JP2005260988A - Optical disk reproducing method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and quickly specify a position where a certain encoding unit is recorded, at a desired point of time and to shorten the time required for reproducing an image signal. <P>SOLUTION: Order table information containing starting positions of sequences is read together with GOP table information containing time information and position information of a GOP for the GOP. In the case of reproduction from a desired point of time, position information corresponding to the desired point of time is identified by referring to the read GOP table information, and the reproduction from the desired point of time is performed according to the identified position information and the read order table information. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image signal recording method and an image signal recording apparatus for encoding and recording an image signal on a disk medium such as an optical disk, and an image signal reproducing method for reproducing an image signal from the disk medium encoded and recorded on the image signal. The present invention also relates to an image signal reproducing apparatus and an image signal recording disk medium.

  As the encoding technology for compressing digital image signals advances, the compressed image signals are recorded on an optical disk, so that searchability and operability are superior compared to conventional tape media such as VTRs. An optical disk device can be realized. Since such an optical disc apparatus is recorded as a digital signal, there is no deterioration due to dubbing compared to the case of recording an analog image signal, and since it is optical recording / reproduction, it is non-contact and excellent in reliability.

  On the other hand, as an encoding method for compressing data of the digital image signal as described above, for example, there is an MPEG (Moving Picture Coding Experts Group) method that is currently being standardized. FIG. 7 shows a simplified configuration of data encoded by an MPEG image signal encoding method having a layer structure.

  In the figure, 100 is a sequence layer composed of GOP (Group of Pictures) which is a unit of encoding of image signals of a plurality of screens and a sequence header specifying an image format, and 101 is a plurality of screens. GOP layer composed of (pictures), 102 is a picture layer composed of a plurality of slices obtained by dividing one screen, 103 is a slice layer composed of a plurality of macroblocks obtained by dividing one slice, and 104 is luminance A macroblock layer composed of 4 blocks of signal (Y), 1 block of color difference signal (RY) and 1 block of color difference signal (BY), 105 is a block composed of 8 pixels × 8 pixels -It is a layer. The encoded data is output as a bit stream (serialized serial data) having the above structure.

  The sequence layer 100 has a structure as shown in FIG. In the figure, 5a, 5b, 5c and 5d are GOPs, and 6a, 6b and 6d are sequence headers (SH). This sequence header is provided for designating an image format such as the number of pixels and the number of lines of an image, and can be added to the head of all GOPs. In the figure, GOP1, GOP2, and GOP4 indicate GOPs with a sequence header added to the head thereof, and GOP3 indicates a GOP without a sequence header. Furthermore, data representing the time since the start of the sequence (title, program) (hereinafter referred to as a time code) is provided at the head of the GOP of each GOP layer.

  Further, GOP (Group of Picture), which is a coding unit in which image signals of a plurality of screens in the MPEG standard are grouped, has a structure as shown in FIG. This figure shows a case where, for example, 10 screens are set to 1 GOP, an image signal of one GOP is generated without using inter-frame prediction, an intra-frame coding screen 107 (hereinafter abbreviated as I picture), Interframe forward prediction encoding screen 108 (hereinafter abbreviated as P picture) generated using forward (previous) interframe prediction based on an I picture or P picture that is temporally previous (past), and time Each signal of bidirectional predictive coding screen 109 (hereinafter abbreviated as B picture) generated using bi-directional prediction using I pictures or P pictures positioned before and after (past and future) as reference screens Consists of. Then, such a structure in which several types of screens (pictures) are combined is recorded in the disc.

  The I picture (plane), P picture (plane), and B picture (plane) constituting the GOP have the following properties. That is, since the I picture 107 is generated by performing DCT (Discrete Cosine Transform), it is possible to reproduce an image without referring to other pictures on this screen alone. , P picture 108 is encoded by performing motion compensation with reference to the screen in the forward direction. Therefore, the picture cannot be reproduced unless the I picture 107 is reproduced. Since 109 is a prediction screen from both directions, an image cannot be reproduced unless the preceding and following I picture 107 or P picture 108 is reproduced.

  Therefore, the P picture and the B picture encoded with reference to other pictures are closed within one GOP as shown by arrows in FIG. 9, that is, the reference screen of the P picture and the B picture is changed to the GOP. If encoding is performed so as to refer to the screen in the image, an image signal of one GOP can be decoded and reproduced by itself.

On the other hand, the B picture 109 encoded by performing prediction in both directions has the smallest amount of data and good encoding efficiency. On the other hand, the B picture 109 cannot be reproduced independently, and the I picture 107 or the P picture Therefore, if the number of B pictures 109 is increased, the amount of buffer memory required for processing increases, and the delay time associated with encoding and decoding increases.
However, in storage media represented by optical disks and the like, an encoding method with high compression efficiency is desired for long-time recording, and the delay time of image reproduction is not a problem. A suitable encoding method is suitable.

  Further, when a digital image signal is recorded on a recording medium such as an optical disk by a data compression encoding method according to the MPEG system, as shown in FIG. 10A, in order to keep the image quality between GOPs constant, each GOP In order to keep the recording time of each GOP constant as shown in FIG. 10 (b), as shown in FIG. A method of recording each GOP at a fixed data rate is considered as a fixed data amount.

  The former method is advantageous over the latter method in that the recording density on the disc can be increased, and the latter method is desirable from the start point of the image of one sequence (title, program). This is advantageous over the former method in that it is easy to predict the recording position of the image data when searching for and reproducing the image signal at the point of time.

  In the former method, the data amount per GOP is, for example, GOP as shown in FIG. 11 (a) ((α) in the figure represents the maximum value of the data rate and (β) represents the average data rate). It changes with time according to the nature of the screen that composes. For example, in three types of images (A), (B), and (C), the image quality per GOP (here, the image S / N after decoding) and the data amount are shown in FIG. Therefore, in the former method, the image quality can be kept constant by making the data amount per GOP of each image variable.

As a disc playback apparatus that employs the MPEG image signal encoding method, for example, there is a video CD (Compact Disc) player. FIG. 12 shows an outline of the track structure in the video CD and the data structure of the user area of one sector in the track. A margin for a predetermined sector is provided before and after each track, and each other sector is set as one MPEG data transmission unit (one pack). Time stamp data, which is data representing the time from the start of the sequence (title, program) to be recorded, is recorded at the front of one pack of image data.
Also, an image signal encoded by the MPEG system is recorded by using a method in which each GOP is recorded with a fixed data rate, that is, each GOP is recorded at a fixed data rate as described above.

  Further, in a video CD, the image signal and audio signal of one entire sequence (title, program) to be recorded are handled as one data file, and the GOP constituting the data file is as shown in FIG. The data is sequentially recorded in continuous sectors on the disk as continuous data. Also, file management data (not shown) such as file identification data and file start sector address is recorded on the track located at the head of the disk, and access to a file consisting of an image signal and audio signal of a desired title is as follows: This is performed based on the file management data.

When an image signal of a desired sequence (title, program) is reproduced, the start sector address of the file recorded by the file management data is determined by the start sector address of the data file corresponding to the sequence. The subsequent sectors are sequentially accessed to reproduce the image signal.
In general, data on a recording medium such as a disk is physically recorded in a recording unit called a sector, and data is recorded (written) and reproduced (read) using this sector as an access unit.

  Next, when a GOP in the middle of a certain sequence (title, program) is reproduced, a sector in the middle of a continuous sector in which the data file is recorded is accessed first. However, as shown in FIG. 12, since the GOP data in the pack of each sector is recorded as continuous data, the GOP data read first is from the middle of the GOP, Other parts that are divided and recorded are read as missing.

  Therefore, since the GOP read out first lacks the reference screen data of the P picture and B picture when it is encoded, only an unnatural image is reproduced even if it is decoded. Do not play as.

  Furthermore, when a GOP that is in the middle of a sequence (title, program) and is reproduced at a desired time from the start point of the sequence, first, based on the fixed data rate of the recorded image signal, etc. The sector address where the target GOP is recorded is predicted. Next, the sector corresponding to the predicted sector address is accessed, the signal recorded in the sector is read, and the time stamp data is detected therefrom. Then, by comparing the detected time stamp data with the desired time point, the sector in which the target GOP is recorded is identified. Further, the GOP is sequentially read from the first GOP recorded in the sector, the time code at the head of the GOP is detected, and when the time code is a desired time point, the GOP is the target GOP. It is specified that the GOP is decoded, and a reproduced image is obtained.

  When playing back a GOP that is in the middle of a sequence (title, program) in a device that plays back an image signal from a conventional optical disk or the like as described above, a part of the first read from the sector that was accessed first is missing. Even if the GOP is decoded and output, it becomes an unnatural image and is not reproduced as an unnecessary one. Therefore, there is a delay until the image signal is reproduced and output.

  In addition, when a conventional recording method is applied to a re-recordable (appendable) medium and editing such as rewriting in GOP units or splicing is performed, image signals are continuously recorded in a recording area in the sector. Therefore, when the GOP to be rewritten is in the middle of a sector, if the entire sector is rewritten, the rear part of the GOP before the GOP to be edited is lost, and when the editing point (editing seam) is reproduced, the GOP Cannot be reproduced and the image is lost. Even if it is forcibly reproduced, only an unnatural image is reproduced.

  Furthermore, when recording is performed by applying the conventional recording method to a re-recordable (appendable) medium, the entire sequence is handled as one file and recorded in consecutive sectors on the disk. At the time of playback, since the position on the disk where the file is recorded can be identified only by the start sector address which is the management data of the file, it is not possible to record / play back to the empty sector caused by repeated erasing and recording. The recording area cannot be used effectively.

  In addition, when a GOP that is in the middle of a sequence (title, program) is played back, particularly when a GOP at a desired time from the start point of the sequence is played back, the target GOP is recorded. The target GOP is recorded by predicting the sector address of a sector based on the data rate of the image signal and comparing the time stamp data representing the time recorded in the sector with the desired time point. It is necessary to perform complicated processing such as identifying the sector being read and identifying the target GOP by comparing the time code at the head of the GOP read sequentially from the sector with the desired time point. The sector in which the GOP at the desired time point is recorded cannot be immediately identified, and a delay occurs until the image signal is reproduced. Furthermore, when the image signal of each GOP is recorded at a variable data rate, the time from the start of the sequence and the recorded position are not in a proportional relationship, so the sector in which the GOP at the desired time is recorded Therefore, it becomes more difficult to immediately specify the sector in which the GOP at the desired time is recorded, and further delay occurs until the image signal is reproduced.

  The present invention has been made to solve the above-described problems, and a first object is to provide a coding unit such as the GOP in the middle of the entire image signal such as the sequence (title, program). Image signal recording method, image signal recording apparatus, image signal reproducing method, image signal reproducing apparatus, and image signal recording disk capable of reducing the time required to reproduce and output an image signal A medium is obtained.

  The second object is to provide an image signal recording method and an image signal that can be easily edited such as rewriting in a coding unit and joining shots, and can be reproduced without loss of a reproduced image even when the edited point is reproduced. A recording apparatus, an image signal reproducing method and an image signal reproducing apparatus, and an image signal recording disk medium are obtained.

  A third object is to provide an image signal recording method, an image signal recording apparatus, an image signal reproducing method, an image signal reproducing apparatus, and an image signal recording capable of recording and reproducing effectively using empty sectors distributed on a disk medium. A disk medium is obtained.

  The fourth purpose is to reproduce a coding unit such as the GOP in the middle of the entire image signal such as the sequence (title, program), and particularly from the start point of the sequence to a desired time point. When reproducing from a certain coding unit, the position where the coding unit at the desired time point is recorded can be easily and immediately specified, and the time required to reproduce the image signal can be shortened. An image signal recording method, an image signal recording device, an image signal reproducing method, an image signal reproducing device, and an image signal recording disk medium are obtained.

  According to the first aspect of the present invention, there is provided an I picture compressed in a frame, a P picture compressed by adding motion compensation with a temporally forward I picture, and an temporally forward or backward I picture or An optical disc on which digital image information composed of GOPs including a B picture compressed by motion compensation by a P picture is recorded in a recording unit, and includes an order table including a start position of a sequence constituting the digital image information Information and GOP table information including time information and position information of the GOP for the GOP are recorded as separate table information, and the position information of the GOP table information is a sequence at the head of the GOP. The position of the recording unit including the earliest position of the header, wherein the sequence is the GOP data A method of playing back an optical disk including the read-out order table information, read out the GOP table information, and when playing back from a desired time point, refer to the read-out GOP table information and An optical disc playback method characterized in that position information corresponding to a desired time point is identified, and playback is performed from the identified position information and the read order table information from the desired time point. .

  The present invention also provides a data file generated for each encoded data obtained by dividing an image signal into encoding units for a predetermined number of images and encoding each of the encoding units independently from the start of the file. An image signal recording disk medium comprising data table information in which time, file size in each file, and file name of each file are associated with each other.

  In the image signal recording method according to the present invention, a data file is generated for each encoded data of the encoding unit, and the data file is recorded from the head portion of the sector which is the access unit of the disk medium. Is.

  In the image signal recording method according to the present invention, information indicating the reproduction order of the data file is further recorded in a predetermined sector area of the disk medium.

  In the image signal recording apparatus according to the present invention, a data file generating unit that generates a data file for each encoded data in an encoding unit, and a data recording unit that records data in a sector that is an access unit of a disk medium; And a recording control means for controlling the data recording means so as to record the data file from the head portion of the sector.

  The image signal recording apparatus according to the present invention further comprises reproduction order information generating means for generating information indicating the reproduction order of the data file.

  In the image signal reproduction method according to the present invention, data is read from a sector group in which a data file generated from encoded data of an encoding unit located in the middle of the entire image signal is recorded, and the first of the sector groups is read out. The encoded unit encoded from the head of the encoded data read out from the sector recorded in is restored, and the encoded data of the restored encoded unit is decoded and output.

  In the image signal reproducing apparatus according to the present invention, the data reading means for reading data from the sector, and the reading for generating the sector address of the sector to be accessed and controlling the data reading means to read the data from the sector at the sector address Control means and coding unit restoring means for restoring coding units from the coded data read by the data reading means are provided.

  In the image signal reproduction method according to the present invention, information indicating the reproduction order of the data file is detected from the signal read from the predetermined sector area, and based on the detected information indicating the reproduction order of the data file. The data file is read from the disk medium, and the encoded data of the encoding unit included in the read data file is decoded to reproduce the image signal.

  In the image signal reproducing apparatus according to the present invention, the data reading means for reading data from the sector, and the reading for generating the sector address of the sector to be accessed and controlling the data reading means to read the data from the sector at the sector address A control means; a reproduction order information detecting means for detecting information indicating the reproduction order of the data file from the data read by the reading means; and a code of a coding unit included in the data file read by the reading means. And decryption means for decrypting the encrypted data.

  In the image signal recording method according to the present invention, a data file is generated for each encoded data of the encoding unit, and the position of the entire image signal and the position recorded on the disk medium are represented by data corresponding to the encoding unit. Data file identification information shown for each file is generated, and the data file and the data file identification information are recorded in predetermined sector areas of the disk medium.

  In the image signal recording apparatus according to the present invention, the data file generating means for generating a data file for each encoded data of the encoding unit, and the position relative to the entire image signal and the position recorded on the disk medium are encoded. Data file identification information generating means for generating data file identification information shown for each data file corresponding to the unit, data recording means for recording data in a sector which is an access unit of the disk medium, data file and data A recording control means for controlling the data recording means so as to record the file identification information in each predetermined sector area of the disk medium.

  In the image signal reproducing method according to the present invention, a position identification signal indicating the position of the entire encoding unit image signal to be reproduced is input, and data file identification information is obtained from a signal read from a predetermined sector area of the disk medium. Based on the detected data file identification information, the position where the data file corresponding to the encoding unit at the position indicated by the position identification signal is recorded on the disk medium is identified and identified. A data file is read based on the read position on the disk medium, and a signal encoded by a coding unit included in the read data file is decoded to reproduce an image signal. .

  In the image signal reproduction apparatus according to the present invention, a position identification signal input means for inputting a position identification signal indicating the position of the entire encoding unit image signal to be reproduced, a data reading means for reading data from a sector of the disk medium, A read control unit that generates a sector address of a sector to be accessed and controls the data read unit to read data from the sector at the sector address, and data file identification information from the data read by the data read unit A data file identification information detecting means for detecting, a recording sector identifying means for identifying a sector in which the data file is recorded on the disk medium based on the data file identification information, and a read data file Decode the signal encoded in the included encoding unit It is obtained by a decoding means for reproducing a signal.

  In the image signal recording disk medium according to the present invention, there is a data data file generated for each encoded data obtained by dividing an image signal into encoding units for a predetermined number of images and independently encoding each encoding unit. , Recorded from the head of the sector which is an access unit.

  In the image signal recording disk medium according to the present invention, information indicating the reproduction order of the data file is further recorded in a predetermined sector area.

  In the image signal recording disk medium according to the present invention, a data file including a signal obtained by encoding an encoding unit consisting of a predetermined number of image signals, a position with respect to the entire image signal, and a position recorded on the disk medium Is recorded in a predetermined sector area of the disk medium, for each data file corresponding to the encoding unit.

  Since this invention is comprised as mentioned above, there exists an effect as shown below.

  According to the first aspect of the present invention, it is possible to easily and immediately specify the position where the encoding unit at the desired time point is recorded, and to shorten the time required to reproduce the image signal. it can.

  In the present invention, a data file is generated for each encoded data of the encoding unit, and the data file is recorded from the head portion of the sector which is an access unit of the disk medium. When reproducing the image signal of the coding unit located in the middle of the whole, the coded data of the coding unit read from the sector accessed first is not lost, and the coding unit recorded at the head of the sector is not lost. The encoded data can be decoded and output, so that the time required to reproduce and output the image signal can be shortened. In addition, when editing such as rewriting and joining shots in coding units, it is possible to prevent loss of encoded data in the coding unit before the editing point. For this reason, rewriting and joining in coding units are possible. Editing such as shooting can be easily performed, and even if the edited point is reproduced, the reproduced image can be reproduced without being lost.

  Further, since the information indicating the reproduction order of the data file is recorded in a predetermined sector area of the disk medium, the information indicating the reproduction order of the data file is detected during reproduction, and the data The data file can be read out and the image signal can be reproduced in accordance with the reproduction order of the file. Therefore, recording and reproduction can be performed by effectively utilizing the empty sectors distributed on the disk medium.

  In addition, a data file is generated for each encoded data of the encoding unit, and the data file is recorded from the head portion of the sector which is an access unit of the disk medium. When reproducing the image signal of the encoding unit that is located, the encoded data of the encoding unit read from the sector accessed first is not lost, and the encoded data of the encoding unit recorded at the head of the sector is not lost. Decoding and outputting can be performed, so that the time required to reproduce and output an image signal can be shortened. In addition, when editing such as rewriting and joining shots in coding units, it is possible to prevent loss of encoded data in the coding unit before the editing point. For this reason, rewriting and joining in coding units are possible. Editing such as shooting can be easily performed, and even if the edited point is reproduced, the reproduced image can be reproduced without being lost.

  Further, since the information indicating the reproduction order of the data file is recorded in a predetermined sector area of the disk medium, the information indicating the reproduction order of the data file is detected during reproduction, and the data The data file can be read out and the image signal can be reproduced in accordance with the reproduction order of the file. Therefore, recording and reproduction can be performed by effectively utilizing the empty sectors distributed on the disk medium.

  Also, from the head of the encoded data read from the first recorded sector of the sector group in which the data file generated from the encoded data of the encoding unit located in the middle of the entire image signal is recorded. Since the encoded unit is restored and the encoded data is decoded and output, the encoded data is lost even when the encoded unit located in the middle of the entire image signal is reproduced. It is possible to output as a reproduced image from the encoded data read from the first recorded sector, thereby reducing the time required to reproduce and output the image signal. can do. In addition, when editing such as rewriting and joining shots in coding units, it is possible to prevent loss of encoded data in the coding unit before the editing point. For this reason, rewriting and joining in coding units are possible. Editing such as shooting can be easily performed, and even if the edited point is reproduced, the reproduced image can be reproduced without being lost.

  In addition, when reproducing an image signal of a coding unit located in the middle of the entire image signal, the read control means reads the sector address where the data file including the coding unit located in the middle of the whole image signal is recorded. The encoding unit decoding means generates a head of encoded data read by the reading means from the sector in which the data file is first recorded among the sector groups corresponding to the sector address group. Since the encoding unit is restored, it is not necessary to consider the lack of encoded data even when reproducing the encoding unit located in the middle of the entire image signal. It is possible to output a reproduced image from the encoded data that has been output, and this shortens the time required to reproduce and output the image signal. Can. In addition, when editing such as rewriting and joining shots in coding units, it is possible to prevent loss of encoded data in the coding unit before the editing point. For this reason, rewriting and joining in coding units are possible. Editing such as shooting can be easily performed, and even if the edited point is reproduced, the reproduced image can be reproduced without being lost.

  Further, the data file is read from the disk medium based on the information indicating the reproduction order of the data file detected from the signal read from the predetermined sector area, and is included in the read data file. Since the encoded data of the above encoding unit is decoded and the image signal is reproduced, the image signal recorded in the sectors distributed on the disk medium can also be reproduced. It is possible to record / reproduce by effectively utilizing the distributed empty sectors.

  The read control means generates a sector address of a predetermined sector area in which information indicating the reproduction order of the data file is recorded at the start of reproduction, and is read from the data read by the data read means After the playback order information is detected from the data by the playback order information detecting means, the sector address is generated based on the playback order information, so that the image signal recorded in the sectors distributed on the disk medium is also played back. For this reason, it is possible to record / reproduce by effectively using the empty sectors distributed on the disk medium.

  Also, data file identification information indicating the position of the entire image signal and the position recorded on the disk medium for each data file corresponding to the encoding unit is recorded in a predetermined sector area of the disk medium. Therefore, when reproducing an image signal of an encoding unit located in the middle of the entire image signal, the position on the disc medium on which the target encoding unit is recorded can be easily detected by detecting the data file identification information. Moreover, it can be identified immediately, and therefore the time required to reproduce the image signal can be shortened.

  Also, data file identification information indicating the position of the entire image signal and the position recorded on the disk medium for each data file corresponding to the encoding unit is recorded in a predetermined sector area of the disk medium. Therefore, when reproducing an image signal of an encoding unit located in the middle of the entire image signal, the position on the disc medium on which the target encoding unit is recorded can be easily detected by detecting the data file identification information. Moreover, it can be identified immediately, and therefore the time required to reproduce the image signal can be shortened.

  Further, the data file identification information is detected from a signal read from a predetermined sector area, and the encoding at the position indicated by the position identification signal is based on the detected data file identification information. The position where the data file corresponding to the unit is recorded on the disk medium is identified, the data file is read based on the identified position on the disk medium, and the read data file is read Since the image signal is reproduced by decoding the signal encoded in the above encoding unit included in the image, the position where the encoding unit at the desired time point is recorded can be easily and immediately specified. For this reason, the time required to reproduce the image signal can be shortened.

  Further, when reproducing the image signal of the coding unit located in the middle of the whole image signal, the recording sector identification means is the coding unit at the position indicated by the position identification signal input by the position identification signal input means. The read control means records the data file corresponding to the coding unit at the position indicated by the position identification signal identified by the recording sector identification means. Since the sector address is generated based on the sector being recorded, it is possible to easily and immediately specify the position where the encoding unit at the desired time is recorded. The time required for reproduction can be reduced.

  In addition, since the data data file is recorded from the head part of the sector which is the access unit, when the image signal of the encoding unit located in the middle of the entire image signal is reproduced from the disk medium, it is accessed first. The encoded data of the encoding unit read from the sector is not lost, and can be decoded and output from the encoded data of the encoding unit recorded at the head of the sector. Therefore, until the image signal is reproduced and output Can be shortened. In addition, when editing such as rewriting and joining shots in coding units, it is possible to prevent loss of encoded data in the coding unit before the editing point. For this reason, rewriting and joining in coding units are possible. Editing such as shooting can be easily performed, and even if the edited point is reproduced, the reproduced image can be reproduced without being lost.

  Further, since the information indicating the reproduction order of the data file is recorded in a predetermined sector area, the information indicating the reproduction order of the data file is detected at the time of reproduction, and according to the reproduction order of the data file indicated by the information. A data file can be read and an image signal can be reproduced. For this reason, it is possible to record and reproduce by effectively utilizing empty sectors distributed on a disk medium.

  Further, since the data file identification information indicating the position relative to the entire image signal and the position recorded on the disk medium for each data file corresponding to the encoding unit is recorded in a predetermined sector area of the disk medium, Thus, when reproducing an image signal of an encoding unit located in the middle of the entire image signal, the position on the disk medium on which the target encoding unit is recorded can be easily detected by detecting the data file identification information. Moreover, it can be identified immediately, and therefore the time required to reproduce the image signal can be shortened.

  According to the first aspect of the present invention, when reading the order table information, reading the GOP table information, and reproducing from a desired time point, the position information corresponding to the desired time point is referred to by referring to the read GOP table information. And the reproduction from the desired time point is performed from the identified position information and the read order table information.

  In the image signal recording method, the data file generated for each encoded data in the encoding unit is recorded from the head portion of the sector. As a result, when the image signal of the encoding unit located in the middle of the entire image signal is reproduced from the disk medium, the encoded data of the encoding unit read from the sector accessed first is not lost, and the start of the sector It is possible to decode and output from the encoded data of the encoding unit recorded in. In addition, when editing such as rewriting and joining shots is performed in coding units, it is possible to prevent missing coded data in the coding unit before the editing point.

  In the image signal recording method, information indicating the data file reproduction order is recorded in a predetermined sector area of the disk medium. As a result, information indicating the reproduction order of the data file can be detected during reproduction, and the data file can be read and the image signal can be reproduced in accordance with the reproduction order of the data file indicated by the data file.

  In the image signal recording apparatus, the data file generated for each encoded data of the encoding unit is recorded from the head portion of the sector. As a result, when the image signal of the encoding unit located in the middle of the entire image signal is reproduced from the disk medium, the encoded data of the encoding unit read from the sector accessed first is not lost, and the start of the sector It is possible to decode and output from the encoded data of the encoding unit recorded in. In addition, when editing such as rewriting and joining shots is performed in coding units, it is possible to prevent missing coded data in the coding unit before the editing point.

  In the image signal recording method, information indicating the data file reproduction order is recorded in a predetermined sector area of the disk medium. As a result, information indicating the reproduction order of the data file can be detected during reproduction, and the data file can be read and the image signal can be reproduced in accordance with the reproduction order of the data file indicated by the data file.

  In the image signal reproducing method, the data file generated from the encoded data of the encoding unit located in the middle of the entire image signal is read from the first recorded sector among the recorded sector group. The encoding unit encoded from the beginning of the encoded data is restored, and the encoded data is decoded and output. As a result, even when a coding unit located in the middle of the entire image signal is reproduced, it is not necessary to consider the lack of coded data, and a reproduced image is obtained from the coded data read from the first recorded sector. It is possible to output as

  In the above image signal reproducing apparatus, when reproducing an image signal of an encoding unit located in the middle of the entire image signal, the read control means reads the data file including the encoding unit located in the middle of the entire image signal. A recorded sector address group is generated, and the encoding unit decoding means is read by the reading means from the sector where the data file is first recorded among the sector groups corresponding to the sector address group. The encoding unit is restored from the beginning of the encoded data. As a result, even when a coding unit located in the middle of the entire image signal is reproduced, it is not necessary to consider the lack of coded data, and a reproduced image is obtained from the coded data read from the first recorded sector. It is possible to output as

  In the image signal recording method, the data file is read and read from the disk medium based on information indicating the reproduction order of the data file detected from a signal read from a predetermined sector area. The encoded data of the encoding unit included in the data file is decoded to reproduce an image signal. As a result, it is also possible to reproduce image signals recorded in sectors distributed on the disk medium.

  In the image signal reproducing apparatus, the read control means generates a sector address of a predetermined sector area in which information indicating the reproduction order of the data file is recorded at the start of reproduction, and is read by the data read means After the reproduction order information is detected by the reproduction order information detecting means from the data read from the data, a sector address is generated based on the reproduction order information. As a result, it is also possible to reproduce image signals recorded in sectors distributed on the disk medium.

  In the image signal recording method, data file identification information indicating the position of the entire image signal and the position recorded on the disk medium for each data file corresponding to the encoding unit is stored in a predetermined sector area of the disk medium. To record. Thus, when reproducing an image signal of an encoding unit located in the middle of the entire image signal, the position on the disk medium on which the target encoding unit is recorded can be easily detected by detecting the data file identification information. Moreover, it becomes possible to identify immediately.

  In the image signal recording apparatus, data file identification information indicating the position of the entire image signal and the position recorded on the disk medium for each data file corresponding to the encoding unit is stored in a predetermined sector area of the disk medium. To record. Thus, when reproducing an image signal of an encoding unit located in the middle of the entire image signal, the position on the disk medium on which the target encoding unit is recorded can be easily detected by detecting the data file identification information. Moreover, it becomes possible to identify immediately.

  In the image signal reproducing method, the data / file identification information is detected from a signal read from a predetermined sector area, and is indicated by the position identification signal based on the detected data / file identification information. The position where the data file corresponding to the coding unit at the position is recorded on the disk medium is identified, and the data file is read and read based on the identified position on the disk medium. Then, the image signal is reproduced by decoding the signal encoded in the encoding unit included in the data file. As a result, it is possible to easily identify and reproduce the position where the coding unit at the desired time is recorded.

  In the above image signal reproducing apparatus, when reproducing an image signal of a coding unit located in the middle of the entire image signal, the recording sector identifying means is a position indicated by the position identification signal input by the position identification signal input means. The sector in which the data file corresponding to the above encoding unit is recorded is identified, and the read control means corresponds to the encoding unit at the position indicated by the position identification signal identified by the recording sector identification means. A sector address is generated based on the sector in which the recorded data file is recorded. As a result, it is possible to easily identify and reproduce the position where the coding unit at the desired time is recorded.

  In the image signal recording disk medium, the data data file is recorded from the head portion of the sector which is an access unit. As a result, when the image signal of the encoding unit located in the middle of the entire image signal is reproduced from the disk medium, the encoded data of the encoding unit read from the sector accessed first is not lost, and the start of the sector Can be decoded and output from the encoded data of the encoding unit recorded in the. In addition, when editing such as rewriting or joining shot is performed in coding units, it is possible to prevent loss of coded data of the coding unit before the editing point.

  In the image signal recording disk medium, information indicating the reproduction order of the data file is recorded in a predetermined sector area. As a result, information indicating the reproduction order of the data file can be detected during reproduction, and the data file can be read and the image signal can be reproduced in accordance with the reproduction order of the data file indicated by the data file.

  In the image signal recording disk medium, the data file identification information indicating the position of the entire image signal and the position recorded on the disk medium for each data file corresponding to the encoding unit is a predetermined sector of the disk medium. Recorded in the area. Thus, when reproducing an image signal of an encoding unit located in the middle of the entire image signal, the position on the disk medium on which the target encoding unit is recorded can be easily detected by detecting the data file identification information. Moreover, it becomes possible to identify immediately.

Example 1.
An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of an optical disk recording / reproducing apparatus in the present embodiment, and FIG. 2 is a sector map diagram showing data arrangement of the optical disk in the present embodiment.
In FIG. 1, 1 is an A / D converter, 2 is encoding means, 3 is GOP file generation means, 4 is GOP information detection means, 5 is GOP file order table (GST) data generation means, and 6 is GOP information table. Data generation means, 7 write control means, 8 data block construction means, 9 modulator, 10 laser drive circuit, 11 optical head control means, 12 optical head, 13 optical disk, and 14 sequence identification signal Input means, 15 time position identification signal input means, 16 reproduction amplifier, 17 demodulator, 18 error correction means, 19 GOP file order table (GST) data detection means, 20 GOP information table / data detection means , 21 is a read control means, 22 is a GOP continuation means, 23 is a decoding means, and 24 is a D / A converter.

  In FIG. 2, 31 is a boot sector for storing a boot code, 32 is a GOP file order table (hereinafter referred to as GST) area for storing GOP file arrangement information to be described later, 33 is a GOP information area, 34 Is the user area.

  In this embodiment, it is assumed that the sector addresses are arranged in ascending order from the inner periphery of the disk, and in particular, an image signal compressed and encoded by the MPEG system is recorded on the optical disk. Further, in the image data encoding method according to the MPEG method, it is not always necessary to attach a sequence header to the front part of the GOP, but here, it is assumed that the GOP3 does not have a sequence header. Further, each GOP is recorded at the variable data rate as described above. Moreover, the same code | symbol in a figure shows the same or an equivalent part.

  Next, the operation during recording in the present embodiment will be described. First, the input image signal is input to the A / D converter 1 and converted into a digital image signal, and then encoded by the encoding means 2 according to the MPEG system and subjected to data compression. As described above, an image signal encoded by the MPEG method is encoded using a GOP composed of a predetermined number of image signals as an encoding unit. The encoded image signal is input to the GOP file generation unit 3. Here, the encoded image signal has the layer structure shown in FIG. 7 as described above. As shown in FIG. 8, the sequence layer, which is the uppermost layer, is composed of GOPs (which may or may not have SH at the front as described above), and each GOP has its head portion. Includes a GOP start code (not shown).

  Therefore, the GOP file generation means 3 detects the GOP start code included in each GOP and separates each GOP accordingly. Further, the sequence start code in the SH of each GOP is detected. Then, a GOP file that is one data file is generated by one separated GOP. The GOP file is input to the data block configuration unit 8 and also input to the GOP information detection unit 4. The GOP file generation means 3 generates a GOP start timing signal based on the detected GOP start code and inputs it to the write control means 7.

  On the other hand, the sequence identification signal is input from the sequence identification signal input means 14 for inputting the sequence identification signal to the write control means 7, and a sequence start sector address indicating from which sector the data of each sequence is recorded is generated. . Then, from the sequence start sector address and the GOP start timing signal, a GOP start sector address indicating from which sector each GOP file is recorded is generated, and GST data generation means 5 and GOP information table data generation means 6 are generated. Output to. Here, it is assumed that the GOP file is sequentially recorded from the sequence start sector address to the sector of the continuous sector address. The case of recording in a recordable empty sector on the disk will be described later. In addition, here, for convenience of explanation, No-1, No-2,... Will be described as the contents of the sequence identification signal.

  Further, as described above, the GOP encoded by the MPEG method in the encoding means 2 has data (time code) indicating the time from the start time of the sequence to which the GOP belongs at the head portion thereof. The GOP information detection means 4 detects information related to the GOP such as a time code from the GOP in each input GOP file, and also the file size and encoding rate from the input GOP file. To detect.

  In the GST data generation means 5, from the sequence identification signal input from the write control means 7 and the GOP start sector address generated for each GOP, for example, each sequence (title, program) as shown in FIG. On the other hand, GST table data storing a sector address that determines the reproduction order of the GOP file of each GOP constituting each sequence is generated and output to the data block configuration means 8.

  The GOP information table / data generation means 6 generates a file name corresponding to each GOP file, the GOP start sector address for each GOP input from the write control means 7, and the GOP information detection means 6 For example, GOP information table data as shown in FIG. 3 is generated according to each file name by the time code indicating the time from the start of the detected sequence, the size of the GOP file, and the encoding rate. And output to the data block constituting means 8. Here, it is assumed that the file name of each GOP can identify the sequence to which the GOP belongs.

The data block construction means 8 performs processing such as adding an error correction code to the input GOP file, and then, in accordance with each GOP file, a data block (hereinafter referred to as GOP file data. (Referred to as a block). An end detection identification code is placed at the end of each GOP file data block.
Similarly, in the data block construction means 8, data blocks of a predetermined format (hereinafter referred to as GST data block and GOP information table data block, respectively) are inputted from the inputted GST data and GOP information table data. .).

The GOP file data block is subjected to predetermined modulation by the modulator 9 and then sent to the laser drive circuit 10. The laser drive circuit 10 outputs a laser modulated in accordance with the modulation signal. Recording is performed on the optical disc 13 through the optical head 12.
At this time, each GOP file data block is recorded in the user area 34 in the sector map shown in FIG. 2 so that each GOP file is arranged from the head portion of the sector.

  Similarly to the GOP file data block, the GST data block and GOP information table data block data are also modulated by the modulator 9 and then recorded on the optical disc 13 by the optical head 12. . At this time, the GST data block and the GOP information table data block are recorded in the sectors of the GST area 32 and the GOP information area 33 in the sector map shown in FIG.

  On the other hand, the write control means 7 manages the sector address where the GOP file, GST data, and GOP information table data are recorded. That is, by sequentially incrementing the GOP start sector address generated as described above, a sector address in which one GOP file is recorded (hereinafter referred to as a GOP recording sector address) is generated. Then, every time the data of the GOP file ends, the GOP recording sector address is generated by sequentially incrementing from the next GOP start sector address. The GOP recording sector address generated in this way is input to the optical head control means 11.

The optical head control means 11 controls the optical head 12 to access a sector on the optical disk corresponding to the GOP recording sector address while tracking.
In this way, each GOP file data block is recorded such that each GOP file is arranged from the beginning of the GOP start sector address.

Similarly, the write control means 7 records GST data and GOP information table data from the sector address corresponding to the head sector of the GST area 32 and the sector address corresponding to the head sector of the GOP information area 33, respectively. A recording sector address to be generated is generated. The GOP recording sector address generated in this way is input to the optical head control means 11, and the optical head control means 11 makes the optical head 12 access the sector on the optical disk corresponding to the recording sector address. To control.
In this way, the GST data block and the GOP information table data block are recorded in the sectors of the GST area 32 and the GOP information area 33, respectively.

As described above, one GOP (including the sequence header for those with a sequence header) is handled as one GOP file. As shown in FIG. Are sequentially recorded from the head portion of the sector indicated by the GOP start sector address. In the figure, for example, SH1 and GOP1 are recorded as one GOP file 1 from the beginning of the sector of sector address n, and the data of GOP file 1 is temporarily in the middle of the sector (in the figure, sector address (n + 5 ) In the middle of the sector)), the subsequent SH2 and GOP2 are recorded as one GOP file 2 from the beginning of the sector of the next sector address (n + 6). Similarly, for example, GOP3 is one GOP file from the beginning of the sector at sector address (n + 10), and SH4 and GOP4 are one GOP file from the beginning of the sector at sector address (n + 18). Are sequentially recorded. Subsequent GOP files are sequentially recorded in the same manner.
In this case, the GOP start sector addresses of the GOP1, GOP2, GOP3, and GOP4 files are n, (n + 5), (n + 10), and (n + 18), respectively.

  Further, for each sequence (title, program), the GOP file order table (GST) data storing data for determining the reproduction order of the GOP file of each GOP constituting each sequence is shown as described above. 2 is recorded in the GOP file order table (GST) recording area 32 shown in FIG. FIG. 4 shows the configuration of GST data recorded in the GST recording area 32. The GST data in FIG. 4 is, for example, each sequence constituting a sequence of a sequence name (title name, program name) of No-1. The GOP file indicates that the GOP start sector address is sequentially recorded in the sectors of address 1, address 2, address 3, address 4,.

  For example, in order to reproduce a sequence with a sequence name (title name) of No-1, the GOP file constituting the sequence is designated as address 1, address 2, address 3, address 4,. -Sequentially read from the sector as the address and reproduce it.

  Further, for each GOP file, the GOP information table data for storing data such as the file name representing the GOP, the time from the start of the GOP sequence, the start sector address, the file size, the encoding rate, etc. is as described above. In this way, it is recorded in the GOP information area 33 shown in FIG. FIG. 3 shows table data recorded in the GOP information area 33. For example, the GOP file of GOP1, that is, the file with the file name “GOP1” has a time “00:12: 00 ”, the sector address where the GOP starts (GOP start sector address) is“ 500000 ”, the file size is“ 300000 ”, and the encoding rate is“ 4.5 ” Is shown. Similarly, for other GOP2, GOP3, GOP4, etc., the GOP file name, the time from the start of the GOP sequence, the start sector address, the file size, the attributes such as the encoding rate, etc. are stored as GOP as table data. Recorded in the information area 33.

  Now, the operation during normal playback will be described. First, in order to read GST data, a read sector address is generated by the read control means 21 so that the optical head 12 accesses the GST recording area 32 on the optical disc 13 shown in FIG. Via the optical head 12. The GST data block read from the GST recording area 32 by the optical head 12 is amplified by the reproduction amplifier 16 and sent to the error correction means 18. The error correction means 18 performs processing such as error detection using an error detection code added in the GST data block, and then sends it to the GST data detection means 19 as GST data.

Similarly, the GOP information table data recorded in the GOP information area 33 on the optical disc 12 is read out and sent to the GOP information table / data detection means 20.
The read GST data and GOP information table / data are stored in the GST data detection means 19 and the GOP information table / data detection means 20, respectively.

  The above operation may be performed immediately after the optical disc 23 is set in the apparatus or immediately after the start of recording and reproduction operations.

  Further, a sequence identification signal for identifying a sequence to be reproduced is input from the sequence identification signal input means 14 to the GST data detection means 20, and the GST data detection means 20 refers to the stored GST data to The start sector address of each GOP file indicating the reproduction order of the GOP file according to the identification signal is determined.

  For example, when GST data as shown in FIG. 4 is read and stored and the content of the sequence identification signal is No-1, each GOP file constituting the sequence has a start sector address. It is determined that data is sequentially recorded in the sectors of address 1, address 2, address 3, address 4,..., And the determined start sector address of each GOP file is output to the read control means 21.

In the read control means 21, the GOP read sector address is generated by sequentially incrementing from address 1 which is the start sector address of the GOP file to be reproduced first among the input start sector addresses.
When the end is detected by the end detection signal of the data block of the GOP file input from the error correction means 18, the GOP file is sequentially incremented from the start sector address 2 of the GOP file to be reproduced next. An address is generated. Similarly, GOP read sector addresses are generated in the same manner.

  The GOP read sector address generated in this way is sequentially sent to the optical head control means 11 to cause the optical head 12 to access the sector of the GOP read sector address.

  Here, if the GOP file is sequentially recorded in a continuous sector according to the reproduction order, after the sequence start sector address is determined at the time of reproduction, there is no need to refer to the GST data. As shown in FIG. 4, when one GOP file is completed, the GOP file may be read sequentially by repeating the operation of jumping to the head of the next sector and reading the next GOP file.

  The GOP file data block sequentially read from each sector of the user area 34 by the optical head 12 is amplified by the reproduction amplifier 16, demodulated by the demodulator 17, and input to the error correction means 18. In the error correction means 18, after error correction or the like is performed, it is sequentially input to the GOP continuation means 22 as GOP file data, and an end identification signal for detecting the end of the GOP file data block. Is output to the read control means 21.

  Then, the GOP continuation means 22 has a predetermined structure in which each GOP file in the separated state is encoded by the MPEG system as shown in FIG. The transmission signal) state GOP data is restored and input to the decoding means 23. The continuous GOP data is expanded and decoded by the decoding means 23 to become a digital image signal, converted into an analog signal by the D / A converter 24, and output as an output image signal.

  Next, a case where a GOP located in the middle of a certain sequence (title, program) is reproduced will be described. As in the normal playback described above, it is assumed that the start sector address of each GOP file indicating the playback order of the GOP file according to the playback sequence is determined. In FIG. The GOP file corresponding to the GOP located at is described as GOP file 2.

  First, the read control means 21 sends the start sector address of the GOP file 2, which is a GOP file corresponding to the GOP located in the middle of the sequence, to the optical head control means 11, and causes the optical head 12 to start with the start sector address (n + 6). ) Is accessed. Similarly to normal reproduction, the sectors are sequentially accessed from the sector of the start sector address (n + 6), and the GOP file data block read from the sector is reproduced by the reproduction amplifier 16, demodulator 17, error correction. The data is input to the GOP continuation means 22 through the means 18 as GOP file data.

  In the GOP continuation means 22, the GOP file 2 recorded in a state where the sector address is separated from the middle of (n + 6) to (n + 9) is encoded by the MPEG system as shown in FIG. The GOP data having a predetermined structure and being in a continuous bit stream (serial transmission signal) state is restored and input to the decoding means 23. Here, since the GOP file 2 is recorded from the head portion of the sector address (n + 6) accessed first, the data of the immediately preceding GOP1 is not read out first. Therefore, GOP data can be restored from the data read out first, decoded by the decoding means 23, converted into an analog signal by the D / A converter 24, and output as an output image signal. be able to.

  Thus, even when a GOP located in the middle of a certain sequence (title, program) is reproduced, a part of the GOP immediately before the GOP is not read from the sector accessed first. Since the GOP is read from the beginning of the accessed sector, it is possible to reduce the time required to reproduce and output the image signal.

  Next, a description will be given of a case where editing such as rewriting and continuous shooting is performed in GOP units. As described above, in the recording state before editing, each GOP is recorded from the head of the sector as shown in FIG. 2, and here, a case where a GOP file after GOP3 is rewritten with another GOP file will be described. To do. In such a case, for example, GOP3 ′, GOP4 ′,... Are newly shown as different GOP files from the head of the sector address (n + 10) recorded in GOP3 as shown in FIG. Record sequentially.

  On the disc that has been rewritten in this way, the GOP2 recorded before editing is not affected by the rewriting and is recorded in the state before editing, so that the editing point (the seam of editing) is reproduced. Even so, the GOP2 that is the GOP before the editing point cannot be reproduced and is not lost, or is not reproduced and becomes an unnatural image.

  Further, a case will be described in which an image signal is recorded / reproduced in / from recordable empty sectors distributed on a disk in a re-recordable (appendable) medium. First, the GOP information table data is read from the start sector address and file size of each GOP file in the GOP information table data read from the GOP information area 33 on the disc in the same manner as the normal reproduction described above. The detecting means 20 discriminates an empty sector on the disk and outputs the sector address of the empty sector to the writing control means 7.

  Then, the write control means 7 determines a free sector area in which GOP files to be additionally recorded can be continuously recorded from the file size extracted by the GOP information detection means 4, and a sequence for additionally recording. Similar to the above-described recording operation, access to the optical head 12 is controlled so that the GOP file is continuously recorded in the recordable continuous sector area from the head portion of the sector.

  On the other hand, the GST data generation means 5 adds and generates GST indicating the start sector address of each GOP file constituting each sequence, corresponding to the sequence to be additionally recorded as shown in FIG. Further, the GOP information table / data generating means 6 generates table data including a recorded GOP file name and information related thereto. Then, as described above, the respective table data is recorded in the GST area 32 and the GOP information area 33 on the optical disc 13.

  When a sequence recorded in sectors distributed on the disk in this way is reproduced, for example, if a GOP file of the sequence No-2 is recorded in sectors distributed on the user area 4, GST By reading the GST recorded in the area 32 and referring to it, the reproduction order of each GOP file arranged in a distributed manner is determined from the start sector address of each GOP file indicating the reproduction order of the sequence No-2. Can be identified.

Thereafter, as in the above-described normal reproduction, the read control means 21 sequentially increments from the input start sector address from the address A which is the start sector address of the GOP file to be reproduced first, and the GOP read sector An address is generated.
When the end of the data block of the GOP file is detected, the GOP file is sequentially incremented from the start sector address B of the GOP file to be reproduced next, and a GOP reproduction sector address is generated. Similarly, GOP read sector addresses are generated in the same manner.

  The GOP read sector address generated in this way is sequentially sent to the optical head control means 11, and the optical head 12 is accessed to the sector of the GOP read sector address, and the image signal is decoded from the read data. Output.

  As described above, even empty sectors distributed on the disk can be recorded in GOP file units, and empty sectors can be used effectively.

  Furthermore, a case where a GOP at a desired time from the start of a certain sequence (title, program) is reproduced will be described. First, a sequence identification signal for identifying a sequence and a time position identification signal indicating a desired time point for reproduction are respectively sent from the sequence identification signal input means 14 and the time position identification signal input means 15 to the GOP information table / data detection means 20. Entered.

  In the same manner as described above, GST data and GOP information table data are read from the GST area 32 and GOP information area 33 on the optical disc 13, respectively, and the GST data detecting means 27 and GOP information table data are read out. It is sent to the detection means 20 and stored. As shown in FIG. 3, the GOP information table data stores the time from the start of the sequence corresponding to the file name of each GOP, the start sector address of the GOP file, the file size, the encoding rate, and the like. Yes. The file name is recorded as identifying the sequence to which the GOP belongs.

  Here, for example, when the content of the input sequence identification signal is No-1 and the GOP at the time 00:13:00 from the start of the sequence is to be reproduced, the GOP information table / data detection means At 20, the GOP information table data stored in advance is referred to, and the GOP file group belonging to the sequence indicated by the content No. 1 of the sequence identification signal is identified from the GOP file name. Then, by referring to the time from the start of the sequence corresponding to the GOP file group of the GOP information table data, the file name is “GOP3” as a GOP file having a time from the start of the sequence of 00 minutes 13 seconds 00 Identify the GOP file and identify that its starting sector address is “500580”. In this way, the GOP file at a desired time from the start of the sequence is specified, and the start sector address of the GOP file is identified (searched). Then, the start sector address identified (searched) in this way is output to the GST data detection means 19.

  The GST data detection means 19 refers to the GST data stored in advance, and sequentially reads the start sector address from the start sector address of the GOP file specified by the GOP information table / data detection means 20, and reads the control means 21. Output to.

Thereafter, in the same manner as the normal reproduction described above, the GOP start sector address input from the GOP file data detection means 20 is incremented sequentially until one GOP is completed, and a GOP read sector address is generated. .
When a data block of the GOP file is detected, the GOP file is sequentially incremented from the start sector address of the GOP file to be reproduced next to generate a GOP reproduction sector address. Similarly, GOP read sector addresses are generated in the same manner.

  The generated sector address is input to the optical head control means 11, the optical head 12 is accessed to the sector of the input sector address, and data is read out. The read data is decoded by the decoding means 23 via the reproduction amplifier 16, demodulator 17, error correction means 18, GOP continuation means 22, and output image signal via the D / A converter 24. Is output as

  As described above, since the GOP data is recorded from the head portion of the sector, there is no need to search for the GOP discriminated within the sector, and the GOP recorded at the head portion of the sector of the GOP file start sector address. It is sufficient to play sequentially.

  As described above, when a GOP at a desired point in time from the start of a certain sequence (title, program) is reproduced, the sector in which the target GOP is recorded can be easily and immediately identified. It is not necessary to search for a GOP discriminated in the image, and the time required to reproduce the image signal can be shortened.

  In the above description, the MPEG method is described as a compression encoding method for image signals. However, the present invention is not particularly limited to this method, and a compression encoding method using a predetermined number of images as an encoding unit. Needless to say, there is nothing to do.

  In addition, the file name of the GOP file in the GOP information table data has been described assuming that the sequence to which the corresponding GOP belongs can be identified. However, for each file name, data that can identify the sequence to which the corresponding GOP belongs is assigned. Alternatively, it may be separately arranged in the GOP information table.

  Further, in the above description, the GOP information table data takes time from the start of the sequence as information indicating the position of the GOP in the sequence (title, program). As long as the information indicates the position of the GOP, for example, information indicating the GOP number from the beginning of the sequence may be used. In such a case, it is possible to input a signal indicating how many GOPs are to be searched from the beginning of the sequence, and to search and reproduce the GOP.

It is a block diagram which shows the structure of one Example of the image signal recording device and image signal reproducing | regenerating apparatus of this invention. It is a sector map figure which shows the area | region arrangement | positioning on the optical disk of one Example of this invention. It is a figure which shows the structure of the GOP information table data of one Example of this invention. It is a figure which shows the structure of the GOP file order table data of one Example of this invention. It is a schematic diagram which shows the access state of the optical head at the time of reproduction | regeneration of one Example of this invention. It is a schematic diagram which shows the recording state of the GOP file by which the edit of the GOP unit of one Example of this invention was performed. It is a data block diagram which shows the data structure of the encoding method by an MPEG system. It is a data block diagram which shows the structure of the sequence layer of the encoding method by MPEG system. It is a structural diagram which shows the structure of GOP of the encoding method by MPEG system. It is a schematic diagram which shows the method of recording GOP encoded by the MPEG system at a variable rate, and the method of recording at a fixed rate. It is a figure which shows an example of the time change of the data amount per 1 GOP in the method of recording GOP encoded by the MPEG system at a variable rate. It is a figure which shows an example of the relationship between the image quality after the decoding of the image signal encoded by the MPEG system, and the data amount per 1 GOP.

Explanation of symbols

2 encoding means, 3 GOP file generation means, 4 GST data generation means, 5 GOP information table / data generation means, 7 write control means, 13 optical disc, 19 GST data detection means, 20 GOP information table / data detection means, 21 Read control means, 23 decoding means, 32 GST area, 33 GOP information area.

Claims (2)

In addition to the I picture compressed in the frame, the P picture compressed by adding the motion compensation by the forward I picture in time, and the motion compensation by the I picture or the P picture in the forward and backward direction An optical disc in which digital image information composed of GOPs including data-compressed B pictures is recorded in a recording unit, and sequence table information including a start position of a sequence constituting the digital image information, and the GOP GOP table information including time information and position information of the GOP is recorded as separate table information, and the position information of the GOP table information is a record including the earliest position of the sequence header at the head of the GOP. The unit position, and the sequence includes an optical data including the GOP data. A method for reproducing a disk,
Read the order table information,
Read the GOP table information,
When reproducing from a desired time point, the position information corresponding to the desired time point is identified by referring to the read GOP table information.
A method of reproducing an optical disc, wherein reproduction from the desired time point is performed from the identified position information and the read order table information. In addition to the I picture compressed in the frame, the P picture compressed by adding the motion compensation by the forward I picture in time, and the motion compensation by the I picture or the P picture in the forward and backward direction An optical disc in which digital image information composed of GOPs including data-compressed B pictures is recorded in a recording unit, and sequence table information including a start position of a sequence constituting the digital image information, and the GOP GOP table information including time information and position information of the GOP is recorded as separate table information, and the position information of the GOP table information is a record including the earliest position of the sequence header at the head of the GOP. The unit position, and the sequence includes an optical data including the GOP data. An apparatus for reproducing a disk,
Means for reading the order table information;
Means for reading the GOP table information;
Means for identifying position information corresponding to the desired time point by referring to the read GOP table information when reproducing from a desired time point;
An optical disc reproducing apparatus comprising: means for reproducing from the desired time point based on the identified position information and the read order table information.

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