JP2007323718A - Video recording medium reproducing method and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To display audio data and video data by sustaining an AV synchronization even when the audio data and the video data are physically made away from each other. <P>SOLUTION: In the image recording medium reproducing method for reproducing the image recording medium wherein the compressed video data and audio data are recorded, the video data and audio data at the temporally synchronized position are read out in the separated state direct from the image recording medium and stored in storage areas (1-2), (1-3), and the video data and audio data are synchronized and output by decoding the stored video data and audio data. Thus, at the time point to acquire the audio data and video data, the audio data and video data are separated and acquired. By means of separating and acquiring the data, a restriction due to buffer sizes of the audio data storage area and video data storage area can be eliminated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a video recording medium playback apparatus that plays back a video recording medium on which MPEG data or the like is recorded, and in particular, a video recording medium playback method and playback that synchronizes audio data and video data that are output synchronously. It relates to the device.

  As an example of the video recording medium, an optical disk will be described as an example.

FIG. 10 is an image diagram of a method for outputting audio data and video data in synchronization in a conventional optical disc playback apparatus. After the data read from the disk (3-0) is stored in the data storage buffer (3-4), it is separated into audio data, video data, and sub-picture data, and the audio data storage buffer (3-1) and video are respectively separated. The data is stored in the data storage buffer (3-2) and the sub-picture data storage buffer (3-3). Thereafter, the audio data and video data are synchronized and decoded.
JP 2000-152182 A (P2000-152182A)

  In the prior art, audio data and video data to be synchronized need to be stored in the audio data storage buffer (3-1) and the video data storage buffer (3-2). If they are not stored in the audio data storage buffer (3-1) and the video data storage buffer (3-2), respectively, they cannot be synchronized. The synchronization range depends on the size of the audio data storage buffer (3-1) and the video data storage buffer (3-2).

  Accordingly, an object of the present invention is to solve the above-described problems, and provides a video recording medium playback method and playback apparatus that can eliminate the synchronization limitation due to the size of the audio data storage buffer and the video data storage buffer. That is.

  In order to solve the above problems, a video recording medium playback method according to claim 1 of the present invention is a video recording medium playback method for playing back a video recording medium in which compressed video data and audio data are recorded. The video data and the audio data are read from the video recording medium in a state in which the video data and the audio data synchronized in time are separated and stored in the storage area, and the stored video data and audio data are decoded. Are synchronized and output.

  The video recording medium playback method according to claim 2 is the video recording medium playback method according to claim 1, wherein the storage area sizes of the video data and the audio data are fixed.

  The video recording medium playback method according to claim 3 is the video recording medium playback method according to claim 1, wherein the storage area of the video data and the audio data is changed to an arbitrary size according to the data structure.

  According to a fourth aspect of the present invention, there is provided the video recording medium reproducing method according to the third aspect, wherein the variation of the storage area size is determined by the bit rate of the data to be reproduced.

  The video recording medium playback method according to claim 5 is the video recording medium playback method according to claim 3, wherein the variation of the storage area size is determined by the encoding method of the data to be played back.

  The video recording medium playback method according to claim 6 is the video recording medium playback method according to claim 1, wherein a free space that is a difference between storage areas of video data and audio data is monitored so that a free space does not occur. Increase the smaller storage area.

  The video recording medium playback method according to claim 7 is the video recording medium playback method according to claim 1, wherein the compressed sub signal is less compressed in output timing than the video data and audio data output timing from the video recording medium. By reading out the picture data in a separated state and storing it in the storage area, priority is given to the synchronous output processing of video data and audio data.

  The video recording medium playback method according to claim 8 is the video recording medium playback method according to claim 1, 2, 3, 4, 5, 6 or 7, wherein video data or audio data recorded on the video recording medium is recorded. Depending on the position, it is determined whether or not video data and audio data can be played back synchronously by the playback method that reads continuously from the video recording medium. If playback is possible, select the playback method that continuously reads the data on the video recording medium. If reproduction is not possible, a reproduction method is selected for reading video data and audio data separately.

  The video recording medium playback apparatus according to claim 9 is a video recording medium playback apparatus that plays back a video recording medium in which compressed video data and audio data are recorded, and is synchronized in time from the video recording medium. The CPU that reads the video data and audio data at the position separately and stores them in the video data storage buffer and the audio data storage buffer, respectively, and the video data and audio data stored in the video data storage buffer and the audio data storage buffer are decoded. And a decoder for outputting in synchronization.

  According to the video recording medium reproducing method of the first aspect of the present invention, the video data and the audio data at the temporally synchronized positions are read from the video recording medium in a separated state, stored in the storage area, and stored. By decoding video data and audio data, the video data and audio data are output in synchronization, so the video data and audio data to be output in synchronization are synchronized regardless of how they are recorded on the recording medium. Can be output. In addition, since the data to be output in synchronization is stored in the storage area, it is possible to delete the AV synchronization block before the data is input to the decode block.

  Since the storage area size of the video data and the audio data is fixed, the buffer management control of the storage area can be facilitated, and the system load can be reduced.

  According to the third aspect of the present invention, the storage area for the video data and the audio data is changed to an arbitrary size depending on the data structure. Therefore, the use efficiency of the buffer can be improved and the system can be realized with less memory.

  According to a fourth aspect of the present invention, in the video recording medium reproducing method according to the third aspect, it is preferable that the change in the storage area size is determined by the bit rate of the data to be reproduced. By reading the data before starting reproduction and measuring the bit rate, the size of the storage area is changed according to the bit rate, so that the memory can be used efficiently.

  According to a fifth aspect of the present invention, in the video recording medium reproduction method according to the third aspect, it is preferable that the change in the storage area size is determined by the encoding method of the data to be reproduced. By reading data before starting reproduction, analyzing the encoding method, and securing a storage area corresponding to it, the memory can be used efficiently.

  According to a sixth aspect of the present invention, in the video recording medium playback method according to the first aspect, the vacant area that is the difference between the storage areas of the video data and the audio data is monitored, and the smaller storage area is increased so that no vacant area is generated. It is preferable to do. It is possible to minimize the number of times data is read from the recording medium and reduce the system load.

  According to a seventh aspect of the present invention, the compressed sub-picture data with less restrictions on the output timing than the output timing of the video data and the audio data is read from the video recording medium in a state of being separated and stored in the storage area. Since the priority is given to the synchronous output processing of audio data, the load on the system can be reduced. That is, since sub-picture synchronization does not require as high accuracy as audio data and video data synchronization, timing control is facilitated by separating sub-picture data and storing it in a storage area from a video recording medium.

  According to the eighth aspect of the present invention, it is determined whether video data and audio data can be reproduced synchronously by a reproduction method of continuously reading from the video recording medium according to the position of the video data and audio data recorded on the video recording medium. If possible, select a playback method that reads data on the video recording medium continuously. If playback is not possible, select a playback method that reads video data and audio data separately. The system load can be reduced by switching the playback method according to the data being recorded.

  According to the video recording medium playback apparatus of the ninth aspect of the present invention, the video data and the audio data at the time synchronized positions are read from the video recording medium in a separated state, and the video data storage buffer and the audio data storage are respectively read. Since it has a CPU for storing in the buffer and a decoder for decoding and outputting the video data and audio data stored in the video data storage buffer and the audio data storage buffer in synchronization with each other, the audio data and video to be output in synchronization Regardless of how the data is recorded on the recording medium, it can be output synchronously. In addition, since the data to be output in synchronization is stored in the video data storage buffer and the audio data storage buffer, it is possible to delete the AV synchronization clock before entering the data into the decode block.

  An embodiment of the present invention will be described in detail with an optical disk as an example with reference to the drawings.

  A first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a block diagram of a method of using a buffer in the first embodiment of the present invention, FIG. 2 is a block diagram of an optical disk reproducing apparatus showing the first embodiment of the present invention, and FIG. 3 is a reproduction of this optical disk reproducing apparatus. It is a flowchart figure for demonstrating a method.

  As shown in FIG. 2, the optical disk reproducing apparatus includes a data reading apparatus (2-2) for reading data from an optical disk (2-1) on which compressed video data and audio data are recorded, and an MPEG system. MPEG decoder (2-3) for decoding audio / video data encoded by, a memory (2-9) for storing data read from the disk, and audio stored in the memory (2-9) Display controller (2-4) for displaying data and video data on display device (2-5), CPU (2-6) as control means for controlling the entire device, addresses of audio data and video data, etc. It has a RAM (2-8) for storing and an input device (2-7) for giving a command by the user.

  A method of reproducing audio data and video data in such an optical disk reproducing apparatus will be described with reference to FIGS.

  From the optical disc (2-1), the video data and the audio data at the temporally synchronized positions are read in a separated state, and are respectively read into the video data storage buffer (1-2) and the audio data storage buffer (1-3) of the memory. By storing and decoding the stored video data and audio data, the video data and audio data are synchronized and output.

  Specifically, first, when the optical disk (2-1) is loaded into the optical disk drive (2-2), the CPU (2-6) records the image at a predetermined position on the optical disk (2-1). The optical disk drive (2-2) reads the table. In this table, addresses of all moving image data, audio data, and caption data that are recorded on the optical disc (2-1) and are to be reproduced at the same time are registered. Then, the CPU (2-6) stores the acquired moving image data, audio data, and caption data addresses in the RAM (2-8) (S401).

  The CPU (2-6) extracts the start address of the moving image data to be reproduced from the RAM (2-8) (S402), and the moving image data to be displayed has already been read into the video data storage buffer (1-2). (S403). If not read, the optical head of the optical disk drive (2-2) is moved to the head address position of the moving image data to be displayed on the optical disk 1 to read the data from the optical disk (2-1) (S404). The stored data is stored in the video data storage buffer (1-2) of the memory (2-9) (1-14) (S405).

  The CPU (2-6) takes out the head address of the audio data to be reproduced simultaneously with the read moving image data from the RAM (2-8) (S406), and the audio data to be reproduced is stored in the audio storage buffer (1). -3) If it does not exist, move the optical head of the optical disk drive (2-2) to the head address position of the audio data to be displayed on the optical disk (2-1) to transfer the data from the optical disk (2-1). Reading (S408), the read data is stored in the audio storage buffer (1-3) of the memory (2-9) (1-14) (S409).

  The CPU (2-6) takes out the head address of the caption data to be reproduced simultaneously with the read moving image data from the RAM (2-8) (S410), and the caption data to be reproduced is stored in the sub-picture storage buffer ( If it does not exist in 1-4), the optical head of the optical disk drive (2-2) is moved to the head address position of the caption data to be displayed on the optical disk (2-1), and the data is transferred from the optical disk (2-1). Is read (S412), and the read data is stored in the sub-picture storage buffer (1-4) of the memory (2-9) (1-14) (S413).

  The MPEG decoder (2-3) includes moving picture data in the video storage buffer (1-2) of the memory (2-9) (1-14) and an audio storage buffer of the memory (2-9) (1-14). The audio data in (1-3) and the subtitle storage buffer (1-4) in the memory (2-9) (1-14) are decoded (1-5) (1-6) (1- 7), moving image data is stored in the video output buffer (1-8), audio data is stored in the audio output buffer (1-9), subtitle data is stored in the sub-picture output buffer (1-10), and the display controller (2- 4) The moving image and the caption are output to the display device (2-5) through 4), and the audio is output to the audio output device (2-10) (1-11) (1-12) (1-13) (S414). The above processing is repeated until there is no data to be reproduced (S415).

  In the conventional display method, as shown in FIG. 10, the data on the optical disk read continuously is stored in the data storage buffer (3-4) on the memory (2-9), and then the data is stored in the video data. The buffer (3-2), audio data storage buffer (3-1), and sub-picture storage buffer (3-3) are allocated. For this reason, the arrangement of image data, audio data, and subtitle data on the disc is more than the size of the video data storage buffer (3-2), audio data storage buffer (3-1), and sub-picture storage buffer (3-3). In such a case, the playback time cannot be synchronized.

  On the other hand, in the present embodiment, the reproduction time can be synchronized with any moving image data, audio data, and caption data from the optical disk.

  A second embodiment of the present invention will be described with reference to FIG. The configuration diagram of the buffer usage method and the block diagram of the optical disk reproducing apparatus are the same as those in the first embodiment, and reference is made to FIGS. 1 and 2.

  As shown in FIG. 4, a video data storage buffer (1-2) and an audio data storage buffer (1-3) are used as buffers for storing data for reading moving image data, audio data, and caption data from the optical disc (2-2). The sub-picture storage buffer (1-4) is fixed to the same size according to the maximum bit rate of data that can be read from the optical disc (S502). Thereby, buffer management can be simplified. By simplifying the buffer processing, the processing capacity of the CPU (2-6) can be reduced, the program size can be reduced, and a system using a cheaper CPU can be constructed. The storage buffer is desirably fixed to the same size according to the maximum bit rate, but may be fixed to a size not corresponding to the maximum bit rate.

  A third embodiment of the present invention will be described with reference to FIG. The configuration diagram of the buffer usage method and the block diagram of the optical disc playback apparatus are the same as those in the first embodiment, and refer to FIGS. 1 and 2.

  This embodiment is a method for improving the buffer usage efficiency by arbitrarily changing the buffer size according to the data to be reproduced.

As shown in FIG. 5, a video data storage buffer (1-2) and an audio data storage buffer (1-3) are used as buffers for storing data for reading moving image data, audio data, and caption data from the optical disc (2-2). ) The size of the sub-picture storage buffer (1-4) is determined by the bit rate of data recorded on the optical disc (S602, S603). Assuming that the time for reading out moving image data, reading out audio data, and reading out subtitle data is 1 second, the size of the video data storage buffer is
It is expressed as bit rate × time taken to read out moving image data next time. Before starting reproduction, moving image data is read and the bit rate is measured (S602), thereby changing the size of the video data storage buffer in accordance with the bit rate (S603). Thereby, the memory (2-9) can be used efficiently. Whether there is moving image data is determined by the buffer size and bit rate (S605), and whether there is audio data and subtitle data is determined by referring to the data stored in the buffer (S609, S613). By making the buffer size efficient, it is possible to reduce the size of the memory (2-9) and to construct a system using a cheaper memory.

  A fourth embodiment of the present invention will be described with reference to FIG. The configuration diagram of the buffer usage method and the block diagram of the optical disc playback apparatus are the same as those in the first embodiment, and refer to FIGS. 1 and 2.

  The present embodiment is also a method for improving the buffer usage efficiency by arbitrarily changing the buffer size according to the data to be reproduced.

  As shown in FIG. 6, a buffer for storing data for reading moving image data, audio data, and caption data from the optical disc (2-2), a video data storage buffer (1-2), and an audio data storage buffer (1-3) The size of the sub-picture storage buffer (1-4) is determined by the encoding method of data recorded on the optical disc (S703). Before starting reproduction, moving image data is read and the encoding method is analyzed to determine the encoding method (S702). Assuming that the time from reading out moving image data to reading out audio data and reading out subtitle data is 1 second, the size of the video data storage buffer conforms to the video CD standard in the case of MPEG1. 4 Mbps x 1 second = 1.4 Mbit size is secured. Since MPEG2 conforms to the DVD video standard, a video data storage buffer having a size of 10 Mbps × 1 second = 10 Mbit is secured. Thus, the memory (2-9) can be used efficiently. Whether there is moving image data is determined by the buffer size and bit rate (S705), and whether there is audio data and subtitle data is determined by referring to the data stored in the buffer (S709, S709). S713). By making the buffer size efficient, it is possible to reduce the size of the memory (2-9) and to construct a system using a cheaper memory.

  A fifth embodiment of the present invention will be described with reference to FIG. The configuration diagram of the buffer usage method and the block diagram of the optical disc playback apparatus are the same as those in the first embodiment, and refer to FIGS. 1 and 2.

  In this embodiment, a free area that is a difference between storage areas for video data and audio data is monitored. That is, in the first embodiment of the present invention, when the necessary moving image data, audio data, and caption data are individually read out, it is necessary to move the pickup on the optical disc and read it out. In general, audio data and subtitle data have a smaller data size than moving image data. Therefore, as shown in FIG. 7, by increasing the size of the audio storage buffer and sub-picture storage buffer (S802), the audio data and subtitle data are obtained. The number of times of reading can be reduced.

  When the video data is 4 Mbps, the audio data is 1 Mbps, and the caption data is 1 Mbps, the video data storage buffer is 4 Mbit, the audio storage buffer is 1 Mbit, the sub-picture storage buffer is 1 Mbit, and the video data is read. If the time for reading out audio data and reading out subtitle data is 1 second, it is necessary to always read by moving the pickup. However, by setting the audio storage buffer and the sub-picture storage buffer to 4 Mbits, it is only necessary to move and read the pickup for 1 second out of 4 seconds.

  By using the above method, it becomes possible to construct a system capable of minimizing the movement of the pickup, extending the mechanical life of the pickup, and reproducing for a long time.

  A sixth embodiment of the present invention will be described with reference to FIG. The configuration diagram of the buffer usage method and the block diagram of the optical disc playback apparatus are the same as those in the first embodiment, and refer to FIGS. 1 and 2.

  In this embodiment, the compressed sub-picture data with less restrictions on the output timing than the output timing of the video data and the audio data is read from the video recording medium in a separated state and stored in the storage area. Prioritize synchronous output processing of data and audio data. That is, as shown in FIG. 8, after the reproduction is started, it is confirmed whether or not the size of the moving image data stored in the video data storage buffer is below a certain level (S901). If it is below a certain level, the moving image data is read out to the video storage buffer (S906). If it is above a certain level, it is checked whether the size of the audio data stored in the audio storage buffer is below a certain level (S902). If it is below a certain level, the audio data is read out to the audio storage buffer (S907). If it is more than a certain value, it is confirmed whether or not 100 ms or more has elapsed since the subtitle data was read (S903). If not, the video data storage buffer check (S901) is repeated. If it has elapsed, it is checked whether the data size of the sub-picture storage buffer is below a certain level (S904). If it is below a certain level, caption data is read (S905). If it is above a certain level, the video data storage buffer check (S901) is repeated. The subtitle data is not checked at short intervals of 100 ms or less, but even if a display shift of 100 ms occurs, there is no problem, so the check is not performed at shorter intervals.

  As described above, it is possible to provide a system capable of reducing the load on the system and reproducing moving image data and audio data without interruption by not shortening the check of the sub-picture storage buffer.

  A seventh embodiment of the present invention will be described with reference to FIG. 1 and FIG. 10 are referred to for the configuration diagram of the buffer usage method, and FIG. 2 is referred to for the block diagram of the optical disk reproducing apparatus.

  In the present embodiment, whether or not video data and audio data can be reproduced in synchronism by a reproducing method (FIG. 10) for continuously reading from the video recording medium depending on the position of video data and audio data recorded on the video recording medium. And a playback method for continuously reading data on the video recording medium and a playback method for reading video data and audio data in a separated state are selected.

  First, the CPU (2-6) reads from the disk (S1001) table (the addresses of all moving image data, audio data, and caption data to be reproduced at the same time which are MPEG-encoded are registered) and data storage Based on the size of the buffer (3-4), it is checked whether or not audio data and video data can be reproduced in synchronism by a reproducing method of continuously reading data from the disc (S1002). If audio data and video data can be reproduced synchronously, a method of continuously reading data on the disc is selected (S1003). If the data cannot be reproduced synchronously, the video of the first to sixth embodiments is selected. A recording medium reproduction method is selected (S1004), and the reproduction method is switched in accordance with the data recorded on the disc.

  According to the above configuration, when the method of continuously reading data on the disc is selected, the number of movements of the pickup and buffer management become easy, extending the mechanical life of the pickup and reducing power consumption. It becomes possible to do.

  The video recording medium playback method and playback apparatus according to the present invention have the effect that video data and audio data to be output in synchronization can be output in synchronism regardless of how they are recorded on the recording medium. However, it is useful in a video recording medium playback apparatus that plays back a video recording medium in which MPEG data is recorded.

It is a block diagram of the buffer usage method of embodiment of this invention. 1 is a block diagram of an optical disc playback apparatus according to an embodiment of the present invention. FIG. 3 is a flowchart of the first embodiment. FIG. 6 is a flowchart of the second embodiment. FIG. 10 is a flowchart of the fourth embodiment. FIG. 10 is a flowchart of the fifth embodiment. FIG. 10 is a flowchart of the sixth embodiment. FIG. 10 is a flowchart of the seventh embodiment. FIG. 10 is a flowchart of the eighth embodiment. It is a block diagram of the conventional buffer usage method.

Explanation of symbols

1-1 Optical disc,
1-2 video data storage buffer,
1-3 Audio data storage buffer,
2-1 Optical disc,
2-2 Data reader 2-3 MPEG decoder,
2-4 Display controller 2-5 Display device,
2-6 CPU,
2-7 Input device,
2-8 RAM,
2-9 Memory

Claims (9)

  A video recording medium playback method for playing back a video recording medium on which compressed video data and audio data are recorded, wherein the video data and audio data at positions synchronized in time are separated from the video recording medium A video recording medium playback method, wherein the video data and audio data are synchronized and output by decoding the video data and audio data read out in a state and stored in a storage area.   2. The video recording medium playback method according to claim 1, wherein a storage area size of the video data and audio data is fixed.   2. The video recording medium playback method according to claim 1, wherein the storage area for the video data and the audio data is changed to an arbitrary size according to a data structure.   4. The video recording medium playback method according to claim 3, wherein the change in the storage area size is determined by a bit rate of data to be played back.   4. The video recording medium playback method according to claim 3, wherein the change in the storage area size is determined by an encoding method of data to be played back.   2. The video recording medium playback method according to claim 1, wherein a free area that is a difference between the storage areas of the video data and the audio data is monitored, and the smaller storage area is enlarged so that no free area is generated.   The compressed video data and the audio data are read out from the video recording medium and stored in a storage area in a state where the compressed sub-picture data with less restrictions on the output timing than the video data and the audio data are output. The video recording medium playback method according to claim 1, wherein priority is given to data synchronous output processing.   When the video data and the audio data can be played back by determining whether the video data and the audio data can be played back synchronously by the playback method of continuously reading from the video recording medium according to the position of the video data and the audio data recorded on the video recording medium. 5. A reproduction method for continuously reading data on the video recording medium is selected, and when reproduction cannot be performed, a reproduction method for reading the video data and audio data in a separated state is selected. , 5, 6 or 7 described above. A video recording medium playback apparatus for playing back a video recording medium on which compressed video data and audio data are recorded,
A CPU for reading out the video data and audio data at positions synchronized in time from the video recording medium and storing them in a video data storage buffer and an audio data storage buffer, respectively;
A video recording medium playback device comprising: a decoder that decodes the video data and audio data stored in the video data storage buffer and the audio data storage buffer, and outputs the data in synchronization.

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