JP4074255B2 - DVD playback apparatus and playback method - Google Patents

Description

  The present invention relates to a DVD (Digital Versatile Disc) -DVD player that plays back video, and more particularly to a playback apparatus and playback method capable of special playback such as reverse slow playback and fast reverse playback.

  In recent years, players that play back optical discs called DVD-videos have been put into practical use and have become popular. DVD-video includes content such as movies and karaoke, and a main picture (main video) and a sub-picture (sub-video) are compressed independently. Movie subtitles and karaoke lyrics are compressed as sub-pictures.

  When the user views a scene of a movie again or listens to a phrase of karaoke again, it is assumed that special reproduction in the reverse direction is performed. In that case, it seems that it is common to judge from the display of the sub-picture to return from the special reproduction in the reverse direction to the normal reproduction. Accordingly, it has been desired to display a sub-picture during special playback in the reverse direction.

  As is well known in this technical field, in the MPEG (Moving Picture Experts Group) image compression technique, the main picture is compressed using about 15 pieces of video data called GOP (Group Of Pictures) as a group of processing units. The That is, the video data of the main picture is encoded for each GOP. One GOP includes an I picture (Intra-Picture), a P picture (Predictive-Picture), a B picture (Bidirectionally Predictive-Picture), There is. An I picture is encoded only within that frame. Since it is a still image mode, it is used for the start of encoding and entry points. A P picture is encoded by motion compensated prediction from a past I picture or P picture. B pictures are encoded using motion compensated prediction using past or future I or P pictures. In the following, I picture, P picture, and B picture may be simply indicated by I, P, and B, respectively.

  As a prior art, there is a “playback apparatus and playback method” that can perform special playback such as reverse playback, fast forward playback, and fast reverse playback of not only a main picture but also a sub picture (see, for example, Patent Document 1).

  With reference to FIG. 1, the reproduction apparatus disclosed in Patent Document 1 will be described. The reproduction apparatus shown in the figure includes an optical pickup 2 that reads a data stream recorded on an optical disc 1, a demodulation circuit 3 that performs 16/8 conversion processing on the data stream, an EEC decoder 4 that performs error correction processing, and a demodulation circuit 3. An EEC memory 5 that temporarily stores a data stream from the image data, a descrambling circuit 6 that performs descrambling processing on the data stream, and a scrambled data stream that is divided into main picture data, sub-picture data, and audio data. And a multiplexer 7.

  The combination of the optical pickup 2, the demodulation circuit 3, the EEC decoder 4, the EEC memory 5, and the descrambling circuit 6 functions as a reading unit that reads the data stream and outputs the read data stream.

  The demodulating circuit 3 converts the 16-bit data stream supplied from the optical pickup 2 into 8 bits, and supplies the converted data stream to the ECC decoder 4.

  The ECC decoder 4 temporarily stores the data stream from the demodulation circuit 3 in the ECC memory 5 and performs error correction processing for each predetermined ECC block. Then, the ECC decoder 4 reads the error-corrected data stream from the ECC memory 5 and supplies it to the descrambling circuit 6.

  The descrambling circuit 6 performs a predetermined descrambling process on the data stream scrambled by, for example, inversion of the color burst signal, and supplies the descrambled data stream to the demultiplexer 7.

  The demultiplexer 7 extracts main picture data, sub-picture data, and audio data from the data stream. The main picture data is video data of a main picture that is a video mainly displayed on the screen. The sub-picture data is video data of sub-pictures such as movie subtitles and karaoke lyrics displayed on the screen. The main picture data and sub-picture data also contain PTS (Presentation Time Stamp) information indicating the reproduction time of each data.

  Specifically, the demultiplexer 7 extracts main picture data from the video pack (V_PCK) of the data stream, sub-picture data from the sub-picture pack (SP_PCK), and audio data from the audio pack (A_PCK). Further, the demultiplexer 7 extracts sub picture address information (SP_SYNCA) (described later) of a navigation pack (hereinafter also referred to as “Navi pack” or “Navi pack”) of a VOBU (Video Object Unit) described later from the data stream. Then, the extracted sub-picture address information (SP_SYNCA) is supplied to the controller 17 described later.

  Therefore, the demultiplexer 7 operates as an address extracting unit that extracts address information from a unit having a main picture to be processed in the read data stream.

  The playback apparatus shown in the figure includes a video decoder 8 that decodes main picture data, a code buffer 9 that temporarily stores main picture data to be decoded, a display memory 10, a sub-picture decoder 11 that decodes sub-picture data, and a decoding A code buffer 12 for temporarily storing subpicture data to be stored, a D / A converter (digital / analog converter) 13, an audio decoder 14 for decoding audio data, and a code buffer 15 for temporarily storing audio data to be decoded And a D / A converter (digital / analog converter) 16 and a controller 17 for controlling each circuit. An arrow 18 indicates a data flow of sub-picture address information SP_SYNCA described later.

  The video decoder 8 temporarily stores the main picture data compressed by the MPEG method supplied from the demultiplexer 7 in the code buffer 9. The video decoder 8 reads the video data from the code buffer 9 under the control of the controller 17, MPEG-decodes this video data, and supplies it to the sub-video decoder 11. The video data decoded by the video decoder 8 is supplied to a display (not shown) via the display memory 10.

  That is, the combination of the video decoder 8 and the code buffer 9 serves as a first decoding unit that decodes the main picture and outputs the decoded main picture.

  The sub-picture decoder 11 temporarily stores the sub-picture data supplied from the demultiplexer 7 in the code buffer 12. The sub-picture decoder 11 reads the sub picture data from the code buffer 12 based on the control of the controller 17 and decodes the sub picture data. Then, the sub video decoder 11 combines the main picture data and the sub picture data and supplies the combined video data to the D / A converter 13. The D / A converter 13 converts the video data to analog and outputs the analog video data via the video terminal.

  That is, the combination of the sub-picture decoder 11 and the code buffer 12 functions as a second decoding unit that decodes the sub-picture and outputs the decoded sub-picture. The sub-picture decoder 11 also functions as an output unit that combines the decoded main picture and the decoded sub-picture and outputs the combined picture.

  The audio decoder 14 temporarily stores the audio data supplied from the demultiplexer 7 in the code buffer 15. The audio decoder 14 reads audio data from the code buffer 15 based on the control of the controller 17 and decodes the audio data. The D / A converter 16 converts the audio data supplied from the audio decoder 14 into analog data and outputs the analog data via an audio output terminal.

  Next, the data stream recorded on the DVD-video will be described with reference to FIGS. FIG. 2 is a timing chart of main pictures and sub-pictures reproduced by a conventional reproducing apparatus. FIG. 3A is a configuration diagram of the video object unit VOBU of the data stream.

  As shown in FIG. 2, the data stream read from the optical pickup 2 is configured in units of video object units VOBU (Video Object Unit). The data stream shown in FIG. 2 has first to third video object units VOBU1, VOBU2, and VOBU3. In FIG. 2, only the picture type of the main picture of the third video object unit VOBU3 is described, and the description of the picture type of the main picture of the first video object unit VOBU1 and the second video object unit VOBU2 is omitted. .

  As shown in FIG. 3A, the video object unit VOBU includes a video pack (V_PAK) composed of main picture data compressed by the MPEG (Moving Picture Experts Group) method and an audio pack composed of compressed audio data. (A_PCK), a sub-picture pack (SP_PCK) composed of sub-picture data, and a navigation pack (NV_PCK) which is management information of these data.

  The navigation pack has synchronization information (SYNCI: Synchronous Information) indicating address information of the sub-picture synchronized with the main picture of the video pack and the audio data. The synchronization information SYNCI includes audio address information (A_SYNCA) indicating the address of audio data synchronized with the main picture, and a sub address indicating the head address of the earliest video object unit VOBU to which the sub-picture synchronized with the main picture belongs. Picture address information (SP_SYNCA). Accordingly, in the same video object unit VOBU, the main picture compressed into the video pack and the sub-picture compressed into the sub-picture pack are not always displayed simultaneously after being decoded.

  A sub-picture unit will be described with reference to FIG. When a predetermined number of sub-picture packs are collected, one sub-picture unit (SP unit: Sub-Picture Unit) is configured. In FIG. 3B, the first to nth sub-picture packs SP_PCK1 to SP_PCKn are collected to constitute one sub-picture unit.

  This SP unit includes a sub-picture unit header (SPUH) consisting of size information of the SP unit, 2-bit pixel data (PXD: Pixel Data) constituting the sub-picture, and a display. It consists of a sub-picture display control sequence table (SP_DCSQT: Sub-Picture Display Control Sequence Table) that controls the sub-picture to be displayed.

  The sub picture display control sequence table SP_DCSQT is a sub picture display control sequence SP_DCSQ (Sub-Picture Display Control Sequence) address information to be executed next. Start address (SP_NXT_DCSQ_SA: Start Address of the next SP_DCSQ), sub picture display control command (SP_DCCMD: SP Display Control Commands) for setting PXD color, display area range, etc. It consists of a sub-picture display control sequence start time (SP_DCSQ_STM: Start Time of SP_DCSQ) indicating execution time.

  The sub-picture unit data 1 shown in FIG. 2 means that it is composed of sub-picture packs of the first video object unit VOBU1 and the second video object unit VOBU2. For convenience of explanation, it is assumed that the video object unit VOBU is composed of one GOP (Group Of Picture), and this GOP is composed of six images. For example, assume that the data stream of the third video object unit VOBU3 is decoded. In this case, main pictures B30, B31, I32, B33, B34, and P35 are displayed, and sub-picture SP unit data 1 is displayed. The sub picture address information SP_SYNCA in the navigation pack of the third video object unit VOBU3 points to the head address of the first video object unit VOBU1. This is because the earliest of the SP unit data 1 is in the first video object unit VOBU1.

  With reference to FIG. 4, the operation of the controller of the playback apparatus will be described. First, the operation when the video P35 of the third video object unit VOBU3 is reproduced will be described. When the reproduction of the video P35 is started, the process proceeds to step S1, and the controller 17 causes the optical pickup 2 to track jump to the head of the video object unit VOBU and proceeds to step 2. Here, the controller 17 causes the optical pickup 2 to track jump to the head of the third video object unit VOBU3.

  In step S2, the controller 17 determines whether or not the video to be displayed is in the same video object unit VOBU as the video processed immediately before. If they are in the same video object unit VOBU, the process proceeds from step S2 to step S6. If they are not in the same video object unit VOBU, the process proceeds from step S2 to step S3. Here, since the video immediately before the video P35 has not been reproduced, the process proceeds from step S2 to step S3.

  In step S3, the controller 17 controls the optical pickup 2 so as to read the sub-picture address information SP_SYNCA of the navigation pack of the video object unit VOBU that has been track-jumped in step S1. Thereby, the sub picture address information SP_SYNCA is supplied to the demultiplexer 7 via the demodulation circuit 3, the ECC decoder 4 and the like. When the controller 17 obtains the sub picture address information SP_SYNCA via the demultiplexer 7, the controller 17 controls the optical pickup 2 so as to jump to the head address of the video object unit VOBU indicated by the sub picture address information SP_SYNCA. Here, the optical pickup 2 makes a track jump to the first video object unit VOBU1. The process proceeds from step S3 to step S4.

  In step S4, the controller 17 controls the optical pickup 2 so as to read the data stream from the head of the video object unit VOBU jumped to the track in the normal reproduction direction. Then, the controller 7 obtains only sub-picture data from the read data stream. The process proceeds from step S4 to step S5.

  In step S5, the controller 17 determines whether or not the data stream has been read out before the video object unit VOBU having the main picture to be displayed. If not, the process returns from step S5 to step S4. When read, the process proceeds from step S5 to step S6. Here, the controller 17 determines whether or not all data streams of the first video object unit VOBU1 and the second video object unit VOBU2 in front of the third video object unit VOBU3 having the main picture to be displayed have been read. to decide. By repeating step S4 and step S5, all the sub-picture data of SP unit data 1 can be acquired.

  In step S6, the controller 17 controls the optical pickup 2 so as to read out all the data streams of the video object unit VOBU having the main picture to be displayed. Here, the controller 17 controls the optical pickup 2 so as to read the entire data stream of the third video object unit VOBU3. The demultiplexer 7 supplies the main picture data to the video decoder 8 and the sub picture data of the SP unit data 1 to the sub video decoder 11. The SP unit data 1 is stored in the code buffer 12 of the sub-picture decoder 11. The process proceeds from step S6 to step S7.

  In step S7, the controller 17 starts decoding the sub-picture data of the sub-picture preceding the normal playback method, and executes the display control sequence DCSQ up to the PTS time of the main picture to be displayed. The sub-picture decoder 11 is controlled. Here, the controller 17 selects the SP unit data 1 on the assumption that the PTS having the largest value among the plurality of SP units having the PTS equal to or smaller than the PTS of the video P35 is used. The controller 17 decodes the sub-picture data of the SP unit data 1, and causes the sub-picture decoder 11 to execute the 0th sub-picture display control sequence start time SP_DCSQ_STM0 up to the PTS of the video P35. Note that sub-pictures are not displayed except for the processing in step S9 described later. The process proceeds from step S7 to step S8.

  In step S8, the controller 17 causes the video decoder 8 to decode the main picture data of the main picture to be displayed. At this time, the controller 17 controls the decoding of the video to be displayed and the selected SP unit and the execution of the display control sequence start time DCSQ_STM to be completed simultaneously. Here, the video decoder 8 decodes only the video I32 which is the I picture and the video P35 which is the P picture of the third video object unit VOBU3. The video decoder 8 does not decode what is not necessary for decoding the video P35. That is, the images B30, B31, B33, B34 are not decoded. The process proceeds from step S8 to step S9.

  In step S9, the controller 17 combines the sub-picture data from the sub-picture decoder 11 and the main picture data from the video decoder 8, and outputs the combined picture data. As a result, the display screen of the display (not shown) is switched to the main picture to be displayed, and is switched to the sub picture of the selected SP unit. Here, the main picture is switched to the video P35, and the sub-picture is switched to the SP unit 3. The process proceeds from step S9 to step S10.

  In step S10, the controller 17 clears the main picture data stored in the code buffer 9, and switches to the video processing to be processed next. The process returns from step S10 to step S1.

  Next, the operation for reproducing the video B34 will be described. When the main picture data stored in the code buffer 9 is cleared and reproduction of the video B34 is started, the process proceeds to step S1. In step S1, the controller 17 causes the optical pickup 2 to track jump to the head of the third video object unit VOBU3. The process proceeds from step S1 to step S2.

  In step S2, the controller 17 determines whether or not the video B34 is in the same third video object unit VOBU3 as the previous video P35. In this case, since it is in the same third video object unit VOBU3, the process proceeds from step S3 to step S6. That is, since the video B34 is the same video object unit VOBU as the video P35, it is not necessary to acquire the sub picture address information SP_SYNCA.

  In step S6, the controller 17 controls the optical pickup 2 so as to read all the data streams of the video object unit VOBU having the video B34. At this time, the demultiplexer 7 extracts only the main picture data from the data stream supplied from the optical pickup 2 via the modulation circuit 3 and the like, and supplies this video data to the video decoder 8. The video decoder 8 stores the video data in the code buffer 9. The process proceeds from step S6 to step S7.

  In step S7, the controller 17 selects the SP unit data 1 having the same PTS as the PTS of the video B34, decodes the sub-picture data of the SP unit data 1, and outputs the 0th sub-picture / up to the PTS of the video B34. The display control sequence start time SP_DCSQ_STM0 is executed by the sub-picture decoder 11.

  In step S8, the controller 17 reads the video data from the code buffer 9, and causes the video decoder 8 to decode the video I32, the video P35, the video B33, and the video B34. At this time, the controller 17 performs control so that the decoding of the video B34 and the selected SP unit data 1 and the execution of the 0th display control sequence start time DCSQ_STM0 are completed simultaneously. The process proceeds from step S8 to step S9.

  In step S9, the controller 17 combines the SP unit data 1 of the sub-picture decoder 11 and the video B34 from the video decoder 8 and outputs the synthesized video. Then, the process proceeds from step S9 to step S10. Thereby, the main picture is switched to the video B34, and the sub-picture is switched to the SP unit data 1 executed until the 0th display control sequence start time DCSQ_STM0. The process proceeds from step S9 to step S10.

  In step S10, the controller 17 clears the main picture data stored in the code buffer 9, and switches to the video processing to be processed next. The process returns from step S10 to step S1.

  As described above, the sub-picture address information SP_SYNCA indicating the position of the sub-picture data is extracted from the navigation pack of the video object unit VOBU having the main picture data to be reproduced, and the sub-picture data is read out. By adjusting the decoding timing of the data and the sub picture data, both the main picture and the sub picture can be displayed.

  As another prior art, there is a “decoding processing method and apparatus” that stabilizes the display of a sub-picture and stabilizes the synchronization of the main video and the sub-picture even during special playback (see, for example, Patent Document 2). . This Patent Document 2 has a detailed description of the navigation pack (NV_PCK). The navigation pack (NV_PCK) will be described below based on the description in Patent Document 2.

  The navigation pack (NV_PCK) is mainly used as control data for performing reproduction / display control of data in the video object unit to which the navigation pack belongs (NV_PCK) and control data for performing data search of the video object unit.

  FIG. 5 shows the navigation pack (NV_PCK) taken out.

  NV_PCK basically includes a picture control information (PCI) packet for controlling a display image and a data search information (DSI) packet existing in the same video object. Each packet is described with a packet header and a substream ID, followed by data. Each packet header describes a stream ID, which indicates NV_PCK, and the substream ID identifies PCI and DSI. Each packet header describes a packet start code, a stream ID, and a packet length, followed by each data.

  The PCI packet is navigation data for changing display contents in synchronization with reproduction of video data in a video object unit (VOBU) to which the packet belongs.

  The PCI packet describes general information PCI general information (PCI_GI), non-seamless angle information (NSML_ANGLI), and recording information (RECI) that is recording information.

  FIG. 6 shows reproduction control general information (PCI_GI).

  The PCI_GI describes general information of the PCI and the following information. That is, PCI_GI is a logical block number (VN_PCK_LBN) that is an address of this navigation pack, a video object unit category (VOBU_CAT) indicating an attribute of a video object unit (VOBU) managed by this PCI, and a video managed by this PCI. User operation control (VOBU_UOP_CTL) indicating user operation prohibition information during the object unit display period, video object unit display start time (VOBU_S_PTM), and video object unit display end time (VOBU_E_PTM) Including. The first video specified by VOBU_S_PTM is an I picture in the MPEG standard. Furthermore, PCI_GI includes a video object sequence end presentation time (VOBU_SE_EPTM) indicating the display time of the last video of the video object unit, and a cell elapse time (C_EPTM) indicating a relative display elapsed time from the first video frame in the cell. ) Etc. are also described.

  NSML_ANGLI described in the PCI indicates the address of the destination (destination) when there is an angle change. That is, the video object also has images captured from different angles. Then, when there is a designation from the user to display a video of an angle different from the currently displayed angle, the address of the VOBU to be transferred for the next reproduction is described.

  The HLI is information for designating a specific area in a rectangular shape on the screen and changing the luminance of this area, the color of the sub-picture displayed here, and the like. This information includes highlight generation information (HL_GI), a button color information table (BTN_COLOR) for allowing the user to select a button for color selection, and a button information table (BTNIT) for a selection button. ing.

  The RECI is video, audio, and sub-picture information recorded in the video object unit, and describes what kind of data is decoded. For example, there are a country code, a copyright holder code, a recording date, and the like.

  The DSI packet is navigation data for executing a search for a video object unit.

  The DSI packet includes general information such as DSI general information (DSI_GI), seamless playback information (SML_PBI), seamless angle information (SML_AGLI), video object unit search information (VOBU_SRI), synchronization information (SYNCI), Is described.

  As shown in FIG. 7, the following information is described in DSI_GI.

  In other words, DSI_GI describes NV_PCK_SCR, which is a system clock reference indicating the NV_PCK decoding start reference time, NV_PCK logical address (NV_PCK_LBN), and VOBU_EA indicating the end address of the video object unit to which this NV_PCK belongs. Yes. Furthermore, in DSI_GI, the end address (VOBU_1STREF_EA) of the first reference picture (I picture) to be decoded first, the end address (VOBU_2NDREF_EA) of the second reference picture (P picture) to be decoded first The end address (VOBU_3RDREF_EA) of the third reference picture (P picture) for the first decoding is described. Furthermore, in DSI_GI, the ID number (VOBU_VOB_IDN) of the VOB to which this DSI belongs, the ID number of the cell to which this DSI belongs (VOBU_C_IDN), and the cell lapse time indicating the relative elapsed time from the first video frame in the cell ( C_ELTM) is also described.

Japanese Patent Laid-Open No. 11-8833 JP-A-11-149717

  When the special reproduction in the reverse direction starts, when the video to be displayed is a video object unit VOBU different from the video processed immediately before, the processing of steps S3, S4, and S5 in FIG. 4 is executed. As described above, the controller 17 reads the sub-picture address information SP_SYNCA, performs a track jump on the optical pickup 2, and re-acquires SP unit data. After acquiring the SP unit data, the controller 17 decodes the sub picture data and main picture data, and switches the display. As a result, the video display update is waited until the decoding of the sub-picture data is completed.

  The problem is that the decoded sub-picture data is discarded when the display of the sub-picture is finished during the forward-direction reproduction before the special reproduction in the reverse direction. The process of inputting only the sub-picture data associated with the main picture puts a load on the entire system, and only the sub-picture is input until the beginning of the video object unit VOBU including the target video is reached. Will wait for an update.

According to the first aspect of the present invention, in a playback device that plays back a data stream including main picture data in which a plurality of main pictures are compressed and sub-picture data of a sub-picture corresponding to the main picture, the data stream is Reading means for reading and outputting the read data stream, first decoding means for decoding the main picture and outputting the decoded main picture, and decoding the sub-picture and decoding the sub-picture And a second decoding unit that outputs the synthesized picture by combining the decoded main picture and the decoded sub-picture, and the second decoding unit is used for backward reproduction. Thus, a reproducing apparatus characterized in that two sets of sub-picture code buffers are provided.

  The reproduction apparatus according to the first aspect further includes means for alternately storing the decoded sub-pictures in the two sets of code buffers so that the two sets of code buffers are not empty during normal reproduction. It is preferable. The playback apparatus according to the first aspect further includes means for creating management data for determining from which address the decoded subpicture stored in the two sets of code buffers should be read. It is preferable. The playback device according to the first aspect preferably further includes means for playing back the sub-pictures stored in the two sets of code buffers in synchronization with the main picture during special playback in the reverse direction. Instead, the playback apparatus according to the first aspect selects the sub-picture stored in the two sets of code buffers using the management data during the special playback in the reverse direction, and synchronizes with the main picture. You may further provide the means to reproduce | regenerate.

According to the second aspect of the present invention, the input step of inputting the data of the main picture, audio, sub-picture, and navigation pack, the first reference time included in the navigation pack, the first and second code buffers A first storage step for storing the code pictures in the selected code buffer, a first extraction step for extracting sub-picture address information from the navigation pack, and determining whether a sub-picture unit corresponding to the main picture exists. And whether the sub-picture address information extracted in the first extraction step is the same as the immediately preceding sub-picture address information when it is determined that “exists” in the first determination step. In the second determination step for determining whether or not A second storage step of storing the decoded sub-picture unit in the selected code buffer, a creation step of creating management data for each video object unit, and a next video object unit A second extraction step for extracting a second reference time included in the navigation pack; and a third determination step for determining whether or not a fixed period has elapsed from the first reference time using the second reference time; , And when it is determined that “a certain period has not elapsed” in the third determination step, the process proceeds to the first extraction step, and it is determined that “a certain period has elapsed” in the third determination step Then, the process proceeds to the first storage step, and when it is determined that “does not exist” in the first determination step, the process proceeds to the second extraction step. Seen, if it is determined that "the same" in the second determination step, playback method is obtained, characterized in that the process proceeds to create a step.

According to a third aspect of the present invention, there is provided a reproduction method for performing reverse reproduction after the reproduction method according to the second aspect, a jump step for jumping to the head of a video object unit, a main picture, and a navigation pack A selection step for selecting management data corresponding to the main picture to be displayed, and a display control sequence (DCSQ) up to the reproduction time stamp (PTS) of the main picture to be displayed. An execution step, a decoding step for decoding up to the main picture to be displayed, a display step for switching the display of the main picture, reading out the decoded data from the code buffer specified by the selected management data, and displaying a sub-picture, Display A determination step for determining whether or not the reproduction time stamp (PTS) of the current picture has reached the first reference time, and if it is determined in this determination step that the first reference time has been reached, the second reference A second input step of inputting only a sub-picture of a certain period using time, and returning to the selection step when it is determined in the determination step that the first reference time has not been reached. Is obtained.

According to a fourth aspect of the present invention, there is provided a reproduction method for performing reverse slow reproduction after the reproduction method according to the second aspect, wherein the step of jumping to the head of the video object unit, the main picture and the navigation pack are A step of inputting, a step of selecting management data corresponding to the main picture to be displayed, a step of executing a display control sequence (DCSQ) up to a reproduction type stamp (PTS) of the main picture to be displayed, and a main picture to be displayed The display of the main picture is switched, the display of the main picture is switched, the decoded data is read from the code buffer specified by the selected management data, and the sub-picture is displayed. Subpic A step of decoding the turbocharger, further comprising reproducing method is obtained.

According to a fifth aspect of the present invention, there is provided a reproduction method for performing reverse skip reproduction after the reproduction method according to the second aspect, wherein the step of jumping the track to the head of the video object unit, the main picture and the navigation pack are The step of inputting, the step of selecting management data corresponding to the main picture to be displayed, the step of determining whether there is sub-picture data that is not displayed, The display control sequence (DCSQ) is executed until the reproduction time stamp (PTS) of the main picture to be displayed, the step of decoding up to the main picture to be displayed, and the display of the main picture are switched and specified by the selected management data. Code buffer A step of reading the decoded data and displaying a sub-picture, and when the determination step determines “Yes”, discards the corresponding sub-picture unit data and proceeds to an execution step. Is obtained.

  In the present invention, two sets of sub-picture code buffers are provided, and the decoded sub-picture data is held for a certain period. By storing the sub-picture data decoded at the time of normal reproduction in either one of the two sets of code buffers, the process of inputting only the sub-picture data of the prior art can be omitted. In other words, by holding the decoding result of the sub-picture data in one of the two sets of code buffers, the period of sub-picture data recovery and decoding processing is reduced, so that the target video is displayed earlier than before. be able to.

  A playback apparatus according to the first embodiment of the present invention will be described with reference to FIG. The basic configuration is the same as that of the playback apparatus of the prior art, and the difference from the prior art is that the size of the code buffer that holds the decoding result of the sub-picture data is added. Here, the first code buffer 12-A and the second code buffer 12-B are described. The description of the individual blocks of the playback device is the same as in the prior art, and is therefore omitted. In the following, the first code buffer 12-A is called (displayed) as code buffer A or simply buffer A, and the second code buffer 12-B is called (displayed) as code buffer B or simply buffer B. In some cases.

  The DVD playback method of the present invention comprises the video object unit VOBU process of FIG. 9 and the special playback process of FIG.

  Referring to FIG. 9, the video object unit VOBU process is a process of inputting video, audio, sub-picture and navigation pack data (step S11), and a process of storing a reference time (NV_PCK_SCR) included in the Navi pack (step S11). S12), processing for extracting sub-picture address information SP_SYNCA from the Navi pack (step S13), processing for determining whether or not a sub-picture unit corresponding to the main picture exists (step S14), and the immediately preceding sub-picture Processing for determining whether the address information is the same as SP_SYNCA (step S15), processing for storing the decoded sub-picture unit in the code buffer (step S16), and creating management data for each video object unit VOBU Processing (Step S17), a process of extracting the reference time (NV_PCK_SCR) included in the Navi pack of the next video object unit VOBU (step S18), and a process of determining whether or not a certain period has elapsed from the reference time (step S19) Consists of.

  Referring to FIG. 12, special playback processing includes processing for jumping to the head of the video object unit VOBU (step S20), processing for inputting a video and a navigation pack (step S21), and management data corresponding to the video to be displayed. A process for selecting the video (step S22), a process for executing the display control sequence DCSQ up to the PTS of the video to be displayed (step S23), a process for decoding the video to be displayed (step S24), and a video display Switching, reading the decoded data from the SPU code buffer, displaying the sub-picture (step S25), determining whether the PTS of the video to be displayed has reached the reference time (step S26), and Sub-picture of a certain period using one reference time Only it constituted de processing (step S27) of inputting.

  The operation of the controller of the playback apparatus according to the present invention will be described with reference to FIG. 2, FIG. 9, FIG. 10, FIG. The following description will be made using the data stream shown in FIG.

  The video object unit VOBU process in FIG. 9 is a process when normal playback in the forward direction is performed.

  In step S11, when normal reproduction is started, the controller 17 inputs the data stream (video (main picture), audio, sub-picture, navigation pack data) shown in FIG.

  In step S12, the controller 17 stores the first reference time (NV_PCK_SCR) included in the navigation pack in the first code buffer 12-A.

  In step S13, the controller 17 controls the optical pickup 2 so as to read the sub picture address information SP_SYNCA in the navigation pack. Thereby, the sub picture address information SP_SYNCA is supplied to the demultiplexer 7 via the demodulation circuit 3, the ECC decoder 4 and the like and extracted. Here, the sub picture address information SP_SYNCA included in the navigation pack of the first video object unit VOBU1 is extracted.

  In step S14, the controller 17 determines whether or not there is a sub-picture unit corresponding to the first video object unit VOBU1 from the sub-picture address information SP_SYNCA of the first video object unit VOBU1 extracted in step S13. . Here, since it is determined that it does not exist, the process proceeds from step S14 to step S18.

  In step S18, the controller 17 extracts the second reference time (NV_PCK_SCR) included in the navigation pack of the next video object unit VOBU. Here, the second reference time is extracted from the navigation pack of the second video object unit VOBU2.

  In step S19, the controller 17 determines whether or not a certain period has elapsed using the first and second reference times. Here, the controller 17 reads the first reference time included in the navigation pack of the first video object unit VOBU1 stored in step S12 from the first code buffer 12-A, and is extracted in step S18. The second reference time included in the navigation pack of the second video object unit VOBU2 is used to determine whether or not a certain period has elapsed.

  As an example, the case where the fixed period is 1 minute will be described. Since the difference between the first reference time of the first video object unit VOBU1 and the second reference time of the second video object unit VOBU2 has not passed 1 minute, the process proceeds from step S19 to step S13. In step S13 here, the controller 17 extracts the sub picture address information SP_SYNCA included in the navigation pack of the second video object unit VOBU2.

  In step S14, the controller 17 determines whether or not there is a sub picture unit corresponding to the second video object unit VOBU2 from the sub picture address information SP_SYNCA of the second video object unit VOBU2 extracted in step S13. . Here, as shown in FIG. 2, since the last two picture periods of the second video object unit VOBU2 are streams associated with the sub-picture unit data 1, the controller 17 determines that it exists.

  In step S15, the controller 17 determines whether or not the extracted sub picture address information SP_SYNCA is the same as the immediately preceding sub picture address information SP_SYNCA. Here, the controller 17 determines whether the sub-picture address information SP_SYNCA of the first video object unit VOBU1 and the sub-picture address information SP_SYNCA of the second video object unit VOBU2 are the same. Since this is not the same, the process proceeds from step S15 to step S16.

  In step S16, the controller 17 stores the result obtained by decoding the sub-picture unit data 1 by the sub-picture decoder 11 in the first code buffer 12-A. In step S17, the controller 17 creates management data for each video object unit VOBU associated with the sub-picture. The role of the management data is to read the sub-picture decoding result data stored in the first code buffer 12-A or the second code buffer 12-B from which address by referring to the management data during special playback. It is for judging whether it is good.

  Here, the configuration of the management data will be described with reference to FIG. The management data includes sub-picture address information SP_SYNCA of the video object unit VOBU, a start address after decoding of the sub-picture unit data, and a sub-picture display control sequence table SP_DCSQT included in the sub-picture unit data. Composed.

  Returning to FIG. 9, in step S17, the controller 17 determines the sub-picture address information SP_SYNCA extracted in step S13, the start address of the decoded sub-picture unit stored in step S16, and the sub-picture of the sub-picture unit. Management data is created in association with the display control sequence table SP_DCSQT, and the process proceeds from step S17 to step S18.

  In step S18, the controller 17 extracts the second reference time (NV_PCK_SCR) included in the navigation pack of the next video object unit VOBU. Here, the controller 17 extracts the reference time (NV_PCK_SCR) included in the third video object unit VOBU3.

  In step S19, the controller 17 determines whether or not a certain period has elapsed using the first and second reference times. Here, the controller 17 reads the first reference time included in the navigation pack of the first video object unit VOBU1 stored in step S12 from the first code buffer 12-A, and is extracted in step S18. The second reference time (NV_PCK_SCR) included in the navigation pack of the third video object unit VOBU3 is used to determine whether or not a certain period has elapsed. Since the fixed period is 1 minute, the determination is no and the process proceeds from step S19 to step S13. In step S13 here, the controller 17 extracts the sub picture address information SP_SYNCA included in the navigation pack of the third video object unit VOBU3.

  In step S14, the controller 17 determines whether or not there is a sub picture unit corresponding to the third video object unit VOBU3 from the sub picture address information SP_SYNCA of the third video object unit VOBU3 extracted in step S13. . As shown in FIG. 2, since the third video object unit VOBU3 is a stream associated with the sub-picture unit data 1, the controller 17 determines that it exists.

  In step S15, the controller 17 determines whether or not the extracted sub picture address information SP_SYNCA is the same as the immediately preceding sub picture address information SP_SYNCA. Here, the controller 17 determines whether or not the sub picture address information SP_SYNCA of the second video object unit VOBU2 and the sub picture address information SP_SYNCA of the third video object unit VOBU3 are the same. In the case of the data stream shown in FIG. 2, since the second video object unit VOBU2 and the third video object unit VOBU3 are associated with the sub-picture unit data 1, the determination here is the same. The process proceeds from step S15 to step S17.

  In step S17, the controller 17 creates management data for each video object unit VOBU associated with the sub-picture. The controller 17 creates management data by associating the sub-picture address information SP_SYNCA extracted in step S13, the start address of the decoded sub-picture unit stored in step S16, and the SP_DCSQT of the sub-picture unit. The process proceeds from step S17 to step S18.

  In step S18, the controller 17 extracts the second reference time included in the navigation pack of the next video object unit VOBU. Here, the controller 17 extracts the second reference time (NV_PCK_SCR) included in the fourth video object unit VOBU4. In step S19, the controller 17 determines whether or not a certain period has elapsed using the first and second reference times. Here, the controller 17 reads the first reference time included in the navigation pack of the first video object unit VOBU1 stored in step S12 from the first code buffer 12-A, and is extracted in step S18. The second reference time (NV_PCK_SCR) included in the navigation pack of the fourth video object unit VOBU4 is used to determine whether a certain period has elapsed. Since the fixed period is 1 minute, the determination is no and the process proceeds from step S19 to step S13.

  The above processing is performed during normal playback in the forward direction. As shown in the image diagram of the code buffer of the sub-picture decoder shown in FIG. 10, the first code buffer 12-A (code buffer A) and the second code buffer 12-B (code buffer B) have a reference time. And sub-picture unit data after decoding. The code buffer for storing the decoded sub-picture unit data is switched alternately at certain intervals.

  Next, the special reproduction process of FIG. 12 will be described. Here, it is assumed that the normal playback is switched to the special playback at the timing of “special playback start” shown in FIG.

  In step S20, the controller 17 performs track jump of the optical pickup 2 to the head of the video object unit VOBU of the video to be displayed (main picture). In step S21, the controller 17 supplies the video data and the navigation pack data to the demultiplexer 7 from the track jump position. In step S22, the controller 17 extracts the sub picture address information SP_SYNCA included in the navigation pack, and selects management data corresponding to the video (main picture) to be displayed using the sub picture address information SP_SYNCA.

  Steps S23 and S24 are the same as steps S7 and S8 of the prior art shown in FIG.

  In step S25, the controller 17 switches the display of the video (main picture), reads the decoded sub-picture unit data from the sub-picture code buffer specified by the selected management data, and displays the sub-picture. Here, the controller 17 reads the decoded sub-picture unit data from the second code buffer 12-B.

  In step S26, the controller 17 determines whether or not the PTS of the video to be displayed (main picture) has reached the first reference time. Here, it is the first reference time stored in the second code buffer 12-B, which is time T3 in FIG. 10, and the controller 17 performs the PTS of the video (main picture) to be displayed and the first reference time T3. And compare. If not, the process returns from step S26 to step S22. If so, the process proceeds from step S26 to step S27. The controller 17 repeats steps S22 to S26 until the display of the sub picture unit data stored in the second code buffer 12-B is finished. When the display of the sub-picture unit data in the second code buffer 12-B is finished, in step S27, the controller 17 uses the second reference time and inputs only the sub-picture for a certain period. Here, the controller 17 inputs only the sub-picture from the time T1 obtained by subtracting a certain period of time (1 minute) from the reference time T2 of the first code buffer 12-A.

  Next, returning to step S20, the controller 17 performs special reproduction from the video immediately before time T3. The controller 17 jumps to the head of the video object unit VOBU of the video to be displayed (main picture). In step S21, the controller 17 supplies the video data and the navigation pack data to the demultiplexer 7 from the track jump position. By repeating the above processing, it is possible to display the main picture and the sub picture during the special reproduction period. The newly input sub-picture is decoded in a period in which the video (main picture) and the navigation pack in step S21 are supplied to the demultiplexer 7.

  Next, the reason why the problems of the known technology are solved will be described. Comparing the processing of the controller in the prior art of FIG. 4 with the processing of the controller according to the present invention of FIG. 12, the processing of supplying only the subpicture performed in steps S3, S4, and S5 to the demultiplexer is as follows: In the present invention, the main reason for the change is step S22. Created during normal playback to select the video to be displayed (main picture) and the decoded sub-picture unit data stored in the first code buffer 12-A and the second code buffer 12-B in advance. This is possible by using management data.

  Next, with reference to FIG. 13, the operation of the reverse slow playback of the playback device according to the second embodiment of the present invention will be described. Since the configuration of the playback apparatus is the same as that of the first embodiment described above, a description thereof will be omitted.

  The reverse slow playback process corresponds to a process of jumping to the head of the video object unit VOBU (step S28), a process of inputting a video (main picture) and a navigation pack (step S29), and a video to be displayed (main picture). Processing for selecting management data to be performed (step S30), processing for executing the display control sequence DCSQ up to the PTS of the video (main picture) to be displayed (step S31), and processing for decoding up to the video to be displayed (main picture) (Step S32) and the process of switching the video (main picture) display, reading the decoded data from the SPU code buffer specified by the selected management data, and displaying the sub-picture (Step S33). Main pic During displaying the catcher), and de-processing to decode the next sub-picture (step S34).

  Next, with reference to FIG. 13, FIG. 15, and FIG. 16, the operation of the reverse slow playback of the playback device according to the second embodiment of the present invention will be described in detail. FIG. 15 shows a timing chart of the main picture and sub-picture during normal playback. FIG. 16 shows a timing chart of the main picture and sub-picture when each picture is repeated by one.

  Here, as an example, it is assumed that the slow playback process in the reverse direction is started when the video P25 of the twelfth video object unit VOBU12 is displayed. The controller 17 jumps the optical pickup 2 to the head of the video object unit VOBU including the video P25.

  Steps S29 to S33 are the same as steps S21 to S25 in the first embodiment illustrated in FIG.

  For step S34, the controller 17 decodes the next sub-picture while displaying the same video (main picture). Here, the controller 17 jumps the optical pickup 2 to the eleventh video object unit VOBU11 which is the previous video object unit VOBU, and obtains the sub picture address information SP_SYNCA from the navigation pack of the eleventh video object unit VOBU11. Extraction is performed, and a track jump is made to the head of the video object unit VOBU including the sub picture unit data 11, and the sub picture unit data 11 is decoded.

  Next, with reference to FIG. 14, the reverse skip reproduction operation of the reproduction apparatus according to the third embodiment of the present invention will be described. Since the configuration of the playback apparatus is the same as that of the first embodiment described above, a description thereof will be omitted.

  The reverse skip playback process corresponds to a process of jumping to the head of the video object unit VOBU (step S35), a process of inputting a video (main picture) and a navigation pack (step S36), and a video to be displayed (main picture). Processing for selecting management data to be performed (step S37), processing for determining whether there is sub-picture data that is not displayed (step S38), processing for discarding the corresponding sub-picture unit data (step S39), and video to be displayed The process of executing the display control sequence DCSQ up to the PTS of (main picture) (step S40), the process of decoding up to the video to be displayed (main picture) (step S41), and the display of the video (main picture) are switched, Selected management data Thus read data decoded from SPU code buffer specified, constructed out with a process of displaying a sub-picture (step S42).

  With reference to FIG. 14, the reverse skip playback operation of the playback apparatus according to the third embodiment of the present invention will be described in detail. When reverse skip reproduction is started, step S35 is processed.

  Steps S35 to S37 are the same as steps S20 to S22 of the first embodiment described above with reference to FIG.

  In step S38, the controller 17 determines whether there is sub-picture data that is not displayed. Here, the controller 17 determines whether there is sub-picture data that is not displayed by determining whether there is management data selected in step S37 and management data that is not used for display. Can do. If there is a sub-picture that is not displayed, the process proceeds from step S38 to step S39. If there is no sub-picture that is not displayed, the process proceeds from step S38 to step S40.

  Steps S40 to S42 are the same as steps S23 to S25 of the first embodiment described above with reference to FIG.

  As described above, the playback apparatus according to the present invention can update video at the time of special playback in the reverse direction faster than before.

  Needless to say, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

It is a block diagram which shows the structure of the reproducing | regenerating apparatus of a prior art. It is a timing chart of the main picture and sub-picture reproduced | regenerated by the reproducing | regenerating apparatus of a prior art. (A) is a block diagram of the video object unit VOBU of the data stream, and (b) is a block diagram of the sub picture unit (SPU) obtained by the sub picture pack (SP_PCK) of the video object unit VOBU. It is a flowchart explaining operation | movement of the controller in the reproducing | regenerating apparatus of a prior art. It is explanatory drawing of a navigation pack (NV_PCK). It is explanatory drawing of the general information of picture control information (PCI). It is explanatory drawing of the general information of data search information (DCI). It is a block diagram which shows the structure of the reproducing | regenerating apparatus concerning this invention. It is a flowchart explaining the normal reproduction | regeneration operation | movement of the video object unit VOBU of the reproducing | regenerating apparatus in connection with this invention. It is an image figure of the code buffer of the sub-picture decoder of the reproducing | regenerating apparatus concerning this invention. It is an image figure of the management data of the reproducing | regenerating apparatus concerning this invention. It is a flowchart explaining the operation | movement of the special reproduction | regeneration of the reproducing | regenerating apparatus concerning this invention. It is a flowchart explaining the operation | movement of the reverse slow reproduction of the reproducing | regenerating apparatus concerning this invention. It is a flowchart explaining the operation | movement of the reverse skip reproduction | regeneration of the reproducing | regenerating apparatus in connection with this invention. It is a timing chart of a main picture and a sub picture during normal reproduction. It is a timing chart of the main picture and sub picture at the time of reverse slow reproduction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical disk 2 Optical pick-up 3 16/8 demodulation circuit 4 ECC decoder 5 ECC memory 6 Descramble circuit 7 Demultiplexer 8 Video decoder 9 Code buffer 10 Display memory 11 Sub-picture decoder 12-A, 12-B Code buffer 13 D / A Converter 14 Audio decoder 15 Code buffer 16 D / A converter 17 Controller

Claims (9)

In a playback device for playing back a data stream including main picture data in which a plurality of main pictures are compressed and sub-picture data of a sub-picture corresponding to the main picture,
Reading means for reading the data stream and outputting the read data stream;
First decoding means for decoding the main picture and outputting the decoded main picture;
Second decoding means for decoding the sub-picture and outputting the decoded sub-picture;
An output means for combining the decoded main picture and the decoded sub-picture and outputting the combined picture;
The reproduction apparatus according to claim 2, wherein the second decoding unit includes two sets of code buffers for the subpicture for backward reproduction.   The apparatus further comprises means for alternately storing the decoded sub-pictures in the two sets of code buffers so that no empty space is generated in the two sets of code buffers during normal reproduction. The reproducing apparatus according to 1.   3. The method according to claim 2, further comprising means for creating management data for determining from which address the decoded sub-picture stored in the two sets of code buffers should be read. Playback device.   3. The playback apparatus according to claim 2, further comprising means for playing back the sub-pictures stored in the two sets of code buffers in synchronization with the main picture during special playback in the reverse direction.   In the special reproduction in the reverse direction, the apparatus further comprises means for selecting the sub picture stored in the two sets of code buffers using the management data and reproducing the sub picture in synchronization with the main picture. The playback apparatus according to claim 3. An input step for inputting data of the main picture, audio, sub-picture and navigation pack;
A first storage step of storing a first reference time included in the navigation pack in a code buffer in which the first and second code buffers are alternately selected;
A first extraction step of extracting sub-picture address information from the navigation pack;
A first determination step of determining whether there is a sub-picture unit corresponding to the main picture;
A second step of determining whether or not the sub-picture address information extracted in the first extraction step is the same as the immediately preceding sub-picture address information when it is determined that “exists” in the first determination step; Judgment steps,
A second storage step of storing the decoded sub-picture unit in the selected code buffer when it is determined as “not the same” in the second determination step;
A creation step for creating management data for each video object unit;
A second extraction step of extracting a second reference time included in the navigation pack of the next video object unit;
A third determination step of determining whether or not a certain period of time has elapsed from the first reference time using the second reference time,
When it is determined that “a certain period has not elapsed” in the third determination step, the process proceeds to the first extraction step, and when it is determined that “a certain period has elapsed” in the third determination step The process proceeds to the first storage step, and when it is determined that “does not exist” in the first determination step, the process proceeds to the second extraction step, and “is the same” in the second determination step. A reproduction method characterized by proceeding to the creating step when it is determined. A playback method for performing reverse playback after the playback method according to claim 6 ,
A jump step for jumping to the head of the video object unit;
A first input step for inputting a main picture and a navigation pack;
A selection step of selecting the management data corresponding to the main picture to be displayed;
An execution step of executing a display control sequence (DCSQ) up to a reproduction time stamp (PTS) of the main picture to be displayed;
A decoding step for decoding up to the main picture to be displayed;
A display step of switching display of a main picture, reading out decoded data from a code buffer specified by the selected management data, and displaying a sub-picture;
A determination step of determining whether a reproduction time stamp (PTS) of the main picture to be displayed has reached a first reference time;
The determination step further includes a second input step of inputting only the sub-picture of a certain period using the second reference time when it is determined that the first reference time has been reached in the determination step. When it is determined that the first reference time has not been reached, the method returns to the selection step. A playback method for performing reverse slow playback after the playback method according to claim 6 ,
Jumping to the beginning of the video object unit;
Inputting a main picture and the navigation pack;
Selecting the management data corresponding to the main picture to be displayed;
Executing a display control sequence (DCSQ) up to the reproduction type stamp (PTS) of the main picture to be displayed;
Decoding up to the main picture to be displayed;
Switching the display of the main picture, reading the decoded data from the code buffer specified by the selected management data, and displaying the sub-picture;
Decoding the next sub-picture while displaying the same main picture. A playback method for performing reverse skip playback after the playback method according to claim 6 ,
Jumping to the beginning of the video object unit;
Inputting a main picture and the navigation pack;
Selecting the management data corresponding to the main picture to be displayed;
Determining whether there is sub-picture data that is not displayed;
A step of executing a display control sequence (DCSQ) up to a reproduction time stamp (PTS) of the main picture to be displayed when it is determined that the determination step is “NO”;
Decoding up to the main picture to be displayed;
Further switching the display of the main picture, reading the decoded data from the code buffer specified by the selected management data, and displaying the sub-picture,
A reproduction method characterized by discarding corresponding sub-picture unit data and proceeding to the execution step when it is determined as “Yes” in the determination step.

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