JPH11296312A - Image/voice recording device and method therefor and image/voice reproducing device and method therefor and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain rewriting and free edition on an image/voice recording medium in a real time. SOLUTION: A packeted data generating part 10 generates packeted data suited for being recorded in an optical disk 5 by compressing an AV(audio/video) signal. A recording and reproducing part 15 records the packeted data from the packeted data generating part 10 in the optical disk 5, and operates reproducing processing for fetching an RF signal from the optical disk 5. A packeted data decoding part 30 reproduces the packeted data from an RF demodulation signal from the recording and reproducing part 15, separates the compressed audio and video signals, and extends and decodes the signals. In this case, the packeted data generating part 10 formats the compressed voice signal first and then the compressed image signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image and audio recording apparatus and method for compressing and encoding an image signal and an audio signal and recording them on a recording medium. The present invention relates to an image / audio reproducing apparatus and method for reproducing an image signal and an audio signal from a recorded recording medium, and a recording medium recording the compressed image signal and the compressed audio signal.

[0002]

2. Description of the Related Art MPEG2 (Moving Picture Experts Group)
Phase 2) broadcast and audio (Audio) video (Vide
o) This is an encoding method used for recording equipment (hereinafter collectively referred to as AV) and is widely used as an information compression technique for audio / video / data (Date).

An AV signal of software such as a movie encoded by MPEG2 is recorded on a digital video disk (Digital Video Disk: DVD), for example.
It has been sold to general users. This DVD
The recording / reproducing apparatus for recording the encoded AV signal employs an MPEG2 system layer for multiplexing the AV signal.

[0004] For example, an example of multiplexing processing using a FIFO will be described. The conditions in this case are as follows. First, the multiplexed stream has a constant bit rate. Also, the length of the packet header and the packet data of all the packets shall be the same. Therefore, a stuffing byte is placed in the time stamp portion when it is not needed. The multiplexing process is as follows. First, the output stream of each video and audio individual encoder is divided into packet data length units to form a packet. Next, regardless of the type of video and audio, each packet is registered in FIFO order in the order in which it was created. Finally, the transmission channel is divided into packet lengths, each of which is referred to as a "packet slot", and transmitted to the transmission channel according to FIFO registration each time a packet slot comes. Even if a packet slot is created, if the FIFO registration is empty, a padding stream packet is used.

[0005]

The above MPEG2
The multiplexing of AV signals using the system layer
Although this is the most suitable method for producing software by authoring, it is not suitable for a moving image recording / reproducing apparatus that rewrites a recording medium while compressing an image / sound inputted as needed. It is also unsuitable for application to a moving image editing apparatus that freely edits a compressed image / audio recorded on a recording medium later. This is because the systematic arrangement (syntax) of the multiplexing is complicated and each data is managed in sector units.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has an image / audio recording apparatus and method optimal for a system capable of real-time rewriting and free editing of an image / audio on a recording medium, and an image / audio reproduction. It is an object of the present invention to provide an apparatus and method, and a recording medium on which the image and sound are recorded by the image and sound recording apparatus and method.

[0007]

In order to solve the above-mentioned problems, an image and sound recording apparatus according to the present invention compresses and encodes an image signal by an image compression means, and compresses and encodes an audio signal by an audio compression means. After the compressed image signal from the compression unit and the compressed audio signal from the audio compression unit, the compressed audio signal is first placed after the compressed image signal by the packet forming unit, and then packetized in units of an integer multiple of the fixed block unit. The recording means records the packetized data on a recording medium. Here, the packet forming means adds characteristic information indicating characteristics of the packetized data in a fixed amount.

Therefore, when the packetized data is reproduced on the reproducing apparatus side, the compressed audio signal can be reproduced first in a short time, so that the compressed audio signal is continuously reproduced while the compressed image signal is reproduced. Can be added.

[0009] Further, the video and audio recording method according to the present invention comprises:
In order to solve the above-mentioned problems, a compressed audio signal obtained by compression-encoding an audio signal is first transmitted, and a compressed image signal obtained by compression-encoding the image signal is thereafter packetized in units of an integer multiple of a fixed block unit and recorded. Record on the medium. Here, characteristic information indicating the characteristics of the packetized data is added to the packetized data in a fixed amount.

[0010] In order to solve the above-mentioned problems, a video / audio reproducing apparatus according to the present invention is arranged such that a compressed audio signal obtained by compression-encoding an audio signal is transmitted first, and a compressed video signal obtained by compression-coding the image signal is transmitted after a fixed block. An image and sound reproducing apparatus for reproducing an image signal and an audio signal from a recording medium in which a packet is recorded in units of an integral multiple of a unit, wherein the reproducing means reads out the reproduction signal from the recording medium, and the packet data decoding means reads out the reproduction signal. The characteristic information indicating the characteristics of the packet is read from the reproduced signal from the reproducing means to decode the packetized data, and the compressed image signal and the compressed audio signal are separated. The compressed image signal is expanded and decoded, and the compressed audio signal from the packet data decoding means is expanded and decoded by the audio expanding means.

Therefore, the compressed audio signal can be reproduced first in a short time, so that the compressed audio signal can be added while continuously reproducing the compressed image signal.

[0012] In addition, the image / audio reproduction method according to the present invention comprises:
In order to solve the above problem, a compressed audio signal obtained by compressing and encoding an audio signal is first recorded, and a compressed image signal obtained by compressing and encoding an image signal is thereafter packetized and recorded in units of an integral multiple of a fixed block unit. An image and sound reproducing method for reproducing an image signal and an audio signal from a recording medium,
Characteristic information indicating characteristics of the packetized data reproduced from the recording medium is read, the compressed image signal and the compressed audio signal are separated, and each of them is decompressed and decoded.

According to another aspect of the present invention, there is provided a recording medium, comprising: a fixed audio signal obtained by compressing and encoding an audio signal; a compressed image signal obtained by compressing and encoding an image signal; It is packetized and recorded using an integral multiple of the unit.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, an audio (Video) (hereinafter, collectively referred to as AV) signal which is input as needed is recorded and reproduced while being rewritten on a recording medium such as an optical disc.
Is an AV recording / reproducing apparatus 1 shown in FIG.

The AV recording / reproducing apparatus 1 is also applicable to a moving picture editing apparatus for freely editing an AV signal recorded on a recording medium. The AV recording / reproducing apparatus 1
As will be described later, the above audio signal is converted into an ATRAC (Adaptive Transform Ac) used for a mini disc (MD) specification.
oustic Coding) 2 and compress the video signal
Compress according to MPEG2. Here, ATRAC2 is a high-efficiency audio encoding method capable of realizing the same sound quality as 128 kbps / CH at 64 kbps / CH while encoding independently for each channel.

As shown in FIG. 1, the AV recording / reproducing apparatus 1 includes a packetized data generating section 10 for generating packetized data suitable for recording the optical disk 5 by compressing the AV signal. A recording / reproducing unit 15 for recording packetized data from the packetized data generating unit 10 on the optical disk 5 and performing a reproducing process such as extracting an RF signal from the optical disk 5; and an RF demodulated signal from the recording / reproducing unit 15 And a packetized data decoding unit 30 that reproduces the packetized data, separates the compressed audio and video signals, and decompresses and decodes each.

The AV recording / reproducing apparatus 1 communicates with an external block and issues an instruction corresponding to the communication.
It comprises a CU unit 2 and a system controller 3 for controlling the packetized data generation unit 10, the recording / reproducing unit 15, and the packetized packetized data decoding unit 30 according to instructions from the MCU unit 2.

The packetized data generation unit 10 includes an audio input unit 12A for sampling an audio signal input from the outside via an audio input terminal 11A, and a highly efficient encoding such as ATRAC2 for the sampled audio signal. An audio compression unit 13A that performs video encoding, a video input unit 12V that samples a video signal input from the outside via a video input terminal 11V, and a video compression that performs high-efficiency encoding such as MPEG2 on the sampled video signal. And a packet forming unit 14 for multiplexing the compressed audio data and the compressed video data, each of which has been subjected to the high-efficiency coding, into packets and further adding the characteristic information of the packets. Here, the audio compression unit 13A and the video compression unit 13V perform the above-described high-efficiency encoding using a common memory 13C. The packet forming unit 14 forms a packet using the memory 14C.

The recording / reproducing section 15 includes a modulating section 16 for modulating the packetized data from the packetized data generating section 10 into a signal suitable for recording on an optical disk, and a modulating section 16.
A magnetic field modulation driver 17 for generating a magnetic field sufficient for recording on the optical disk 5 based on a modulation signal from the magnetic head 18, the magnetic head 18, and the magnetic head 18 opposed to the magnetic head 18 with the optical disk 5 interposed therebetween. An optical system 19, such as a laser pickup, which is disposed at a position and irradiates a recording laser beam to the recording position of the magnetic field modulation data, and irradiates a reading laser beam;
RF amplifier 2 for amplifying the signal read by
0, an RF signal demodulation unit 21 for demodulating the RF signal from the RF amplifier unit 20, and a servo circuit for servo-controlling the optical system 19 and a spindle motor 23 described later based on a servo error signal from the RF amplifier 20. 22, a spindle motor 23 for rotating the optical disk 5, and an RF
Address Implement Groove (Address)
in Pre-groove (ADIP) signal; an ADIP signal demodulation unit 24 that demodulates a signal; an ADIP decoding unit 25 that performs error checking on a data string from the ADIP signal demodulation unit 24 to obtain address information and sends the address information to the MCU unit 2 And comprising.

Further, the packetized data decoding unit 30
A packet decoding unit 31 that decodes packetized data from the RF signal from the F signal demodulation unit 21 and separates compressed audio data and compressed video data, and an audio decompression unit that decompresses the compressed audio data separated by the packet decoding unit 31 Unit 32A and a video decompression unit 32V for decompressing the compressed video data separated by the packet decoding unit 31
And an audio output unit 33A that converts audio data from the audio decompression unit 32A into an audio output signal based on a reference signal from a reference signal generation unit 4 inside the system controller 3 and supplies the audio output signal to an audio output terminal 34A.
And a video output unit 33V that converts video data from the video decompression unit 32V into a video output signal based on the reference signal from the reference signal generation unit 4 and supplies the video output signal to a video output terminal 34V.
And comprising. Here, the packet decryption unit 31 decrypts the packet using the memory 31C. The audio decompression unit 32A and the video decompression unit 32V perform decompression processing using a common memory 32C.

Next, the operation of the AV recording / reproducing apparatus 1 having the above configuration will be described with reference to FIG. FIG. 2A shows generation of packetized data by the packetization generation unit 10, and FIG. 2B shows decoding of packetized data by the packetization data decoding unit 30.

First, the audio signal input from the external block via the audio input terminal 11A of FIG.
It is supplied to the audio input unit 12A. The audio input unit 12A samples the audio signal with a predetermined code length according to the reference signal from the reference signal generation unit 3 inside the system controller 3 as shown in FIG. Then, the audio sampling signal is converted to the audio compression unit 13A.
To supply. The audio compression unit 13A temporarily stores the audio sampled signal from the audio input unit 12A in the memory 1
3C, a predetermined number of data are collected and read, and compressed audio data is output irregularly by a high-efficiency encoding method such as ATRAC2. At this time, as shown in FIG. 2A, the audio compression unit 13A performs an EDC encoding process for checking a reproduction signal of the compressed audio data at the time of reproduction, and an ECC encoding process for adding parity for error correction. Is applied.

A video signal input from an external block via the video input terminal 11V of FIG. 1 is supplied to a video input unit 12V. The video input unit 12V samples the video signal according to the reference signal from the reference signal generation unit 3 with a predetermined code length as shown in FIG. The video compression unit 13V temporarily stores the video sampled signal from the video input unit 12V in the memory 13C, collects a predetermined number of data, reads out the data, and decodes the compressed video data by the high-efficiency encoding method such as MPEG. Output periodically. At this time, as shown in FIG. 2A, the video compression unit 13V performs an EDC encoding process for checking a playback signal of the compressed video data during playback and an ECC encoding process for adding parity for error correction. Is applied.

The packet forming section 14 temporarily stores compressed audio data (ATRAC2 data) and compressed video data (MPEG2 data) supplied from the audio compression section 13A and the video compression section 13V at irregular intervals in the memory 14C. Thereafter, in accordance with an instruction from the system controller 3, the compressed data is read out from the memory 14C by a predetermined unit, multiplexed, and the characteristic information is added as identification information. The packetized output data is held and output at appropriate timing. Note that multiplexing and addition of identification information may be performed at the time of storage in the memory 14C.

Up to this point, the packetized data generation unit 10
FIG. 3 shows a detailed flow of packetization processing performed by the packetized data generation unit 10 in the operation described above. The audio compression unit 13A performs encoding using ATRAC2, and the video compression unit 13V performs encoding using MPEG2. Here, the above-described units of the packetized data generation unit 10 are controlled by the system controller 3 to perform a packetization process.

First, after erasing the buffer contents of the memory 13C in step S1, the sampled audio signal from the audio input unit 12A is supplied to the audio compression unit 13A in step S2, and the ATRAC2 using the memory 13C is used.
Start encoding (abbreviated to ATRAC only in the figure). Further, in step S3, the sampled video signal from the video input unit 12V is supplied to the video compression unit 13V, and the MPEG2 (only MPEG is abbreviated in the figure) encoding using the memory 13C is started.

In step S4, it is determined whether the MPEG2 data subjected to the MPEG2 encoding is completed for one GOP, and whether the data of a predetermined number of frames is completed in step S5. Proceeding to S6, the packet forming unit 14 extracts the MPEG2 data from the memory 13C. Also in step S7, the ATRAC2 data corresponding to the MPEG2 data is extracted from the memory 13C.

In step S8, the packet forming unit 14 prepares a packet property (characteristic information) described later for indicating the characteristics of the packet, and writes the packet property in the memory 14C. After that, the ATRAC2 data is written to the packet forming unit 14 in step S9, and
0 causes MPEG2 data to be written.

In the processing from step S4 to step S10, in step S11, the audio input section 12A
This process is repeated until it is determined that there is no input data in the video input unit 12V.

In the flowchart shown in FIG. 3, audio data is recorded first because of the operation of the packetized data decoding unit 30 side. The reason will be described below.

The data read from the recording / reproducing unit 15 is stored in a memory 31C used as a buffer memory in the packetized data decoding unit 30, and is reproduced at a predetermined time. In the state of continuous reproduction, since data up to several seconds ahead is stored in the memory 31C, no special consideration is required for the order of data stored in the packet.

However, immediately after random access, data is read from a new position, and the contents of this buffer are temporarily cleared. In order to start playback as soon as possible, it is necessary to have a structure that allows processing to be started before the entire packet is read.

The packetized video and audio are information in the same time zone, respectively, but the amount of audio data is about 1/30 smaller than the amount of video data. If the audio data is placed first, all the audio data can be read in a short time, and the audio can be added while sequentially reading the read video data. However, if the video data is first and the audio data is later, the read video data must be played back without audio, or stored once in the memory 31C until the video data is completely read and the audio data can be read. Must.

The unit of packetization in the packet forming section 14 shown in FIG. 2 may be in conformity with the MD_DATA (DATA) 2 standard. MD_DATA2 specifies that a color still image or audio can be recorded in the data area based on the MD_DATA standard that can record and play back data in addition to MD audio, and is called a so-called Picture MD. ing. By adopting a large capacity of 640 MB and a high-efficiency image compression technology, it has become possible to record many still images.

In MD_DATA2, data is managed in cluster units. Therefore, the packet forming unit 14 matches the unit of the packetization with the cluster unit. Therefore, the AV recording / reproducing apparatus 1 can easily perform the rewriting process and the editing operation process. Here, one cluster is 32 KByte. Further, the packet forming unit 1
In No. 4, the maximum time of a packet is specified to be about 2 to 3 seconds. The reason for this is that if it is too long, the performance of random access deteriorates, and if it is too short, packet management becomes troublesome, and data that does not match the cluster unit occurs and waste becomes noticeable. is there. The maximum time of this packet will be described later in detail.

FIG. 4 shows the configuration of a packet formed by the packet forming unit 14 in this manner. For the AV data, at least one track management system (Track_Management_System) is used for every 10 seconds of data in the reproduction time.
Are packetized into packet data composed of allocation units (Allocation_units). That is,
AV data is composed of several AV packets. As shown in FIG. 4, each AV packet is composed of an integer number of clusters starting from the head of a certain cluster and ending with a certain cluster. The first part of the first cluster (packet property: Packet_Pro
perty) contains 256 bytes of characteristic information indicating the characteristics of the packet.
Is added. The characteristic information includes data indicating that the packet is an AV packet, conditions when the AV packet is recorded, for example, recording date and time, information on AV encoding,
There is information indicating the deviation of the AV data. After the packet property where this characteristic information is recorded, n_soun
The compressed audio data (ATRAC2 data) composed of d_unit and the compressed video data (MPEG2 data) composed of m_video_sequence are recorded. The number of bytes of the compressed audio data and the compressed video data can be freely set, and information on the number of bytes is also written as characteristic information in the packet property. Similarly, the number of clusters of the packet itself is also described as the characteristic information. The AV packet can be independently reproduced.

Each packet is placed in a physically and logically continuous area. The area allocated to each data is a byte unit. Then, it is assumed that the compressed video data always follows the compressed audio data,
As shown in FIG. 4, there may be an unrecorded area between them and at the end. However, “0” is filled in the unrecorded area.

The longest time of one packet is the queue (cu
e) It is appropriate to limit the step of review to 5 seconds or less in order to make the review step fine and prevent a reduction in the display time at the time of random access. On the other hand, if the packet length is too short, the unused area (average 0.5 cluster / packet) generated when the packet is rounded up in cluster units becomes noticeable. For the above reasons, the packet length is 4-6MB
At a normal bit rate of ps, about 2 seconds (60 frames) is considered appropriate. However, in order to reduce the number of packets, it is appropriate to limit the time to about 3 to 5 seconds for a low-rate image of 1 MBps or less. Preferably, in the case of a low bit rate, for example, if an image is 64 KBps, one cluster can accommodate about 4 seconds. 1 cluster together with audio
It is considered appropriate to set the packet to about 3 seconds.

The size of an AV packet containing only audio is one cluster. At this time, a maximum of 144 channel sound units (channel_so
und_units (ATRAC2_level12) data is stored.

The meaning of AV packetization is that if a packet is formed and a jump is made to the beginning, reproduction can be performed from there. Therefore, since the beginning of the packet is like a cue point, random access can be made at various points as the length of the packet becomes shorter.

However, if it is too short, it becomes difficult to control the rate of video data, and as described above,
An unused area having an average of 0.5 clusters / packet is generated at the end. Since this is wasteful, it is considered appropriate to set the packet length to about 2 to 3 seconds at the bit rate of 4 to 6 MBps as described above. However, for images with low bit rate of 1 MBps or less, 3
About 5 seconds is considered appropriate.

Since the length of each packet can be arbitrarily set, the length of each packet can be determined by looking at the head of a certain packet, so that the next packet can be easily skipped. be able to. However, it may be difficult in the case of random access such as jumping to the minute and second.

Therefore, an index indicating how clusters are arranged in an AV packet is prepared, and this packet creates a table (AV_Information_Table) indicating how many clusters and how many frames contain video, and based on the table, Random access may be possible.

The table (AV_Information_Table) will be briefly described. Table showing packet types
The ID is 1 byte as Table ID, and the number of bytes from the next byte position to the Table ID of the next table is Next table p
Recorded as 1 byte as ointer. For images,
Set the data start position in bytes from the beginning of the packet to Lo.
The cation of Video Data is recorded as 4 bytes, the video recording start count is 6 bytes, the video recording end count is 6 bytes, and so on. Furthermore, for audio, the audio data start position is 4 bytes, and the audio recording start count is 6 bytes.
In es, the voice recording end count is recorded as 6 bytes or the like.

Here, the exact start times and lengths of the audio and video data contained in one packet do not match. This means that the audio is eg AT
When encoded using RAC2, the unit of one sound unit (su) is 1024 / 44.1KHz (= 23.22ms),
This is because, when the video is encoded using MPEG2, since the video is configured at a frame rate of 29.97 Hz (= 33.37 ms), the video does not start and have the same length. That is, as shown in FIG. 5, the video data (MPEG2 data) and the audio data (ATRAC2 data) start at the same time, but after that, the frame rate (= 33.37 ms) and the sound unit (= 23.22 ms)
Due to the difference between the two, there is always a gap between them.

Therefore, the packetized data generator 10 of the AV recording / reproducing apparatus 1 records an appropriate number based on the video data, and stores the audio data so as to minimize the error. If there is a slight difference between the two, the length of the data is also included in the packet property at the beginning of the packet so that it can be strictly checked if necessary. The difference between the two is a level that is not actually recognized by the user. That is, as shown in FIG. 5, the audio data ATR for the video data MPEG2
AC2 deviation shall be recognized within ± 0.5su (= 11.61ms). This is less than 30ms. Then, on average, the error always falls within the predetermined error range, and the real-time property of rewriting on the optical disk 5 and freely editing is secured.

The formation of the AV packet in the packet forming section 14 has been described above. This AV packet is sent to the modulation section 16 of the recording / reproduction section 15. The modulator 16 modulates the AV packetized data into a signal suitable for recording on an optical disk. Then, the modulation signal from the modulation unit 16 is sent to the magnetic field modulation driver 17. The magnetic field modulation driver 17 drives the magnetic field head 18 to generate a magnetic field in the magnetic field head 18 sufficient to record the modulation signal, and causes the optical disk 5 to record the magnetic field as a magnetic field modulation signal.

Next, the recording / reproducing unit 15 reads a signal recorded on the optical disk 5 using the optical system 19 according to the instruction of the system controller 3, and sends the read signal to the RF amplifier 20.

The RF amplifier 20 generates an RF signal to generate an RF signal.
The signal is sent to the signal demodulation unit 21. In addition, an error signal such as a focus error or a tracking error is generated to generate a servo circuit 2
Send to 2. Furthermore, an ADIP signal is generated and sent to the ADIP signal demodulation unit 24.

In the servo circuit 22, the RF signal from the optical system 19
The optical system 19 and the spindle motor 23 are controlled so that the read signal sent to the amplifier unit 20 is in an appropriate state. Here, the spindle motor 23 is controlled so that the optical disk 5 rotates at an appropriate rotation speed.

On the other hand, the signal sent to the RF signal demodulation unit 21 is subjected to a process reverse to that of the modulation unit 16 and a demodulation operation is performed. The demodulated signal is supplied to the packetized data decoding unit 30.
The packet is sent to the packet decoding unit 31 at irregular intervals and processed as shown in FIG.

That is, the packet decoding unit 31 receives the signal output irregularly from the RF signal demodulation unit 21 and separates it into compressed audio data and compressed video data by referring to the characteristic information contained therein. , Once memory 3
Store it in 1C. After that, according to the instruction of the system controller 3, each of them is irregularly stored in the memory 31 by a necessary amount.
It is read from C and sent to the audio decompression unit 32A and the video decompression unit 32V. However, the data may be separated at the time of storage in the memory 31C.

Then, the audio decompression unit 32A decompresses the compressed audio data (ATRAC data) in the reverse order of the compression process performed by the audio compression unit 13A, reads out the compressed audio data in the memory 32C in accordance with the order of recording. , And outputs the sampled audio signal to the audio output unit 33A. In detail, the signal once stored in the memory 32C is subjected to ECC decoding processing and error correction,
Further, whether or not the error-corrected data is correct is checked by an EDC decoding process. Then, the checked signal is sent to the audio output unit 33A.

The audio output unit 33A converts the sampled audio signal into an audio output signal in accordance with the reference signal from the reference signal generation unit 4,
Output from 4A to external block.

The video decompression unit 32V decompresses the compressed video data (MPEG data) in the reverse order of the compression process performed by the video compression unit 13V, and stores the decompressed video data in the memory 32C.
The data is read out in accordance with the recording order,
Output to V as a standardized video signal. More specifically, the signal once stored in the memory 32C is subjected to ECC decoding processing and error correction, and further, it is checked by EDC decoding processing whether the error-corrected data is correct. Then, the checked signal is output to the video output unit 33.
Sent to V.

The video output unit 33V converts the sampled video signal into a video output signal according to the reference signal from the reference signal generation unit 4, and outputs the video output signal from the video output terminal 34V to an external block.

As described above, the audio output signal and the video output signal output from the audio output terminal 34A and the video output terminal 34V of the AV recording / reproducing apparatus 1 to, for example, an external block are the same as the audio data previously recorded on the recording medium. Since it is obtained by reproducing the video data following it, the audio data can be read within a short time and added to the sequentially read video data. Also,
During recording, the deviation amount of audio data from video data is specified within ± 0.5su, so that on average it always falls within a predetermined error range, and rewriting and editing on the recording medium can be freely performed. This is a signal in which real-time operation is performed.

The ADIP signal demodulator 24 demodulates the ADIP signal to obtain a data string cut on the optical disk 5. Further, the ADIP decoding unit 25 checks for errors and obtains address information. This is MCU unit 2
And used as a reference for recording / reproducing.

The reference signal generator 4 in the system controller 3 includes an audio input unit 12 A and a video input unit 1.
2V, audio output unit 33A and video output unit 22V
Supplies a reference signal for audio sampling and a reference signal for video sampling, each having a predetermined frequency. The frequencies of these two reference signals are kept constant by, for example, a PLL.

[0060]

According to the present invention, rewriting and free editing of video and audio on a recording medium can be performed in real time. In addition, since the recording device and method form packetized data after the image is put first after the sound, the compressed sound signal can be reproduced first in a short time in the reproducing device and method. The compressed audio signal can be added while reproducing the image signal.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an AV recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining an operation of the AV recording / reproducing apparatus.

FIG. 3 is a flowchart showing a detailed flow of packetization processing performed by a packetized data generation unit inside the AV recording / reproducing apparatus.

FIG. 4 is a format diagram showing a configuration of a packet generated by a packetized data generation unit inside the AV recording / reproducing apparatus.

FIG. 5 is a diagram for explaining a shift between video data (MPEG2 data) and audio data (ATRAC2 data).

[Explanation of symbols]

1 AV recording / reproducing device, 5 optical disc, 10 packetized data generating unit, 15 recording / reproducing unit, 30 packetized data decoding unit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04N 5/92 H04N 5/92 E 5/928 7/13 Z 7/24

Claims (7)

[Claims] 1. An image and sound recording apparatus for recording an image signal and an audio signal on a recording medium, comprising: an image compression unit for compressing and encoding the image signal; an audio compression unit for compressing and encoding the audio signal; Packet forming means for compressing the compressed image signal from the compression means and the compressed audio signal from the audio compression means, followed by the compressed audio signal after the compressed audio signal, and packetizing in units of an integral multiple of a fixed block unit; Recording means for recording the packetized data from the packet forming means on a recording medium. 2. The video and audio recording apparatus according to claim 1, wherein said packet forming means adds characteristic information indicating characteristics of said packetized data in a fixed amount. 3. A video / audio recording method for recording an image signal and an audio signal on a recording medium, comprising: a compressed audio signal obtained by compression-encoding the audio signal first; After that, the packetized data is packetized in units of an integral multiple of the fixed block unit, and recorded on a recording medium. 4. The video / audio recording method according to claim 3, wherein characteristic information indicating characteristics of said packetized data is added in a fixed amount. 5. A recording medium in which a compressed audio signal obtained by compressing and encoding an audio signal is first encoded, and a compressed image signal obtained by compressing and encoding an image signal is packetized in units of an integral multiple of a fixed block unit. An image and audio reproducing apparatus for reproducing an image signal and an audio signal, comprising: a reproducing unit for reading a reproduction signal from the recording medium; and packetizing data by reading characteristic information indicating characteristics of a packet from the reproduction signal from the reproducing unit. Packet data decoding means for separating the compressed image signal and the compressed audio signal, image decompression means for decompressing and decoding the compressed image signal from the packet data decoding means, and An audio / video reproduction apparatus comprising: audio expansion means for expanding and decoding the compressed audio signal. 6. A recording medium in which a compressed audio signal in which an audio signal is compression-coded and a compressed image signal in which an image signal is compression-coded later are packetized and recorded in integral multiples of fixed block units. A video / audio reproduction method for reproducing an image signal and an audio signal, wherein characteristic information indicating characteristics of packetized data reproduced from the recording medium is read to separate the compressed image signal and the compressed audio signal, An image / sound reproducing apparatus characterized in that each of them is decompressed and decoded. 7. A method in which a compressed audio signal obtained by compressing and encoding an audio signal is first recorded, and a compressed image signal obtained by compressing and encoding an image signal is packetized and recorded in integral multiples of fixed block units. Characteristic recording medium.