × 20 bits / Sample per field. The audio data is converted from 960 sample / field × 20 bit / sample to 800 sample / field × 24 bit / sample by the conversion unit. The converted audio data has the same number of samples per field and the same number of bits per sample as the underlying device. The audio recording format is the same as the underlying device, with the same error correction processing as the underlying device. Record as follows.
[0033]
In the audio recording apparatus according to the present invention, audio data format conversion processing can also be performed in the ECC decoding processing circuit. At that time, only the audio clock used for the baseband is input to the ECC decoding processing circuit. For example, even when a VTR with a field frequency of 50 Field / s and a baseband side audio processing clock frequency of 48 KHz is created based on a VTR with a field frequency of 60 Field / s and a baseband side audio processing clock frequency of 48 KHz, the audio clock is only 48 KHz. Enter. 48 KHz × 50/60 = 40 KHz is not necessary.
[0034]
Audio data format conversion is performed immediately before the output of the ECC decode processing circuit. For the conversion of audio data, registers for the number of bits per audio baseband sample of the underlying playback device are provided, and the format of the audio data is converted by cyclically writing to and reading from the register using LSB fast or MSB fast. To do. In addition, the writing side appropriately includes a writing break in order to match the reading side data rate. For example, when a device having a field frequency of 50 Field / s and 960 samples / field × 20 bits / sample is made for a device based on a field frequency of 60 Field / s and 800 samples / field × 24 bits / sample, the ECC decoding processing circuit uses 24 units. A register of (24 bits) is provided, where the LSB fast is cyclically written to the register at 24 bits / sample, the LSB fast is read from the register at 20 bits / sample, and the format conversion of the audio data is realized. The writing side rests writing once every 6 samples.
[0035]
The control of the circuit before the audio data format conversion is extended in response to a break in writing the audio data format conversion register. That is, the internal counter operation for the control signal is rested in accordance with the rest of the audio data format conversion register writing. For example, when a device having a field frequency of 50 Field / s is made for a device based on a field frequency of 60 Field / s, writing of the format conversion register of 1 sample audio data in 6 samples is suspended. At the same time, the control signal internal counter is also closed. Therefore, the cycle of the control signal is 6/5 of 60 Field / s, and the processing performed at 800 field / s at 800 sample (1 field) takes 960 sample (1 field) at 50 Field / s and the same processing is performed. .
[0036]
When reading / writing the audio data format conversion register during forward playback and backward playback, an automatic selection operation is performed to select LSB fast or MSB fast. This is because the order in which the audio data comes in the forward playback and the reverse playback is reversed, and the format conversion is reversed by MSB fast packing and LSB fast packing. Therefore, it is necessary to appropriately control whether the audio data format is converted in the MSB fast format or the LSB fast format in accordance with forward playback and reverse playback.
[0037]
During shuttle playback, when the audio data format conversion process is performed, data from different fields are mixed and the data is played back. However, the first and last data packs of the audio data format conversion sequence all contain the original one sample. Since the pack that contains the data will come, only the data that can be converted to the original data is reproduced as valid data. Data other than the beginning and end of the format conversion sequence of audio data cannot be completely converted, and different sample data should be mixed and converted in format, and these samples are processed as concealment as errors. If the upper effective data bit number is limited, an audio data format conversion sample other than the first and last of the audio data format conversion sequence can be obtained, so that more data than the above can be used as valid data for shuttle playback sound. In this case, however, LSB bits equal to or less than the limit number of bits are replaced with 0 data.
[0038]
As for video, on the recording side of this device, the conversion unit converts the video image frame of the input signal of the target field frequency to be the same as the image frame of the underlying device, and at the same time, converts the clock to the field frequency ratio multiple. . For example, assuming that the base device is 2200 sample / Line × 1125 Line / Field (effective area 1920 sample × 1080 Line, clock 74.25 MHz) at a field frequency of 60 field / s, the target device has a field frequency of 50 field / s, 2640 sample / Line ×. If 1125 Line / Field (effective area 1920 sample × 1080 Line, clock 74.25 MHz), 2640 sample / Line × 1125 Line / Field (effective area 1920 sample × 1080 Line, clock 74.25 MHz) of the target device in the conversion unit is 2200 sample / Line × 125 line. / Field (effective area 1920sample × 1080Lin e. Clock is converted to 61.875 MHz (= 74.25 MHz × 50/60).
[0039]
Video compression processing, video encoding processing such as error correction coding, etc., are performed exactly the same processing as the base device with a clock that is twice the field frequency ratio of the base device and the target device before the conversion unit, and the recording format is the same as the base device To be. For example, if the base device has a field frequency of 60 fields / s, a video compression processing output clock of 46.4 MHz, and the target device has 50 fields / s, the video compression processing output clock of the target device is 46.4 MHz × 50/60 = 38.6666 MHz. Performs the same processing as the device.
[0040]
On the other hand, on the playback side of this device, video decoding processing such as error correction processing and video decompression is exactly the same as that of the base device up to the video decode clock converter with a clock that is twice the field frequency ratio of the base device and the target device. . For example, if the base device has a field frequency of 60 fields / s, a video expansion input clock of 46.4 MHz, and the target device has 50 fields / s, the video expansion input clock of the target device is 46.4 MHz × 50/60 = 38.6666 MHz and is completely the same as the base device. Do the same process.
[0041]
The video decoding clock conversion unit converts the video image frame of the output signal of the target field frequency into a desired image frame and at the same time converts it into a desired clock. For example, assuming that the base device is 2200 sample / Line × 1125 Line / Field (effective area 1920 sample × 1080 Line, clock 74.25 MHz) at a field frequency of 60 field / s, the output of the target device has a field frequency of 50 field / s, 2640 sample / s If it is Line × 1125 Line / Field (effective area 1920 sample × 1080 Line, clock 74.25 MHz), on the input side of the video decode clock converter, the same frame and clock as the base device are multiplied by the field frequency ratio of the base device and the target device. 2200 sample / Line × 1125 Line / Field (effective area 1920 sample × 1080 Line, clock 61.875 MHz (= 7 It has become .25MHz × 50/60)). This is converted into 2640 sample / Line × 1125 Line / Field (effective area 1920 sample × 1080 Line, clock 74.25 MHz) of the target device.
[0042]
When the number of video lines and effective image frames differ depending on the field frequency as in the standard (SD), the recording side uses the same number of video lines and effective image frames as the base device in the encoding system of the target device and the clock. Is provided with a conversion unit with a video line conversion filter for converting the signal to a field frequency ratio of the base device and the target device. For example, let us consider a case where the image frame and the clock are different from the effective area 720 sample × 480 Line (13.5 MHz) at the field frequency 60 field / s and the effective area 720 sample × 576 Line (13.5 MHz) at the 50 field / s. In order to cope with this, line conversion is performed from 720 sample × 576 Line of 50 field / s to 720 sample × 480 Line of 60 field / s by filtering, and the clock frequency is converted to 13.5 MHz × 50/60 = 11.25 MHz.
[0043]
On the other hand, on the playback side, when the number of video lines and the effective image frame are different depending on the field frequency as in the standard (SD), the decoding system of the target device has the same video image frame as the base device and the clock is the same as the base device. A conversion unit with a video line conversion filter is provided for converting a video signal having a field frequency ratio of the target device into a desired video frame and clock frequency. For example, assuming that the base device has a field frequency of 60 fields / s and an effective area of 720 samples × 480 lines (13.5 MHz), and the output of the target device has a field frequency of 50 fields / s and 720 samples × 576 lines (13.5 MHz), video On the input side of the conversion unit with a line conversion filter, since the clock is the same as the base device and the clock is a field frequency ratio of the base device to the target device, 720 sample × 480 Line (clock 11.25 MHz (= 13.5 MHz × 50/60) )It has become. This is converted into 720 sample × 576 Line (13.5 MHz) of the target device by a conversion unit with a video filter.
[0044]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is a method for simplifying a recording / reproducing apparatus corresponding to a different field frequency based on the system when a recording / reproducing apparatus having a certain field frequency exists. As a specific example, a VTR recording / reproducing apparatus is taken as an example, and hence the term “recording / reproducing apparatus” will not be used. However, the present invention is not limited to the VTR. This VTR has a built-in CPU, and executes a computer program to realize an audio recording method, an audio reproduction method, a video recording method, and a video reproduction method, each having a predetermined procedure. This computer program is stored in a ROM, hard disk, or other medium, and is incorporated in the VTR. The CPU of the VTR reads out a computer program from this medium and executes it.
[0045]
FIG. 1 is a block diagram of a VTR corresponding to a field frequency of 60 Field / s. This is the basic VTR. (A) shows the recording side, and (B) shows the reproduction side. The input video signal is sent to the video baseband processing unit 1. The video baseband processing unit 1 operates with a 74.25 MHz clock. Here, brightness, chroma, etc. are controlled. The signal processed by the video baseband processing unit 1 is sent to the video compression unit 2. Here, the video signal is compressed, put on a 46.4 MHz clock, and sent to the ECC encoding & audio / video combination unit 4.
[0046]
On the other hand, the input audio signal has a sampling frequency of 48 KHz. When the number of samples per field is calculated, 48K / 60 = 800 sample / field. One sample is 24 bits. This input audio signal is sent to the audio baseband processing unit 3 for audio baseband processing. For example, gain adjustment or the like is performed here. The signal processed by the audio baseband processing unit 3 is sent to the ECC encoding & audio / video combination unit 4. The ECC encoding & audio / video combining unit 4 generates an error correction code (ECC) for each of audio and video, adds C1 and C2 parities, and performs data processing to match the tape format. The input clock of the ECC encode & audio / video combination unit 4 is 46.4 MHz for video and 48 KHz for audio. The output is 94 MHz serial data as tape recording data.
[0047]
The audio input data of the ECC encoding & audio / video combination unit 4 is serial and is sent in 1 sample 64 bits. An audio serial data format is shown in FIG. As can be seen here, the serial data is sent in the AES / EBU format with two channels mixed. Z, M, J, E, V, U, C, and P are flags, respectively, and main line data is sent in LSB fast. FIG. 2 shows a data format of 24 bits / sample and 20 bits / sample. Thus, the audio input of the ECC encode & audio / video combination unit 4 is serial data. In FIG. 1, 48 KHz is written, which means that when one sample is counted as one clock, the rate is 48 KHz, that is, the sampling frequency. Since the audio input of the ECC encode & audio / video combination unit 4 is serial data, it is 48 KHz × 64 bits / sample = 3.072 MHz when written at the clock frequency of the serial data. However, the sampling frequency, which is a frequency with 1 sample as one unit, is important for audio. In this example, 1 sample is accidentally sent in 64-bit serial, but it may be sent in 256 bit. For this reason, only 48 KHz, which is important in FIG. 1, is described, and the audio clock is described by the sampling frequency before this.
[0048]
The signal generated by the ECC encoding & audio / video combination unit 4 is recorded on the tape. The signal reproduced from the tape is input to the ECC decode & audio / video separation unit 5. The ECC decode & audio / video separating unit 5 separates the audio and video data, and then decodes (decodes) the error correction code to perform error correction. The video data is output on a clock of 46.4 MHz and input to the video decompression unit 6. In the video decompression unit 6, the compression is released and a video baseband signal is output. This signal is sent to the video baseband processing unit 7. The video baseband processing unit 7 controls the brightness, chroma, etc., and then outputs a VTR. On the other hand, the audio is subjected to error correction processing by the ECC decoding & audio / video separation unit 5 and then output from the ECC decoding & audio / video separation unit 5 in the audio baseband. At this time, the number of samples per field and the number of bits per sample are 800 samples / field and 24 bits / sample. This signal is sent to the audio baseband processing unit 8 at a sampling frequency of 48 KHz. The audio baseband processing unit 8 performs output audio gain control and the like. This signal becomes the VTR output audio.
[0049]
FIG. 3A is a video recording format diagram with a field frequency of 60 Field / s. One field is composed of six tracks, and one track constitutes a video 1 ECC (error correction code) block (product code). Since there are 6 Tracks / Fields, the video has 6 ECC blocks / field. V in the tape footprint diagram of FIG. 3A represents video, and the video is divided into two sectors on one track. One ECC block of video is 250 sync / track, and 125 syncs are provided per sector, and 250 syncs are provided for two sectors. That is, there is 250 Sync data in one track, and this ECC block configuration is as shown in FIG. One sync means one piece of data in the C1 direction of the ECC block. The C1 ECC parity is 12 bytes, and the C2 ECC parity is 24 bytes. Video data is compressed data.
[0050]
FIG. 4 is an audio recording format diagram with a field frequency of 60 Field / s. In the tape footprint diagram shown in FIG. 4A, A0 represents the audio channel 0, A1 represents the audio channel 1, A2 represents the audio channel 2, and A3 represents the audio channel 3. The audio ECC block configuration is composed of one field for each audio channel. Audio is recorded on a track by 4 Sync per channel. Therefore, collecting 6 tracks of data for one field results in 4 Sync / track channel × 6 Track / Field = 24 Sync / field channel, which constitutes an ECC block of one audio channel. As shown in FIG. 4B, an audio ECC block is configured, and 12 bytes are allocated as the C1 ECC parity and 12 bytes are allocated as the C2 ECC parity. Since there are 24 bits per audio sample, this is divided into 8 bits × 3 symbols. As shown in FIG. 4 (B), 1 Sample is configured to enter from the MSB as 3 bytes of data in the same Sync. Since one field contains 800 sample data, a data frame for 4 samples is left in the ECC block, but user data is allocated here. Audio sample data contains uncompressed data.
[0051]
FIG. 5 is a block diagram of a VTR that realizes a field frequency of 50 Field / s. (A) shows the recording side, and (B) shows the reproduction side. This VTR is based on the VTR having a field frequency of 60 Field / s shown in FIG. The video compression unit 2, audio baseband processing unit 3, ECC encoding & audio / video combining unit 4, ECC decoding & audio / video separation unit 5, video decompression unit 6 and audio baseband processing unit 8 are all basic 60 Fields. Use exactly the same block as the / s compatible VTR. Each of the video baseband processing unit 1 ′ and the video baseband processing unit 7 ′ is a baseband processing block for video encoding / decoding, but has a processing clock of 74.25 MHz and a video base having a base field frequency of 60 Field / s. Since the processing clocks of the band processing unit 1 and the video baseband processing unit 7 are the same and almost the same processing can be used, the video baseband processing unit 1 ′, the video baseband processing unit 1, and the video baseband processing unit 7 are actually used. 'And the video baseband processing unit 7 have almost no circuit difference.
[0052]
The video clock converter 11 is a clock converter whose output is 61.875 MHz which is 50/60 times the field frequency ratio with respect to the input 74.25 MHz. This example considers high-definition, and the video effective frame area is a picture frame of 1920 sample × 1080 line (or 1440 sample × 1080 line) in both cases of the field frequencies of 50 Hz and 60 Hz. The difference between the effective picture frames at 50 Hz and 60 Hz is as follows. Therefore, even if the frequency is 61.875 MHz which is 50/60 times, the invalid area is simply discarded, and all the valid area becomes valid data as it is.
[0053]
FIG. 6 shows the difference between each field frequency and the image frame in the processing process. (A) shows an image frame with a field frequency of 60 Hz, (B) shows an image frame with a field frequency of 50 Hz, and (C) shows an image frame (signal form) after processing the image frame with a field frequency of 50 Hz by the video clock converter 11. . Thus, the signal form (C) after processing by the video clock converter 11 is exactly the same as the signal form (A) of 60 Field / s and 74.25 MHz including the invalid region.
[0054]
The 61.875 MHz output signal output from the video clock converter 11 is sent to the video compression unit 2. If the output clock is set to 38.666 MHz which is 50/60 times, the clock and the data rate are only 50/60 times for the video compression unit 2, and the processing is exactly the same as the base 60 Field / s VTR. . In other words, it can be said that the role of the video clock converter 11 is to perform the processing after the video clock converter 11 at the rate of 50/60 times exactly the same as the base 60 Field / s compatible VTR.
[0055]
On the other hand, on the audio side, the audio data pack unit 9 performs the same function as the video clock converter 11 on the video side. As shown in FIG. 5, the audio data pack unit 9 converts 48 KHz, 960 sample / field × 20 bits / sample (= 19200 bits / field) into 40 KHz, 800 sample / field × 24 bits / sample (= 19200 bits / field). . Both of these audio data can be converted because the total number of bits per field is the same as 19200 bits / field. Here, 40 KHz = 48 KHz × 50/60, and the audio side can perform exactly the same processing as the base field frequency 60 field / sVTR at a rate of 50/60 times after the audio data pack unit 9.
[0056]
FIG. 7 shows a detailed configuration of the audio data pack unit 9. As can be seen from FIG. 7A, the audio data pack unit 9 includes a FIFO control and a FIFO unit. One sequence of the data pack is 48 samples (20 bits / sample) and 6 samples. Although 20 bits / sample × 6 samples = 120 bits, this is converted into 120 bits = 24 bits / sample × 5 samples in a 40 KHz system (24 bits / sample). Audio data is serially input to the audio data pack unit 9, and is written in 1 bit serial at 48 × 48 KHz of 48 KHz system. At this time, the Z, M, J, E, V, U, C, and P flags are not written in the FIFO, but only the data is written in the FIFO. This is read out serially by 1 bit at 40 × 40 KHz 64 × 40 KHz. However, the flag portion is cleared to 0 without being read from the FIFO (the flag is meaningless data in the subsequent stage). Reading is performed for each sample with 24 bits as 1 sample and sent to the ECC encoding & audio / video combination unit 4. As shown in FIG. 7B, the start point of the sequence is performed at the beginning of the field. As this control signal, the audio data pack unit 9 receives a signal Field-Start indicating the head of the field. FIG. 7B shows how data packs are written to and read from the FIFO. The reason why the FIFO is delimited by 4-bit squares is to make it easier to understand the state of 20-bit-> 24-bit conversion. Actually, it is written every 1 bit as described above, and every 1 bit. It has been read. As for Field-Start, when converting from 48 KHz system to 40 KHz system, the FIFO control in the audio data pack unit 9 outputs a signal Field-Start, and indicates information indicating where the field head is in the converted 40 KHz system. put out. Based on this information, the ECC encoding & audio / video combination unit 4 separates audio field breaks and cuts out audio data to create an ECC block.
[0057]
The video input and audio input of the ECC encoding & audio / video combination unit 4 shown in FIG. 5 are both 50/60 times the rate compared to the case of 60 Field / s. Since the output of the ECC encoding & audio / video combining unit 4 is also 50/60 times the rate, the ECC encoding & audio / video combining unit 4 processes exactly the same processing as in the case of 60 Field / s at a rate of 50/60 times. Will do. As a matter of course, the same circuit can be used in the case of 60 Field / s and 50 Field / s. Then, it is recorded on the tape at a rate of 50/60 times. At this time, the tape running speed, the drum rotation speed, etc. are all 50/60 times the field frequency ratio compared to the case of 60 Field / s. Therefore, the footprint is the same for the base field frequency 60 Field / s VTR and the 50 Field / s VTR.
[0058]
On the other hand, in tape reproduction, data at a rate of 50/60 times the basic field frequency 60 Field / s is input to the ECC decode & audio / video separation unit 5. The ECC decode & audio / video separation unit 5 performs processing at a rate 50/60 times that of 60 Field / s. For this reason, both video output and audio output have a rate 50/60 times that of 60 Field / sVTR. As a matter of course, the ECC decoding & audio / video separation unit 5 is exactly the same processing as in the case of 60 Field / s and only has a different rate, so the same circuit as 60 Field / s can be used. The video output of the ECC decode & audio / video separation unit 5 enters the video decompression unit 6. The video decompression unit 6 also has an input / output processing rate of 50/60 times that of 60 Field / s. Of course, the same circuit can be used as in the case of 60 Field / s. Here, the video clock converter 12 on the reproduction side performs the reverse function of the video clock converter 11 on the recording side. The video clock converter 12 returns from 61.875 MHz, which is a 50/60 rate of 60 Field / s, to 74.25 MHz. As shown in FIG. 6, the effective area does not change, and the invalid area (blanking part) increases to 74.25 MHz. The video baseband processing unit 7 ′ performs video baseband processing and adjusts brightness, chroma, and the like. The field frequency 50 Field / s output of the video baseband processing unit 7 ′ becomes the VTR output.
[0059]
On the other hand, the audio is subjected to error correction processing by the ECC decoding & audio / video separation unit 5 and then input to the audio data depacking unit 10 in a state where the data is packed at 40 KHz, 800 sample / field × 24 bits / sample. The audio data depack unit 10 unwinds the data pack by performing the reverse function of the audio data pack unit 9 and restores the original 48 KHz, 960 sample / field × 20 bits / sample. Details of the audio data depacking unit 10 are shown in FIG. As shown in FIG. 6A, the signal Field-Start indicating the field head is correctly transmitted even if the data is converted from 40 KHz to 48 KHz by the FIFO control as in the audio data pack unit 9. The signal Field-Start on the writing side is a very important signal as the starting point of the data depacking sequence. As in the case of the audio data pack unit 9, the sequence is 5 samples × 24 bits / sample = 120 bits for the 40 KHz system (write side), and 6 samples × 20 bits = 120 bits for the 48 KHz system (read side). Also in the audio data depacking unit 10, the signal Field-Start is the data depacking sequence start point.
[0060]
The 48 kHz, 960 sample / field × 20 bits / sample processed by the audio data depacking unit 10 is input to the audio baseband processing unit 8, and after performing audio baseband processing such as gain adjustment, the field frequency is output as a VTR output. It is output at 50 Field / s, 48 KHz, 960 sample / field × 20 bits / sample. Thus, based on the field frequency of 60 Field / s VTR, it corresponds to the field frequency of 50 Field / s.
[0061]
So far, the case of the field frequency of 50 Field / s has been described, but other field frequencies can also be handled. FIG. 9 shows a block diagram in the case of a field frequency of 48 Field / s. (A) shows the recording side, and (B) shows the reproduction side. The base VTR is the field frequency 60Field / sVTR in FIG. The video side uses the video clock converter 11 and the video clock converter 12 to convert the rate to the field frequency ratio as in the case of the field frequency of 50 Field / s, and in this case, 74.25 MHz <----> 59.4 MHz. (= 74.25 MHz × 48/60).
[0062]
This situation is shown in FIG. (A) shows an image frame with a field frequency of 60 Hz, (B) shows an image frame with a field frequency of 48 Hz, and (C) shows an image frame (signal form) after processing the image frame with a field frequency of 48 Hz by the video clock converter 11. . As can be seen from FIG. 10, as in the case of the field frequency of 50 Field / s, the effective area is not changed by the conversion of the input video clock converter 11 and the output video clock converter 12, and only the invalid area (blanking area) is changed. It can be seen that after conversion, the image frame of the original 60 Field / sVTR including the invalid area and the effective area is exactly the same.
[0063]
On the other hand, when considering audio, the total number of bits per audio field is set to be the same between the base field frequency 60 Field / sVTR and the field frequency 48 Field / sVTR, which is convenient at the field frequency 48 Field / s. The number of samples per field, not the number of bits per sample. Audio can be recorded at 800 Sample / field × 24 bits / Sample per field with the base 60 Field / s VTR. Based on this, consider a case where the audio input unit is 48 KHz with 48 field / s VTR. Since it is 48 field / s, it becomes 1000 sample / field. If simply converted, 800 sample / field × 24 bits / sample = 19200 bits / field, so 1000 samples / field × 19.2 bits / sample. Since 19.2 bits per sample is not an integer number of bits, it cannot be realized. Therefore, it is converted into 800 sample / field × 24 bit / sample via 960 sample / field × 20 bit / sample which is close to this. As shown in FIG. 9, the audio rate converter 13 once converts 1000 samples / field × 20 bits / sample (48 KHz, 48 Field / s) to 960 samples / field × 20 bits / sample (46.08 KHz, 48 Field / s). The audio data pack unit 9 converts this signal into 800 samples / field × 24 bits / sample (36.864 KHz = 46.08 KHz × 48/60, 48 Field / s). As with the field frequency of 50 Field / s, encoding is performed at the field frequency ratio rate.
[0064]
The decoding process is performed in reverse to the encoding process, and the audio data depacking unit 10 converts 800 sample / field × 24 bit / sample (36.864 KHz, 48 Field / s) to 960 sample / field × 20 bit / sample (46.08 KHz, 48 Field / s). Are converted into 1000 samples / field × 20 bits / sample (48 KHz, 48 Field / s) by the audio rate converter 14 and output as a VTR. At this time, the sampling rate is converted to 46.08 KHz, but since the human audible range is generally 20 KHz, the sampling frequency only needs to exceed 40 KHz even if applied to the sampling theorem, such as D / A, A / D, etc. Considering performance, it is considered that a sampling frequency of 46.08 KHz is sufficient. In this way, when the number of bits per sample where the total number of bits is the same is considered, even if the number of bits does not become an integer bit, the number of bits per sample is an integer without reducing the sampling frequency so much by using a sampling rate converter. Can be a bit.
[0065]
When considering the field frequency of 48 Field / s, without using the sampling rate converter of the above method, add 200 samples of stuffing (insignificant data) to 1000 samples / field × 19 bits / sample and convert to 800 samples / field × 24 bits / sample. May be. However, in this case, since the audio data pack / depack sequence becomes long, a large FIFO is required. That is, the least common multiple becomes higher in the numerical relationship between 19 bits and 24 bits than the relationship between 20 bits and 24 bits, and the size of the FIFO increases accordingly.
[0066]
Up to this point, the description has been given by taking the high-vision as an example. Therefore, even if the field frequency is different as in the examples shown in FIGS. 11 and the video clock converter 12 do not perform line conversion filter processing. However, in the case of the standard (SD), the number of lines in the effective area is different from 720 sample × 480 Line at a field frequency of 60 Field / s and 720 sample × 576 Line at a field frequency of 50 Field / s. become. FIG. 11 shows a block diagram of the standard standard field frequency 60Field / sVTR based on FIG. (A) shows the recording side, and (B) shows the reproduction side. The audio baseband processing unit 3 and the audio baseband processing unit 8 are the same as in the example of FIG. The input video baseband processing unit 15, the video compression unit 16, the ECC encoding & audio / video combining unit 17, the ECC decoding & audio / video separating unit 18, the video decompressing unit 19, and the output video baseband processing unit 20 are for SD. Processing block.
[0067]
FIG. 12 shows a block diagram of an SD field frequency of 50 Field / sVTR based on a field frequency of 60 Field / sVTR. (A) shows the recording side, and (B) shows the reproduction side. FIG. 13 shows the respective image frames and the image frames after processing with a field frequency of 50 Field / s. (A) shows an image frame with a field frequency of 60 Hz, (B) shows an image frame with a field frequency of 50 Hz, and (C) shows an image frame (signal form) after processing the image frame with a field frequency of 50 Hz by a video clock converter. In FIG. 12, video baseband processing units 21 and 24 perform input video baseband processing and output video baseband processing, respectively, but are for a field frequency of 50 Field / s, and because the number of lines is different, the field frequency of 60 Field / The processing is completely different from the video baseband processing units 15 and 20 in FIG. 11 corresponding to s. The video line & clock converter 22 in FIG. 12 corresponds to the video clock converter 11 in FIG. 5, and an effective image frame 720 sample × 576 Line having a field frequency of 50 Field / s is converted into an effective image frame 720 sample × having a base field frequency of 60 Field / s. Line conversion filter processing for conversion to 480 Line is performed. As shown in FIG. 13, the video line and clock converter 22 converts the image frame and also changes the clock.
[0068]
The video line & clock converter 23 in FIG. 12 corresponds to the video clock converter 12 in FIG. 5, and an effective image frame 720 sample × 480 Line having a base field frequency of 60 Field / s is converted into an effective image frame 720 sample × having a field frequency of 50 Field / s. Line conversion filter processing for conversion to 576 Line is performed to restore the original number of lines. As shown in FIG. 13, the video line & clock converter 23 converts the image frame and also changes the clock. As in the high-definition example, the video compression unit 16, the ECC encoding & audio / video combination unit 17, the ECC decoding & audio / video separation unit 18 and the video decompression unit 19 only change the rate, and the circuit is the base field. The same frequency as 60 Field / sVTR can be used. Audio can be processed in the same way as in the high-definition example, and the audio data pack unit 9, audio data depack unit 10, audio baseband processing unit 3 and audio baseband processing unit 8 are completely the same as the high-definition VTR in FIG. The same thing. Although the case of SD has been described as an example, a different field frequency VTR can be created from the base field frequency VTR by applying filter processing for converting the image frame even if the image frames are different.
[0069]
Here, a developed form of the VTR shown in FIG. 5 will be described. The audio data depacking unit 10 of the VTR corresponding to the field frequency 50 Field / s shown in FIG. 5 is built in the ECC decoding & audio / video separating unit 5 to have the function therein, and its block diagram. Is shown in FIG. (A) shows the recording side, and (B) shows the reproduction side. FIG. 14 shows a common VTR corresponding to both field frequencies of 60 Field / s and 50 Field / s. The frequencies described in FIG. 14 having different values for 60 Field / s and 50 Field / s are in a relationship of field frequency ratio multiplication. For example, the output of the video compression unit 2 has a relationship of 38.6666 MHz = 46.4 MHz × 50/60, which is a field frequency ratio multiple.
[0070]
FIG. 15 shows a specific configuration of the ECC encoding & audio / video combination unit 4 ′. Here, the video that has undergone C2ECC processing by the video C2ECC processing unit 35 is sent to the SDRAM read / write control unit 31. On the other hand, the serial data of the audio is serial / parallel converted by the S / P converter 25, and the data is sent to the controller 26. The controller 26 performs RateConvRAM write control (data write control of the RateConv28) and ECC start control (process start control of the other controller 29). The controller 26 includes a conversion register 34. This part will be described in detail later. The RateConvRAM 28 is a Dual Port RAM, in which a clock is changed from an audio 48 kHz system clock to an internal system clock (66 MHz). The controller 29 performs RCRAM (RateConvRAM28) read control, C2RAM30 control, C2ECC parity addition processing, and SDRAM write address generation. The SDRAM read / write control unit 31 controls access to the SDRAM 32. The C1ECC processing unit 33 performs SDRAM read address generation and C1ECC parity addition, and outputs RF data on the RF clock rate. The audio timing generator 27 receives a field signal and a sampling period (FS) signal and counts one field. In this case, since both the field frequency is 60 Field / s and 50 Field / s, the sampling frequency is 48 KHz. Therefore, when the field frequency is 60 Field / s, 800 samples per field are counted by the counter, and the controller 26 and the C1 ECC processor 33 process the processing timing. In the case of a field frequency of 50 Field / s, 960 samples per field are counted by a counter, and processing timing is given to the controller 26 and the C1 ECC processing unit 33.
[0071]
FIG. 16 shows an audio timing chart of the ECC encode & audio / video combination unit 4 ′. FIG. 16 shows a process of a field frequency of 60 Field / s and one sample of 24 bits / sample. That is, when the field frequency is 50 Field / s, the processing timing after 20 bits / sample is converted to 24 bits / sample is written. First, the basic 60 Field / s timing will be described. The RateConvRAM 28 is internally divided into 3 banks, and 48 samples × 24 bits / sample data can be stored in each bank. The numbers in FIG. 16 indicate RCRAMbankNo. Is shown. It can be seen that 800 sample / field is processed at 48 sample / bank × 16 bank + 32 sample (1 bank). Audio data is written to the RateConvRAM 28 at an FS (sampling frequency 48 KHz) rate. Fld-Start (Field-Start) and C2-Start are processing timing control signals coming from the controller 26, and new field data from the Fld-start is written to the RateConvRAM 28. It can be seen from FIG. 16 that new field data is written in the RateConvRAM 28 in order from bank 2 and 0. When the next C2-Start arrives, the C2, ECC processing of bank2, 0 is started. Read from the RateConvRAM 28 in the C2 direction at a system clock of 66 MHz. The controller 29 performs C2ECC processing, adds C2 parity, and then writes the data in the C2RAM 30 in the C2 direction. When writing to all the C2RAMs is completed, the data is read from the C2RAM in the C1 direction, sent to the SDRAM read / write control unit 31 together with the SDRAM write address, and written to the SDRAM 32. Such processing is performed in time division from channel 0 to channel 7 in order. C2-Start comes every time 2 banks are written in the RateConvRAM 28, and the last of the field is C2-Start simultaneously with the Fld-start signal to process the data remaining in the current field. At the end of the field, as a result, processing of 32 samples which is less than 1 bank is performed. Fld-Start and C2-Start are generated from a control signal input from the audio timing generator 27 by the controller 26. In this way, audio ECC encoding processing with a field frequency of 60 Field / s is performed. At the basic field frequency 60 Field / s, the conversion register 34 is not used.
[0072]
Next, a case where a signal having a field frequency of 50 Field / s is input will be described. As can be seen from FIG. 14, when the field frequency is 50 Field / s, the audio input to the ECC encoding & audio / video combination unit 4 ′ comes at 960 samples / field × 20 bits / sample (48 KHz). The audio data pack is converted into 800 sample × 24 bits / sample, and the convert register 34 in FIG. 15 functions as the audio data pack. The S / P converter 25 in FIG. 15 processes the data of 960 samples / field × 20 bits / sample in the same manner as the field frequency of 60 fields / s and performs serial / parallel conversion. The parallel data coming from the S / P converter 25 to the controller 26 comes in 8-bit units with LSB fast. When sending 20 bits / sample, it is divided into LSB 4 bits, MDB (intermediate) 8 bits and MSB 8 bits. This is converted into 24-bit data by the conversion register 34. The unit of the sequence is 960 samples / field × 20 bits / sample, and 6 samples are converted into one sequence, which is converted into 24 bits and 5 samples. That is, 6 samples × 20 bits / sample is converted into 5 samples × 24 bits / sample. Therefore, 960 sample / field × 20 bits / sample is converted to 800 sample / field × 24 bits / sample.
[0073]
An explanatory diagram of the operation of the convert register 34 is shown in FIG. The conversion register 34 has 24 registers (for 24 bits). The input data is 20 bits / sample, and as shown in FIG. 17, the audio data is written in the MSB in the LSB fast order in the register with the signal Field-Start as the head of the conversion processing sequence. As described above, one sample data is decomposed into three parts, LSB 4 bits, MDB 8 bits, and MSB 8 bits, so 1 sample is also written in the register in 3 parts. At the time of writing, when it reaches the MSB of the register, it returns to the LSB and writes it cyclically. In FIG. 17, the left side of the conversion register represents a bit being written, and the right side represents a bit being read. For example, looking at the fourth from the left of the conversion register in FIG. 17, it can be seen that writing is only MSB 4 bits and reading is LSB 8 bits. Note that when writing and reading to the convert register compete at the same time, writing has priority.
[0074]
The conversion register 34 is read for the first 1 sample, and then read from the LSB in units of 8 bits. This is the write data to the RCRAM. In the figure, A to F represent independent samples, and explain what kind of data packing is performed in the audio data pack processing. The conversion register 34 is read with a 48 kHz clock, but a break is entered at the start sample of the sequence, and control is performed so that writing to the RateConvRAM 28 is also suspended when the read is absent. In other words, in 1 sample every 6 samples, reading from the conversion register 34 and writing to the RCRAM 28 are suspended. In addition, the internal counter that generates the C2ECC processing start control signal, the Fld-Start signal, the C2-Start signal, and the like to the controller 29 also generates a signal by resting once every 6 samples in the 48 KHz system. . The counter operation of 95 samples (48 KHz system) at a field frequency of 60 field / s operates at 114 samples (48 KHz system) (= 95 × 6/5) at 50 Field / s. From the part where Fld-start and C2-Start overlap in FIG. 16, the next C2-Start has a field frequency of 60 Field / s and an interval of 96 samples (48 KHz). Considering this at a field frequency of 50 Field / s At 114 sample, the counter for 95 samples (60 field / s) advances, and since the next 1 sample starts the sequence, it becomes a break, and at the next 1 sample, the counter advances, and the counter for 96 samples (60 field / s) advances. That is, C2-Start following Fld-start comes out at 116 samples (114 + 1 + 1). In this way, the C2ECC process of the controller 29 also operates at a field frequency ratio multiple. What is important at this time is that the RateConvRAM 28 and the controller 29 and later operate at a frequency ratio doubled by the RAM write control and the process start control, and the RateConvRAM 28 and the controller 29 have no circuit compared to the field frequency of 60 field / s. It is not necessary to change. Also, the rate conversion of the field frequency ratio is performed by resting the internal counter and control at a rate of 1 sample in 6 samples at the time of audio data pack conversion, and the two clocks of 48 KHz and 40 KHz shown in FIG. 7 are used. Compared with the system in which audio data is packed, rate conversion can be performed with only one 48 KHz clock and only 24 registers.
[0075]
Next, FIG. 18 shows an internal block configuration of the ECC decoding & audio / video separation unit 5 ′ on the reproduction side. In the C1ECC decoding processing unit 36, C1ECC decoding (error correction) is performed on the RF data, and the data is written into the SDRAM 32 via the SDRAM read / write control unit 31. The video is C2ECC-decoded by the video C2ECC decode processing unit 42 and the data read from the SDRAM 32 by the SDRAM read / write control unit 31 to output video data. On the other hand, although it is audio, the timing generator 38 obtains a field signal and a sampling period (FS) signal and counts one field. In this case, since the sampling frequency is 48 KHz for both the field frequencies 60 Field / s and 50 Field / s, when the field frequency is 60 Field / s, 800 samples per field are counted by a counter, and the controller 39 and the C1 ECC decoding processing unit 36 are processed at the same timing. In the case of a field frequency of 50 Field / s, 960 samples per field are counted by a counter, and processing timing is given to the controller 39 and the C1 ECC decoding processing unit. The controller 39 creates C2ECC decode processing timing and sends the timing to another controller 37. The controller 39 controls the reading of the RateConvRAM 28. There is a conversion register 41 inside the controller 39, which will be described in detail later. The controller 37 performs C2ECC decoding in accordance with the C2ECC decoding process start timing signals Fld-Start and C2-Start from the controller 39. Necessary data is read in the C1 direction from the SDRAM 32 via the SDRAM read / write control unit 31, and written in the C2RAM 30 in the C1 direction. After the data is stored in the C2RAM 30, the data is read in the C2 direction, the C2ECC decoding process is performed, and the data is written in the RateConvRAM 28. The operation of the controller 37 and the writing to the C2RAM 30 and the RateConvRAM 28 are performed with an internal system clock of 66 MHz. The controller 39 reads data from the RateConvRAM 28 in a 48 KHz system. The data is sent to the S / P converter 40. The S / P converter 40 performs concealment processing, mute processing, and the like, and then the data is parallel-serial converted to become an audio output of the ECC encode & audio / video separation unit 5 ′.
[0076]
FIG. 19 shows an audio timing chart of the ECC decode & audio / video separation unit 5 ′. FIG. 19 shows a process of a field frequency of 60 Field / s and 1 sample of 24 bits / sample. That is, when the field frequency is 50 Field / s, the processing timing before the conversion from 24 bits / sample to 20 bits / sample is written. First, the basic 60 Field / s timing will be described. The RateConvRAM 28 is internally divided into 3 banks, and 48 samples × 24 bits / sample data can be stored in each bank. The numbers in FIG. 19 indicate RCRAMbankNo. Is shown. It can be seen that 800 sample / field is processed at 48 sample / bank × 16 bank + 32 sample (1 bank). Fld-Start and C2-Start are processing timing control signals coming from the controller 39, and new field data is read from the RateConvRAM 28 from the Fld-start. In FIG. 19, it can be seen that the new field data is read from the RateConvRAM 28 in order from bank 2 and 0. Thereafter, data is read from the RateConvRAM 28 at an FS rate without any breaks. As can be seen from FIG. 19, the bank of the RateConvRAM 28 is cyclically read. C2-Start is issued every time 2 banks of the RateConvRAM 28 are read. Since the new field data must be read from the RateConvRAM 28 from the time when Fld-Start is issued, the first bank of the new field is C2ECC decoded at C2-Start before Fld-Start. In FIG. 19, bank2 is the first bank in the new field, and this is C2ECC processed. In the first process of the new field, one bank of RCRAM is processed. When Fld-Start comes, the next 2 banks are processed, and thereafter, every time C2-Start comes, the processing is performed for 2 banks. In this way, the audio ECC decoding process with a field frequency of 60 Field / s is performed. The conversion register 41 is not used at the basic field frequency of 60 Field / s.
[0077]
Next, the case where the field frequency is 50 Field / s will be described. As can be seen from FIG. 14, at the field frequency of 50 Field / s, the audio output of the ECC decode & audio / video separation unit 5 ′ is depacked as audio data and output at 960 sample / field × 20 bits / sample (48 KHz). The 800 register / field × 24 bit / sample is audio data depacked and converted into 960 sample / field × 20 bit / sample, but the convert register 41 in FIG. 18 functions as the audio data depack. Data read from the RateConvRAM 28 in FIG. 18 is 24 bits / sample, and comes in 800 samples / field × 24 bits / sample. This data is converted to 960 sample / field × 20 bits / sample by performing audio data depack conversion in the conversion register 41. When sending 20 bits / sample to the S / P conversion unit 40, the controller 39 in FIG. 18 divides it into LSB 4 bits, MDB (intermediate) 8 bits, and MSB 8 bits in the same way as at the time of encoding. The unit of the conversion sequence is 960 samples / field × 20 bits / sample as in encoding, and 6 samples is one sequence. That is, 5 samples × 24 bits / sample is converted to 6 samples × 20 bits / sample. Therefore, 800 sample / field × 24 bit / sample is converted to 960 sample / field × 20 bit / sample.
[0078]
An operation explanatory diagram of the convert register 41 is shown in FIG. There are 24 conversion registers (for 24 bits). The input data is 24 bits / sample, and the audio data is written to the register with the signal Field-Start as the head of the conversion processing sequence as shown in FIG. At this time, in the case of the forward reproduction (Forward) shown in (A), the data is written in the MSB in order with LSB fast. Also, in the case of reverse playback (Reverse) shown in (B), data is written in the order of LSB in MSB fast order. In addition, when reading is performed in the forward direction, data is read out in order toward the MSB in LSB fast. If the playback is in the reverse direction, the data is read out in order toward the LSB with MSB fast. When data is output from the controller 39 to the S / P conversion unit 40, the data is divided into three LSB 4 bits, MDB (intermediate) 8 bits, and MSB 8 bits in accordance with the LSB fast or MSB fast in the conversion register read. Therefore, LSB fast is used for forward playback, and MSB fast is used for backward playback. In decoding, as in encoding, both writing and reading are cyclically written to / read from the conversion register 41. If writing and reading compete at the same time, reading is performed first.
[0079]
The conversion register is controlled so as to rest after writing 1 sample after writing 5 samples. That is, for 1 sample in 6 samples, reading from the RateConvRAM 28 = writing to the conversion register 41 is suspended. In addition, an internal counter for generating a C2ECC decode processing start control signal, Fld-Start signal, C2-Start signal, etc. to the controller 37 is also rested once every 6 samples in a 48 KHz system to generate a signal. The counter operation of 95 samples (48 KHz system) at a field frequency of 60 field / s operates at 114 samples (48 KHz system) (= 95 × 6/5) at 50 Field / s. From the part where Fld-start and C2-Start overlap in FIG. 19, the next C2-Start has a field frequency of 60 Field / s and an interval of 96 samples (48 KHz), but this is considered at a field frequency of 50 Field / s. The counter for 95 samples (60 fields / s) advances at 114 samples, the counter advances at the next 1 sample, and the counters advance for 96 samples (60 fields / s). That is, C2-Start next to Fld-start comes out at 115 sample (114 + 1). In this way, the C2 ECC decoding process of the controller 37 also operates at a field frequency ratio multiple. What is important at this time is that the RateConvRAM 28 and the controller 37 are operating at a frequency ratio doubled by the RAM read control and the process start control. The RateConvRAM 28 and the controller 37 change the circuit as compared with the case of the field frequency of 60 field / s. There is no need to do that. Further, the controller 39 performs rate conversion by multiplying the field frequency ratio by resting the internal count and control at a rate of 1 sample in 6 samples at the time of audio data depack conversion, and the 48 KHz and 40 KHz2 in FIG. Compared with a system that depacks audio data using two clocks, the rate conversion can be performed with only one clock of 48 KHz and with only 24 registers.
[0080]
Now consider shuttle playback (Shuttle playback). Data from various fields are mixed during shuttle playback. At the time of normal reproduction, the ECC blocks in FIG. 4 are all in the same field within one field. Therefore, C2ECC decoding can be performed. However, the Sync data (data in the C1 direction) remains the same during shuttle reproduction, but when the Sync data is viewed in the C2 direction, the Sync data between different fields are mixed and C2 ECC decoding cannot be performed. Therefore, when audio data depacking is performed during shuttle reproduction, the audio data depacking sequence is protected as shown in FIG. 21, but each data packed is another inter-field data. What should be noted here is that the sample data packed in 24 bits in the audio data pack remains as it is, and the bit data in the data pack does not fall apart. A0, B0, B1, C1, C2, D2, D3, E3, E4, and F4 in FIG. 21 are separate sample data. A to F represent the first data in the data depacking sequence, the numbers after the alphabet represent the fields, and all the pieces of disjoint field data are shown as audio data depacked. . As can be seen from FIG. 21, in 5 samples of the audio data depacking sequence (24 bits / sample after data packing), it can be seen that A0 and F4 are included in the first and last data packs without any loss. That is, it can be seen that these A0 and F4 can always be restored to the original 20-bit / sample data without loss even after audio data depacking. Since data other than A0 and F4 are mixed with each other, this is processed as error data by the S / P converter 40 in FIG. Specifically, the output is configured by interpolating invalid data with valid data. FIG. 21 shows how the audio data changes in the series of processes.
[0081]
Even if all 20 bits are not restored to the original data without any loss in the application in the above case, a method of using the data if the MSB 16 bits are restored can be considered. This is shown in FIG. For 20-bit sample data that has been depacked in audio data, LSB 4 bits are replaced with 0 and MSB 16 bits are enabled. In this way, A0, B1, and F4 become effective data as shown in FIG. Similar to the above, the concealing process is performed as error data except for these reproducible data. Here, the LSB 4 bits are uniformly set to 0 so that all 20 bits of A0 and F4 can be reproduced, but this is for simplifying the process, and since the entire 20 bits of the audio data depacking sequence can be reproduced, these There is also a method in which the LSB 4 bit is used as reproduction data without changing the LSB 4 bit to 0.
[0082]
【The invention's effect】
According to the present invention, it is possible to realize an audio recording / reproducing apparatus that supports all kinds of field frequencies and audio sampling frequencies without changing the format, based on an audio recording / reproducing apparatus corresponding to a certain field frequency. In addition, since almost all processing such as audio baseband changes the rate, the processing content is the same as the recording / reproducing apparatus of the base field frequency, so the same circuit can be used. In addition, even if an audio recording / playback device that supports all types of field frequencies is realized with a single device, most circuits can be used in common at different field frequencies, making it easy to record audio that supports multifield frequencies. A playback device can be realized.
[0083]
According to the present invention, format conversion of audio data can be easily processed by the ECC encoding processing circuit. A device (FIFO) dedicated to audio data format conversion is not required. Further, since it is not necessary to put a clock dedicated to audio data format conversion into the ECC encoding processing circuit, it is only necessary to input one type of baseband audio clock to the ECC encoding processing circuit. Format conversion can be realized by providing only 24 registers (24 bits) in the ECC encoding processing circuit. The ECC encoding processing circuit based on most of the processing (eg rate conversion RAM processing, C2 ECC encoding processing) after the format conversion of the audio data can be used as it is by simply changing a part of the control of the ECC encoding processing circuit, so that there is almost no additional circuit. unnecessary.
[0084]
According to the present invention, the format conversion of audio data can be easily executed by the reproduction side ECC decoding processing circuit as well as the recording side ECC encoding processing circuit. An audio data format conversion dedicated device (FIFO) is not required. Further, since it is not necessary to input a clock dedicated to audio data format conversion to the ECC decoding processing circuit, it is only necessary to input one type of baseband audio clock to the ECC decoding processing circuit. The format conversion can be realized by providing only 24 registers (24 bits) in the ECC decoding processing circuit. By changing only a part of the control of the ECC decoding processing circuit, most of the processing before the format conversion of the audio data (for example, rate conversion RAM processing, C2 ECC decoding processing) can be performed as it is. Since it can be used, almost no additional circuit is required. It also supports trick play such as forward variable playback and reverse variable playback.
[0085]
According to the present invention, a medium on which audio data is converted and recorded is a reproduction target. Here, during shuttle playback, packed data between different fields is played back, and even if this is restored as it is by reverse format conversion, the MSB and LSB of completely different inter-field samples are synthesized by reverse format conversion. It becomes. Therefore, the data value is completely different from the data at the time of recording. This makes the shuttle playback sound a loud noise. For this reason, when shuttle playback of audio data packs is performed, all data is unavoidably muted. Therefore, when shuttle playback is performed by mixing audio data belonging to different fields, shuttle playback sound can be produced by outputting only valid samples including the correct bit string among samples returned to the native format by the conversion unit. it can.
[0086]
According to the present invention, it is possible to realize a video recording / reproducing apparatus corresponding to all kinds of field frequencies and video picture frames without changing the format, based on a video recording / reproducing apparatus corresponding to a certain field frequency. In addition, since most processes such as video baseband processing, video compression, expansion, and error correction coding only change the rate and the processing contents are the same as those of the recording / reproducing apparatus of the base field frequency, the same circuit can be used. Furthermore, even if a single device realizes a video recording / playback device that supports all types of field frequencies, most of the circuits can be used in common at different field frequencies. A playback device can be realized. In addition, when the effective video frames are the same, the recording media formats are all the same regardless of the field frequency. Therefore, even if media recorded at a certain field frequency is reproduced at a different field frequency, the image can be reproduced.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an example of a basic digital audio / video recording / reproducing apparatus.
FIG. 2 is a schematic diagram showing audio data input serially.
FIG. 3 is a format diagram of video data.
FIG. 4 is a format diagram of audio data.
FIG. 5 is a block diagram showing an embodiment of a digital audio / video recording / reproducing apparatus according to the present invention.
6 is a schematic diagram for explaining the operation of the digital audio / video recording / reproducing apparatus shown in FIG. 5. FIG.
7 is a schematic diagram for explaining an operation of an audio data pack unit included in the digital audio / video recording / reproducing apparatus shown in FIG. 5; FIG.
FIG. 8 is a schematic diagram for explaining an operation of an audio data depacking unit included in the digital audio / video recording / reproducing apparatus shown in FIG. 5;
FIG. 9 is a block diagram showing another embodiment of the digital audio / video recording / reproducing apparatus according to the present invention.
10 is a schematic diagram for explaining the operation of the digital audio / video recording / reproducing apparatus shown in FIG. 9. FIG.
FIG. 11 is a block diagram showing another example of a basic digital audio / video recording / reproducing apparatus.
FIG. 12 is a block diagram showing another embodiment of a digital audio / video recording / reproducing apparatus according to the present invention.
13 is a schematic diagram for explaining the operation of the digital audio / video recording / reproducing apparatus shown in FIG.
FIG. 14 is a block diagram showing an embodiment of a digital audio / video recording / reproducing apparatus according to the present invention.
15 is a block diagram showing a configuration of an ECC encoder & audio / video combining unit included in the digital audio / video recording / reproducing apparatus shown in FIG. 14;
16 is a schematic diagram for explaining an operation of an ECC encoder & audio / video combination unit included in the digital audio / video recording / reproducing apparatus shown in FIG. 14;
FIG. 17 is a schematic diagram for explaining the operation of a conversion register included in the ECC encoder & audio / video combination unit shown in FIG. 16;
18 is a block diagram showing a configuration of an ECC decoder & audio / video separating unit included in the digital audio / video recording / reproducing apparatus shown in FIG.
FIG. 19 is a schematic diagram for explaining the operation of an ECC decoder & audio / video separating unit included in the digital audio / video recording / reproducing apparatus shown in FIG. 14;
20 is a schematic diagram for explaining the operation of a conversion register included in the ECC decoder & audio / video separation unit shown in FIG. 19;
FIG. 21 is a schematic diagram showing an example of shuttle playback operation performed by the digital audio / video recording / playback apparatus shown in FIG. 14;
FIG. 22 is a schematic diagram showing another example of shuttle playback operation performed by the digital audio / video recording / playback apparatus shown in FIG. 14;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Video baseband process part, 2 ... Video compression part, 3 ... Audio baseband process part, 4 ... ECC encoding & audio / video combination part, 5 ... ECC decoding & audio / video separation part, 6 ... Video expansion part, DESCRIPTION OF SYMBOLS 7 ... Video baseband process part, 8 ... Audio baseband process part, 9 ... Audio data pack part, 10 ... Audio data depack part, 11 ... Video clock converter, 12 ... Video clock converter, 13 ... Audio rate converter, 14 ... Audio rate converter, 26 ... Controller, 34 ... Convert register, 39 ... Controller, 40 ... S / P converter, 41 ... Convert register

Claims (40)

An input unit that has a predetermined sampling frequency and a specific field frequency, accepts audio data based on a specific format that defines a specific data array and a bit array in a field unit, and performs at least baseband processing of the audio data;
It is designed to process audio data based on a basic format that has a predetermined sampling frequency and basic field frequency and defines a basic data array and bit array in field units, and operates with a clock according to the sampling frequency. A processing unit that performs encoding processing for error correction of audio data conforming to the basic format;
In a digital audio recording apparatus comprising an output unit for writing audio data output from the processing unit to a recording medium,
A conversion unit is arranged between the input unit and the processing unit, and when the specific field frequency of the audio data is different from the basic field frequency and the specific format is different from the basic format, the conversion unit is based on the specific format. While conforming to the format, the sampling frequency is converted according to the ratio between the natural field frequency and the basic field frequency, and the audio data is passed to the processing unit,
The digital audio recording apparatus, wherein the processing unit operates with a clock according to the converted sampling frequency and performs an encoding process for error correction of audio data conforming to the basic format.   The conversion unit reconfigures the number of samples per field and the number of bits of one sample while maintaining the total number of bits per field determined by the product of the number of samples per field and the number of bits of one sample. 2. The digital audio recording apparatus according to claim 1, wherein the sampling frequency is converted by adapting the format to the basic format and changing the number of samples per field.   When the total number of bits per field determined by the product of the number of samples per field and the number of bits per sample differs between the specific format and the reference format, the conversion unit converts the sampling frequency of the input audio data. The number of samples per field is corrected, and the total number of corrected bits per field determined by the product of the corrected number of samples per field and the number of bits of one sample is determined by the reference format. 3. The digital audio recording apparatus according to claim 2, wherein the digital audio recording apparatus is adapted to the total number of bits per field.   When the total number of bits per field determined by the product of the number of samples per field and the number of bits per sample differs between the specific format and the standard format, the converter assigns dummy data that matches the number of missing bits. 3. A digital audio recording apparatus according to claim 2, wherein the total number of bits per field is corrected by being added to the format, so that the total number of bits on the specific format side matches the total number of bits on the reference format side. .   The conversion unit writes audio data composed of a bit stream of serially arranged samples to the FIFO in units of bits on the specific format side and reads out data in units of bits on the basic format side to obtain the number of samples per field and one sample. 3. The digital audio recording apparatus according to claim 2, wherein the number of bits is changed and the specific format is adapted to the basic format.   6. The digital audio recording apparatus according to claim 5, wherein the conversion unit controls writing and reading of audio data to and from the FIFO in synchronization with a specific field frequency, thereby adapting the specific format to the basic format. . The processing unit includes an encoding unit that incorporates the conversion unit as a conversion unit and performs an encoding process for error correction of audio data;
When the inherent field frequency of the audio data is different from the basic field frequency and the inherent format is different from the basic format, the converting means converts the inherent format to conform to the basic format, and then passes the audio data to the encoding means.
The encoding means operates with a clock corresponding to a predetermined sampling frequency, and errors in audio data conforming to the basic format while pausing as needed at a rate corresponding to the ratio between the natural field frequency and the basic field frequency. 2. The digital audio recording apparatus according to claim 1, wherein an encoding process for correction is performed.   The conversion means rearranges the number of samples per field and the number of bits per sample while maintaining the total number of bits per field determined by the product of the number of samples per field and the number of bits per sample. 8. The digital audio recording apparatus according to claim 7, wherein the inherent format is converted into a basic format.   The conversion means includes a register with a bit number corresponding to the number of bits per sample in the basic format side, and cyclically writes audio data in a unique format consisting of a bit stream of serially arranged samples to the register while The audio data is cyclically read from the register while pausing at a rate corresponding to the ratio of the number of bits per sample on the format side to the number of bits per sample on the basic format side, and the number of samples per field 9. The digital audio recording apparatus according to claim 8, wherein the number of bits of one sample is changed to convert the unique format into a basic format. An input unit that reads audio data from a recording medium that has a certain sampling frequency and a specific field frequency and that conforms to a basic format that defines a basic data arrangement and a bit arrangement in a field unit;
Designed to process audio data that has a predetermined sampling frequency and basic field frequency and is based on the basic format, operates at a clock according to the sampling frequency, and is used for at least error correction of audio data that conforms to the basic format. A processing unit for performing a decryption process;
In a digital audio reproduction apparatus comprising an output unit that performs at least baseband processing of audio data output from the processing unit and supplies the audio data to a reproduction device.
The processing unit is operable with a clock according to the sampling frequency of the read audio data, performs a decoding process for error correction of audio data conforming to the basic format,
When a conversion unit is arranged between the processing unit and the output unit, and the inherent field frequency of the read audio data is different from the basic field frequency and the specific format is different from the basic format, the conversion unit is The audio data that conforms to the basic format is returned to the native format, and the sampling frequency of the read audio data is converted into a predetermined sampling frequency according to the ratio between the natural field frequency and the basic field frequency, and the audio data is converted. A digital audio reproducing apparatus, wherein the digital audio reproducing apparatus is passed to the output unit.   The conversion unit rearranges the number of samples per field and the number of bits of one sample while maintaining the total number of bits per field determined by the product of the number of samples per field and the number of bits of one sample. 11. The digital audio reproducing apparatus according to claim 10, wherein the sampling frequency is converted by changing the number of samples per field while returning the audio data from the basic format to the inherent format.   When the total number of bits per field determined by the product of the number of samples per field and the number of bits per sample differs between the specific format and the standard format, the conversion unit temporarily changes the basic format to the specific format. 12. The digital audio reproducing apparatus according to claim 11, wherein the sampling frequency of the returned audio data is converted to correct the number of samples per field, and the audio data is finally converted into a specific format. .   When the total number of bits per field determined by the product of the number of samples per field and the number of bits per sample differs between the specific format and the standard format, the conversion unit temporarily adds extra audio data that conforms to the basic format. 12. The digital audio reproducing apparatus according to claim 11, wherein the dummy data is added to approximately return to the native format, and then the dummy data is deleted to finally convert the audio data to the native format.   The conversion unit writes audio data including a bit stream of serially arranged samples into the FIFO in units of bits on the basic format side and reads out the data in units of bits on the specific format side, thereby obtaining the number of samples per field and one sample. 12. The digital audio reproducing apparatus according to claim 11, wherein the number of bits is changed to return the basic format to the inherent format.   15. The digital audio reproducing apparatus according to claim 14, wherein the conversion unit controls writing and reading of audio data to and from the FIFO in synchronization with a specific field frequency, thereby returning the basic format to the specific format. The processing unit includes the conversion unit as a conversion unit, and includes a decoding unit that performs decoding processing for error correction of audio data,
The decoding means operates with a clock according to a predetermined sampling frequency, and performs error correction of audio data that conforms to the basic format while pausing as needed at a rate corresponding to the ratio between the natural field frequency and the basic field frequency. Decryption process for
When the inherent field frequency of the read audio data is different from the basic field frequency and the inherent format is different from the basic format, the converting means returns the audio data that conforms to the basic format to the inherent format and returns the audio data 11. The digital audio reproducing apparatus according to claim 10, wherein data is passed to the output unit.   The converting means rearranges the number of samples per field and the number of bits of one sample while maintaining the total number of bits per field determined by the product of the number of samples per field and the number of bits of one sample. 17. The digital audio reproducing apparatus according to claim 16, wherein the audio data is returned from the basic format to the inherent format.   The conversion means includes a register of the number of bits corresponding to the number of bits per sample in the basic format side, and a ratio corresponding to the ratio between the number of bits per sample in the specific format side and the number of bits per sample in the basic format side In the cyclic format, audio data in the basic format consisting of the bit stream of serially arranged samples is cyclically written to the register, while cyclically delimited by the number of bits per sample in the specific format side. 18. The digital audio reproducing apparatus according to claim 17, wherein the audio data is read out and the basic format is returned to the inherent format by rearranging the number of samples per field and the number of bits of one sample.   When switching between forward playback and reverse playback of audio data, the conversion means writes and reads audio data to and from the register on the one hand with the MSB of the bit string at the head and the LSB on the other hand. 19. The digital audio reproducing apparatus according to claim 18, wherein The conversion unit rearranges the number of samples per field and the number of bits of one sample while maintaining the total number of bits per field determined by the product of the number of samples per field and the number of bits of one sample. Return audio data from basic format to native format,
Further, when a shuttle playback control unit is provided and shuttle playback is performed by mixing audio data belonging to different fields, only the valid samples including the correct bit sequence among the samples returned to the inherent format by the conversion unit are output to the output unit. The digital audio reproducing apparatus according to claim 10, wherein   The shuttle playback control unit passes an alternative sample obtained by interpolating a valid sample to the output unit in place of an invalid sample that does not have a correct bit sequence among samples returned to a specific format. The digital audio reproducing apparatus according to claim 20.   The shuttle reproduction control unit replaces the incorrect bit string with 0 for at least a part of the invalid samples including the correct bit string and the incorrect bit string among the samples returned to the inherent format, and converts the invalid bit string into a valid sample. 21. The digital audio reproducing apparatus according to claim 20, wherein An input unit that accepts video data having a predetermined sampling frequency and a specific field frequency and based on a specific format related to the image frame, and at least performs baseband processing of the video data;
Designed to process video data that has a predetermined sampling frequency and basic field frequency and is based on the basic format for the image frame, and operates on a clock according to the sampling frequency, and compresses video data that conforms to the basic format And a processing unit for performing an error correction encoding process;
In a digital video recording apparatus comprising an output unit for writing video data output from the processing unit to a recording medium,
When a conversion unit is arranged between the input unit and the processing unit, and the specific field frequency of the video data is different from the basic field frequency, the conversion unit adapts the specific format to the basic format while maintaining the specific field. Converting the sampling frequency in accordance with the ratio of the frequency and the basic field frequency and passing the video data to the processing unit;
The digital video recording apparatus, wherein the processing unit operates with a clock according to the converted sampling frequency, and performs video data compression processing and error correction coding processing conforming to the basic format.   When the specific format matches the basic format, the conversion unit converts the sampling frequency according to the ratio between the specific field frequency and the basic field frequency while maintaining the specific format, and passes the video data to the processing unit. 24. The digital video recording apparatus according to claim 23.   When the unique format matches the basic format, the conversion unit preserves the valid data that enters the image frame as it is, maintains the unique format, and adjusts invalid data that does not enter the image frame to convert the sampling frequency. 25. The digital video recording apparatus according to claim 24, wherein:   When the specific format is different from the basic format, the conversion unit converts the specific format into the basic format, converts the sampling frequency according to the ratio of the specific field frequency to the basic field frequency, and converts the video data into the basic format. 24. The digital video recording apparatus according to claim 23, wherein the digital video recording apparatus is passed to a processing unit.   When the number of data lines included in the image frame of the specific format is different from the number of data lines included in the image frame of the basic format, the conversion unit adjusts the number of data lines included in the image frame to 27. The digital video recording apparatus according to claim 26, wherein the format is converted into the basic format. An input unit for reading from a recording medium video data having a sampling frequency and a specific field frequency and adapted to a basic format related to an image frame;
It is designed to process video data based on the basic format with a predetermined sampling frequency and basic field frequency, and operates with a clock according to the sampling frequency to decode video data that is compatible with the basic format. A processing unit for performing the conversion process and the expansion process;
In a digital video reproduction apparatus comprising an output unit that performs at least baseband processing of video data output from the processing unit and supplies the video data to a reproduction device.
The processing unit is operable with a clock according to the sampling frequency of the read video data, performs decoding processing and decompression processing for error correction of video data conforming to the basic format,
When a conversion unit is arranged between the processing unit and the output unit, and the intrinsic field frequency of the read video data is different from the basic field frequency, the conversion unit The data is returned to the inherent format, and the sampling frequency of the read video data is converted into a predetermined sampling frequency according to the ratio between the inherent field frequency and the basic field frequency, and the video data is passed to the output unit. Digital video playback device.   When the specific format is the same as the basic format, the conversion unit converts the sampling frequency according to the ratio between the specific field frequency and the basic field frequency while maintaining the specific format, and passes the video data to the output unit. 29. A digital video reproduction apparatus according to claim 28.   When the specific format is the same as the basic format, the conversion unit adjusts invalid data that does not enter the image frame and converts the sampling frequency while maintaining the specific format while leaving the valid data in the image frame as it is. 30. A digital video reproduction apparatus according to claim 29, wherein:   When the specific format is different from the basic format, the conversion unit converts the video data conforming to the basic format to the specific format and converts the sampling frequency according to the ratio between the specific field frequency and the basic field frequency. 29. The digital video reproduction apparatus according to claim 28, wherein the video data is transferred to the output unit.   When the number of data lines included in the image frame of the specific format is different from the number of data lines included in the image frame of the basic format, the conversion unit adjusts the number of lines of data included in the image frame to adjust the video data. 32. The digital video reproduction apparatus according to claim 31, wherein the original format is returned to the original format. An input procedure having a predetermined sampling frequency and a specific field frequency, and receiving audio data based on a specific format that defines a specific data array and a bit array in a field unit, and performing at least baseband processing of the audio data;
Programmed to process audio data based on a basic format having a predetermined sampling frequency and a basic field frequency and defining a basic data arrangement and bit arrangement in a field unit, and based on an operation clock corresponding to the sampling frequency. A processing procedure for performing encoding processing for error correction of audio data conforming to the format,
In a digital audio recording method comprising an output procedure for writing audio data passed from the processing procedure to a recording medium,
When the natural field frequency of the audio data is different from the basic field frequency and the natural format is different from the basic format, a conversion procedure is performed between the input procedure and the processing procedure, and the natural format is adapted to the basic format while the natural field is adapted. Converting the sampling frequency according to the ratio of the frequency and the fundamental field frequency and passing the audio data to the processing procedure;
The digital audio recording method according to claim 1, wherein the processing procedure performs an encoding process for error correction of audio data conforming to the basic format in accordance with an operation clock corresponding to the converted sampling frequency. An input procedure for reading audio data from a recording medium having a sampling frequency and a specific field frequency and adapted to a basic format that defines a basic data arrangement and a bit arrangement in a field unit;
Code for at least error correction of audio data having a predetermined sampling frequency and a basic field frequency and programmed to process audio data based on the basic format and conforming to the basic format according to an operation clock according to the sampling frequency Processing procedure to perform
In a digital audio reproduction method comprising an output procedure for performing at least baseband processing of audio data passed from the processing procedure and supplying the audio data to a reproduction device,
The procedure performs a decoding process for error correction of audio data conforming to the basic format according to an operation clock corresponding to the sampling frequency of the read audio data,
When the natural field frequency of the read audio data is different from the basic field frequency and the natural format is different from the basic format, a conversion procedure is performed between the processing procedure and the output procedure, and the conforming to the basic format is performed. The audio data is returned to a specific format, and the sampling frequency of the read audio data is converted into a predetermined sampling frequency in accordance with a ratio between the specific field frequency and the basic field frequency, and the audio data is passed to the output procedure. Digital audio playback method. An input procedure for receiving video data having a predetermined sampling frequency and a specific field frequency and based on a specific format related to the image frame, and performing at least baseband processing of the video data;
A video data compression process adapted to process video data having a predetermined sampling frequency and a basic field frequency and based on a basic format related to a picture frame, and conforming to the basic format in accordance with an operation clock corresponding to the sampling frequency; A processing procedure for performing an error correction encoding process;
In a digital video recording method comprising an output procedure for writing video data passed from the processing procedure to a recording medium,
When the natural field frequency of the video data is different from the basic field frequency, a conversion procedure is performed between the input procedure and the processing procedure, and the ratio between the natural field frequency and the basic field frequency is adjusted while adapting the natural format to the basic format. In response to converting the sampling frequency and passing the video data to the processing procedure,
In the digital video recording method, the processing procedure includes performing compression processing of video data conforming to the basic format and encoding processing for error correction in accordance with an operation clock corresponding to the converted sampling frequency. An input procedure for reading from a recording medium video data having a sampling frequency and a specific field frequency and conforming to a basic format relating to a picture frame;
Decoding processing for error correction of video data that has a predetermined sampling frequency and basic field frequency and is programmed to process video data based on the basic format and conforms to the basic format according to an operation clock according to the sampling frequency And a processing procedure for performing decompression processing;
In a digital video reproduction method for performing at least baseband processing of video data passed from the processing procedure and performing an output procedure for supplying the video data to a reproduction device,
The processing procedure performs error correction decoding processing and decompression processing of video data conforming to the basic format in accordance with an operation clock corresponding to the sampling frequency of the read video data,
When the native field frequency of the read video data is different from the basic field frequency, a conversion procedure is performed between the processing procedure and the output procedure, and the video data conforming to the basic format is returned to the native format. A digital video reproduction method characterized by converting a sampling frequency of the read video data into a predetermined sampling frequency in accordance with a ratio between a natural field frequency and a basic field frequency and passing the video data to the output procedure. A program medium for storing a computer program that is executed by a digital audio recording apparatus and that realizes a digital audio recording method comprising a series of procedures,
The computer program receives audio data based on a specific format having a predetermined sampling frequency and a specific field frequency and defining a specific data array and a bit array in a field unit, and performs at least baseband processing of the audio data Input procedure,
Programmed to process audio data based on a basic format having a predetermined sampling frequency and a basic field frequency and defining a basic data arrangement and bit arrangement in a field unit, and based on an operation clock corresponding to the sampling frequency. A processing procedure for performing encoding processing for error correction of audio data conforming to the format,
An output procedure for writing the audio data passed from the processing procedure to a recording medium,
When the natural field frequency of the audio data is different from the basic field frequency and the natural format is different from the basic format, a conversion procedure is performed between the input procedure and the processing procedure, and the natural format is adapted to the basic format while the natural field is adapted. Converting the sampling frequency according to the ratio of the frequency and the fundamental field frequency and passing the audio data to the processing procedure;
A program medium storing a computer program characterized in that the processing procedure performs an encoding process for error correction of audio data conforming to the basic format in accordance with an operation clock corresponding to the converted sampling frequency. A program medium for storing a computer program that is executed by a digital audio reproducing apparatus and that realizes a digital audio reproducing method comprising a series of procedures,
The computer program has an input procedure for reading audio data from a recording medium having a certain sampling frequency and a specific field frequency and adapted to a basic format that defines a basic data arrangement and a bit arrangement in a field unit;
Code for at least error correction of audio data having a predetermined sampling frequency and a basic field frequency and programmed to process audio data based on the basic format and conforming to the basic format according to an operation clock according to the sampling frequency Processing procedure to perform
An output procedure for performing at least baseband processing of the audio data passed from the processing procedure and supplying the audio data to a playback device;
The procedure performs a decoding process for error correction of audio data conforming to the basic format according to an operation clock corresponding to the sampling frequency of the read audio data,
When the inherent field frequency of the read audio data is different from the basic field frequency and the inherent format is different from the basic format, a conversion procedure is performed between the processing procedure and the output procedure, and the conforming to the basic format is performed. The audio data is returned to a specific format, and the sampling frequency of the read audio data is converted into a predetermined sampling frequency in accordance with the ratio between the specific field frequency and the basic field frequency, and the audio data is passed to the output procedure. A program medium storing a computer program. A program medium for storing a computer program that is executed by a digital video recording apparatus and that realizes a digital video recording method comprising a series of procedures,
The computer program receives video data having a predetermined sampling frequency and a specific field frequency and based on a specific format related to a picture frame, and an input procedure for performing at least baseband processing of the video data;
A video data compression process adapted to process video data having a predetermined sampling frequency and a basic field frequency and based on a basic format related to a picture frame, and conforming to the basic format in accordance with an operation clock corresponding to the sampling frequency; A processing procedure for performing an error correction encoding process;
An output procedure for writing the video data passed from the processing procedure to a recording medium,
When the natural field frequency of the video data is different from the basic field frequency, a conversion procedure is performed between the input procedure and the processing procedure, and the ratio between the natural field frequency and the basic field frequency is adjusted while adapting the natural format to the basic format. In response to converting the sampling frequency and passing the video data to the processing procedure,
A program storing a computer program characterized in that the processing procedure performs compression processing of video data conforming to the basic format and encoding processing for error correction in accordance with an operation clock according to the converted sampling frequency Medium. A program medium for storing a computer program that is executed by a digital video playback apparatus and that realizes a digital video playback method comprising a series of procedures,
The computer program includes an input procedure for reading video data from a recording medium having a certain sampling frequency and a specific field frequency and adapted to a basic format related to a picture frame;
Decoding processing for error correction of video data that has a predetermined sampling frequency and basic field frequency and is programmed to process video data based on the basic format and conforms to the basic format according to an operation clock according to the sampling frequency And a processing procedure for performing decompression processing;
An output procedure for performing at least baseband processing of the video data passed from the processing procedure and supplying the video data to a playback device;
The processing procedure performs error correction decoding processing and decompression processing of video data conforming to the basic format in accordance with an operation clock corresponding to the sampling frequency of the read video data,
When the native field frequency of the read video data is different from the basic field frequency, a conversion procedure is performed between the processing procedure and the output procedure, and the video data conforming to the basic format is returned to the native format. A program medium storing a computer program which converts the sampling frequency of the read video data into a predetermined sampling frequency according to the ratio between the natural field frequency and the basic field frequency and passes the video data to the output procedure .

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