JP2007328878A - Reproduction device, reproduction method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quickly display a screen after switching a reproduction mode. <P>SOLUTION: When usual reproduction is selected as a reproduction mode, a picture, which is used only in usual reproduction, is read out from a recording medium 11 and stored in a normal buffer 22. In addition, when the reproduction mode is changed to fast-forwarding reproduction/fast-rewinding reproduction, a picture, which is also used in the fast-forwarding reproduction/fast-rewinding reproduction, is read out from the recording medium 11 and stored in a skip buffer 21 so that displaying a screen may immediately is executed in the fast-forwarding reproduction/fast-rewinding reproduction. When instructions to change a reproduction mode to the fast-forwarding reproduction/fast-rewinding reproduction are made, a picture which is prepared in the skip buffer 21 is used, and the displaying of a screen is made. This technology is applied to a reproduction device which reproduces video content. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a playback device, a playback method, and a program, and more particularly to a playback device, a playback method, and a program that can quickly display a screen after switching playback modes.

  Conventionally, in the playback mode of a video content such as a recorded program, assuming that the video content is a content with a picture rate of 30 pictures / second, normal playback that plays back all the pictures, every 10 pictures, 30 There is special reproduction in which only pictures that appear at predetermined intervals such as every picture are skipped and reproduced.

  Special playback is used, for example, when confirming the rough contents of video content in a short time or searching for a position that the user wants to see.

  In a playback apparatus equipped with such a normal playback function and special playback function, the code of the video content read from the recording medium such as a hard disk is normally stored once in the buffer, and the code stored in the buffer is stored in the buffer. Decoding is performed on the target. The video obtained by decoding is displayed on the display and can be viewed by the user.

Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique that can reduce the processing amount when performing special reproduction such as fast-forward reproduction and can improve the data access speed during fast-forward reproduction.
JP 2001-126398 A

  In a conventional playback device, for example, when the user instructs to start special playback during normal playback, the decoding process for normal playback is stopped and read from the recording medium until then. Then, after all the codes stored in the buffer are once discarded, the codes necessary for special reproduction are read from the recording medium and stored in the buffer.

  Therefore, according to such a method, even if a code that can also be used for special reproduction has already been read from the recording medium and stored in the buffer, it is necessary to read the same code again from the recording medium. Therefore, of course, there is a delay before the screen display can be performed after the reproduction mode is switched to the special reproduction.

  The same applies to the case where the user instructs to start normal playback during special playback.

  In addition, when reading the necessary code in the reproduction mode after switching is triggered by the instruction to switch the reproduction mode, the time for reading the necessary code from the recording medium cannot be removed, This also causes the inability to quickly display the screen after switching the playback mode.

  The present invention has been made in view of such a situation, and makes it possible to quickly perform screen display after switching the reproduction mode.

  A playback device according to an aspect of the present invention provides video content read from a recording medium, normal playback for decoding all the pictures constituting the video content, and a predetermined interval between pictures constituting the video content In a playback apparatus that plays back in any one of the playback modes of the special playback that decodes only the pictures that appear in the above, a first buffer that stores pictures used as decoding targets only during the normal playback, and the special playback The second buffer for storing pictures used as decoding targets, the third buffer for storing pictures to be decoded, and the normal reproduction among pictures read from the recording medium The picture used as the decoding target only in the first buffer is stored in the first buffer. First control means for storing the pictures used as the second buffer respectively in the second buffer, and the pictures stored in the first and second buffers are read in the order of decoding according to the playback mode, Second control means for storing in the third buffer, and decoding means for decoding the picture stored in the third buffer by the second control means and displaying the video, the first control The means further decodes at the time of the special reproduction at least one of the previous position and the subsequent position with respect to the position of the picture used for displaying the video by the decoding means. The picture used as the target of the is stored in the second buffer.

  In the second control means, when the reproduction mode is switched from the normal reproduction to the special reproduction, the picture stored in the second buffer by the first control means up to that time is decoded. Can be read and stored in the third buffer.

  The first control means erases the picture stored in the second buffer in accordance with the position of the picture used for displaying the video, and the second control unit erases the picture. Other pictures used as decoding targets can be stored in the area even during the special reproduction.

  The first control means reads the same picture as the picture read from the second buffer by the second control means and stored in the third buffer, and the picture is decoded by the decoding means. Even after being performed, the second buffer can continue to be stored for a certain period.

  In the first control means, when the picture is decoded by the special reproduction, the first control means further includes a time position before and after the position of the picture used for video display by the decoding means. The picture used as a decoding target only at the time of the normal reproduction at the position of at least one of the positions can be stored in the first buffer.

  When there are a plurality of modes with different intervals of pictures to be decoded as the special playback mode, the second buffer is configured to include the same number of areas as the number of the special playback modes. be able to.

  The respective modes of the special reproduction can be assigned to the respective areas constituting the second buffer.

  The first control means includes a picture that is a decoding target in common among two or more modes of the plurality of special reproduction modes, and a mode in which the picture is a decoding target in common. The second buffer area allocated to the mode having the largest interval between pictures to be decoded can be stored.

  The reproduction method or program according to one aspect of the present invention decodes a picture read out from a recording medium, which is used as a decoding target only during normal reproduction, into the first buffer and also during special reproduction. The pictures used as the target of the image are stored in the second buffer, and the pictures stored in the first and second buffers are read in the decoding order according to the playback mode and stored in the third buffer. The video stored in the third buffer is decoded to display a video, and at least one of the previous position and the subsequent position in terms of the position of the picture used for the video display A step of storing, in the second buffer, a picture used as a decoding target even at the time of the special reproduction.

  In one aspect of the present invention, among pictures read out from a recording medium, a picture that is used as a decoding target only during normal playback is used as a decoding target in the first buffer and also during special playback. Pictures to be stored are respectively stored in the second buffer, and the pictures stored in the first and second buffers are read in the order of decoding according to the playback mode and stored in the third buffer. In addition, the picture stored in the third buffer is decoded and video is displayed, and at least one of the previous position and the subsequent position is temporally based on the position of the picture used for displaying the video. A picture used as a decoding target at any position in the special reproduction is stored in the second buffer.

  According to one aspect of the present invention, it is possible to quickly display a screen after switching the reproduction mode.

  Embodiments of the present invention will be described below. Correspondences between the constituent elements of the present invention and the embodiments described in the specification or the drawings are exemplified as follows. This description is intended to confirm that the embodiments supporting the present invention are described in the specification or the drawings. Therefore, even if there is an embodiment which is described in the specification or the drawings but is not described here as an embodiment corresponding to the constituent elements of the present invention, that is not the case. It does not mean that the form does not correspond to the constituent requirements. On the contrary, even if an embodiment is described herein as corresponding to the invention, this does not mean that the embodiment does not correspond to other than the configuration requirements. .

  The playback apparatus according to one aspect of the present invention (for example, the playback apparatus 1 in FIG. 1) is configured to perform normal playback for decoding video pictures read from a recording medium and decoding all the pictures constituting the video content; In a playback device that plays back in one of the playback modes of special playback that only decodes pictures that appear at a predetermined interval among the pictures that make up a picture, a picture that is used as a decoding target only during the normal playback is stored A first buffer (for example, the normal buffer 22 in FIG. 1), a second buffer (for example, the skip buffer 21 in FIG. 1) for storing pictures used as decoding targets in the special playback, A third buffer (for example, the code buffer 17 in FIG. 1) for storing a picture to be decoded, and reading from the recording medium. Of the pictures that are output, a picture that is used as a decoding target only during the normal playback is used as the first buffer, and a picture that is used as a decoding target during the special playback is used as the second buffer. First control means (for example, the special playback control unit 12 in FIG. 1) to be stored, and the pictures stored in the first and second buffers are read in the order of decoding according to the playback mode, Second control means (for example, code buffer control unit 15 in FIG. 1) to be stored in the third buffer, and pictures stored in the third buffer are decoded by the second control means to display a video Decoding means (for example, the decoder 18 in FIG. 1), and the first control means further determines the position of the picture used for video display by the decoding means. As standards, at least one of the position of the position after the temporally previous position, to store the picture used the as special playback target it is also decoded at the second buffer.

  The reproduction method or program according to one aspect of the present invention decodes a picture read out from a recording medium, which is used as a decoding target only during normal reproduction, into the first buffer and also during special reproduction. The pictures used as the target of the image are stored in the second buffer, and the pictures stored in the first and second buffers are read in the decoding order according to the playback mode and stored in the third buffer. The video stored in the third buffer is decoded to display a video, and at least one of the previous position and the subsequent position in terms of the position of the picture used for the video display And a step (for example, step S17 in FIG. 5) of storing the picture used at the time of the special reproduction in the second buffer.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration example of a playback apparatus 1 according to an embodiment of the present invention.

  The playback device 1 has a normal playback function for playing back all the pictures constituting the video content, and a special playback function for skipping only the pictures that appear at predetermined intervals.

  For example, in the case of video content with a picture rate of 30 pictures / second, double speed that not only reproduces all 30 pictures in 1 second but also reproduces 30 pictures in 0.5 seconds Normal playback also includes fast-playback playback at ½ and slow-playback playback at 1/2 times speed that plays back 30 pictures in 2 seconds.

  On the other hand, when the video content with a picture rate of 30 pictures / second is, for example, content in MPEG (Moving Picture Experts Group) format, it is special to play back only I pictures that appear at a predetermined interval among the pictures of the entire video content. Included in playback.

  Hereinafter, special playback in the time axis direction (forward direction) will be referred to as fast forward playback, and special playback in the direction opposite to the time axis direction will be referred to as fast reverse playback. In addition, simply normal playback refers to normal playback in the time axis direction.

  As shown in FIG. 1, the playback apparatus 1 having such a function basically includes a recording medium 11, a special playback control unit 12, a playback buffer 14, a code buffer control unit 15, a code buffer 17, a decoder 18, And a frame buffer 19. A switch 13 is provided between the recording medium 11 and the reproduction buffer 14 and is connected to one of the terminals 13a to 13d. Further, a switch 16 is provided between the reproduction buffer 14 and the code buffer 17 and is connected to one of the terminals 16a to 16d.

  The recording medium 11 is composed of a hard disk or the like, and records video content in a predetermined format such as MPEG2. Each picture constituting the video content recorded on the recording medium 11 is read by the special reproduction control unit 12 at a predetermined timing.

  The special playback control unit 12 selects a buffer as a storage destination of a picture (code) of the video content read from the recording medium 11 according to the currently selected playback mode, and switches the connection of the switch 13.

  For example, when the normal playback is selected as the playback mode, the special playback control unit 12 switches the connection of the switch 13 to read out the picture used only for the normal playback from the recording medium 11 and output it to the normal buffer 22. In addition, when the playback mode is switched to fast forward playback / fast reverse playback, pictures used in fast forward playback / fast reverse playback are recorded on the recording medium so that the screen display can be immediately performed in fast forward playback / fast reverse playback. 11 and output to the skip buffer 21. The order in which pictures are read and the buffer in which the read pictures are stored will be described in detail later.

  When the picture read from the recording medium 11 is a picture used only for normal playback and is an I picture encoded in the screen, the special playback control unit 12 connects the switch 13 to the terminal 13d to read the picture. The stored picture is stored in the normal I buffer 41 of the normal buffer 22.

  Also, the special playback control unit 12 is a case where the picture read from the recording medium 11 is a picture used only for normal playback, and is a P picture or B picture that requires inter-screen prediction in order to display a video. The switch 13 is connected to the terminal 13e, and the read picture is stored in the normal PB buffer 42 of the normal buffer 22.

  When the picture read from the recording medium 11 is an I picture that is also used in fast forward playback / fast reverse playback, the special playback control unit 12 skips the skip buffer in accordance with the fast forward playback / fast reverse playback magnification used. The I picture read out from the recording medium 11 is stored in any one of the 120 times skip buffer 31, 21 times skip buffer 32, and 10 times skip buffer 33.

  Here, pictures used in normal playback and fast forward playback / fast reverse playback at each magnification will be described.

  FIG. 2 is a diagram illustrating an example of a picture used for reproduction. The horizontal axis shown in FIG. 2 represents the time axis.

  In FIG. 2, one short vertical solid line and one short vertical broken line represent one picture used for reproduction. In normal playback, all pictures are used for playback, so the solid line is dense, and the pictures used for playback are shown in a band-like black.

  In 120-times fast-forward playback / fast-reverse playback, I-pictures appearing at intervals of 120 pictures when only I pictures are arranged are played back. In 30-times fast-forward playback / fast-rewind playback, 30 pictures are played back. The reproduction of the I picture that appears at the picture interval is performed. In fast forward playback / fast reverse playback of 10 times, I pictures that appear at intervals of 10 pictures when only I pictures are arranged are played back.

The interval between pictures P ₁ and P _{2 in} FIG. 2 represents an interval of 120 pictures, and the interval between pictures P ₁₁ and P ₁₂ represents an interval of 30 pictures. The interval between pictures P ₂₁ and P ₂₂ represents the interval between 10 pictures.

For example, when instructed to start 120-times fast-forward playback at the timing of time t ₁ during normal playback, the picture used first for video display is located at a time after time t ₁ , The picture P ₃₂ is a picture for fast-forward playback of 120 times that is closest to the time t ₁ . Instructed to start 120 times fast-forward playback at time t ₂ during normal playback, or to start 120 times fast-forward playback at time t ₁ during 30 times fast-forward playback even if it is, a picture that is first used to display the image is located at a later time than the respective times, the picture P ₃₂ of the 120 times the fast forward picture for reproduction in the position closest to the respective times .

In addition, during 30 times fast-forward playback, when instructed to start 10-times fast-forward playback at the timing of time t ₃ or when instructed to start normal playback, it is first used for video display. The picture to be displayed is a picture located at time t ₃ .

  In FIG. 2, a picture used in fast forward playback / fast reverse playback of 30 times and 10 times is represented by one short vertical broken line. This indicates that the data is not stored in the fast reverse playback buffer.

For example, when 30 times fast forward playback / fast reverse playback is performed and when 10 times fast forward playback / fast reverse playback is performed, the same picture is played back at the timing of time t _4. One picture read out from 11 can be shared by fast-forward playback / fast-reverse playback at both magnifications. The stored picture is used to perform fast forward playback / fast reverse playback of 30 times or 10 times.

Similarly, when fast-forward playback / fast-rewind playback of 120 times, 30 times, and 10 times is performed, the same picture is played back at the timing of time t ₅ , so one picture read from the recording medium 11 is saved. It can be shared by fast-forward playback / fast-reverse playback at all magnifications. At that timing, pictures stored in a 120-times skip buffer 31 which is a 120-times fast-forward playback / fast-reverse playback buffer are used. , 120 times, 30 times, or 10 times fast forward playback / fast reverse playback is performed.

  In FIG. 2, the picture used for normal playback is shown in black, but the picture used for fast forward playback / fast reverse playback is not stored in the normal buffer 22 which is a buffer for normal playback. Even during normal reproduction, if the picture to be reproduced is stored in the skip buffer 21, the picture stored in the skip buffer 21 is used.

  Returning to the description of FIG. 1, for example, the special playback control unit 12 uses the I picture read from the recording medium 11 as an I picture that is used for fast forward playback / fast reverse playback at any magnification of 120 times, 30 times, and 10 times. In some cases, the switch 13 is connected to the terminal 13a, the read picture is stored in the 120x skip buffer 31, and the switch 13 is connected to the terminal if it is an I picture that is also used in 30x and 10x fast forward playback / fast reverse playback. 13b, and the read picture is stored in the 30x skip buffer 32. In addition, when the I picture read from the recording medium 11 is an I picture that is also used in fast forward playback / fast reverse playback of 10 times, the special playback control unit 12 connects the switch 13 to the terminal 13c and sets the read picture to 10 It is stored in the double skip buffer 33.

  The reproduction buffer 14 includes independent buffer areas of a skip buffer 21 and a normal buffer 22, and a 120 × skip buffer 31, a 30 × skip buffer 32, and a 10 × skip buffer 33 are further formed in the skip buffer 21. Is done. In the normal buffer 22, a normal I buffer 41 and a normal PB buffer 42 are formed.

  The 120 × skip buffer 31 of the skip buffer 21 is a buffer allocated mainly for 120 × fast forward playback / fast reverse playback, and stores a predetermined number of I pictures supplied via the switch 13. . When the large magnification is in the relationship of n times the small magnification (n is a positive integer), such as 120 times and 30 times, 120 times and 10 times, as described above, it is stored in the 120 times skip buffer 31. The picture is also used in 30 times fast forward playback / fast reverse playback and 10 times fast forward playback / fast reverse playback. If necessary, pictures stored in the 120-times skip buffer 31 are also used in normal playback.

  In the 120-times skip buffer 31, such an I picture is temporally previous (past) and temporally subsequent (future) based on the position of the picture used for the current screen display. Things are stored. The previous I picture stored in the 120-times skip buffer 31 can be immediately displayed on the screen after switching the playback mode when 120-times fast-rewind playback is instructed. The I picture later in time is for enabling the screen display immediately after switching the playback mode when 120-times fast-forward playback is instructed. is there.

  The 30-times skip buffer 32 is a buffer allocated mainly for 30-times fast-forward playback / fast-reverse playback, and stores a predetermined number of I pictures supplied via the switch 13. When the large magnification is in the relationship of n times the small magnification, such as 30 times and 10 times, as described above, the pictures stored in the 30 times skip buffer 32 are 10 times fast forward playback / fast reverse playback. Also used in If necessary, the picture stored in the 30-times skip buffer 32 is also used in normal playback.

  The 30 times skip buffer 32 stores such an I picture that is temporally previous and temporally based on the position of the picture used for the current screen display. . The previous I picture stored in the 30-times skip buffer 32 can be immediately displayed on the screen after switching the playback mode when the fast-rewind playback of 30 times is instructed. The I picture later in time is for enabling the screen display after switching the playback mode to be performed immediately when the fast forward playback of 30 times is instructed. is there.

  The 10 × skip buffer 33 is a buffer allocated mainly for 10 × fast forward playback / fast reverse playback, and stores a predetermined number of I pictures supplied via the switch 13. If necessary, the picture stored in the 10-times skip buffer 33 is also used in normal playback.

  The 10-times skip buffer 33 stores such an I picture that is temporally previous and temporally based on the position of the picture used for the current screen display. . The time-previous I picture stored in the 10 × skip buffer 33 can be immediately displayed on the screen after switching the playback mode when 10 × fast reverse playback is instructed. The I picture later in time is for allowing the screen display after switching the playback mode to be performed immediately when a fast forward playback of 10 times is instructed. is there.

  A normal I buffer 41 of the normal buffer 22 stores a predetermined number of I pictures supplied via the switch 13 and used only for normal reproduction.

  The normal PB buffer 42 stores a predetermined number of P pictures and B pictures used in normal reproduction.

  In the normal I buffer 41 and the normal PB buffer 42, pictures used only in normal reproduction are temporally previous and temporally later with reference to the position of the picture used for the current screen display. It has been made to be able to store things.

  The code buffer control unit 15 reads the pictures stored in the reproduction buffer 14 in the decoding order by switching the connection of the switch 16 and stores the read pictures in the code buffer 17.

  The code buffer 17 stores the picture supplied from the reproduction buffer 14 under the control of the code buffer control unit 15.

  The decoder 18 decodes the pictures stored in the code buffer 17 in the order in which they are stored, and stores the results in the frame buffer 19.

  The frame buffer 19 stores the decoding result supplied from the decoder 18. Based on the decoding result stored in the frame buffer 19, the screen is displayed on the display.

  Next, the reading of pictures and the like performed by the playback apparatus 1 having the above configuration will be described.

  FIG. 3 is a diagram illustrating an example of the structure of video content to be reproduced. With reference to FIGS. 4 to 8, description will be given of reading out pictures when the video content having the structure shown in FIG. 3 is targeted.

  In FIG. 3, the first GOP of the GOP (Group Of Picture) constituting the video content is GOP0, GOP478 which is the 479th GOP, GOP479 which is the 480th GOP, GOP480 which is the 481st GOP, GOP481,... 482th GOP is shown.

One GOP consists of 15 pictures. Although partially omitted in FIG. 3, for example, GOP479 is represented by I _479-2 , B _479-0 , B _479-1 , P _479-5 , B _479-3 , B _479-4 , P _479-8 , _B479-6 , _B479-7 , _P479-11 , _B479-9 , _B479-10 , _P479-14 , _B479-12 , _B479-13 . I represents an I picture, P represents a P picture, B represents a B picture, and this order represents the decoding order. The number assigned to each picture represents the GOP number and display order. Display _{order, B 479-0, B 479-1, I} 479-2, B 479-3, B 479-4, P 479-5, B 479-6, B 479-7, P 479-8, B _479-9 , _B479-10 , _P479-11 , _B479-12 , _B479-13 , and _P479-14 .

  FIG. 4 is a diagram illustrating a flow of a picture during normal reproduction.

During normal playback, screen display is performed by reading and decoding the pictures stored in the code buffer 17 by the decoder 18 in the order in which they are stored, as shown in step S1. In the example of FIG. 4, since the first picture I 478-2 in the decoding order of _GOP478 is stored in the code buffer 17, screen display is performed using, for example, a picture of GOP477 before GOP478. It has been broken.

  The area of the code buffer 17 in which the picture consumed by the decoder 18 is stored becomes an empty area.

  In the empty area of the code buffer 17 generated by the consumption of the picture, the continuation picture of the last picture in the decoding order currently stored in the code buffer 17 is transferred from the reproduction buffer 14 by the code buffer control unit 15. It is read out and transferred to the code buffer 17 as shown in step S2. The transferred picture is stored in the empty area as a picture to be decoded following the last picture stored in the code buffer 17.

  For example, the area of the normal PB buffer 42 in which the picture transferred to the code buffer 17 is stored is released as an empty area as shown in step S3.

  Even in normal playback, a picture stored in the skip buffer 21 may be used as a picture to be decoded. At this time, the area of the skip buffer 21 in which the picture transferred to the code buffer 17 is stored. Is also released as a free area. As shown in FIG. 4, the GOP I picture with a number that is a multiple of 120 is stored in the 120-times skip buffer 31, and when decoding a GOP I picture with a number that is a multiple of 120 in normal playback, 120 times The I picture stored in the skip buffer 31 is used.

  Also, the GOP I picture with the number of multiples of 30 excluding the number of multiple of 120 is stored in the 30-times skip buffer 32, and when decoding the GOP I picture with the number of multiples of 30 in normal playback, An I picture stored in the 30-times skip buffer 32 is used.

  Similarly, an I picture of a GOP with a multiple of 10 except for a number that is a multiple of 120 and a number that is a multiple of 30 is stored in the 10-fold skip buffer 33, and a GOP with a number that is a multiple of 10 in normal playback. When decoding an I picture, the I picture stored in the 10 × skip buffer 33 is used.

  For example, when an empty area is generated in the normal PB buffer 42 by transferring a picture to the code buffer 17, a picture following the last picture in the decoding order currently stored in those buffers is specially recorded from the recording medium 11. It is read by the reproduction control unit 12 and stored in a free area as shown as step S4. When the picture read from the recording medium 11 is an I picture, reading from the recording medium 11 is performed only when the I picture is not already stored in the skip buffer 21.

  The picture used for the screen display is updated as time passes, and the I picture past the picture used for the current screen display, which does not need to be stored in the skip buffer 21, is shown as step S5. Thus, the area that has been erased from the skip buffer 21 and that stores the I picture is released as a free area.

  An I picture that does not need to be stored in the skip buffer 21 is read from the recording medium 11 in advance and stored in the skip buffer 21 in response to an instruction to switch the playback mode to fast forward playback / fast reverse playback. It is an I picture other than the I picture that needs to be stored.

  For example, when it takes 1.5 seconds for one picture to be read from the recording medium 11 and to be displayed on the screen, the screen display using each picture is 0 in fast forward playback / fast reverse playback. If switching is performed at intervals of 5 seconds, the three pictures necessary for the 1.5 second screen display are read in advance from the recording medium 11 and stored in the skip buffer 21 when special playback is instructed. It is an I picture that needs to be kept.

In the example of FIG. 4, when an instruction is given to switch the playback mode from normal playback to 10-fold fast reverse playback, it is used for the current screen display among the I pictures stored in the skip buffer 21. past from pictures, from I _470-2 are I-picture closest time to the current time, I _460-2, I _450-2, but decoding in the order of ... is performed, the next I _450-2 reads the I _440-2 that decoding is performed from the recording medium 11, the time until it becomes possible to perform screen display using _{I 440-2, I 470-2, I 460-2} , I 450 _-2 can be connected with only three I pictures, I _470-2 , I _460-2 , I _450-2 I pictures can be played back 10 times faster. An I picture that needs to be stored in the skip buffer 21 in order to be instructed to switch That.

Conversely, I _470-2, as I _460-2, I _440-2 used in the next screen display of I _450-2 is 10 times the fast reverse playback is read from the recording medium 11 when directed _However , since the screen can be displayed by the timing of the screen display using I _440-2 , it is for when the playback mode is instructed to be switched to 10 times fast reverse playback. Therefore, the I picture is not required to be stored in the skip buffer 21.

Note that when 10-times fast-rewind playback is instructed, codes stored in the 10-times skip buffer 33 are used for decoding I _470-2 and I _460-2 , and for decoding I _450-2. The code stored in the 30-times skip buffer 32 is used.

Further, when an instruction is given to switch the playback mode from normal playback to 10-times fast-forward playback, among the I pictures stored in the skip buffer 21, the current one that is in the future than the picture used for current screen display from I _480-2 which is an I-picture closest time to the _{time, I 490-2, I 500-2, I} 510-2, but decoding in the order of ... is performed, the next I _510-2 It reads the I _{520 - 2} decoding is performed from the recording medium 11, the time until it becomes possible to perform the screen display using _{I 520-2, I 480-2, I 490-2} , I 500- ₂ , I _510-2 , if four I pictures can be connected, I _480-2 , I _490-2 , I _500-2 , I _510-2 I pictures It is necessary to store in the 10 times skip buffer 33 in response to an instruction to switch the mode to 10 times fast forward playback. I picture with.

When 10 times fast forward reproduction is instructed, the decoding of the I _480-2 used the code stored in the 120-fold skip buffer 31, 10x skip the decoding of the I _490-2 and I _500-2 The code stored in the buffer 33 is used. A code stored in the 30-times skip buffer 32 is used for decoding I _510-2 .

  In this manner, the skip buffer 21 is preceded by a picture for enabling the screen display after switching to be performed immediately when the playback mode is instructed to be switched to fast forward playback / fast reverse playback. Are read from the recording medium 11 and prepared.

  When an unnecessary area is generated in, for example, the 10 × skip buffer 33 of the skip buffer 21 by erasing unnecessary pictures, it is stored in the 120 × skip buffer 31 or the 30 × skip buffer 32 used for 10 × fast-forward playback. An I picture that is not a picture and that follows the last I picture already stored in the skip buffer 21 is read from the recording medium 11 as shown in step S6 and stored in the generated free space.

  Reading of pictures as described above and storing the read pictures in the respective buffers are repeated during normal reproduction. That is, even during normal playback, not only pictures used in normal playback but also pictures used in fast forward playback / fast reverse playback are read from the recording medium 11 and stored in the skip buffer 21.

  FIG. 5 is a diagram showing a picture flow when an instruction is given to switch the playback mode from normal playback to 30-times fast-forward playback.

  When it is instructed to switch the playback mode to 30 times fast-forward playback, the screen display by the decoder 18 and the frame buffer 19 is stopped as shown in step S11. For example, the code buffer control unit 15 displays the current screen display. A time stamp indicating the position of the picture used in the above is acquired.

  At this time, as shown in step S12, the pictures stored in the code buffer 17, the normal I buffer 41, and the normal PB buffer 42 are erased collectively. In the fast-forward playback of 30 times, the pictures stored in the normal I buffer 41 and the normal PB buffer 42 are not used, so it can be said that they are unnecessary pictures.

  Furthermore, at this time, among the buffers constituting the skip buffer 21, pictures stored in the 10-times skip buffer 33, which is a fast-forward / fast-reverse playback buffer having a smaller magnification than the fast-forward playback magnification instructed to be played back. Are collectively erased as shown in step S13. In 30-times fast-forward playback, the picture stored in the 10-times skip buffer 33 is not used, so it can be said that it is an unnecessary picture. On the other hand, the picture stored in the 120-times skip buffer 31 may be used even in 30-times fast-forward playback, and is a necessary picture and is not deleted.

  When an unnecessary picture is erased, as shown in step S14, it is in the closest position after the time stored in the 30-times skip buffer 32 and used for the current screen display. The pictures are sequentially read from the picture by the code buffer control unit 15 and transferred to the code buffer 17. When a picture used for 30-times fast-forward playback is stored in a 120-times skip buffer 31 that is a fast-forward / fast-reverse buffer having a magnification larger than the magnification of the fast-forward playback instructed to be played, skip 120 times The picture stored in the buffer 31 is read by the code buffer control unit 15 and transferred to the code buffer 17.

  In the decoder 18, the picture stored in the code buffer 17 is decoded, and screen display by fast-forward playback of 30 times is started.

  In this way, when switching to the playback mode is instructed, the picture used for fast-forward playback after switching is not started to be read from the recording medium 11, and the recording medium is instructed before switching to the playback mode is instructed. 11, the fast-forward playback is started by using the picture read in advance from 11 and prepared in the skip buffer 21.

  As a result, it is possible to immediately display the screen after switching the playback mode, as compared with the case where reading of a picture used for fast-forward playback is started from the recording medium 11 after an instruction to switch the playback mode is given.

  The picture used for the screen display is updated with the passage of time, and the past I picture is erased from the picture used for the current screen display, which is no longer required to be stored in the 30 times skip buffer 32. The area where the picture is stored is released as an empty area. In the area of the 30-times skip buffer 32 released as a free area, the I picture following the last stored I picture is read from the recording medium 11 and stored as shown in step S15.

  When an unnecessary I picture is erased, as shown in step S16, a P picture that is used in normal playback and is temporally later than the I picture used for the current screen display, B A picture is read from the recording medium 11 and stored in the normal PB buffer 42.

  Here, the picture stored in the normal PB buffer 42 is for enabling the screen display after switching to be performed immediately when an instruction to switch the playback mode to normal playback is given. Since the I picture is used for 30 times fast-forward playback, if the P picture and B picture following the I picture are prepared in the normal PB buffer 42 in advance, the I picture used for 30 times fast-forward playback is combined. Therefore, normal playback can be started immediately without reading out the necessary picture from the recording medium 11.

  At this time, the P picture and B picture stored in the normal PB buffer 42 following the I picture erased in step S13 are erased, and the area of the normal PB buffer 42 in which the erased picture is stored is It is released as a free area.

  If the stream is encoded with open GOP, a B picture that cannot be decoded without a picture of the immediately preceding GOP is not read from the recording medium 11 in step S16.

  When a P picture or B picture is stored in the normal PB buffer 42 in response to an instruction to switch the playback mode, fast-forward playback / fast-forward at a magnification larger than the magnification of the fast-forward playback instructed to play back. Of the I pictures stored in the 120 × skip buffer 31 which is a buffer for backward playback, the picture used for screen display need not be stored by updating as time passes. The past I picture is erased from the picture used for the screen display and is released as a free area. In the area of the 120-times skip buffer 31 released as a free area, the I picture following the last stored I picture is read from the recording medium 11 and stored as shown in step S17.

  When it is instructed to switch the playback mode from normal playback to 30-times fast-forward playback, the above picture flow is realized. Even when an instruction is given to switch from normal playback to fast-forward playback at other magnifications, basically the same processing is performed, and the same picture flow as that shown in FIG. 5 is realized.

  Note that pictures used for fast-forward playback at a magnification smaller than the fast-forward playback after switching are not necessary for fast-forward playback at the magnification after switching, so immediately after switching the playback mode from normal playback to fast-forward playback, Such a picture is not read from the recording medium 11. Of course, in consideration of the bandwidth of the bus used for accessing the recording medium 11 and the response when the magnification is lowered, when there is no problem with the load on the bus, fast-forward reproduction / rewinding at a small magnification is possible. A picture for reproduction may be read out from the recording medium 11 in advance and stored in the skip buffer 21.

  FIG. 6 is a diagram showing a picture flow when an instruction to switch the playback mode from 30-times fast-forward playback to normal playback is given.

  When it is instructed to switch the playback mode to normal playback, the screen display by the decoder 18 and the frame buffer 19 is stopped as shown in step S21, and is used for the current screen display by the code buffer control unit 15, for example. A time stamp representing the position of the current picture is obtained.

  At this time, as shown in step S22, the pictures stored in the code buffer 17 are erased collectively.

  When the picture stored in the code buffer 17 is deleted, as shown in step S23, the picture specified by the time stamp obtained in step S21 is transferred again from the 30-times skip buffer 32 to the code buffer 17. The

  In the decoder 18, the picture stored in the code buffer 17 is decoded, and the same screen as that displayed when the playback mode is instructed to be switched to the normal playback is displayed. Thereby, it is possible to prevent the display screen from changing suddenly, and it is possible to perform transition of the screen display at the time of switching the reproduction mode in a natural manner.

  When the same screen as the screen that was displayed when normal playback was instructed is displayed, as shown in step S24, the screen that is stored in the normal PB buffer 42 is displayed following the displayed screen. The P picture and B picture to be used are transferred to the code buffer 17. While the fast-forward playback of 30 times is performed, a predetermined number of P pictures and B pictures are prepared in the normal PB buffer 42 in response to an instruction to switch the playback mode to normal playback ( Step S16 in FIG.

  In the decoder 18, the picture stored in the code buffer 17 is decoded, and the screen display by normal reproduction is started.

  In this way, when switching to the playback mode is instructed, the picture used for normal playback after switching is not started to be read from the recording medium 11, and the recording medium is instructed before switching to the playback mode is instructed. 11 is read in advance, and the picture prepared in the skip buffer 21 is used to start normal reproduction.

  As a result, it is possible to immediately display the screen after switching the playback mode, compared to the case of starting reading out the picture used for normal playback from the recording medium 11 after the instruction to switch the playback mode.

  The picture that is not transferred to the code buffer 17 and remains in the normal PB buffer 42 is erased as shown in step S25.

  When the picture in the normal PB buffer 42 is deleted, the P picture and B picture following the picture transferred from the normal PB buffer 42 to the code buffer 17 in step S24 are read from the recording medium 11 as shown in step S26. And stored in the normal PB buffer 42. Also, if the I picture after the picture transferred to the code buffer 17 is not already stored in the skip buffer 21 as an instruction to switch the playback mode, the recording medium 11 It is read and stored in the normal I buffer 41.

  When a picture is not stored in advance in the 10-times skip buffer 33, which is a fast-forward playback / fast-reverse playback buffer smaller than the fast-forward playback magnification before switching the playback mode, it is used for the current screen display. With reference to the position of the current picture, the temporally previous I picture and temporally subsequent I picture used in 10-times fast forward playback / fast reverse playback are read from the recording medium 11 as step S27. As shown, it is stored in the 10 times skip buffer 33. When fast-forward playback of 30 times is being performed, the pictures stored in the 10-times skip buffer 33 are collectively erased as unnecessary pictures (step S13 in FIG. 5).

  The picture used for the screen display is updated with the passage of time, and it is no longer necessary to store the picture in the skip buffer 21, and the past I picture from the picture used for the current screen display is deleted. The area in which the picture is stored is released as an empty area. In the area of the skip buffer 21 released as an empty area, the I picture following the last stored I picture is read from the recording medium 11 and stored as shown in step S28.

  When it is instructed to switch the playback mode from 30 times fast-forward playback to normal playback, the above picture flow is realized. When an instruction is given to switch the playback mode from fast-forward playback at other magnifications to normal playback, basically the same processing is performed, and the same picture flow as shown in FIG. 6 is realized.

  FIG. 7 is a diagram showing a picture flow when an instruction is given to switch the playback mode from 30 times fast forward playback to 120 times fast forward playback.

  When it is instructed to switch the playback mode to 120 times fast-forward playback, the screen display by the decoder 18 and the frame buffer 19 is stopped as shown in step S31. For example, the code buffer control unit 15 displays the current screen display. A time stamp indicating the position of the picture used in the above is acquired.

  At this time, as shown in step S32, the pictures stored in the code buffer 17 and the normal PB buffer 42 are erased collectively. In fast-forward playback of 120 times, since the picture stored in the normal PB buffer 42 is not used, it can be said that it is an unnecessary picture. The pictures stored in the normal I buffer 41 and the 10-times skip buffer 33 have already been deleted during 30-times fast-forward playback (steps S12 and S13 in FIG. 5).

  Further, at this time, as shown in step S33, among the buffers constituting the skip buffer 21, the buffer stores pictures, and fast-forward playback / playback at a magnification smaller than the fast-forward playback magnification at which playback is instructed. The pictures stored in the 30-times skip buffer 32, which is a fast reverse playback buffer, are erased all at once. In the 120-times fast-forward playback, the picture stored in the 30-times skip buffer 32 is not used, so it can be said that it is an unnecessary picture.

  When an unnecessary picture is erased, as shown in step S34, it is in the nearest position after the picture stored in the 120-times skip buffer 31 and used for the current screen display. The pictures are sequentially read from the picture by the code buffer control unit 15 and transferred to the code buffer 17.

  In the decoder 18, the picture stored in the code buffer 17 is decoded, and screen display by fast-forward playback of 120 times is started.

  In this way, when switching to the playback mode is instructed, the picture used for fast-forward playback after switching is not started to be read from the recording medium 11, and the recording medium is instructed before switching to the playback mode is instructed. 11, the fast-forward playback is started by using the picture read in advance from 11 and prepared in the skip buffer 21.

  As a result, it is possible to immediately display the screen after switching the playback mode, as compared with the case where reading of a picture used for fast-forward playback is started from the recording medium 11 after an instruction to switch the playback mode is given.

  The picture used for the screen display is updated with the passage of time, and the past I picture is deleted from the picture used for the current screen display, which is no longer required to be stored in the 120-fold skip buffer 31. The area where the picture is stored is released as an empty area. In the area of the 120-times skip buffer 31 released as an empty area, the I picture following the last stored I picture is read from the recording medium 11 and stored as shown in step S35.

  When an unnecessary I picture is erased, as shown in step S36, a picture that is used in normal reproduction and is temporally later than the I picture used for the current screen display, B A picture is read from the recording medium 11 and stored in the normal PB buffer 42.

  Here, the picture stored in the normal PB buffer 42 is for enabling the screen display after switching to be performed immediately when an instruction to switch the playback mode to normal playback is given. Since the I picture is used for 120 times fast-forward playback, if the P picture and B picture following the I picture are prepared in the normal PB buffer 42 in advance, the I picture is used together with the 120 times fast-forward playback. Therefore, normal playback can be started immediately without reading out the necessary picture from the recording medium 11.

  At this time, the P picture and the B picture stored in the normal PB buffer 42 following the I picture deleted in step S33 are deleted, and the area of the normal PB buffer 42 in which the deleted picture is stored is It is released as a free area.

  If the stream is encoded by open GOP, a B picture that cannot be decoded without a picture of the previous GOP is not read from the recording medium 11 in step S36.

  When there is fast-forward playback / fast-reverse playback at a magnification larger than the magnification of the fast-forward playback instructed to be played back, the picture used for screen display is updated with the passage of time and stored in the skip buffer 21. When a picture that no longer needs to be stored is generated, it is erased, and the area where the erased picture was stored is released as an empty area. In the area of the skip buffer 21 released as an empty area, the I picture following the last stored I picture is read from the recording medium 11 and stored.

  When an instruction is given to switch the playback mode from 30 times fast forward playback to 120 times fast forward playback, the above picture flow is realized. Even when an instruction is given to switch the playback mode from fast-forward playback at a predetermined magnification to fast-forward playback at a higher magnification, the same processing is performed and the same picture flow as shown in FIG. 7 is realized. Is done.

  FIG. 8 is a diagram showing a picture flow when an instruction is given to switch the playback mode from 30 times fast forward playback to 10 times fast forward playback.

  When it is instructed to switch the playback mode to 10 times fast-forward playback, the screen display by the decoder 18 and the frame buffer 19 is stopped as shown in step S41. For example, the code buffer control unit 15 displays the current screen display. A time stamp indicating the position of the picture used in the above is acquired.

  At this time, as shown in step S42, the pictures stored in the code buffer 17 and the normal PB buffer 42 are erased collectively. The pictures stored in the 30-times skip buffer 32, the 10-times skip buffer 33, and the normal I buffer 41 have already been deleted during 30-times fast-forward playback (steps S12 and S13 in FIG. 5).

  When the pictures stored in the code buffer 17 and the normal PB buffer 42 are deleted, if no pictures are stored in the 10-times skip buffer 33 in advance, the position of the picture used for the current screen display As a reference, the temporally previous I picture and temporally subsequent I picture used in 10 times fast forward playback / fast reverse playback are read from the recording medium 11 and shown as step S43. It is stored in the 10 times skip buffer 33.

  When an I picture is stored in advance in the 10-times skip buffer 33 or newly stored, as shown in step S44, a picture following the picture specified by the time stamp acquired in step S41 Is read from the 10-times skip buffer 33 and transferred to the code buffer 17.

  In the decoder 18, the picture stored in the code buffer 17 is decoded, and screen display by 10-times fast-forward playback is started.

  If there is a fast-forward playback / fast-rewind playback with a magnification smaller than the fast-forward playback magnification before switching and larger than the fast-forward playback magnification after switching, the current screen used for fast-forward playback / fast-rewind playback at that magnification The temporally previous I picture and temporally subsequent I picture are read from the recording medium 11 with reference to the position of the picture used for display, and stored in the skip buffer 21.

  The picture used for the screen display is updated with the passage of time, and it is no longer necessary to store the picture in the skip buffer 21, and the past I picture from the picture used for the current screen display is deleted. The area in which the picture is stored is released as an empty area. In the area of the skip buffer 21 released as an empty area, the I picture following the last stored I picture is read from the recording medium 11 and stored as shown in step S45.

  When screen display of 10-times fast-forward playback is started, as shown in step S46, a picture that is used in normal playback and that is later in time than the I picture used in the current screen display. Pictures and B pictures are read from the recording medium 11 and stored in the normal PB buffer 42.

  Here, the picture stored in the normal PB buffer 42 is for enabling the screen display after switching to be performed immediately when an instruction to switch the playback mode to normal playback is given. Since the I picture is used for 10 times fast-forward playback, if the P picture and B picture following the I picture are prepared in the normal PB buffer 42 in advance, it is combined with the I picture used for 10 times fast-forward playback. Therefore, normal playback can be started immediately without reading out the necessary picture from the recording medium 11.

  At this time, the P picture and B picture stored in the normal PB buffer 42 following the I picture erased in step S45 are erased, and the area of the normal PB buffer 42 in which the erased picture is stored is It is released as a free area.

  If the stream is encoded by open GOP, the B picture that cannot be decoded without the picture of the immediately preceding GOP is not read from the recording medium 11 in step S46.

  For pictures stored in 120-times skip buffer 31 and 30-times skip buffer 32, which are buffers for fast-forward playback / fast-rewind playback of 30 times and 120 times, which are larger than the magnification of fast-forward playback instructed to switch, When a picture that is no longer required to be stored by updating the picture used for screen display over time is erased, it is erased, and the area where the erased picture was stored is free space Opened. In the areas of the 120-times skip buffer 31 and the 30-times skip buffer 32 that have been released as free areas, the I picture following the last I picture that has already been stored is read from the recording medium 11 as shown in step S47. And stored.

  When it is instructed to switch the playback mode from 30 times fast forward playback to 10 times fast forward playback, the picture flow as described above is realized. Even when an instruction is given to switch the playback mode from fast-forward playback at a predetermined magnification to fast-forward playback at a smaller magnification, the same processing is performed and the same picture flow as shown in FIG. 8 is realized. Is done.

  As described above, the playback apparatus 1 can switch the playback mode from normal playback to fast-forward playback / fast-reverse playback, or from fast-forward playback / fast-reverse playback to normal playback. When instructed, a picture that has been read from the recording medium 11 before switching is used to display the screen after switching the playback mode.

  As a result, since it is not necessary to start reading a necessary picture from the recording medium 11 triggered by an instruction to switch the playback mode, the screen display after switching can be immediately performed without causing the user to feel a delay in screen display. Can start.

  In addition, since the playback apparatus 1 has an independent area for each playback mode in the skip buffer 21 as a storage area for pictures read out from the recording medium 11 in advance, fast-forward playback / fast-rewind playback at a certain magnification. In addition, pictures that are not necessary for the reproduction can be erased in a batch, and picture management can be simplified. For example, when pictures used for fast-forward playback / fast-reverse playback at each magnification are stored together in one area, processing is complicated, such as specifying and erasing unnecessary picture storage locations. Although it becomes a thing, such a thing can be prevented.

  Further, even when the position of a picture used for screen display is updated, a predetermined number of past pictures are continuously stored in the skip buffer 21 and the normal buffer 22 with reference to the position, so that fast rewinding is possible. When switching to playback is instructed, or when switching to normal playback in the direction opposite to the time axis direction is instructed, the screen display after switching can be performed immediately.

  For pictures that are commonly used in fast-forward playback / fast-reverse playback at two or more magnifications, the code is stored only in the buffer assigned to fast-forward playback / fast-rewind playback at a larger magnification, and fast-forward at a lower magnification. Since the code is also used in the reproduction / fast reverse reproduction, it is not necessary to store the same code in the buffer assigned to the fast forward reproduction / fast reverse reproduction at each magnification. Thereby, the frequency of access to the recording medium 11 can be reduced, and the capacity of each buffer can be reduced.

  In the above, 120 times fast forward playback / fast reverse playback uses pictures that appear at exactly 120 picture intervals on the time axis, and 30 times fast forward playback / fast reverse playback uses strictly on the time axis. In this case, pictures appearing at 30 picture intervals are used, and in 10-times fast forward playback / rewind playback, pictures appearing at exactly 10 picture intervals on the time axis are used. Need not be at exactly the same interval as the fast-forward playback / fast-reverse playback magnification, and a predetermined error may be allowed. For example, an error is allowed at intervals smaller than the magnification of fast forward playback / fast reverse playback.

  For example, in 120-times fast-forward playback / fast-reverse playback, after a certain picture is used, the I picture after 120 pictures on the time axis is used, and then the I picture after 110 pictures on the time axis is used. For example, the interval may vary. As described above, the frequency of access to the recording medium 11 may be reduced by selecting a picture to be reproduced in consideration of the position of a picture that has already been read.

  Further, in the above, the picture read out in advance from the recording medium 11 during the reproduction of the video content in the predetermined reproduction mode is the time based on the position of the picture used for the current screen display. Although it is assumed that the picture is at both the front and rear positions, only the picture at the previous position in time or only the picture at the rear position may be read out in advance.

  In the above, the case where the video content to be played back is the content of the MPEG2 format has been described, but the same processing can be applied to the case of playing back video content in other formats.

  Further, in the above description, the case where the recording medium from which the video content is read is the hard disk has been described, but the same processing can be applied to the case where the video content is read from another recording medium such as an optical disk. .

  The series of processes described above can be executed by hardware or can be executed by software. When a series of processing is executed by software, a program constituting the software executes various functions by installing a computer incorporated in dedicated hardware or various programs. For example, it is installed from a program recording medium in a general-purpose personal computer or the like.

  FIG. 9 is a block diagram showing an example of the configuration of a personal computer that executes the above-described series of processing by a program.

  A CPU (Central Processing Unit) 101 executes various processes according to a program stored in a ROM (Read Only Memory) 102 or a storage unit 108. A RAM (Random Access Memory) 103 appropriately stores programs executed by the CPU 101 and data. These CPU 101, ROM 102, and RAM 103 are connected to each other by a bus 104.

  An input / output interface 105 is also connected to the CPU 101 via the bus 104. Connected to the input / output interface 105 are an input unit 106 made up of a keyboard, mouse, microphone, and the like, and an output unit 107 made up of a display, a speaker, and the like. The CPU 101 executes various processes in response to commands input from the input unit 106. Then, the CPU 101 outputs the processing result to the output unit 107.

  The storage unit 108 connected to the input / output interface 105 includes, for example, a hard disk, and stores programs executed by the CPU 101 and various data. The communication unit 109 communicates with an external device via a network such as the Internet or a local area network.

  The drive 110 connected to the input / output interface 105 drives a removable medium 111 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, and drives programs and data recorded there. Get etc. The acquired program and data are transferred to and stored in the storage unit 108 as necessary.

  As shown in FIG. 9, a program recording medium that stores a program that is installed in a computer and can be executed by the computer includes a magnetic disk (including a flexible disk), an optical disk (CD-ROM (Compact Disc-Read Only). Memory, DVD (Digital Versatile Disc), a magneto-optical disk, a removable medium 111 that is a package medium composed of a semiconductor memory, or the ROM 102 in which a program is temporarily or permanently stored, or a storage unit 108 It is comprised by the hard disk etc. which comprise. The program is stored in the program recording medium using a wired or wireless communication medium such as a local area network, the Internet, or digital satellite broadcasting via a communication unit 109 that is an interface such as a router or a modem as necessary. Done.

  In the present specification, the steps for describing a program are not only processes performed in time series in the order described, but also processes that are executed in parallel or individually even if they are not necessarily processed in time series. Is also included.

It is a block diagram which shows the structural example of the reproducing | regenerating apparatus which concerns on one Embodiment of this invention. It is a figure which shows the example of the picture used for reproduction | regeneration. It is a figure which shows the example of the structure of a video content. It is a figure which shows the flow of the picture in normal reproduction | regeneration. It is a figure which shows the flow of a picture when it is instruct | indicated to switch reproduction | regeneration mode from normal reproduction | regeneration to 30 times fast-forward reproduction | regeneration. It is a figure which shows the flow of a picture when it is instruct | indicated that switching a reproduction | regeneration mode from 30 times fast forward reproduction to normal reproduction. It is a figure which shows the flow of a picture when it is instruct | indicated to switch reproduction | regeneration mode from fast-forward reproduction of 30 times to fast-forward reproduction of 120 times. It is a figure which shows the flow of a picture when it is instruct | indicated to switch reproduction | regeneration mode from 30 times fast forward reproduction to 10 times fast forward reproduction. And FIG. 16 is a block diagram illustrating a configuration example of a personal computer.

Explanation of symbols

  1 playback device, 11 recording medium, 12 special playback control unit, 14 playback buffer, 15 code buffer control unit, 17 code buffer, 18 decoder, 19 frame buffer, 21 skip buffer, 22 normal buffer, 31 120 times skip buffer, 32 30 times skip buffer, 33 10 times skip buffer, 41 normal I buffer, 42 normal PB buffer

Claims (10)

The video content read from the recording medium includes normal playback for decoding all the pictures constituting the video content, and special playback for decoding only the pictures appearing at predetermined intervals among the pictures constituting the video content. In a playback device that plays back in any of the playback modes,
A first buffer for storing a picture used as a decoding target only during normal reproduction;
A second buffer for storing a picture used as a decoding target even in the special reproduction;
A third buffer for storing a picture to be decoded;
Of the pictures read from the recording medium, a picture used as a decoding target only during the normal playback is stored in the first buffer, and a picture used as a decoding target during the special playback is stored in the first buffer. First control means for storing each in a second buffer;
Second control means for reading out the pictures stored in the first and second buffers in the order of decoding according to the playback mode, and storing them in the third buffer;
Decoding means for decoding a picture stored in the third buffer by the second control means and displaying an image;
The first control means further includes the special reproduction of at least one of a previous position and a subsequent position with respect to a position of a picture used for video display by the decoding means. A playback apparatus for storing a picture used as a decoding target in the second buffer also in the case of. When the second control means switches the reproduction mode from the normal reproduction to the special reproduction, the pictures stored in the second buffer by the first control means up to that time are decoded in the order of decoding. The playback device according to claim 1, wherein the playback device is read and stored in the third buffer. The first control means erases the picture stored in the second buffer according to the position of the picture used for video display, and stores the picture in the area of the second buffer from which the picture is erased. The playback apparatus according to claim 2, wherein another picture used as a decoding target is stored even in the special playback. The first control means reads the same picture as the picture read from the second buffer by the second control means and stored in the third buffer, and the picture is decoded by the decoding means. The playback apparatus according to claim 2, wherein the second buffer is continuously stored in the second buffer for a certain period of time. When the picture is decoded by the special reproduction, the first control means is further configured to use the position of the picture used for displaying the video by the decoding means as a reference and the position before and after the time. The playback device according to claim 1, wherein a picture used as a decoding target only at the time of the normal playback, which is at least one of positions, is stored in the first buffer. 2. When there are a plurality of modes with different intervals of pictures to be decoded as the special playback modes, the second buffer is configured with the same number of regions as the number of the special playback modes. The playback device described in 1. The playback device according to claim 6, wherein each of the special playback modes is assigned to each of the areas constituting the second buffer. The first control means is configured to select a picture to be decoded in common in two or more modes of the plurality of modes for special reproduction, among the modes to be decoded in common with the pictures. The playback apparatus according to claim 7, wherein the playback apparatus stores the second buffer area allocated to the mode having the largest interval between pictures to be decoded. The video content read from the recording medium includes normal playback for decoding all the pictures constituting the video content and special playback for decoding only pictures that appear at a predetermined interval among the pictures constituting the video content. Play in one of the playback modes,
A first buffer for storing a picture used as a decoding target only during normal reproduction;
A second buffer for storing a picture used as a decoding target even in the special reproduction;
In a playback method of a playback device comprising: a third buffer for storing a picture to be decoded;
Of the pictures read from the recording medium, a picture used as a decoding target only during the normal playback is stored in the first buffer, and a picture used as a decoding target during the special playback is stored in the first buffer. Each stored in a second buffer,
The pictures stored in the first and second buffers are read in the order of decoding according to the playback mode and stored in the third buffer,
Decoding the picture stored in the third buffer and displaying the video;
With reference to the position of the picture used for video display, the picture used as a decoding target at the time of the special reproduction at least one of the previous position and the subsequent position in time A playback method comprising the steps of: The video content read from the recording medium includes normal playback for decoding all the pictures constituting the video content and special playback for decoding only pictures that appear at a predetermined interval among the pictures constituting the video content. Play in one of the playback modes,
A first buffer for storing a picture used as a decoding target only during normal reproduction;
A second buffer for storing a picture used as a decoding target even in the special reproduction;
In a program for causing a computer to execute playback processing of a playback device including a third buffer for storing a picture to be decoded,
Of the pictures read from the recording medium, a picture used as a decoding target only during the normal playback is stored in the first buffer, and a picture used as a decoding target during the special playback is stored in the first buffer. Each stored in a second buffer,
The pictures stored in the first and second buffers are read in the order of decoding according to the playback mode and stored in the third buffer,
Decoding the picture stored in the third buffer and displaying the video;
With reference to the position of the picture used for displaying the video, the picture used as the decoding target at the time of the special reproduction at least one of the previous position and the subsequent position in terms of time A program including a step for storing in a buffer of 2.

Images