JP3476144B2 - Editing method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an editing method, and more particularly to an editing method for editing block data recorded on a rewritable recording medium. 2. Description of the Related Art Recent advances in information processing technology have
2. Description of the Related Art It has been widely practiced to compress digital audiovisual information and record it on an information recording medium. Especially for video information, the amount of information is enormous, and advanced compression techniques are used in order to effectively use the limited amount of information recorded on the information recording medium. A typical example of this advanced compression technique is not only data compression using correlation within a frame that is a unit of video, but also compression using correlation between a plurality of temporally adjacent frames. Today, it is widely used for recording and transmitting video information. [0003] When editing the result of data compression, if frame correlation is used, deletion in frame units becomes impossible. This is because the reference source frame cannot be decoded if there is no reference destination frame to be correlated. Therefore, in many cases, a plurality of frames are divided into blocks in preparation for subsequent editing, and encoding is performed so that blocks can be handled independently without performing frame correlation processing between blocks. It is well known that the block data coded in block units have different data capacities depending on the complexity of the video in the block and the degree of correlation between frames. Now, these block data are recorded on the information recording medium, but the block data is arranged from the head of the sector so as to occupy an integer number of sectors, and the reproduction operation is taken into consideration in reproducing. There is a need. Therefore, a measure is taken by performing encoding including embedded data at the end of block data by a known method.
Thus, the block data is recorded in the information area A shown in FIG. In order to efficiently compress video information, the video information is often divided into blocks each having a different number of frames. That is, it is necessary to consider that the display periods of the respective blocks shown in FIG. 7 are different from each other on a frame period basis. Furthermore, since the compression rates per block are different from each other, the capacities of the block data are different from each other as shown in FIG. [0006] The above situation is described by linear pulse code modulation (PC
M) and the like, it is very difficult to perform search playback in which time is specified and playback is started from a block data sequence, as compared with a case where the relationship between time lapse and the total amount of encoded data is proportional. It is expected that there is. In order to solve this problem, conventionally, a time recording position comparison table is separately recorded, and search reproduction is performed using this comparison table, as disclosed in Japanese Patent Application Laid-Open No. 9-23404 (title "Media Recording Method"). , Apparatus and medium reproducing apparatus ”). In this medium recording method, video information, which is predetermined main information, is converted into an MPEG (Motion Picture), which is an international standard for moving images.
A method of generating a plurality of GOPs (Groups of Pictures), which are compression units, by encoding using a ving Picture Experts Group) method and recording the generated plurality of GOPs on a recording medium. Generates a start address of data for each time unit when divided and
It is recorded on a recording medium together with P. In other words, according to this medium recording method, the time recording position comparison table is composed of a sequence of reproduction start addresses for each predetermined time unit, and coded data is divided into blocks in a compression unit called GOP. G as playback start address
Information indicating the start position of the OP is recorded. FIG. 7 conceptually shows this state. [0009] However, the above-mentioned conventional method is used in a situation where the block data string is not updated, for example, in a situation where the block data string is recorded on a read-only medium. Although this function works well for search reproduction, a problem may occur when the block data sequence is updated. When a block data string is recorded on a rewritable recording medium, its contents can be edited. As an example, as shown in FIG. 8, a reproduction skip instruction in units of block data can be considered. Generally, information specifying a reproduction section and its reproduction order is recorded on a recording medium as reproduction control data, so that it is not always necessary to delete the skipped block data. When the block indicated by D in FIG. 8 is skipped, the reproduction period s of the block indicated by D becomes zero during reproduction. Also, since the reproduction start address 3 indicates the section to be skipped, it must be deleted from the time recording position comparison table. The period s is the period u
Therefore, all reproduction start addresses after the reproduction start address 4 must be updated to indicate a correct position. For this purpose, it is necessary to recalculate the address information based on the relationship between the block capacity after the block D and the reproduction period, and the editing process may be extremely complicated. The present invention has been made in view of the above points,
It is an object of the present invention to provide an editing method capable of performing editing for designating a section skip for a block data sequence extremely simply and at high speed. In order to achieve the above object, an editing method of the present invention divides a temporally continuous image signal into blocks of a predetermined time unit based on an image unit, A first recording area in which a plurality of block data after data compression by the encoding in which the code amount for each block is variable is recorded in time series, and the predetermined block data is reproduced from the first recording area. For example, a time recording position comparison table including first time correction data and one or more pieces of reference data for each fixed time interval u based on the display time of the image unit is stored in the first recording area. A rewritable information recording medium having a m second recording area corresponding to each of m (m is a natural number) continuous reproduction sections set for the recorded block data;
The n-th (n is a natural number) reference data in each of the time recording position comparison tables starts reproduction from the first block data of one continuous reproduction section corresponding to each of the time recording position comparison tables (n × n). u) time (u is said corresponding one points to the block data to be continuously played back in the sections shown to Bed b <br/> Kkudeta position information being reproduced at the time of the lapse of the fixed time interval), the block data The reproduction start time of the block data indicated by the position information and the (n ×
u) The first time correction data in each time recording position comparison table includes a set of time difference information of a difference from time. When the information indicates the block data to be reproduced at the point of time when (n × u) -c time has elapsed from the start of the reproduction of the two continuous reproduction sections, the rewritable information recording medium which is the data for correcting the time c is used. a read step of reading the time recording position control table, a portion of the predetermined continuous playback section including a plurality of control data of said m consecutive playback sections in the block data recorded in the information recording medium A skip period instructing step for instructing a skip period to be skipped, and the time recording position comparison table read out in the readout step. For a plurality of reference data constituting the time recording position comparison table corresponding to the predetermined continuous playback section, the reference data indicating the block data corresponding to the skip period is deleted, and the reference data corresponding to the period before the skip period is deleted. To be divided into a first control data group, which is a group of control data indicating block data, and a second control data group, which is a group of control data indicating block data corresponding to a period after the skip period. Deleting the second time correction data corresponding to the first time correction data for the second control data group in the skip period;
From the beginning of the block data immediately after
Block pointed to by the first control data in the data group
The reproduction time immediately before the data and the second control data
Sum with the time difference information of the first control data in the loop
A first time recording position comparison table consisting of the first time correction data and a first control data group; a second time correction data and the second control data group And writing a second time recording position comparison table comprising the following to the second recording area of the information recording medium. According to the present invention, for example, when editing such that one section of a series of block data is skipped on the rewritable information recording medium, one continuous playback section in the first recording area is reduced to two sections. Will be split. Therefore, first, the time recording position comparison table corresponding to the continuous reproduction section in which the skip period is set, which has been already recorded, is read from the information recording medium. Then, with respect to the target data constituting the read time recording position comparison table, the reference data indicating the block data corresponding to the skip period is deleted, and the reference data corresponds to the continuous reproduction section temporally preceding the skip period. A first control data group which is a group of control data indicating block data to be copied, and a second control which is a group of control data which indicates block data corresponding to a continuous reproduction section temporally after the skip period. Divide into data groups. Next, correction time data (second correction time data) needs to be newly given to the second control data group corresponding to the continuous reproduction section temporally after the skip period. The reproduction time length of the block data to be reproduced before the block data pointed to by the first control data in the second control data group is calculated, and the second correction time data is calculated based on the reproduction time length. Then, a new time recording position comparison table (second time recording position comparison table) is created by combining the second correction time data with the second and subsequent corrected time data, which are the second reference data group and the deleted reference data. Then, this is written in the second recording area of the information recording medium. Thus, the reproducing apparatus that reproduces the information recording medium on which the new time recording position comparison table has been written by the editing method of the present invention reproduces the information using the new time recording position comparison table, so that each reference data is reproduced. It becomes possible to know exactly at what point in time the information is viewed from the beginning of the continuous reproduction section, and it is possible to accurately execute search reproduction by specifying time without error. further,
According to the present invention, it is not necessary to update a lot of comparison data in the time recording position comparison table, so that extremely simple and high-speed editing can be performed. Next, an embodiment of the present invention will be described with reference to the drawings. First, an embodiment of the information recording medium used in the present invention will be described. FIG. 1 shows the data arrangement of one form of the information recording medium and the data format of the time recording position comparison data. This information recording medium is a rewritable information recording medium divided into sectors of a fixed data amount, which divides time-continuous information into blocks, changes the code amount of each block, and uses an integer number of sectors. As shown by 11 to 11 in FIG. 1, k block data (k is a natural number corresponding to the length of information to be recorded) and block data in the information area A in time series are shown as 11 to 11 in FIG. Has been recorded. The above-mentioned information is, for example, video information and audio information multiplexed by compression encoding in the MPEG system. For example, the block data is configured in GOP units, but the details are not the gist of the present invention. Description is omitted. In the information area B of the information recording medium different from the information area A, the time recording position reference data 12 is recorded. This time recording position comparison data 12 is
As will be described later, when there are m continuous playback sections in the information area A by editing, the time recording position comparison data 12
Are recorded in the information area B (m = 3 as an example in FIG. 1, and m = 3 in the initial recording before the editing is performed).
1). The time recording position reference data 12
1 includes time correction data 12a and z (z is a natural number) reference data 12b, as shown in FIG. The time correction data 12a is data for correcting the time c when the n-th control data becomes information at the time when (n × u) -c time has elapsed from the start of reproduction after the editing described later is performed. is there. Each of the reference data 12b is data for each fixed time interval u, and includes block data position information 13 and time difference information 14. The block data position information 13 of the n-th reference data of each time recording position reference data 12 starts reproduction from the first block data of one continuous reproduction section in the information area A corresponding to the time recording position reference data 12. At the time point when (n × u) time has elapsed. The time difference information 14 includes the reproduction start time of the block data indicated by the block data position information 13 and the above (n × u)
Indicates the time difference from the time. When information is first recorded on the information recording medium (in an initial state before rewriting by editing is performed), a series of block data 11 to 11
Are continuously reproduced, and search reproduction at a designated time is possible using the time recording position reference data 12. FIG. 2 shows an example of the relationship between block data and reference data during initial recording, which are recorded on the information recording medium. In the figure, the fixed time interval u is "60" (the unit is seconds, but it may be a frame), five control data 1-5 are recorded in the information area B, and the control data 1-5 As the block data position information shown, a relative sector address from the head of the information area A is used, and the block data position information shown by the reference data 1 to 5 is, as shown in FIG. Block data start addresses “120”, “26”
0 "," 360 "," 460 ", and" 620 "As a result, the time recording position comparison data 12 recorded in the information area B at the time of the initial recording is, as shown in FIG. The value of the time correction data 12a is "0",
The block data position information 13 is a value of the above-described relative address, and the time difference information 14 is a value shown in FIG. 3 based on FIG. For example, the block data position information 12 of the reference data 4 indicating the block position of the data block shown in FIG.
460 ", and the reproduction start time is earlier by" 20 "than the sum (integrated value) of the fixed time intervals indicated by the reference data 4, as shown in FIG. 2, so that the time difference information 14 is shown in FIG. As described above, the time recording position reference data 12 is the reference data 12b, the block position information 13, and the time difference information 1.
4 are associated with each other as a set, and are also referred to as time recording position comparison tables in this specification. Next, an editing apparatus that executes an embodiment of the editing method according to the present invention will be described. FIG. 4 shows a block diagram of the editing device. As shown in the figure, the editing apparatus reads out (reproduces) a time recording position comparison table from a rewritable recording medium 21 which is the above-described information recording medium, and an information reading unit 22 reads out the time recording position reference table. Information memory 23 for temporarily storing the recorded time recording position comparison table, a skip period instructing unit 24 for instructing the skip period, and reading the time recording position comparison table stored in the information memory 23. And a control unit 25 that performs various processes corresponding to the skip period specified for the data and writes back the information to the information memory 23.
The information writing unit 26 writes the information written back into the rewritable recording medium 21, an information decoding unit 27, and an information display unit 28. Here, the control unit 25 applies a division process, a comparison data deletion process, a time correction data calculation process, a division process and a division process corresponding to the designated skip period to the time recording position comparison table read from the information memory 23. A plurality of comparison tables are formed by combining the partially deleted comparison data and the time correction data, and processing for writing back to the information memory 23 is executed. Further, the information decoding unit 27 includes the information reading unit 22.
Decrypts the read block data. The information display unit 28 displays the video information decoded by the information decoding unit 27. Next, a description will be given of the processing relating to the time recording position comparison table by the editing apparatus of FIG. 4 when the skip period instruction section 24 instructs to skip the block data indicated by D in FIG. The information is read from the rewritable recording medium 21 by the information reading unit 22 in FIG.
As shown in FIG. 5A, the time recording position comparison table transferred to the information memory 23 is the same as the time recording position comparison table of the rewritable recording medium 21 at the time of the initial recording shown in FIG. Next, the skip instruction from the skip period instruction section 24 indicates that the block data indicated by D in FIG. 2 is to be skipped.
5 is performed between the block data indicated by the reference data 3 and the block data indicated by the reference data 3, the control unit 25 sets the skip start timing as a division point between the reference data 2 and the reference data 3 as shown in FIG. To divide. Subsequently, the control unit 25 deletes the control data 3 indicating the block data (of FIG. 2) to be skipped as shown in FIG. 5 (c). Subsequently, the control unit 25
Calculates time correction data for the period after the skip. This is obtained by integrating the reproduction periods from the block data after skipping to immediately before the block data indicated by the reference data 4 (in FIG. 2), and becomes time correction data = fixed time interval− (integrated value + time difference information of control data 4). It is calculated based on the formula. In the example of FIG. 2, the control data 4 after the skip
There is one block data indicated by S immediately before the block data indicated by, and "20" which is a reproduction period of the block data S is obtained. The time difference information “20” of the reference data 4 is added to this value, and the value after the addition is subtracted from the fixed time interval u (= 60) to calculate “20” as the time correction data. Next, the control unit 25 compares the time correction data calculated in this way with the deleted control data which is a control data group corresponding to a continuous reproduction section temporally after the skip period. A second time recording position comparison table is added to the control data 4 and the control data 5, as shown in FIG. 5D. This second time recording position comparison table is written back to the information memory 23 together with the first time recording position comparison table which is a set of the comparison data 1, the comparison data 2 and their time correction data. The time recording position comparison table shown in FIG. 5D written back to the information memory 23 is read by the information writing unit 26 and written into the information area B of the rewritable recording medium 21. As a result, the details of the recording time recording position comparison table of the rewritable recording medium 21 after writing are shown in FIG. A second time recording position comparison table 32 for data 4 and 5 is provided. That is, one comparison table is prepared for the continuous playback section. After confirming the normal writing back, the time record position comparison table of FIG. 3 before editing may be deleted. As a result, at the time of reproducing the rewritable recording medium 21, the search operation can be accurately performed in consideration of the fact that the reference data is the information at the time earlier by the time correction data. That is, in the example of FIG. 2, the continuous reproduction section after the skip period starts from the block data S, and the reference data 4 which is the first reference data from the continuous reproduction start position is the original data from the continuous reproduction start position. It can be seen that the information is not “60”, but information “40” earlier by “20” of the time correction data in the second time recording position comparison table 32 shown in FIG. The action can be performed. Also, in the above formula, the only item that actually needs to be calculated is the integrated value, and this integrated value may be directly used as the time correction data. As described above, in the reproducing apparatus for reproducing the information recording medium on which the new time recording position comparison table has been written by the editing method of the present invention, the correction time is required even in the reproduction after editing. Using the data and time difference information, it is now possible to know exactly at what point each control data is viewed from the beginning of the continuous playback section, and accurately execute search playback at the specified time without error become able to.
Further, according to the present invention, it is not necessary to update a lot of comparison data in the time recording position comparison table, so that extremely simple and high-speed editing can be performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of a data arrangement and a time recording position comparison data format of one form of an information recording medium to be edited by the editing method of the present invention. FIG. 2 is a diagram showing a relationship between a data block at the time of initial recording of an information recording medium to be edited by the editing method of the present invention, a designated skip period, and reference data. FIG. 3 is a diagram illustrating an example of a time recording position comparison table; FIG. 4 is a block diagram of an editing apparatus that executes an embodiment of an editing method according to the present invention. 5 is an explanatory diagram of processing of a time recording position comparison table by the editing device in FIG. 4; FIG. 6 is an explanatory diagram of a time recording position comparison table after editing by the editing device of FIG. 4; FIG. 7 is a diagram showing an arrangement of block data and a reproduction period. FIG. 8 is an explanatory diagram of skip reproduction of block data. [Description of Signs] 11 1 to 11 k Block data 12 Time recording position reference data 12 a Time correction data 12 b Reference data 13 Block data position information 14 Time difference information 21 Rewritable recording medium 22 Information reading unit (reading means) 23 Information memory (memory means) 24 skip period instructing unit (skip period instructing unit) 25 control unit (dividing unit, deleting unit, calculating unit, writing back unit) 26 information writing unit (writing unit) 27 information decoding unit 28 information display unit

Continuation of the front page (56) References JP-A-11-155130 (JP, A) JP-A-11-96730 (JP, A) JP-A-10-155138 (JP, A) JP-A-9-251176 (JP, A) , A) JP-A-9-23404 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 20/12 G11B 27/00-27/10 H04N 5/91

Claims (1)

(57) [Claims 1] A temporally continuous image signal is divided into blocks of a predetermined time unit based on an image unit, and encoding is performed by changing a code amount of each block. A first recording area in which a plurality of block data after data compression are recorded in chronological order, first time correction data for reproducing predetermined block data from the first recording area , and
1 for each fixed time interval u based on the display time in image units
A time record position comparison table consisting of two or more control data,
A rewritable rewritable medium having m recording areas corresponding to m (m is a natural number) continuous reproduction sections set for the block data recorded in the first recording area, respectively. The information recording medium, wherein the n-th (n is a natural number) reference data in each time recording position comparison table is reproduced from the first block data of one continuous reproduction section corresponding to each time recording position comparison table. starting (n × u) time (u is the fixed time interval) indicates to Bed b <br/> Kkudeta position refers to the block data of the corresponding one of continuous regeneration in a section being reproduced at the time that has elapsed Information, the reproduction start time of the block data indicated by the block data position information, and the (n ×
u) The first time correction data in each time recording position comparison table includes a set of time difference information of a difference from time. When the information indicates the block data to be reproduced at the point of time when (n × u) -c time has elapsed from the start of the reproduction of the two continuous reproduction sections, the rewritable information recording medium which is the data for correcting the time c is used. a read step of reading the time recording position control table, a portion of the predetermined continuous playback section including a plurality of control data of said m consecutive playback sections in the block data recorded in the information recording medium A skip period instructing step for instructing a skip period to be skipped, and the time recording position comparison table read out in the reading step. For a plurality of reference data constituting the time recording position comparison table corresponding to the predetermined continuous reproduction section, the reference data indicating the block data corresponding to the skip period is deleted, and the reference data corresponding to the period before the skip period is deleted. To be divided into a first control data group, which is a group of control data indicating block data, and a second control data group, which is a group of control data indicating block data corresponding to a period after the skip period. - a deletion step, for said second control data group, the second time correction data corresponding to the first time correction data, the
From the beginning of the block data immediately after the skip period,
Point to the first control data in the second control data group
Playback time until immediately before the block data and the second pair
Time difference of the first control data in the reference data group
A calculating step for calculating based on the sum of the information, a first time recording position comparison table including the first time correction data and a first control data group, the second time correction data and the second time correction data. A writing step of writing a second time recording position comparison table composed of the reference data group of the information recording medium into the second recording area of the information recording medium.