JPH1075424A - Recording/reproduction device for compressed image data and compressed audio data, recording medium and transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain the edit of video data and audio data in the unit of group of picture(GOP) by synchronizing the video data and the audio data so as to record/reproduce the compressed image information and the compressed audio information. SOLUTION: The high efficiency coding processing of an audio signal is made complete by an adaptive transform acoustic coding(ATRAC) encoder 26 in the processing unit of an image signal by a moving picture expert group(MPEG) encoder 23 and delay amount information of the audio signal with respect to the image signal is generated in a control section 60. Then compressed image data generated by the MPEG encoder 23 and the compressed audio data generated by the ATRAC encoder 26 is recorded and delay information of the audio signal with respect to the image signal generated by a control means 61 are recorded on a recording medium 30 for each processing unit of the image signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a recording / reproducing apparatus, a recording medium, and a transmission system for compressed image information and compressed audio information.

[0002]

2. Description of the Related Art Since a digital video signal has an extremely large amount of information, if the digital video signal is to be recorded for a long time on a small recording medium having a small amount of stored information, the video signal is encoded with high efficiency (data compression). In order to meet such demands, a high-efficiency coding method using correlation of video signals has been proposed. One of such methods is MPEG (Moving Picture Expert).
Group) system. The MPEG system first reduces the redundancy in the time axis direction by taking the difference between frames of a video signal, and then performs discrete cosine transform (DC
T) and the like, the video signal is efficiently encoded by reducing the redundancy in the spatial axis direction.

In the MPEG system, a certain unit of moving image, that is, several images are grouped into a group of pictures (GOP: Gr
Oup of Pictures), which enables independent reproduction in GOP units. Then, in order to enable random access (reproduction from the middle) in GOP units in the moving image sequence, a sequence header (SH) can be added to the GOP as shown in FIG. In this sequence header, initial data required for reproduction by the decoder, such as image size and pixel aspect ratio, are entered. Decoder, encoding information (bit stream)
, The sequence header of the specified GOP is detected, and decoding is started from that GOP, whereby the video sequence can be reproduced from the middle.

[0004] An image (Picture) in a GOP is roughly classified into I
It has three types of pictures, P pictures and B pictures, and the image signal of each frame is encoded as any type of picture.

That is, for example, as shown in FIG.
An image signal of a frame is defined as a GOP and is defined as one unit of processing.
In FIG. 10, frames denoted by "I", "P", and "B" represent frames encoded by I, P, and B pictures, respectively.

[0006] An I picture has an Intra frame.
) An encoded image, which is provided to ensure the independence of the GOP. In this I picture, all macroblocks are intra-coded.

[0007] Also, a P picture is inter-frame (Inter-picture).
frame) A prediction residual signal is encoded using a predictive coded image that is an I picture or a P picture that is temporally past in the forward predictive coded image.
In this P picture, intra-frame coding and inter-frame coding can be selected for each macroblock.

[0008] Further, a B picture has a bidirectional prediction (Bidi
rectional predictive) coded image and the past I
Not only a picture or P picture is used as a prediction image, but also a prediction residual signal is encoded using a future I picture or P picture as a prediction image. The macroblock type in the B picture includes intra-frame encoding that does not use both forward and backward predictions, forward prediction encoding predicted from past reproduced images, backward prediction encoding predicted from the future,
There is interpolative predictive coding that uses both front and back prediction.

When a video signal is compressed by the MPEG method and recorded on a recording medium such as a disk or a tape, for example, as shown in FIG.
It is becoming mainstream to compress video signals.

As a high-efficiency coding (data compression) compression method for digital audio signals, for example, sub-band coding or orthogonal transform using human auditory characteristics (aural masking light or minimum audibility) is used. ATR
The AC (Adaptive Transform Acoustic Cording) method has been put to practical use in mini disc systems and the like.
In this mini disk system, as shown in FIG.
A process of compressing audio data of 16 bits (2 bytes) sampled at a sampling frequency (44.1 kHz) independently for L and R into 512 bytes (1024 bytes) for each compression unit using 512 samples (1024 bytes) as one compression unit. Is going.

[0011]

By the way, the video signal is compressed by the MPEG system as described above,
When an audio signal is compressed by the TRAC method and is recorded on a recording medium such as a disk or a tape, the video signal is compressed using 15 frames as a GOP.
Since the sampling time of the audio signal is 44.1 kHz while the time of P is 1001/2000 (second), the number of samples in one GOP (1001/2000 (second)) is as small as 22,072.05. And it is difficult to synchronize video and audio.

Accordingly, an object of the present invention is to perform recording / reproduction of compressed image information and compressed audio information by synchronizing video and audio in view of the above-mentioned conventional situation, and to convert video and audio in GOP units. An object of the present invention is to provide a recording / reproducing apparatus, a recording medium, and a transmission system for compressed image information and compressed audio information that enable editing.

[0013]

According to the present invention, there is provided an apparatus for recording compressed image data and compressed audio data, comprising: a first high-efficiency encoding process for performing high-efficiency encoding on an image signal to generate compressed image data; Means, a second high-efficiency encoding means for performing high-efficiency encoding processing on the audio signal to generate compressed audio data, and a second high-efficiency encoding processing means for each image signal processing unit by the first high-efficiency encoding processing means. The control means for completing the high-efficiency encoding processing of the audio signal by the second high-efficiency encoding processing means and generating the delay amount information of the audio signal with respect to the image signal, and the first high-efficiency encoding processing means Along with the generated compressed image data and the compressed audio data generated by the second high-efficiency encoding processing means, the delay amount information of the audio signal with respect to the image signal generated by the control means is stored in the image. Characterized in that it comprises a recording means for recording on the recording medium for each processing unit of the item.

In the recording apparatus for compressed image data and compressed audio data according to the present invention, the recording means includes, for example,
The delay amount information is added as header data for each processing unit of the image signal, and is recorded on a recording medium together with the compressed image data and the compressed audio data.

In the apparatus for recording compressed image data and compressed audio data according to the present invention, the control means includes, for example, the first high-efficiency encoding processing means as delay information of an audio signal with respect to the image signal. Is supplied to the recording means.

Further, in the apparatus for recording compressed image data and compressed audio data according to the present invention, the control means includes:
For example, as the delay amount information of the audio signal with respect to the image signal, time information for delaying the audio signal in synchronization with the image signal during reproduction is supplied to the recording unit.

The recording medium for compressed image data and compressed audio data according to the present invention includes the compressed image data generated by the first high-efficiency encoding process and the processing unit of the first high-efficiency encoding process. The compressed audio data generated by the completed second high-efficiency encoding process and the delay amount information of the audio signal for delaying the audio signal to synchronize with the image signal at the time of reproduction are combined with the first high-efficiency encoding. It is characterized by being recorded in the processing unit of the processing.

In the recording medium for compressed image data and compressed audio data according to the present invention, for example, the delay amount information is recorded as header data for each processing unit together with the compressed image data and compressed audio data.

The compressed image data recorded on the recording medium of the compressed image data and the compressed audio data according to the present invention is generated by, for example, a high-efficiency encoding process of the MPEG system. Is generated from audio data having a sampling frequency of at least one by the ATRAC system, and one sound frame is 512 samples. In the monaural mode, the number of sound frames of 46 or 47 sound frames is used. 92, 93 or 9 in mode
By using the number of sound frames of 4 sound frames, 15 frames in the MPEG system can be converted into 1G
It is completed for each processing unit to be OP.

The compressed image data recorded on the recording medium of the compressed image data and the compressed audio data according to the present invention is generated by, for example, a high-efficiency encoding process of the MPEG system, and the compressed audio data has a frequency of 48 kHz. One sound frame is generated from audio data of a sampling frequency by ATRAC high-efficiency encoding processing,
024 samples, the number of sound frames of 23 or 24 sound frames in the monaural mode, and the number of sound frames of 46 or 247 sound frames in the stereo mode.
The processing is completed for each processing unit in which 15 frames in the EG method are defined as 1 GOP.

In the recording medium for compressed image data and compressed audio data according to the present invention, for example, the processing unit number information of the image signal may be compressed image data and compressed audio data as delay information of the audio signal with respect to the image signal. It is recorded with.

Further, the recording medium for the compressed image data and the compressed audio data according to the present invention may include, for example, time information for delaying the audio signal in synchronization with the image signal during reproduction, as delay information of the audio signal with respect to the image signal. Are recorded together with the compressed image data and the compressed audio data.

According to the present invention, there is provided a playback apparatus for compressed image data and compressed audio data, comprising: a compressed image data generated by a first high-efficiency encoding process; and a processing unit for the first high-efficiency encoding process. The compressed audio data generated by the completed second high-efficiency encoding process and the delay amount information of the audio signal for delaying the audio signal to synchronize with the image signal at the time of reproduction are combined with the first high-efficiency encoding. What is claimed is: 1. A reproducing apparatus for reproducing an image signal and an audio signal from a recording medium recorded in a processing unit of processing, comprising: reproducing means for reproducing compressed image data, compressed audio data and delay amount information from the recording medium; First high-efficiency decoding processing means for applying a first high-efficiency decoding process corresponding to the first high-efficiency coding process to the compressed image data reproduced by the means to generate an image signal; A second high-efficiency decoding means for applying a second high-efficiency decoding process corresponding to the second high-efficiency encoding process to the compressed audio data reproduced by the means to generate an audio signal; A delay unit for delaying and outputting the audio signal generated by the high-efficiency decoding processing unit, and controlling a delay amount of the audio signal by the delay unit based on the delay amount information reproduced by the reproduction unit. The control means for outputting an audio signal synchronized with the image signal generated by the first high-efficiency decoding processing means from the delay means.

In the apparatus for reproducing compressed image data and compressed audio data according to the present invention, the reproducing means includes, for example,
The compressed image data, the compressed audio data, and the delay amount information are reproduced from a recording medium in which the delay amount information is recorded together with the compressed image data and the compressed audio data as header data for each processing unit.

In the apparatus for reproducing compressed image data and compressed audio data according to the present invention, the reproducing means may include, for example, as a delay amount information of the audio signal with respect to the image signal, a processing unit number information of the image signal may be a compressed image data. The compressed image data, the compressed audio data and the delay amount information are reproduced from a recording medium recorded together with the data and the compressed audio data, and the control means converts the audio signal into an image signal based on the processing unit number information of the image signal. Time information to be delayed for synchronization is generated, and the delay amount of the audio signal by the delay means is controlled. The control means includes, for example, a memory table for associating processing unit number information of the image signal with time information for delaying the audio signal in synchronization with the image signal.

Further, in the apparatus for reproducing compressed image data and compressed audio data according to the present invention, the reproducing means includes:
For example, as a delay amount information of the audio signal with respect to the image signal, from a recording medium in which time information for delaying the audio signal to be synchronized with the image signal at the time of reproduction is recorded together with the compressed image data and the compressed audio data,
The compressed audio data and the delay amount information are reproduced.

[0027] A transmission system for compressed image data and compressed audio data according to the present invention comprises: a first high-efficiency encoding means for performing a first high-efficiency encoding process on an image signal to generate compressed image data; A second high-efficiency encoding unit for performing a second high-efficiency encoding process on the audio signal to generate compressed audio data; and a second high-efficiency encoding unit for processing the image signal by the first high-efficiency encoding unit. The control means for completing the high-efficiency encoding processing of the audio signal by the second high-efficiency encoding processing means and generating the delay amount information of the audio signal with respect to the image signal, and the first high-efficiency encoding processing means Along with the generated compressed image data and the compressed audio data generated by the second high-efficiency encoding processing means, the delay amount information of the audio signal with respect to the image signal generated by the control means is stored in the image. A transmission device for transmitting compressed image data and compressed audio data via a medium for each processing unit of the signal, and compressed image data, compressed audio data and delay amount information transmitted from the transmission device via the medium And a first high-efficiency decoding unit that performs a first high-efficiency decoding process corresponding to the first high-efficiency encoding process on the compressed image data reproduced by the reproducing unit to generate an image signal. Efficiency decoding processing means, and a second high-speed decoding means for performing a second high-efficiency decoding process corresponding to the second high-efficiency encoding process on the compressed audio data reproduced by the reproducing means to generate an audio signal. Efficiency decoding processing means, delay means for delaying and outputting the audio signal generated by the second high-efficiency decoding processing means, and delay based on the delay amount information reproduced by the reproduction means. Controlling the delay amount of the audio signal by the means to output the audio signal synchronized with the image signal generated by the first high-efficiency decoding processing means from the delay means; And a playback device for audio data.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

The present invention is applied to, for example, a recording / reproducing system having a configuration as shown in FIG. In this recording / reproducing system, a recording system signal processing unit 20 to which a video signal and an audio signal are supplied from an input unit 10, and a video signal and an audio signal which have been subjected to compression processing by the recording system signal processing unit 20 are recorded. Recording medium 30 and recording medium 3
0, a reproduction signal processing unit 40 for reproducing a video signal and an audio signal, a monitor unit 50 to which the video signal and the audio signal reproduced by the reproduction signal processing unit 40 are supplied, and the recording signal processing unit 20 And a control unit 60 of the reproduction system signal processing unit 40.

The input unit 10 comprises a video camera 12 provided with a microphone 11, and converts a video signal obtained as an image pickup output and a microphone output and a two-channel (L, R) audio signal into the recording system signal processing unit 2.
0 is supplied.

The recording system signal processing section 20 includes an A / D converter 21, a camera process processing circuit 22, and an MPEG encoder 23, which constitute a processing system for a video signal supplied from the input section 10. A / D converter 2 constituting a processing system of the audio signal supplied from section 10
4L, 24R, memory 25 and ATRAC encoder 2
6, a multiplexer 27 and a channel coding circuit 28 which constitute a processing system for converting the compressed image data and compressed audio data generated by the MPEG encoder 23 and ATRAC encoder 26 into recording signals,
The clock generator 29 supplies a sampling clock to the A / D converters 21, 24L, 24R.

The clock generator 29 has a frequency of 1
A sampling clock of 3.5 MHz and 48 kHz is generated, a sampling clock of 13.5 MHz is supplied to the A / D converter 21, and a frequency of 48.
0 kHz sampling clock is supplied to the A / D converter 2
4L, 24R.

In the processing system for the video signal supplied from the input unit 10, the A / D converter 21 samples the video signal with the sampling clock of 13.5 MHz and digitizes it. The video signal data obtained by digitizing the video signal by the A / D converter 21 is supplied to the camera process processing circuit 22, and is converted into luminance signal data and chroma signal data by the camera process processing circuit 22. . The luminance signal data and the chroma signal data obtained by the camera process processing circuit 22 are supplied to the MPEG encoder 23, and the MPEG encoder 23 performs a data compression process according to the MPEG system. In the MPEG encoder 23, 15 frames are used as a GOP in the image data including the luminance signal data and the
A compression process is performed for each P to generate compressed image data.
The MPEG encoder 23 determines that the compression process has ended by 1G.
Each OP is notified to the computer 61 of the control section 60, and the generated compressed image data is supplied to the multiplexer 27.

In the processing system for the audio signal supplied from the input unit 10, the A / D converters 24L, 24L
With 4R, the audio signal of two channels is sampled for each channel by the sampling clock of 48.0 kHz and digitized. A / D converter 24
The two-channel audio data obtained by digitizing the two-channel audio signal by the L and 24R is supplied to the ATRAC encoder 26 after the timing with the image data is adjusted via the memory 25. A above
The TRAC encoder 26 performs a data compression process on audio data of two channels in accordance with the ATRAC system, and changes the state of the compression process to the computer 61 of the control unit 60.
, And the generated compressed audio data is supplied to the multiplexer 27.

The multiplexer 27 supplies, for each GOP, header data supplied from the control unit 60, for example, GOP No. And the compressed image data supplied from the MPEG encoder 23 and the compressed audio data supplied from the ATRAC encoder 26 are sequentially synthesized and supplied to the channel encoder 28.

Here, in the data compression processing of the ATRAC system, eight coding modes are defined, but the coding mode = ATRAC (1), Leave
11, channel no. = 2 as an example,
The data compression processing by the TRAC encoder 26 will be described.

In this coding mode, 512 samples (one channel) are encoded into 212 bytes of compressed data.

Since the sampling frequency of the audio signal in this recording / reproducing system is 48.0 kHz, the number of audio samples in one GOP is 2402.
There are four. Therefore, looking at only one channel, if 24024 audio samples are divided into 512 sample units, 46 + 472 samples are obtained.

The GOP (GOP No. =
0) indicates the remainder of audio samples at the end of each GOP when audio and video are started simultaneously, that is, the time margin of the audio signal with respect to the video signal.

[0040]

[Table 1]

In Table 1, GOP No. = 0 to 11
Up to this point, since 47 sound frames are grouped together in one GOP, the number of surplus audio data samples at the end of each GOP increases. GOP No. =
It can be seen that the surplus of the audio data is reduced by setting the GOP of 12 to 46 sound frames. Thus, by periodically mixing the combination of 46 sound frames / GOPs into 47 sound frames / GOPs, the video and audio data rates can be synchronized on average.

In practice, as shown in Table 1, GOP N
o. = GOPs of 12, 25, 38, 51, and 63 as 46 sound frames / GOP, so that 64 GOPs
Video and audio are completed using the OP as a large unit.

The recording system signal processor 20 is controlled by the computer 61 of the controller 60 to record video and audio data on the recording medium 30 in GOP units according to the procedure shown in the flowchart of FIG. .

That is, when the recording is started, the computer 61 of the control unit 60 first sets the GOP No. Is determined (step S1), and GOP N is used as header data.
o. To the multiplexer 27 and the number of audio frames to be recorded to the multiplexer 27 (step S2).

The multiplexer 27 records header, video, and audio data on the recording medium 30 based on the information from the computer 61 (step S3).

The computer 6 of the control unit 60
When the recording of data for one GOP is completed (step S4), 1 determines whether or not to record the next GOP (step S5). If the determination result in step S5 is "YES", the process returns to step S1, and
The next GOP is recorded. If the result of the determination in step S5 is "NO", the process waits for the next recording.

FIG. 3 shows an actual situation in which video and audio data are recorded on the recording medium 30 by the recording system signal processing section 20.

That is, on the recording medium 30, video and audio data for one GOP are recorded as a minimum unit. At the start of recording, the phases of video and audio data match. And which GOP
GOP No. is added as header data so that the data can be reproduced without any problem. Then, following the header data, video data for one GOP and audio data for two channels (47 sound frames × 2 = 94 sound frames) are recorded.

As described above, GOP No. = 12,2
For a GOP of 5, 38, 51, 63, 46 × 2 =
The audio data of the 92 sound frames is recorded, and the audio data of the other 94 sound frames are recorded.

When recording continuously, GOP No. = 6
When the recording of No. 3 is completed, the number of video and audio data should match at that time without any excess or shortage, so GOP No is returned to 0 and recording is repeated.

A reproduction signal processing unit 40 for reproducing a video signal and an audio signal from the recording medium 30 on which the compressed image data and the compressed audio data are recorded as described above outputs the reproduction output from the recording medium 30 to header data, A channel decoding circuit 41 and a demultiplexer 42 constituting a processing system for converting a compressed image data and a compressed audio data into a reproduced signal, and an MPEG decoder 43, a video decoder 44 and a D / A constituting a video signal reproducing system.
It comprises a converter 45, an ATRAC decoder 46, a memory 47, a digital filter 48, and D / A converters 49L and 49R, which constitute an audio signal reproduction processing system.

In the reproduction-system signal processing section 40, the demultiplexer 42 separates header data, compressed image data and compressed audio data from the reproduction signal supplied from the recording medium 30 via the channel decoding circuit 41. . The header data obtained by the demultiplexer 42 is supplied to the computer 61 of the control unit 60. The compressed image data is supplied to a video signal reproduction processing system. Further, the compressed audio data is supplied to an audio signal processing system.

In the video signal reproduction processing system, the compressed image data supplied from the demultiplexer 42
The MPEG decoder 43 performs data expansion processing according to the PEG method, and reproduces luminance signal data and chroma signal data. The luminance signal data and the chroma signal data reproduced by the MPEG decoder 43 are converted by the video decoder 44 into a predetermined standard television system such as N
It is converted into video signal data conforming to the TSC system.
The video signal data obtained by the video decoder 44 is further converted by a D / A converter 45 into an analog video signal. Then, the video signal reproduction processing system supplies the analog video signal thus reproduced from the recording medium 30 to the monitor device 50 via the video signal output terminal 40V.

In the above-mentioned video signal reproduction processing system,
The compressed image data supplied from the demultiplexer 42 is subjected to data expansion processing in accordance with the ATRAC method by the AT.
The audio data is reproduced by the RAC decoder 46. The audio data reproduced by the ATRAC decoder 46 is supplied to a digital filter 48 after adjusting the timing with the image data via a memory 47 controlled by a computer 61 of the control unit 60. The audio data read from the memory 47 is separated into two channels (L, R) by the digital filter 48 and converted into two-channel analog audio signals by the D / A converters 49L and 49R.

The audio signal reproduction processing system supplies the 2-channel analog audio signal reproduced from the recording medium 30 to the monitor device 50 through the audio signal output terminals 40L and 40R.

Here, in the control unit 60, the computer 61 refers to the ROM table 62 and refers to the header data (G data) obtained by the demultiplexer 42.
OPNo. ), And controls the memory 47 so as to read out the audio data with the delay amount that can be synchronized with the decoded video signal.

The reproduction system signal processing unit 40 is controlled by the computer 61 of the control unit 60 to reproduce video signals and audio signals from the recording medium 30 in GOP units according to the procedure shown in the flowchart of FIG. .

Here, it is assumed that the data recorded on the recording medium 30 has been recorded continuously for a long time.

When the reproduction is started from an arbitrary GOP specified by the user with a term code or the like, first, the GOP No. recorded in the header data part is read. Is read, and the relationship between the image data to be reproduced and the audio data is known.

That is, the computer 61 of the control unit 60 first starts the demultiplexer 4 when the reproduction is started.
2 is read from the header data (step S11).
Referring to the OM table 62, the demultiplexer 4
The delay amount of the audio data is obtained based on the header data (GOP No.) obtained in step 2, and the delay amount information of the decoded audio signal is sent to the memory 47 so that the decoded video signal is synchronized ( Step S1
2).

In the memory 47, based on the delay amount information given by the computer 61 of the control section 60, the delay amount information is sent to the digital filter 48 with the audio data to which the necessary delay amount is given (step S13). . It should be noted that only the output start timing of the audio data needs to be delayed, and thereafter the video and audio are synchronized by outputting the reproduced image data and audio data at the same rate. Then, the synchronized image data and audio data are converted into analog signals by the D / A converters 49V, 49L, and 49R and output to an external device (step S1).
4).

The computer 6 of the control unit 60
When the reproduction of the data for one GOP is completed (step S15), 1 determines whether or not to reproduce the next GOP (step S16). If the determination result in step S16 is "YES", the process returns to step S11 to reproduce the next GOP. This step S
If the determination result at 16 is "NO", the next reproduction is waited for.

In this case, the control unit 60 determines, for example, the GOP No. as shown in Table 2 below. And the ROM table 62 for the audio start time, it is possible to know the relationship between the image data to be reproduced and the audio data.

[0064]

[Table 2]

Table 2 shows the delay time of the audio signal with respect to the video signal in each GOP, that is, the audio start time. Table 2 is a rewrite of Table 1 above, and shows the time for 48.0 kHz (normalized at 20.8 μsec).

Further, in the recording / reproducing system having such a configuration, the video signal and the audio signal are controlled by the computer 61 of the control section 60 in GOP units according to the procedure shown in the flowchart of FIG. Perform after-recording (hereinafter called after-recording).

That is, in the post-recording mode, the GOP specified by the user for post-recording is reproduced,
The header data is stored in the computer 61 of the control unit 60 (Step S21).

When the audio signal to be dubbed is input, the input audio signal is invalidated for the delay time of the audio data based on the header data, and the compressed audio data of the audio signal input after the time is already used. It overwrites the recorded compressed audio data (step S22).

That is, for example, GOP No. = 2 G
Taking the case of replacing the audio data of the OP part as an example, the first 80 × (1/48 kHz) of this GOP ≒
The sound corresponding to the image for 1.667 msec is already G
OP No. = 1, and the voice of this portion cannot be replaced. Since the replacement unit is GOP ≒ 0.5 sec, this restriction does not cause much problem.

Therefore, the first 80 samples of the audio signal captured in accordance with the image are discarded, ATRAC encoding is performed from the 81st sample, and the length to be replaced (the minimum unit is sound frame = 512 × (1/4))
8 kHz) ≒ 10.667 msec) ATRAC encode and rewrite the data. The rest is the original ATRA
By overwriting the C-encoded compressed audio data as it is, dubbing of the audio data can be performed in sound frame units, which are not GOP units.

The computer 6 of the control unit 60
When the post-recording of data for one GOP is completed (step S23), 1 determines whether or not to post-record the next GOP (step S24). If the result of the determination in step S24 is "YES", the flow returns to step S21 to post-record the next GOP. Also,
If the result of the determination in step S24 is "NO", the process waits for the next post-record instruction.

In the above embodiment, GOP No. is used as header data. Was recorded, but the above GOP No. Alternatively, the disclosure time of the audio signal shown in Table 2 above may be recorded as header data as it is. In this case, the computer 61 of the control unit 60
The disclosure time given as header data is sent to the memory 47 without reference to the ROM table 62.

If the maximum value of the disclosure time of the audio signal is set to a large value, the degree of freedom of the recording position (combination) of the image data and the audio data at the time of recording is increased. For example, 65, 53 where the maximum value is represented by 16 bits
Assuming that the audio data is specified as 5, the audio data can be output in synchronization with the image and audio during reproduction even if the audio data recording position on the recording medium 30 is ahead of the audio data by 2.7 GOP.

Further, ATRAC in the above-described embodiment is used.
In the data compression processing of the system, the coding mode using 512 samples (one channel) as a data compression processing unit has been described. However, a coding mode using 1024 samples (one channel) as a data compression processing unit may be employed. .

In this case, by combining 23 and 24 sound frames (1024 samples) to be recorded in each GOP in the same manner as the above-described method, the sound frames are divided into 128 GOPs as a large unit. And GOP can be synchronized.

Table 3 shows the delay of the output timing of the audio data of each GOP at this time.

[0077]

[Table 3]

In this case, GOP No. Is 12
Therefore, the header data has 7 bits.

In the above embodiment, the sampling frequency of the video signal and the sampling frequency of the audio signal are set so as to be synchronized. However, the compression recording method when the sampling frequency of the video signal and the audio signal is asynchronous is shown in FIG.
Shows the signal state.

The case where the sampling frequency of the audio signal such as the ATRAC system is 44.1 kHz corresponds to this case.

When the sampling frequency of the video signal and the sampling frequency of the audio signal are asynchronous, it cannot be assumed that the number of GOPs and the number of sound frames (compression units) are exactly integers in a certain time unit.

Therefore, the time of the image data and the time of the audio data are matched at the start of recording. Strictly speaking, since an asynchronous clock is used, a deviation within one block occurs.

When the compressed image data and the compressed audio data are collectively recorded in GOP units, the time lag between the video signal and the audio signal is recorded as header data, whereby the sound frame in one GOP is recorded. Can be any number.

In this case, the recording system signal processing unit 20 in the recording / reproducing system shown in FIG. 1 is controlled by the computer 61 of the control unit 60, and in GOP units according to the procedure shown in the flowchart of FIG. To record video and audio data on the recording medium 30.

That is, the recording system signal processing unit 20
When the recording starts, the encoding process and the recording process on the recording medium 30 are performed in parallel.

In the encoding process, the audio signal is encoded simultaneously with the encoding of the video signal of one GOP (step S31). The MPEG encoder 23 notifies the computer 61 of the control unit 60 of the end timing of one GOP (step S32). At that moment, the computer 61 instructs the multiplexer 27 to record up to the sound frame being encoded as 1 GOP data together with the video signal (step S3).
3). Then, the computer 61 counts and stores the time T0 from the end timing of the GOP to the end of the encoding of the audio sound frame (step S34).

In the recording process, the computer 6
The time T0 at the time of encoding the immediately preceding GOP stored in 1 is sent to the multiplexer 27 as header data (step S35). Since T0 is not stored immediately after the start of recording, T0 = 0. Then, the multiplexer 27 records the previously encoded image data, audio data, and header data on the recording medium 30 based on the information from the computer 61 (step S36).

The computer 6 of the control unit 60
When the recording of the data of one GOP is completed (step S37), 1 determines whether or not to record the next GOP (step S38). If the determination result in step S38 is "YES", first, the encoding process and the recording process for the next GOP are performed. This step S
If the result of the determination at 38 is "NO", the next recording is awaited.

The reproduction-system signal processing section 40 is controlled by a computer 61 of the control section 60 so that the reproduction-system signal processing section 40 shown in FIG.
The video signal and the audio signal are reproduced from the recording medium 30 in GOP units according to the procedure shown in the flowchart of FIG.

That is, the computer 61 of the control unit 60 first starts the demultiplexer 4 when the reproduction is started.
2 is read from the header data (T0) (step S4).
1) The delay amount (T0) information of the decoded audio signal is sent to the memory 47 so as to synchronize with the decoded video signal (step S42).

In the memory 47, based on the delay (T0) information given by the computer 61 of the control unit 60, the audio data with the required delay is sent to the digital filter 48 (step S43). Then, the synchronized image data and audio data are converted into a D / A converter 49.
V, 49L, and 49R are converted into an analog signal and output to an external device (step S44).

The computer 6 of the control unit 60
When the reproduction of the data of one GOP is completed (step S45), 1 determines whether or not to reproduce the next GOP (step S46). If the result of the determination in step S46 is "YES", the flow returns to step S41 to reproduce the next GOP. This step S
If the determination result at 46 is "NO", the next reproduction is awaited.

In the case of continuous shooting, as shown in FIG. 6, by providing a mechanism for skipping the sound of a temporally overlapping portion at the time of reproduction, recording can be performed in the same manner as when recording is started. . Furthermore, dubbing can be performed in sound frame units.

[0094]

In the apparatus for recording compressed image data and compressed audio data according to the present invention, the first high-efficiency encoding means performs high-efficiency encoding on the image signal to generate compressed image data. In performing the high-efficiency encoding process on the audio signal by the second high-efficiency encoding processing unit to generate the compressed audio data and recording the compressed audio data on the recording medium, the control unit executes the processing by the first high-efficiency encoding processing unit. The high-efficiency encoding processing of the audio signal by the second high-efficiency encoding processing unit is completed for each processing unit of the image signal, and the delay amount information of the audio signal with respect to the image signal is generated. Along with the compressed image data generated by the efficiency encoding processing means and the compressed audio data generated by the second high efficiency encoding processing means, the image signal generated by the control means is processed. Since the delay amount information of the audio signal is recorded in the recording medium for each processing unit of the image signal, in the reproduction system from the recording medium, the delay amount information of the audio signal with respect to the image signal is obtained from the recording medium, and the video and Synchronized reproduction of the compressed image information and the compressed audio information can be enabled by synchronizing the audio.

The recording medium of the compressed image data and the compressed audio data according to the present invention includes the compressed image data generated by the first high-efficiency encoding process and the processing unit of the first high-efficiency encoding process. The compressed audio data generated by the completed second high-efficiency encoding process and the delay amount information of the audio signal for delaying the audio signal to synchronize with the image signal at the time of reproduction are combined with the first high-efficiency encoding. Since the information is recorded in the processing unit of the processing, the reproduction system obtains the delay amount information of the audio signal with respect to the image signal from the recording medium, synchronizes the video and the audio, and synchronously reproduces the compressed image information and the compressed audio information. Can be made possible.

In the apparatus for reproducing compressed image data and compressed audio data according to the present invention, the first high-efficiency decoding means applies the first high-efficiency decoding to the compressed image data reproduced from the recording medium by the reproducing means. Processing, to generate an image signal, and to perform a second high-efficiency decoding process on the compressed audio data reproduced from the recording medium by the reproducing device, to obtain an audio signal. By controlling the delay means for delaying and outputting the audio signal generated by the second high-efficiency decoding processing means based on the delay amount information reproduced from the recording medium by the reproduction means. The audio signal synchronized with the image signal generated by the first high-efficiency decoding processing means can be output from the delay means.

Therefore, according to the present invention, recording / compressing of compressed image information and compressed audio information is performed by synchronizing video and audio.
A recording / reproducing apparatus for compressed image information and compressed audio information which reproduces and enables editing of video and audio in GOP units;
A recording medium and a transmission system can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a recording / reproducing system to which the present invention is applied.

FIG. 2 is a flowchart showing a recording operation by a recording signal processing unit in the recording / reproducing system.

FIG. 3 is a diagram showing an actual state of recording video and audio data on a recording medium by the recording system signal processing unit.

FIG. 4 is a flowchart showing a reproducing operation by a reproducing system signal processing unit in the recording / reproducing system.

FIG. 5 is a flowchart showing an operation of the after-recording mode in the recording / reproducing system.

FIG. 6 is a diagram illustrating a state where video and audio data are recorded on a recording medium by the recording system signal processing unit when the sampling frequency of the video signal and the audio signal is asynchronous.

FIG. 7 is a flowchart showing a recording operation by the recording-system signal processing unit when the sampling frequencies of the video signal and the audio signal are asynchronous in the recording / reproducing system.

FIG. 8 is a flowchart showing a reproduction operation by the reproduction system signal processing unit when the sampling frequencies of the video signal and the audio signal are asynchronous in the recording / reproduction system.

FIG. 9 is a diagram showing a GOP and a sequence header in the MPEG system.

FIG. 10 is a diagram illustrating a configuration example of a GOP in the MPEG system.

FIG. 11 is a diagram showing a GOP of 15 frames.

FIG. 12 is a diagram showing a compression method of an audio signal in a mini disc system.

[Explanation of symbols]

10 input unit, 20 recording system signal processing unit, 21, 24
L, 24R A / D converter, 23 MPEG encoder, 25 memory, 26 ATRAC encoder, 27
Multiplexer, 28-channel encoding circuit, 30 recording medium, 40 reproduction-system signal processing unit, 41
Channel decoding circuit, 42 demultiplexer, 43 MPEG decoder, 45, 49L, 49R
D / A converter, 46 ATRAC decoder, 47 memory, 60 control unit, 61 computer, 62 RO
M table

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Claims (16)

[Claims] A first high-efficiency encoding unit for performing high-efficiency encoding on an image signal to generate compressed image data; and a high-efficiency encoding process on an audio signal to generate compressed audio data. The second high-efficiency encoding unit and the high-efficiency encoding process of the audio signal by the second high-efficiency encoding unit are completed for each image signal processing unit by the first high-efficiency encoding unit. Control means for generating delay information of the audio signal with respect to the image signal; compressed image data generated by the first high-efficiency encoding processing means; and control information generated by the second high-efficiency encoding processing means. Recording means for recording, on a recording medium, delay information of an audio signal with respect to the image signal generated by the control means, together with the compressed audio data, on a recording medium basis for each processing unit of the image signal. A recording device for image data and compressed audio data. 2. The apparatus according to claim 1, wherein said recording means adds the delay amount information as header data for each processing unit of the image signal, and records the information together with the compressed image data and the compressed audio data on a recording medium. Recording apparatus for compressed image data and compressed audio data according to the present invention. 3. The control means supplies processing unit number information of the image signal by the first high-efficiency encoding processing means to the recording means as delay information of an audio signal with respect to the image signal. 3. The recording apparatus for compressed image data and compressed audio data according to claim 2, wherein 4. The information processing apparatus according to claim 1, wherein the control unit supplies, to the recording unit, time information for delaying the audio signal in synchronization with the image signal at the time of reproduction, as delay information of the audio signal with respect to the image signal. Item 3. A recording device for compressed image data and compressed audio data according to Item 2. 5. The compressed image data generated by the first high-efficiency encoding process and the compressed image data generated by the second high-efficiency encoding process completed for each processing unit of the first high-efficiency encoding process. Compressed audio data and delay amount information of the audio signal for delaying the audio signal in synchronization with the image signal at the time of reproduction are recorded in the processing unit of the first high-efficiency encoding process. Recording medium for compressed image data and compressed audio data. 6. The compressed image data is generated by a high-efficiency encoding process of the MPEG system, and the compressed audio data is generated by a high-efficiency encoding process of the ATRAC system from audio data having a sampling frequency of 48 kHz. The above-mentioned MPEG system is realized by using 512 sound samples and 46 or 47 sound frames in the monaural mode and 92, 93 or 94 sound frames in the stereo mode. 6. The recording medium for compressed image data and compressed audio data according to claim 5, wherein the recording is completed for each processing unit in which 15 frames are 1 GOP. 7. The compressed image data is generated by a high-efficiency encoding process of the MPEG system. The compressed audio data is generated from audio data of a sampling frequency of 48 kHz by a high-efficiency encoding process of the ATRAC system. The sound frame is 1024 samples, the number of sound frames of 23 or 24 sound frames is used in the monaural mode, and the number of sound frames is 46 in the stereo mode.
6. The recording of compressed image data and compressed audio data according to claim 5, wherein the processing is completed for each processing unit in which 15 frames in the MPEG system are defined as 1 GOP by using the number of sound frames of 247 sound frames. Medium. 8. A recording medium for compressed image data and compressed audio data according to claim 5, wherein said delay amount information is recorded together with compressed image data and compressed audio data as header data for each processing unit. . 9. The compressed image data according to claim 8, wherein processing unit number information of the image signal is recorded together with the compressed image data and the compressed audio data as the delay amount information of the audio signal with respect to the image signal. And a recording medium for compressed audio data. 10. As the delay amount information of the audio signal with respect to the image signal, time information for delaying the audio signal in synchronization with the image signal at the time of reproduction is recorded together with the compressed image data and the compressed audio data. A recording medium for the compressed image data and the compressed audio data according to claim 8. 11. The compressed image data generated by the first high-efficiency encoding process and the compressed image data generated by the second high-efficiency encoding process completed for each processing unit of the first high-efficiency encoding process. The compressed audio data and the delay information of the audio signal that is delayed in order to synchronize the audio signal with the image signal at the time of reproduction are stored in a recording medium in which the first high-efficiency encoding process is performed. A reproduction device for reproducing compressed image data, compressed audio data, and delay amount information from the recording medium; and a first reproduction device for reproducing the compressed image data reproduced by the reproduction device. First high-efficiency decoding processing means for performing a first high-efficiency decoding process corresponding to the efficiency coding process to generate an image signal; and a second high-efficiency decoding device for compressing the audio data reproduced by the reproducing means. Second high-efficiency decoding means for performing a second high-efficiency decoding process corresponding to the rate encoding process to generate an audio signal, and an audio signal generated by the second high-efficiency decoding processing means Delay means for delaying and outputting the first efficient decoding processing means by controlling a delay amount of the audio signal by the delay means based on the delay amount information reproduced by the reproduction means. And a control unit for outputting an audio signal synchronized with the image signal generated by the delay unit from the delay unit. 12. The reproduction means according to claim 1, wherein said delay amount information is transmitted from a recording medium in which the delay amount information is recorded as header data for each processing unit together with the compressed image data and the compressed audio data. The apparatus for reproducing compressed image data and compressed audio data according to claim 11, wherein the apparatus reproduces the compressed image data and the compressed audio data. 13. The image processing apparatus according to claim 1, wherein the reproduction unit is configured to output, from the recording medium in which the processing unit number information of the image signal is recorded together with the compressed image data and the compressed audio data, as the delay amount information of the audio signal with respect to the image signal, The control means reproduces the compressed audio data and the delay amount information. The control means generates time information for delaying the audio signal to be synchronized with the image signal based on the processing unit number information of the image signal. 13. The apparatus for reproducing compressed image data and compressed audio data according to claim 12, wherein the amount of delay is controlled. 14. The compressed image data according to claim 13, wherein said control means comprises a memory table for associating processing unit number information of the image signal with time information for delaying the audio signal in synchronization with the image signal. A playback device for compressed audio data. 15. The reproduction means stores, as delay amount information of an audio signal with respect to the image signal, time information for delaying the audio signal in synchronization with the image signal during reproduction together with the compressed image data and the compressed audio data. 13. The apparatus for reproducing compressed image data and compressed audio data according to claim 12, wherein the apparatus reproduces compressed image data, compressed audio data, and delay amount information from a recording medium. 16. A first high-efficiency encoding means for performing a first high-efficiency encoding process on an image signal to generate compressed image data, and a second high-efficiency encoding process on an audio signal. A second high-efficiency encoding unit for generating compressed audio data; and an audio signal level of the second high-efficiency encoding unit for each processing unit of the image signal by the first high-efficiency encoding unit. Control means for completing the efficiency encoding process and generating delay amount information of the audio signal with respect to the image signal; compressed image data generated by the first high efficiency encoding means; and the second high efficiency code Compressed image data provided by sending means for sending, via a medium, delay amount information of an audio signal with respect to the image signal generated by the control means together with the compressed audio data generated by the conversion processing means via a medium for each processing unit of the image signal A transmitting device for image data and compressed audio data; a reproducing device for reproducing compressed image data, compressed audio data and delay amount information transmitted from the transmitting device via a medium; and a compressed image data reproduced by the reproducing device. First high-efficiency decoding processing means for performing a first high-efficiency decoding process corresponding to the first high-efficiency encoding process to generate an image signal, and compressed audio data reproduced by the reproduction means. Second high-efficiency decoding means for performing a second high-efficiency decoding process corresponding to the second high-efficiency encoding process to generate an audio signal, and the second high-efficiency decoding means A delay unit that delays and outputs the audio signal generated by the first unit, and controls a delay amount of the audio signal by the delay unit based on the delay amount information reproduced by the reproduction unit. A transmission system comprising: a compressed image data and compressed audio data reproducing device including a control unit that causes the delay unit to output an audio signal synchronized with the image signal generated by the high-efficiency decoding processing unit.