JP2002176622A - Video signal recording method and video signal recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a video signal recorder that can facilitate reproduction of a recording signal at high-speed and continuation of the recording operation, even at the occurrence of an error of a recording medium, in the case of recording an encoded video signal onto a random accessible recording medium. SOLUTION: A management information generating means 57 generates and records an image, resulting from applying in-frame coding to the encoded video signal or termination part information of an image subjected to prescribed unidirectional prediction coding, after a temporary storage means 55 temporarily stores the encoded signal generated by an encoder 53, so that the signal is recorded ion a recording medium 63. When error is detected in the recording medium, after deleting the encoded signal stored in the temporary storage means 55, the signal processing for recording is restarted, so as to reduce an interruption time of the recoding and the high-speed reproduction can be conducted easily by the video signal recorder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal recording method for recording a video and an audio signal obtained by receiving a TV broadcast as a compression-encoded signal on a recording medium such as a hard disk, and a video signal recording. Related to the device.

[0002]

2. Description of the Related Art A video signal recording apparatus using a randomly accessible recording medium such as a hard disk as a recording medium has a short access time for recording.
It has functions such as being able to record V broadcast programs at the same time and recording and reproducing video signals simultaneously.

A video signal recording apparatus having such a simultaneous recording / reproducing function is a cache recording / reproducing apparatus which allows a currently broadcast program to be viewed while continuously shifting the time from the present to the past, and a program which has started recording in the past. Has a convenient recording function, such as chase playback that can be played back in a manner that catches up with the program currently being recorded, and it will be introduced into the home together with the VTR used as a conventional time shift machine in the future. It is considered.

[0004] In the conventional monitor of a recording signal in a VTR, a recording signal supplied to the VTR is directly supplied to a monitor TV for viewing, and the monitor video is in the middle of a recording circuit. Although the signal can be monitored, it is impossible to know how the image is actually recorded on the recording medium, whether the image quality of the recorded image is abnormal, or whether the recording is not performed due to any cause.

On the other hand, in a video signal recording device having a simultaneous recording / reproducing function, a recorded signal can be confirmed while reproducing a video being recorded in real time, so that a defect at the time of recording can be known at that time. And recording errors can be minimized.

[0006] Furthermore, during recording, a video to be watched again,
In addition, when there is an overlooked video, the recording and playback functions performed using the hard disk are convenient functions for the viewer, such that the past video can be viewed by a simple operation while continuing the recording. A PVR (personal video recorder) equipped with a recording function has also been developed.

[0007]

By the way, in a video signal recording apparatus using a hard disk as a recording medium, the video signal recording apparatus has a high random access property, so that the
It is possible to configure a video signal recording device having a recording and recording / reproducing function that the TR does not have. However, when a hard disk as a recording medium uses a device developed as a peripheral device for a computer, it is continuously connected to the medium. It is necessary to record a large amount of video data supplied by a video recorder and to perform a reproducing operation of the recorded video signal by a function more than that of a conventional VTR. In order to realize a video signal recording device for recording a signal for that purpose, There are several issues that need to be resolved.

[0008] The problem is that when a coded video signal is recorded and the recorded video signal is reproduced at a high speed, a large amount of the video signal is read in accordance with the reproduction speed to generate a high-speed reproduced video signal. However, it is necessary to increase the medium access speed, the read speed of the recorded video signal, and the decoding operation of the read signal for that purpose. It is necessary to be able to read a video signal at a high speed, and to improve the operation speed.

In a recording medium such as a hard disk, an error signal may be included in a video signal recorded due to an influence of a defect on a signal recording surface of the recording medium.
When such an error signal occurs, in a conventional storage device for a computer, a retry operation is performed to obtain a reproduced signal that does not include an error signal by performing, for example, 10 times of repeated reproduction.

[0010] However, in the case of reproducing a video signal, a continuous read operation is required, and recording or reproducing operation of the hard disk repeatedly many times may cause a breakdown of the video signal, so that high-speed reproduction of the video is not possible. However, it is necessary to reduce the operation time for processing an error signal for a defect of a recording medium, and it is also required to solve the problem.

Further, signals recorded on a recording medium in a video signal recording device include an encoded video signal and management data of the encoded video signal. The recording is performed by setting different areas for each signal on a recording medium.

In particular, when a write error occurs in a management data recording area for obtaining a high-speed reproduced image, a long time is required for the error processing, and the recording function is stopped. There is a need for a processing method for resuming, and a solution is also required.

Accordingly, the present invention provides a video signal recording apparatus using a recording medium having excellent random access properties, such as a hard disk, in which a coded signal having a sufficient reproduction speed even for high-speed reproduction of a recorded video signal is provided. And a method of recording two types of signals having different error resilience on a recording medium, and a method of recording two types of signals having different error resilience on a recording medium. A solution for the configuration of the apparatus is shown, and recording of a video signal using a recording medium such as a hard disk realized for a computer is more preferable than a recording function of a conventional VTR, such as high-speed reproduction and simultaneous recording and reproduction. Recording video signals that have recording and playback characteristics and are not easily affected by error signals caused by defects in the recording medium. Method, and is intended to provide a structure of a video signal recording apparatus.

[0014]

A video signal recording method and a video signal recording apparatus according to the present invention comprise the following means 1) to 4) to solve the above-mentioned problems. That is,

1) The supplied video signal is obtained as a coded signal which is an intra-frame coded image and a plurality of inter-frame coded images as a coded image unit, and is obtained together with management data for managing the obtained coded signal. In a method for recording a video signal to be recorded on a randomly accessible recording medium,
A first step (56) of obtaining data amount information from the beginning of the coded image unit to the end portion where the intra-frame coded image is arranged, and the data step including the data amount information obtained by the first step; The method includes at least a second step (57) of obtaining management data and a third step (61, 63) of recording the management data obtained in the second step in a predetermined area of the recording medium. Characteristic video signal recording method.

2) The supplied video signal is obtained as an encoded signal which is obtained by encoding an intra-frame encoded image, a plurality of unidirectional inter-frame encoded images, and a plurality of bidirectional inter-frame encoded images as encoded image units. In a method of recording a video signal to be recorded on a recording medium that can be randomly accessed together with management data for managing the obtained encoded signal, the unidirectional interframe code arranged at a predetermined position from the beginning of the encoded image unit A first step (56) of obtaining data amount information up to the end of the coded image, a second step (57) of obtaining the management data including the data amount information obtained by the first step, A third step (61, 63) of recording the management data obtained in the second step in a predetermined area of the recording medium. Signal recording method.

3) The supplied video signal is obtained as a coded signal which is an intra-frame coded image and a plurality of inter-frame coded images as a coded image unit, and together with management data for managing the obtained coded signal. In a video signal recording apparatus for recording on a randomly accessible recording medium, header detecting means (56) for obtaining data amount information from the beginning of the encoded image unit to the end portion where the intra-frame encoded image is arranged; Management data generation means (57) for generating the management data including the data amount information obtained by the header detection means, and management data for recording the management data generated by the management data generation means in a predetermined area of the recording medium And a recording means (61, 63).

4) The supplied video signal is obtained as an encoded signal in which an intra-frame encoded image, a plurality of unidirectional inter-frame encoded images, and a plurality of bidirectional inter-frame encoded images are encoded image units. In a video signal recording device that records the obtained encoded signal on a recording medium that can be randomly accessed together with management data for managing the encoded signal, the unidirectional inter-frame encoding arranged at a predetermined position from the beginning of the encoded image unit Header detecting means (56) for obtaining data amount information up to the end of the image; management data generating means (57) for generating the management data including the data amount information obtained by the header detecting means; Management data recording means (61, 63) for recording the management data generated by the generation means in a predetermined area of the recording medium. A video signal recording device.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a video signal recording method and a video signal recording apparatus according to the present invention including a video signal reproducing apparatus for reproducing the recorded signal will be described below. explain. FIG. 1 shows a schematic block diagram of a video signal recording / reproducing apparatus that records and reproduces a video signal on the hard disk, and outlines the configuration and operation during normal recording and reproduction.

The video signal recording / reproducing apparatus 40 shown in FIG. 1 comprises a recording section 50, a medium section 60, and a reproducing section 70. A monitor TV 90 is connected to the reproducing section 70 by wire, and the recording section 50 and the reproducing section With respect to the operation performed on 70, the content of the operation performed by the viewer is transmitted to the reproduction unit 70 by infrared rays using the remote control 95.

First, the recording unit 50 comprises a TV tuner 51, A
It comprises a / D converter 52, an MPEG-2 encoder 53, a stream analyzer 54, a REC-FIFO 55, a header detector 56, a microcomputer 57, and a temporary storage memory 58.

The medium unit 60 includes a hard disk recording / reproducing unit 61, a hard disk 63, and a read / write controller 65. The reproducing unit 70 includes a buffer memory 7
1, an MPEG-2 decoder 72, an OSD 73, a D / A converter 74, a microcomputer 76, a temporary storage memory 78, and a remote control interface 79.

Next, the operation of the video signal recording / reproducing apparatus 40 configured as described above will be outlined. First, the TV tuner 51 receives a video signal of a reception channel set by the remote controller 95 or the like from among the broadcast waves coming from the antenna, and supplies the received video signal to the A / D converter 52. MPEG-
2 encoder 53.

In the MPEG-2 encoder 53, the supplied video signal is an ISO / IEC (International Or
ganization for Standardization / International Ele
MPEG-2 defined by the ctrotechnical Commission)
(Moving picture experts group-2) Compression-encoded according to the standard, and the compression-encoded signal is supplied to a stream analyzer 54 and a header detector 56 described later.

In the stream analyzer 54, the format of the compression-coded signal is analyzed, and the coded information signal obtained by the analysis and the supplied coded signal are REC-coded.
It is supplied to the FIFO 55.

The REC-FIFO 55 records (REC: re
A first-in first-out (FIFO) operation of a signal for cording, that is, a circuit for temporarily storing supplied input signals and supplying the signals as output signals in the order in which the signals are input. Container 61
Supplied to

In the hard disk recording / reproducing device 61,
The supplied signal is a signal divided for each sector size for recording on the hard disk 63, and the divided signal is supplied to the hard disk 63 whose operation is controlled by the write / read controller 65, and the supplied signal is It is recorded in a predetermined sector area of a disc-shaped recording medium (not shown) of the hard disk 63.

The above-mentioned header detector 56 has M
For example, a GOP (Gr.
The encoding information relating to the data configuration of “up of picture” is supplied, and the supplied encoding information is supplied to the microcomputer 57.

The microcomputer 57 generates hard disk management information (hereinafter sometimes referred to as management data) for smoothly recording and reproducing information on the hard disk 63 based on the supplied encoded information. The generated management information is temporarily stored in the temporary storage memory 58, and the temporarily stored hard disk management information is appropriately transmitted to the hard disk 6 via the hard disk recording / reproducing device 61.
3 in a predetermined area.

In this manner, the received channel video signal and the above-mentioned hard disk management information are recorded on the hard disk 63, and the supplied and recorded video signal is transmitted to another recording medium such as a VTR. When the signal is an analog signal, the video signal is supplied to the A / D converter 52, where the same processing is performed and the video signal is recorded on the hard disk 63.

If the video signal to be recorded is, for example, B
MP such as S digital broadcasting and digital terrestrial broadcasting
If the signal is encoded by a method such as EG-2, the encoded signal is directly supplied to the stream analyzer 54 and the header detector 56 without passing through the MPEG-2 encoder, and the same signal processing is performed. Is recorded on the hard disk 63.

Note that the MPEG-2 encoder 53 is a GO
When the apparatus has a function of supplying encoded information related to the configuration of P, or when encoded information such as a GOP is supplied as auxiliary information in digital broadcasting or the like, the information is supplied to the header detector 56. Alternatively, the header detector 56 may generate management information including encoded information based on the information and supply the generated management information to the microcomputer 57.

A video signal recorded on an analog TV broadcast, a digital television broadcast, or another recording medium in this manner is a compression-encoded video signal, and the video signal is recorded on the hard disk 63 together with management information. .

Next, the operation of reproducing the recorded signal of the hard disk 63 recorded in this way will be outlined. First, when the play button is operated by the remote control 95, the operation content is transmitted to the remote control interface 79 by a modulated infrared ray, and the operation content of the remote control key is supplied to the microcomputer 76.

From the microcomputer 76, a control signal generated in accordance with the operation content is supplied to the write / read control circuit 65.
The hard disk 63 is controlled by a write / read controller 65, and the hard disk 63 reads a signal at a specified location, and the read signal is supplied to a hard disk recording / reproducing device 61.

The hard disk recording / reproducing unit 61 amplifies the signal read from the hard disk 63, corrects the characteristics, detects the reproduced error signal, and the like. The signal subjected to such signal processing is stored in a buffer memory. 71
Supplied to

In the buffer memory 71, the compression-encoded signal is temporarily stored, and in response to a request from the MPEG-2 decoder, the temporarily stored signal is read out and its MP
It is supplied to the EG-2 decoder 72.

In the MPEG-2 decoder 72, the supplied signal is encoded by the encoder 53 according to the MPEG-2 standard.
The digital video signal obtained by decoding is decoded by a method complementary to the method of compression encoding, and the decoded digital video signal may include information such as, for example, that the cache recording / reproduction is in progress.
A display signal to be displayed on a display device is multiplexed by an SD (On Screen Display) 73, and the multiplexed digital video signal of the display signal is supplied to a D / A converter 74, converted to an analog video signal, and converted. The analog video signal is supplied to the monitor TV 90 and displayed.

The display signal multiplexed on the OSD 73 is a video RA (not shown) built in the OSD 73.
The signal stored in M or the temporary storage memory 78
The display content information stored in the
The display signal supplied to the D 73 and generated based on the information supplied to the OSD 73 is multiplexed and displayed on the video signal supplied from the MPEG-2 decoder 72.

In this manner, both the intra-frame compression and the inter-frame compression signal encoded using the motion compensation technique are recorded on the hard disk 63 in the supplied video signal by the MPEG-2 system. . Then, the signal recorded on the hard disk 63 is read out and decoded by the MPEG-2 decoder. Next, an image signal encoded by the MPEG-2 method will be described.

FIG. 2 shows the types of images handled by the MPEG-2 system. In the figure, frame images (pictures) constituting a video signal are arranged in the time direction with names of I, B, and P, and the I is an intra-coded I (Intra-coded). ) A frame (picture).

P is a P (Predictive) that is predictively encoded in one direction as indicated by an arrow at the bottom of the figure.
and B is a B (Bidirectionally predictive-co) in which a motion prediction vector is obtained and encoded from both the past and future directions.
ded) frame.

As described above, an image encoded by MPEG-2 is composed of frame images having three types of properties. For example, I frames are arranged every 15 frames. A group of 15 frame images up to the start of the I-frame of
Picture).

The reason why an image is treated as a unit of the GOP is that an image encoded in this way is decoded by decoding an I frame, and then decoding P and B frames. GO needs to decode the frame
This is because an I frame is arranged at the head of P.

If the I-frame has not been decoded, the subsequent P-frame and B-frame cannot be decoded, and the decoding of the incoming data is based on the image of the I-frame of the next supplied GOP. The data is decrypted after waiting.

The GOP interval at that time is 15 frames when N = 15, ie, NTSC (na
nation television system committee color televisio
In the case of a video signal of 30 frames per second as in (n system), a GOP signal to be coded every 0.5 seconds (15/30 = 0.5) is obtained and decoded.

Therefore, for example, in order to read data recorded on the hard disk 63 and immediately decode the data, the GOP
It is necessary to obtain the first data of the GOP by accessing it. For this purpose, management information indicating the position where the first part of the GOP is recorded is used to shorten the read time.

Next, a description will be given of recording of management information and an encoded signal for shortening the reading time. Video encoded signal recording / reproducing device 4 shown in FIG.
In the hard disk 63 of No. 0, a bit stream, which is an encoded signal obtained by encoding by the MPEG-2 encoder 53, is stored in a stream area, and management information including the coding information of the bit stream is stored in a management data area. It is recorded separately.

The coded signal recorded in the stream area is a variable-length coded signal obtained by being coded by the MPEG-2 encoder 53. The length of the bit stream per unit time, that is, the GOP The number of bytes of the data to be configured has a different value according to the set image quality mode and according to the information amount of the video to be encoded.

Next, recording of such a variable-length coded bit stream in the stream area will be described. The recording area of the hard disk 63 is managed for each unit divided into predetermined recording capacities called sectors, and a stream area for recording a video signal has a plurality of sectors, for example, 1024 sectors as one cluster. Is recorded.

The bit stream is encoded by the MPEG-2 encoder 53 and the stream analyzer 5
4 is temporarily stored in the REC-FIFO 55 via the
When the amount of the bit stream temporarily stored in the C-FIFO 55 exceeds the cluster size, the bit stream is written to a predetermined cluster of the hard disk 63.

The management information such as the address indicating the position of the written bit stream and its cluster is used to manage the bit stream recorded by a so-called file management system.

Next, a method for reproducing a recorded bit stream at a high speed will be described with respect to the realization of a video signal recording apparatus which performs recording under the management of management information.

That is, the MPEG shown in FIG.
In a bit stream obtained by compression encoding according to the -2 method, signals of an I frame that is intra-coded every 15 frames are usually arranged, and decoding of this bit stream is started from the I frame. I have.

Therefore, in such a bit stream, the I frame is obtained and decoded, and the signal of the next I frame is decoded without decoding the P and B frames.
When an image of only a frame is obtained and displayed, a reproduced image at a speed of 15 times is obtained.

However, if the bit stream recorded in the stream area only records the signal obtained from the MPEG-2 encoder 53 as it is, the recording of the GOP (Group of Picture) of the encoded signal starts. The position is not specified, and thus the start position of the I frame is also unknown (undefined).

If the compression encoding of the bit stream is a fixed rate and the data amount of the GOP is a fixed amount,
Although it is possible to specify the start point of the GOP assuming that a position that is an integral multiple of the GOP size from the head of the bit stream is the start position of the GOP, the start position of the GOP is specified when the compression encoding is a variable length method. It is not possible.

Therefore, information for arbitrarily accessing a predetermined position of the bit stream is generated, and the bit stream is managed based on the generated information. And the operation parameter information at the time of compression encoding are generated as management data.

The management data is stored in the stream analyzer 5
4 and its stream analyzer 54
Then, the supplied bit stream is analyzed, and the packet information obtained by the analysis is supplied to the microcomputer 57.

The information supplied to the microcomputer 57 is G
The number of bytes of the entire OP, the number of bytes of the I frame, the number of frames of the GOP, the number of bytes up to the end position of each P frame, and the like. The microcomputer 57 manages the information including the GOP based on the supplied information. Data is generated, and the generated management data is temporarily stored in the temporary storage memory 58, and is written to the management data area of the hard disk 63 as needed.

The information on these GOPs is M
When supplied directly from the PEG2 encoder 53 to the header detection circuit 56, the microcomputer 57 can generate the above management data based on the supplied information.

Next, the structure of a bit stream managed by the management data and recorded on the hard disk 63 will be described. FIG. 3 shows a relationship between a bit stream written to a cluster and a GOP.

FIG. 9 shows a state in which a GOP, which is variable-length data, is recorded in a fixed-length cluster area, and that the cluster area is composed of a plurality of sectors.

The consecutively arranged sectors are consecutively assigned logical numbers called LBAs (Logical Block Address), and the LBAs of the sectors in the cluster are assigned.
BA is continuous.

As described above, a GOP signal is recorded in a cluster which is a fixed-length data area.
Is variable length, so that G
The number of OPs is undefined, and in a normal case, data of a GOP is recorded over a plurality of clusters.

In order to easily access the position of a GOP recorded at an undetermined position, recording position information of each GOP is necessary. Generally, the position information of a GOP in a stream is used as management information or A method such as storing in a header is used, and the storing method will be further described.

In this example, the number of frames per GOP is 15
, The MPEG-2 encoding is performed, so that only the I frame is decoded and displayed for each frame of the video signal, so that a search video of 15 times speed is obtained, and the I frame is skipped while skipping 1 GOP for each frame. Decoding only a 30x search video, etc.
A high-speed playback video of double speed or higher can be realized by decoding a signal of only an I frame and forming a video signal.

Therefore, regarding the method of obtaining only the signal of the I frame, since the normal management data has the address value of the recording start position of the GOP, the G value is determined based on the address value.
The OP signal is read, and the I-frame signal stored in the first part of the GOP is supplied to the MPEG-2 decoder for decoding.

The GO recorded continuously in this way is
By reading the data of P and decoding the image of the I frame, it is possible to obtain a high-speed reproduction video of 15 times speed.
However, the read speed of the hard disk in that case,
Because it requires a readout speed 15 times faster than normal playback,
As the hard disk, an expensive hard disk having a high read speed is used.

Therefore, it is assumed that the management information stores I-frame data amount information for reading only the I-frame, not the entire GOP, or I-frame end portion information.

Since the ratio of the data amount occupied by the I frame in the GOP is about 30% when the number of frames of the GOP is set to 15, only the I frame is read as compared with the case where all data of the GOP is read. Read time can be reduced to about 30%.

As described above, by storing the I-frame data amount information for reading out only the I-frame or the I-frame end information in the management information, the reading speed of the hard disk during high-speed reproduction can be reduced. The access speed of the buffer memory 71 for temporarily storing data obtained by reading and the amount of the memory do not have to be increased unnecessarily. Unnecessary operation time for decoding an image or discarding P and B frame images can be reduced.

The operation for obtaining a high-speed reproduced image at a 15-times speed has been described above. However, when obtaining a high-speed reproduced image at a 30-times or 45-times speed, an alternate GOP or every other GOP is used. Similarly, a high-speed playback video can be obtained by obtaining and decoding only an I-frame image signal, and a high-speed playback video of an integer multiple of 15 can be obtained in the same manner.

The operation speed for the I-frame in the case of encoding by MPEG-2 has been described above. However, for image data compressed by another encoding method, the encoded image unit is a frame. In the case of a configuration including an inner coded image and a plurality of inter-frame coded images, a high-speed playback video can be obtained by reading and decoding an intra-coded image from the image unit. is there.

As described above, according to the method shown in the above-described embodiment, a video signal obtained by receiving an analog TV broadcast is compression-encoded, or a digital broadcast which is compression-coded and broadcast is received. Recording medium that can obtain video signals, such as video signals supplied in a frame, and a plurality of inter-frame coded images as a coded image unit, and can randomly access the obtained coded signals together with management data for managing the coded signals. In the method for recording a video signal to be recorded in a frame, management data for recording data amount of an intra-frame coded image or data amount information from the beginning of the coded image unit to the end portion where the intra-frame coded image is arranged By reproducing and decoding a plurality of intra-frame encoded images recorded on the recording medium continuously based on the information, thereby obtaining the recording medium. Data reading speed, and without increasing unnecessarily the operation speed of the encoded signal decoder, it is possible to obtain a high speed reproduced video from recorded video signal on a recording medium.

According to the configuration shown in the above-mentioned embodiment, the video signal obtained by receiving the analog TV broadcast is compression-encoded, or the digital broadcast which is compressed and coded and broadcast is received and supplied. And the like, obtain an intra-frame encoded image and a plurality of inter-frame encoded images as encoded image units, and record the obtained encoded signal on a randomly accessible recording medium together with management data for managing the encoded signal. The video signal recording device reproduces management data in which the data amount of the intra-frame encoded image or the data amount information from the beginning of the encoded image unit to the end portion where the intra-frame encoded image is arranged is reproduced. Data on the recording medium by continuously reproducing and decoding a plurality of intra-frame encoded images recorded on the recording medium based on the information. Look out speed, and without increasing unnecessarily the operation speed of the encoded signal decoder, it is configured of a video signal recording apparatus for obtaining high-speed reproduction video from recorded video signal on a recording medium.

Next, a method of obtaining a high-speed reproduced video of less than 15 times speed will be described together with data constituting a GOP. FIG. 4 schematically shows the relationship between each of the I, P, and B frame images constituting the GOP and the image data amounts thereof.

In the figure, at the beginning of a GOP, data of an I frame exists for a period of about 30%, and then the first and second data
B frames B1, B2 and a first P frame P1,
The image data of the second P frame P2 exists in two of them.

Here, if the three frame image data of the I frame, the P1 frame, and the P2 frame are read out and decoded, a reproduced video at 5 × speed can be obtained. In such a 5 × speed reproduction, the image data up to the P2 frame is read, and it is not necessary to read the remaining image data below B5, and the hard disk 63 reads the GOP data to be reproduced next.

Therefore, the reading time of the image data can be shortened, and the effect of the shortening is achieved by the MPEG-2 decoder 72.
Also reduces the calculation time. Similarly, when performing 7.5-times speed reproduction, two frames I and P1 are read and decoded, and image data after B3 is read.
A similar operation can be performed by omitting decoding and decoding.

According to the method of the embodiment described above, a video signal obtained by receiving an analog TV broadcast is compressed and coded, or a digital broadcast which is compressed and coded and broadcast is received and supplied. A video signal is obtained as an intra-frame encoded image, a plurality of unidirectional inter-frame encoded images, and a plurality of bidirectional inter-frame encoded images as encoded image units,
In a method of recording a video signal to be recorded on a recording medium that can be randomly accessed together with management data for managing the obtained encoded signal, an arrangement of a predetermined number of inter-frame encoded images from a start position of an intra-frame encoded image is provided. The reproduction of the management data in which the data amount information up to the end part is recorded is obtained, and the intra-frame coded image and the predetermined inter-frame coded image recorded on the recording medium are reproduced based on the obtained information. By reading out and decoding the coded signal, the video read speed is faster than the video signal recorded on the recording medium without unnecessarily increasing the data reading speed of the recording medium and the operation speed of the coded signal decoder. Can be obtained.

According to the configuration of the above embodiment, the video signal obtained by receiving the analog TV broadcast is compression-encoded, or the digital broadcast which is compressed and coded and broadcast is received and supplied. Such as a video signal such as an intra-frame coded image, a plurality of unidirectional inter-frame coded images, and a plurality of bidirectional inter-frame coded images as a coded image unit, and managing the obtained coded signal. In a recording device for a video signal to be recorded on a recording medium that can be randomly accessed together with data, data amount information is recorded from a position where an intra-frame encoded image starts to an end portion where a predetermined number of inter-frame encoded images are arranged. The obtained management data is reproduced to read the intra-frame coded image and the predetermined inter-frame coded image recorded on the recording medium based on the obtained information. By decoding the encoded signal, the speed of reading data from the recording medium and the operation speed of the encoded signal decoder need not be unnecessarily increased. Of the video signal recording device for obtaining the video signal.

The method of reading out and decoding a necessary portion of the coded signal recorded in GOP units to obtain a high-speed playback video has been described above. It is necessary to access the first position of the GOP and read data. Next, a method for accessing the first position of such a GOP will be described.

The first position of the GOP is accessed by obtaining the data of the management information. The management information shown in this example stores the number of frames of the image data constituting the GOP. That is, a normal GOP is composed of images of 15 frames. For example, when a scene signal is applied to a video signal supplied to the MPEG-2 encoder 53,
Since the MPEG-2 encoder 53 reconstructs the GOP, the number of frames of the GOP is less than 15.

As described above, when the number of frames of a GOP changes, the GOP at the correct time position is determined using the aforementioned GOP frame number information recorded as management information.
Can be obtained.

If the information on the number of frames of the GOP cannot be obtained, the information on the total number of images is obtained by decoding all the images of the GOP signal, and the reproduction time information for high-speed reproduction control is obtained from the information on the total number of images. To get
It becomes impossible to perform the reproducing operation in which the reading time and the decoding time as described above are shortened.

As described above, by storing the number-of-frames information in the management information, it is possible to obtain accurate time information of a GOP for performing high-speed reproduction, and to access a cluster area storing data of a target GOP. The high-speed reproduction can be performed while doing so.

The GOP data is recorded in a single cluster. In addition, the GOP data is recorded over two clusters and, in the case of a GOP having a larger data amount, over three clusters.

Next, how to indicate the position of GOP data recorded over such a plurality of clusters will be described. In the example of the video signal recording / reproducing apparatus shown here, G
The OP is recorded in a maximum of three or less clusters, and the position information of the GOP is specified in the cluster area.

The recording position of the GOP is specified by the cluster number and the offset information from the first position of the cluster to the position where the GOP starts in the first cluster where the GOP is recorded. Is continuously recorded in the second cluster, 2
The cluster number of the third cluster is used based on the cluster number of the third cluster when recording is performed consecutively on the third cluster.

When such a GOP is recorded over the second or third cluster, the data of the GOP following the first position of those clusters is recorded. The offset information up to is specified only for the first cluster.

The data to be written in the last cluster in which the data of the GOP is recorded starts from the beginning, and the end position of the data is determined by the GO stored in the management information.
It is determined by the number of bytes of P. Also, GOP data is read at the time of reproduction by reading the data of all frame images of the GOP in the case of normal reproduction or the like as described above in the case of high-speed reproduction.
An operation of reading a bit stream recorded only for a frame, up to a P1 frame, or up to a P2 frame is performed.

[0093] Even when the GOP is divided into a plurality of clusters and recorded, if the clusters are recorded continuously on the disk, the LBA added to each sector is specifically read. (Logical Block Addr
If ess) is continuous, it is possible to perform read processing for a plurality of continuous sectors without performing an access operation for each sector.

FIG. 5 shows the relationship between the cluster number and the sector number. The figure shows the relationship between the cluster number and the sector number when one cluster is composed of 5 sectors. (1) is the sector number assigned to consecutive clusters, and (2) is the consecutive number. It shows the relationship of sector numbers to clusters that do not.

In the access of the cluster structure as in (1), only the cluster 3 can be accessed to read the data of the sectors 11 to 25, but the data recorded in the discontinuous cluster as in (2) is read. Therefore, an access operation to the clusters 3 and 6 is required.

For example, in the case of a hard disk in which one cluster is made up of 256 sectors, one sector has 256 sectors.
It is possible to read data recorded up to the sector by a single read process. When reading data of the same number of sectors, when reading 256 sectors recorded in non-consecutive clusters, for example, the data is divided into 128 sectors and read twice. When reading 256 sectors at a time, the read processing speed can be increased.

FIG. 6 schematically shows a state where GOP data is recorded in the cluster area. In the figure, cluster n
Is from sectors 21 to 25 and cluster n + 1 is from sector 2
6 to 30 and the sectors 23 to 28 are GO
P data is recorded.

Even when GOP data is recorded in a plurality of clusters as described above, the reproduction accesses the cluster n, skips the sectors 21 and 22 indicated by the offset value a, and starts reproduction from the sector 23.

Since the sector 26 is continuous with the sector 25 of the cluster n, it can be reproduced continuously as it is. Conversely, when GOP data is recorded in a discontinuous cluster, there is a method of re-recording the discontinuous GOP data in a continuous cluster to shorten the reproduction time. Is similar to defragmentation in a computer.

In many cases, recording of a bit stream on a hard disk on which recording and erasing are repeated is performed on a discontinuous empty area. In such a case, the recording position is moved independently in cluster units. By doing so, the clusters can be rearranged (defragmentation processing).

The cluster rearrangement process can be performed by changing only the cluster number in the GOP information recorded as the management information at the time of the cluster move process, and the rearrangement process can be easily performed. In the method, the amount of information stored as management information is small.

In this manner, the GOP information and the numerical information for accessing the GOP information are written as arranged data in the management data area, and the written data is read out and recorded on the hard disk at higher speed. G
It is possible to read necessary image information from OP information or GOP information and smoothly perform operations such as high-speed reproduction.

As described above, the management information shown in this embodiment includes the number of bytes of the entire GOP, the number of bytes of the I frame,
Information such as the number of P frames and the number of bytes up to the end position of each P frame is stored. Based on the information, a high-speed reproduction of a video signal recorded in a sector or cluster structure on a hard disk is performed. An example was mentioned.

Next, error processing that occurs when a compression-encoded bit stream is written to a hard disk will be described.

The write error processing is performed by the video signal recording / reproducing apparatus 40 shown in FIG.
An error signal generated when a bit stream is recorded in the bit stream recording area is detected by a circuit built in the hard disk 63 or the hard disk recording / reproducing device 61, and data processing to be performed when the error signal is thus detected About the method.

The error processing that occurs when writing or reading data in a peripheral device of a general computer device is performed by, for example, performing a retry ten times when an error occurs during reproduction of a recorded signal. In many cases, when a normal signal is not obtained even after the retry, an error message is issued and the processing operation is often stopped.

When the retry of the hard disk is repeated, the stream to be recorded cannot be written for a long time (for example, several seconds to ten and several seconds), and data during that time is discarded without being recorded.
Alternatively, since it is not preferable that the reproduction of the stream is stopped for a long time because the stream is not supplied to the decoder, the video signal recording / reproducing apparatus 40 shown in FIG. If the error processing is not completed within a predetermined time, the hard disk outputs error information.

If the retry operation is not restricted, R
An overflow of the EC-FIFO 55 and an underflow state of the buffer memory 71 occur, which undesirably breaks down the recording and reproduction of the bit stream.

[0109] The processing in the case where a so-called write error occurs in which a write signal in the stream area of the hard disk 63 contains error data, will be described below.

Here, the writing of the bit stream to the hard disk 63 is performed in cluster units as described above. When one cluster is composed of 1024 sectors,
Actually, writing is performed by 256 sectors × 4 times, but when an error is detected in one of the four writing processes, all bit streams recorded in one cluster are read. Treated as an error.

This is because the cluster is treated as a logical unit when recording a bit stream, and especially in the case of a hard disk which is frequently used, such cluster write errors are likely to occur.

It is a fatal defect that the recording operation is sometimes terminated in the recording / reproducing apparatus by using such a hard disk which is frequently used, so that a write error may occur during recording. Even in this case, it is preferable to restart the recording by the return process.

FIG. 7 schematically shows a state where a GOP signal is normally recorded in a cluster. The figure shows a state where GOPm to GOPm + 3 are normally recorded in clusters n-1 to n + 1.

FIG. 8 schematically shows how a GOP signal is recorded for a cluster when a write error occurs. FIG. 9 shows a case where a write error occurs at the point of, and how GOP data is handled in response to the write error will be described.

That is, when a write error occurs during the recording of the cluster n + 1, all the GOP data recorded in the area of the cluster n + 1 is treated as an error. In this case, the data of GOPm + 1 to GOPm + 3 is It is determined that an error has occurred, and the GOP information is deleted from the management information temporarily stored in the temporary storage memory.

In this case, REC-FIFO5
5 cannot determine how much data has been transferred to the cluster that caused the error,
At this point, all data of the bit stream temporarily stored in the REC-FIFO 55 is erased, and thereafter, temporary storage of new bit stream data is started.

The process of the signal processing is as follows. 1) The stream analyzer 54 stops the transfer of the bit stream supplied from the MPEG-2 encoder 53 to the REC-FIFO 55 from the beginning of the next GOP.

2) The stream analyzer 54 deletes the supplied data without supplying the bit stream to the REC-FIFO 55 from the beginning of the GOP data following the currently supplied GOP data.

3) After the stream analyzer 54 confirms the start of erasure of the bit stream, the REC-FIFO
The data temporarily stored in 55 is deleted.

4) GO stored in temporary storage memory
The P information is stored as normal until the GOP information recorded in the cluster immediately before the cluster in which the write error occurred, and subsequent GOPs are invalidated.
Erase OP information.

5) A “use prohibited” mark is added to the management information of the cluster in which a write error has occurred, and subsequent recording is prohibited.

6) The stream analyzer 54 checks the following G
The supply of the bit stream to the REC-FIFO 55 is started from the first data of the OP.

7) Writing is started from the next cluster in which a write error has occurred, but the first GOP information at which recording is resumed includes discontinuity indicating "a new and discontinuous GOP starts from here". Add a data flag. By these data processing, the recording operation is restored.

FIG. 9 schematically shows the recording state of GOP data that has been subjected to the data processing accompanying the recovery from the write error. In the figure, GOP of cluster n
m is recorded, the position of the next GOP is vacant, and the stream after the write error recovery has data recorded after GOPq from the first position of cluster r + 1.

Since the discontinuous data flag is added to the management information of GOPq, the reproduction of the bit stream from this GOPq is performed by obtaining the “new, discontinuous GOP starts from here” flag of the GOP information. Then, the decoding process of the discontinuous bit stream is started.

Here, when the discontinuous data flag is not added, this bit stream is a part of which is missing, and it is determined that PTM (pulse time modulation) is discontinuous, and the bit stream is decoded. Since the processing may not be performed normally, this discontinuous data flag is necessary to prevent such abnormal decoding processing.

As described above, when a write error occurs due to a defect or the like in the stream recording area of the hard disk, predetermined signal processing is performed after the data error is detected, and the subsequent recording operation is restarted. As mentioned, the solution was described.

Next, error processing of management information recorded in the management data area will be described. That is, the hard disk 6
Reference numeral 3 denotes a stream area for recording a compression-encoded bit stream and a management data area for recording management information for managing the stream, and these data are recorded in different areas.

In the case of data recorded in the stream area, an error that occurs during reproduction of the bit stream is reproduced by retrying. If the error processing is not completed by retrying for a predetermined time, the error is not processed by the hard disk. Outputs certain information and continues reproduction of the next signal.

This is because, when the bit stream data is reproduced with some errors included therein, the reproduced image is likely to have a block error, and there is little trouble in viewing.

However, in the case of management information recorded in the management data area, if error data is included in the management information, the bit stream cannot be managed, and the related bit stream cannot be reproduced. . Therefore, the read / write of the management data area is to process the error data in the error data processing mode used for a normal computer.

When the operation in the error data processing mode is performed, the read / write of the management data area is performed as usual in the number of retry processes in order to secure sufficient data reliability. An automatic replacement process is also performed.

In the automatic replacement process, recording is performed by designating a recording area in which no data error occurs instead of a recording area in which a data error occurs, and the replacement of the recording area is recorded in an error data management area of the hard disk. The replacement process is automatically performed according to the address information.

Therefore, when a write error occurs during the writing of the management data, the operation mode becomes an error data processing operation mode including the automatic replacement processing, and the processing may require several tens of seconds, and the bit stream cannot be written during that time. .

In the example of the video signal recording / reproducing apparatus 40 shown in FIG. 1, the recording of the bit stream temporarily stored in the REC-FIFO 55 on the hard disk 63 is stopped. Overflow occurs.

As described above, the video signal recording / reproducing apparatus stops the recording operation, but it is preferable that the recording operation is automatically restored at the stage when the automatic replacement process is completed. The automatic return process will be described.

First, when the automatic replacement process is started,
The temporary storage data in the REC-FIFO 55 overflows. However, by detecting the overflow, it is determined that the recording apparatus is not operating normally, and the same processing operation as that when a bit stream write error occurs is performed.

The operation is as follows: from the stream analyzer 54 to the REC-FIFO 55
Of data supplied to the REC-FIFO 55, erasing of data in the stream analyzer 54, erasing of stored data in the REC-FIFO 55, erasing of invalid GOP information, confirmation of completion of the automatic restoration process, restarting and writing of the bit stream to the REC-FIFO 55 The discontinuous data flag is added to the restart GOP information.

As described above, the bit stream that has overflowed and the bit stream that is undergoing the automatic return process are not recorded, but the bit stream that is supplied thereafter is normally recorded.

The video signal supplied during the processing time related to ensuring the reliability of the data recorded in the management data area is not recorded, but the recording after the automatic restoration processing is not performed. Unwanted operations can be avoided.

The above description has been given of the recovery processing of the recording operation accompanying the automatic recovery processing of the write error in the management data area. However, such a recovery processing is performed when the recording operation is stopped due to another cause and after the cause is recovered. It is also used as a recording restart processing method.

Incidentally, it is preferable that the capacity of the hard disk recorded in this way is as large as possible because the recording time can be lengthened. Automatic recovery processing for an error sector area may be performed also in the bit stream recording area, and it is desirable that the area on which the automatic recovery processing is performed be a recordable area.

That is, as described above, if an error occurs during the recording of a bit stream in a cluster, the cluster is set to “use prohibited” and the subsequent signal recording is prohibited. Is, for example, 1024
Even when an error occurs in only one of the sectors, use of the entire cluster is prohibited.

If the hard disk itself performs the automatic replacement of the sector, the bit stream can be recorded in the sector. However, the automatic replacement process may require several tens of seconds, so that the process is not performed during the recording of the bit stream, and the operation is performed during a standby time when the recording and reproducing operations are not performed.

The automatic replacement processing operation is performed, for example, at the time of the automatic check operation of the hard disk performed when the power supply of the apparatus is turned on, for the cluster marked with the use prohibition mark.
Read and write with the automatic replacement function turned on,
If no error is detected, the use prohibition mark is removed, and recording in the cluster area is enabled.

The state in which no error is detected is as follows.
There are cases such as when sectors are automatically replaced inside the hard disk, or when no error was detected during the current read / write inspection.In either case, the cluster or sector for which recording was prohibited in the stream recording area Release the use prohibition state of.

As described above, the automatic replacement process is not executed during the recording / reproduction of the bit stream, but when the power is turned on, or
By performing the automatic replacement process in a standby state in which reproduction is not performed, the recording area of the sector or cluster of the hard disk can be restored, and the recording capacity of the hard disk can be increased.

As described above, the MPEG-
2. A signal recording method for smooth high-speed reproduction, an error processing method for a stream recording area, and an information data management area for a video signal recording / reproducing apparatus that records and reproduces a bit stream obtained by compression encoding in 2. Solutions such as resurrection processing after error processing in
The configuration of the solved device has been described.

A record in which those problems have been solved,
A video signal recording / reproducing device 40 having a reproducing function as an integral unit
There is a method of configuring the video signal recording device including the recording unit 50 and the medium unit 60, and the reproducing unit 70 as a video signal reproducing device.

Further, the video signal recording device and the video signal reproducing device can be installed at different locations, and the devices installed at remote locations can be operated by being connected via a home network or the like.

At this time, the video signal recording device is set as a home server and installed in the home, a video signal reproducing device is connected to the home server via a home network, and the video signal reproducing device is installed in a room where a monitor television is installed. Each is installed as a plurality of set-top boxes.

In this case, the home server is configured as a bit stream transmitting device, and the set-top box is configured as a bit stream receiving terminal. The two are connected by a high-speed wireless LAN or a home LAN, and are connected to a hard disk while performing two-way communication. The video signal information to be recorded is recorded and played back via a set-top box operated by a user according to an operation command from each room, and the supplied video signal is viewed on a monitor TV. To do.

As described above, when the recording device and the reproducing unit as the transmitting terminal and the receiving terminal are installed at remote locations and are operated by being connected by the communication means, a plurality of transmitting terminals and a plurality of receiving terminals are connected. It is also possible to configure a network type video system which is operated by being connected to a network.

Although the recording medium used for the medium unit of the recording apparatus has been described as an example of a hard disk, the recording medium is a medium that can be accessed at high speed, for example, a magneto-optical disk, a RAM type or a RW type DVD, Obviously, the present invention can be applied to an apparatus using a recording medium capable of other random access such as a semiconductor memory type recording medium.

Furthermore, the video signal encoding method is MPEG.
The -2 method has been described as an example, but the compression encoding method is not limited to this, and a method in which intra-frame encoding commonly called motion JPEG is applied and a code amount for each of a plurality of images is set, or MPEG-4 system, MPEG-7
System, MPEG-21 system whose standardization is about to start, and other systems that use fractal compression methods.
When encoding is performed in image units having a plurality of types of compression rates, a video signal recording apparatus to which the above-described technology is applied can be configured.

[0156]

According to the first aspect of the present invention, the reproduction speed of the video signal recorded on the recording medium is increased without increasing the data reading speed of the recording medium and the operation speed of the coded signal decoder more than necessary. There is an effect that a recording method of a video signal capable of obtaining a video can be provided.

Further, according to the second aspect of the present invention, the reproduction speed of the video signal recorded on the recording medium is increased without increasing the data reading speed of the recording medium and the operation speed of the coded signal decoder more than necessary. It is possible to obtain an image and to provide a recording method of an image signal for the image.

Further, according to the third aspect of the present invention, the reproduction speed of the video signal recorded on the recording medium is increased without increasing the data reading speed of the recording medium and the operation speed of the coded signal decoder more than necessary. There is an effect that a configuration of a video signal recording device for obtaining a video can be provided.

According to the fourth aspect of the present invention, the reproduction speed of the video signal recorded on the recording medium is increased without increasing the data reading speed of the recording medium and the operation speed of the coded signal decoder more than necessary. There is an effect that a configuration of a video signal recording device for obtaining a video can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a video signal recording / reproducing apparatus according to an embodiment of the video signal recording apparatus of the present invention.

FIG. 2 is a diagram showing the structure of a frame signal to be encoded by performing motion compensation according to the MPEG-2 system.

FIG. 3 is a diagram illustrating a relationship between a bit stream written to a cluster and a GOP according to the embodiment of the present invention.

FIG. 4 is a diagram showing I and G constituting a GOP according to an embodiment of the present invention;
FIG. 5 is a diagram illustrating a relationship between each frame image of P and B and an amount of image data thereof.

FIG. 5 is a diagram illustrating a relationship between a cluster number and a sector number of a recording area according to the embodiment of the present invention.

FIG. 6 is a diagram showing a state where GOP data is recorded in a cluster area according to the embodiment of the present invention.

FIG. 7 is a diagram illustrating a state in which a GOP signal is normally recorded in a cluster according to an embodiment of the present invention.

FIG. 8 is a diagram showing how a GOP signal is recorded for a cluster when a write error occurs according to an embodiment of the present invention.

FIG. 9 is a diagram showing a recording state of GOP data according to a write error recovery according to the embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 40 video signal recording / reproducing device 50 recording unit 51 TV tuner 52 A / D converter 53 MPEG-2 encoder 54 stream analyzer 55 REC-FIFO 56 header detector 57 microcomputer 58 temporary storage memory 60 medium unit 61 hard disk recording / reproducing device 63 hard disk 65 Write / read controller 70 Playback unit 71 Buffer memory 72 MPEG-2 decoder 73 OSD 74 D / A converter 76 Microcomputer 78 Temporary storage memory 79 Remote control interface 90 Monitor TV 95 Remote control

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C053 FA20 FA23 GB06 GB15 GB29 GB38 HA24 HA33 JA21 KA01 KA24 KA25 LA06 5C059 KK17 MA00 PP05 PP06 PP07 RB08 RB14 RC05 RC28 RF02 RF14 SS02 SS13 SS17 UA05 UA32 5D044 AB07 BC01 DE04 FG24

Claims (4)

[Claims] 1. A video signal to be supplied is obtained as an encoded signal which is an intra-frame encoded image and a plurality of inter-frame encoded images as encoded image units, and together with management data for managing the obtained encoded signal. A method for recording a video signal to be recorded on a randomly accessible recording medium, comprising: a first step of obtaining data amount information from the beginning of the encoded image unit to an end portion where an intra-frame encoded image is arranged; A second step of obtaining the management data including the data amount information obtained in step 1, a third step of recording the management data obtained in the second step in a predetermined area of the recording medium, A method for recording a video signal, comprising at least: 2. A video signal to be supplied is obtained as an encoded signal including an intra-frame encoded image, a plurality of unidirectional inter-frame encoded images, and a plurality of bidirectional inter-frame encoded images as encoded image units, In a method of recording a video signal to be recorded on a recording medium that can be randomly accessed together with management data for managing the obtained encoded signal, the unidirectional interframe code arranged at a predetermined number from the beginning of the encoded image unit A first step of obtaining data amount information up to the end of the coded image, a second step of obtaining the management data including the data amount information obtained by the first step, and a second step of obtaining the management data including the data amount information obtained by the first step. A third step of recording the management data obtained in a predetermined area of the recording medium. 3. A video signal to be supplied is obtained as an encoded signal including an intra-frame encoded image and a plurality of inter-frame encoded images as encoded image units, together with management data for managing the obtained encoded signal. A video signal recording apparatus for recording on a randomly accessible recording medium, comprising: header detecting means for obtaining data amount information from the beginning of the encoded image unit to an end portion in which an intra-frame encoded image is arranged; Management data generation means for generating the management data including the data amount information obtained by the above, and management data recording means for recording the management data generated by the management data generation means in a predetermined area of the recording medium. A video signal recording device characterized by comprising: 4. A video signal to be supplied is obtained as an encoded signal including an intra-frame encoded image, a plurality of unidirectional inter-frame encoded images, and a plurality of bidirectional inter-frame encoded images as encoded image units, In a video signal recording device that records the obtained encoded signal on a recording medium that can be randomly accessed together with management data for managing the encoded signal, the unidirectional inter-frame encoding arranged at a predetermined number from the beginning of the encoded image unit Header detection means for obtaining data amount information up to the end of the image; management data generation means for generating the management data including data amount information obtained by the header detection means; And a management data recording means for recording management data in a predetermined area of the recording medium.