JP2003235014A - Optical disk playback apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk playback apparatus capable of producing an accurate sub processing signal even in the case of performing repeat playback. <P>SOLUTION: In the optical disk playback apparatus for playing back a recording medium 1 on which video data, a plurality of sub picture data related to the video data, and control data specifying a display period for each of the plurality of sub picture data are recorded, when receiving a repeat playback instruction for a designated period, the optical disk playback apparatus reads data configuring at least one sub picture unit from a point of time back to by a prescribed time from the repeat playback start point of time of the video data, stores the data into a storage section 51 and reproduces the stored data of the sub picture unit together with the video data. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a DVD (Digital Ver.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc reproducing device for reproducing a satile disc) and the like, and particularly to an optical disc reproducing device capable of repeat reproduction.

[0002]

2. Description of the Related Art First, a physical recording format on a DVD will be described with reference to FIG. As shown in the figure,
The DVD has a lead-in area (LI) 2 recorded on the innermost peripheral portion of the disc and a lead-out area (LO) recorded on the outermost peripheral portion of the disc, and video information and audio information are recorded between them. Multiple video title sets (V
It is recorded by being divided into (TS) 4 (VTS # 1 to VTS # n). VTS is a term indicating a group (set) of related works (titles) having the same specifications and attributes. A video manager (VMG) 3 is recorded at the beginning of the area where the VTS 4 is recorded. In the VMG 3, information relating to the entire video information and audio information recorded on the DVD is recorded.

Further, in one VTS 4, first, video title set information (VTSI) 5 in which common control information in a title is recorded is recorded, and thereafter, reproduction data such as concrete video and audio is recorded. To be done. That is, the video object set (VOBS) 6 for menu, the VOBS 7 for title, and the VTSI 8 for backup are recorded. The VOBS 7 for title is composed of up to 9 video objects (VOBs) 9.

Further, one VOB 9 is composed of a plurality of cells (C
ELL) 10. Note that CELL is the minimum unit of normal reproduction, and here, one VOB 9
Is composed of a plurality of cells 10.

Further, one CELL 10 is composed of a plurality of video object units (VOBU) 11. Here, each of the plurality of video object units VOBU # 1 to VOBU # n is a reproduction unit divided for each multi-scene, and each VO
BU is an information unit including video information, audio information, and sub-picture information (sub-picture such as subtitles in a movie).

[0006] One VOBU 11 includes a navigation pack 12 and a video pack 13 in which video data is recorded.
And an audio pack 14 in which audio is recorded and a sub-picture pack 15 in which sub-picture (sub-picture data) is recorded.

According to the DVD standard, the audio data that can be recorded on the DVD is up to 8 channels, and the sub-picture (sub-picture data) can be up to 32 types. Further, according to the DVD standard, the navigation pack 12 in one VOBU 11 must be made to exist in the DVD as recording data, but the video pack 13, the audio pack 14, and the sub-picture pack 15 do not necessarily have to exist, and if they do exist. Also, the number and order of the settings are arbitrary.

The series of packs is called a bitstream, and the structure of these packs is an international standard MPEG.
(Moving Picture Image Coding Experts Group) 2 system.

The bit stream reproduced from this DVD is composed of the video pack 13, the audio pack 14, and the sub-picture pack 15 as described above.
It is time-division multiplexed with 8 bytes as one pack.

The unit for displaying the subtitle image is a sub-picture unit, which is composed of a maximum of 31 sub-picture packs. The sub-picture unit is generated by accumulating a sub-picture pack having a pre-selected sub-stream ID in a sub-picture buffer described later to form one sub-picture unit, and then performing a decoding process by a sub-picture decoder described later. .

FIG. 3 shows the structure of the sub-picture unit. The sub-picture unit is a sub-picture unit header (SPUH) 20, pixel data (PXD)
21 and a sub-picture display sequence control table (SPDCSQT) 22.
Each sub-picture pack includes a pack header 24,
It includes a packet header 25, a substream ID 26, and subpicture data 27.

The SPUH 20 has a fixed length of 4 bytes. The SPUH 20 has data indicating the data capacity of the sub picture unit, the PXD 21, and the SPDCS.
It contains the start address for starting the display of the sub-picture generated by the QT22. In the PXD 21, the bitmap data in each horizontal line is run-length compressed, and the run-length compression is inversely processed and expanded to obtain the value of each pixel.

The SPDCSQT 22 includes a plurality of sub-picture display control sequences (SPDCS).
Q) 23 are arranged in the order in which they are read from the DVD by the pickup described later. One SPDCSQ23 is
The start address of the next SPDCSQ 23, the display control command, and the execution time of the display control command are described.

This sub-picture unit defines a presentation time stamp (PTS) which is time information for synchronizing the timing of displaying the data of the sub-picture unit with video data and audio data. Is the basic unit of decoding processing.

FIG. 4 is a diagram showing the structure of a conventional optical disk reproducing apparatus. The data recorded on the DVD 1 is read by the optical pickup 30 constituting the reading unit, amplified by the amplifier 31, and subjected to waveform equalization processing by the equalizer 32. Then, the DVD demodulation error correction unit 33 performs demodulation processing and error correction processing, and inputs the MPEG bit stream to the source decoder 45.

In the source decoder 45, the demultiplexer (DEMUX) unit 34 discriminates the stream ID inserted in each pack and separates it into video data, audio data and sub-picture data, and the video decoder 38, sub It is distributed to each decoding circuit of the picture decoder 39 and the audio decoder 40. In the sub-picture processing, the pack of the sub-stream ID designated by the host microcomputer 44 is separated and written in the memory 42, read from the memory 42 as necessary, and decoded by the sub-picture decoder 39.

Since the user selects arbitrary subtitles and audio from a maximum of 32 languages of subtitles and a maximum of 8 languages of audio, each circuit of the sub-picture decoder 39 and the audio decoder 40 has a sub-stream ID existing in the sub-picture pack. One subtitle stream and one audio stream are selected as the identification signal. Then, the video data generated by the video decoder 38 and the sub-picture data generated by the sub-picture decoder 39 are combined by the combining unit 46 and output to the NTSC / PAL encoder 47. When a plurality of sub-picture streams are recorded on one DVD, sub-picture packs with sub-stream IDs other than those previously selected by the user are discarded as unnecessary data when the sub-stream ID is detected.

In the NTSC / PAL encoder 47, the video data and sub-picture data generated by the video decoder 38 and the sub-picture decoder 39 are divided into N frames.
It is converted into a TSC video signal or a PAL video signal and output from the video signal output terminal.

The audio data is MPEG audio, multi-channel surround audio, linear P
Only the bitstream selected from CM is D / A
It is output to the converter 48, converted into an audio signal, and output from the audio signal output terminal.

[0020]

In recent years, an optical disk reproducing apparatus usually has a repeat reproducing function, that is, a function of repeatedly reproducing between a repeat reproducing start point and a repeat reproducing end point inputted from an input key of a remote controller or a main body. ing.

By the way, as described above, the video data,
When reproducing a DVD in which audio data and sub-picture data are time-division multiplexed and recorded, for example, when the sub-picture decoder 39 decodes the display data before the display data is stored in the sub-picture buffer as a complete sub-picture unit. It is not possible to get an accurate display.

For example, when playing a movie including subtitles created in the sub-picture unit, a start address for displaying the beginning of one scene of the movie and a time (period) for displaying the subtitle are set in the sub-picture unit. Has been done. Further, the sub-picture data to be displayed as a subtitle in a certain scene is usually multiplexed and recorded as a sub-picture pack at the head of the scene or a position before it. Then, this sub-picture pack is accumulated in the sub-picture buffer to form one sub-picture unit, and then decoded by the sub-picture decoder.

Therefore, when the repeat reproduction is performed by the optical disk reproducing apparatus, the plurality of sub picture packs recorded on the DVD which are multiplexed and recorded on the DVD before the repeat reproduction start point are treated as one complete sub picture unit as a sub picture buffer. Cannot be stored in. Therefore, the subtitles are not accurately displayed in the scene immediately after the repeat reproduction start point.

The phenomenon that subtitles are not displayed in this way is VT
Since it does not occur in R or Laser Disc (registered trademark), it may be uncomfortable for the user. It should be noted that the subtitle display in the above case is accurately performed from the point of time when video, audio, and subtitles are synchronized after one subpicture unit is stored in the subpicture buffer.

The present invention has been made in view of these problems, and provides an optical disk reproducing apparatus capable of generating an accurate sub-picture signal even when repeat reproduction is performed.

[0026]

The present invention adopts the following means in order to solve the above problems.

In an optical disc reproducing apparatus for reproducing a recording medium on which video data, a plurality of sub-picture data which are data related to the video data, and control data defining a display period for each of the plurality of sub-picture data are recorded, The optical disk reproducing device, when receiving the repeated reproduction instruction of the designated section, reads the data forming the at least one sub-picture unit from a time point which is traced back from the start point of the repeated reproduction of the video data, and stores the data in the storage section. At the same time, the stored sub-picture unit data is reproduced together with the video data.

[0028]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a diagram illustrating an optical disk reproducing device according to an embodiment of the present invention. In the figure, reference numeral 49 denotes an operation unit, for example, which designates and inputs a reproduction start point A and a reproduction end point B during repeat reproduction. A sub-picture control unit 50 controls the reading unit to read sub-picture data from the reproduction start point A up to a predetermined time (for example, 30 seconds) from the DVD. 5
A sub-picture storage unit 1 stores the read sub-picture data.

The data recorded on the DVD 1 is read by the optical pickup 30 and amplified by the amplifier 31,
Waveform equalization processing is performed by the equalizer 32. And DVD
The demodulation error correction unit 33 performs demodulation processing and error correction processing, and inputs the MPEG bit stream to the source decoder 45.

In the source decoder 45, the demultiplexer (DEMUX) unit 34 discriminates the stream ID inserted in each pack and separates it into video data, audio data and sub-picture data, and the video decoder 38, the sub-decoder It is distributed to each decoding circuit of the picture decoder 39 and the audio decoder 40. As for the processing of the sub-picture, the pack of the sub-stream ID designated by the host microcomputer 44 is separated and written in the memory 42, read out from the memory 42 as necessary and decoded by the sub-picture decoder 39.

The user operates the operation unit 49, for example, to select an arbitrary subtitle and voice from subtitles in a maximum of 32 languages and voices in a maximum of 8 languages. As a result, each circuit of the sub-picture decoder 39 and the audio decoder 40 uses the sub-stream ID existing in the sub-picture pack and the audio pack as an identification signal to select one subtitle stream and audio selected by the user operating the operation unit 49. Select a stream. Then, the video data generated by the video decoder 38 and the sub-picture data generated by the sub-picture decoder 39 are combined by the combining unit 46 and output to the NTSC / PAL encoder 47. When a plurality of sub-picture streams are recorded on one DVD, a sub-picture pack having a sub-stream ID other than the sub-stream ID selected by the user operating the operation unit 49 has detected the sub-stream ID. At that time, it is discarded as unnecessary data.

In the NTSC / PAL encoder 47, the video data and sub-picture data generated by the video decoder 38 and the sub-picture decoder 39 are divided into N frames.
It is converted into a TSC video signal or a PAL video signal and output from a video signal output terminal (not shown).

The audio data is MPEG audio, multi-channel surround audio, linear P
D / A only the bitstream selected from CM
The signal is output to the converter 48, converted into an audio signal by the D / A converter 48, and output from the audio signal output terminal.

The operation section 49 supplies signals to the host microcomputer 44 which indicate the reproduction start point A and the reproduction end point B at the time of repeat reproduction. The host microcomputer 44 controls the reading unit via a drive control unit (not shown) so as to read the data recorded on the DVD, based on the instruction signal from the operation unit 49.

The drive control section controls the optical pickup 30 and a DVD rotation drive section (not shown) under the control of the host microcomputer 44 to read data from the DVD 1.

When the host microcomputer 44 receives the instruction signal indicating the start point A and the end point B of the repeat reproduction from the operation section 49, the sub picture control section 50 outputs the instruction signal to instruct the reproduction start. The video decoder 38, the sub-picture decoder 39, and the audio decoder 40 are controlled so that the reproduction is temporarily stopped. The sub-picture control unit 50 is composed of a microcomputer, and when it detects that the instruction signal from the operation unit 49 is completed via the host microcomputer 44, the host microcomputer 44 starts reproduction from a point (point A) for a predetermined time. (Eg 30
The sub-picture data up to the second second) is controlled to be read from the DVDl. The reason for selecting the predetermined time (30 seconds) will be described later.

The sub-picture storage unit 51 reads from the DVD1 under the control of the sub-picture control unit 50.
The sub-picture data from 30 seconds before the start of reproduction is stored. The sub-picture control unit 50 also controls the sub-picture decoder 39 to decode the sub-picture data stored in the sub-picture storage unit 51. Further, the sub-picture control unit 50 determines whether the sub-picture unit is generated by the sub-picture decoder 39, and if the sub-picture unit is generated, outputs the decoded sub-picture unit.

When the sub-picture unit is generated by the sub-picture decoder 39, the sub-picture controller 50 instructs the host microcomputer 44 to start output of each of the video data, sub-picture data and audio data. Under control of the sub-picture control unit 50, the host microcomputer 44 instructs the video decoder 38, the sub-picture decoder 39, and the audio decoder 40 to start output of video data, sub-picture data, and audio data, respectively.

The synthesizing unit 46 synthesizes the video data output from the video decoder 38 and the sub-picture data output from the sub-picture decoder 39, and the NTSC
/ PAL to the encoder 47. NTSC / PAL
The encoder 47 converts the video data output from the video decoder 38 and the sub-picture data output from the sub-picture decoder 39 into an NTSC video signal or a PAL video signal and outputs it from a video signal output terminal (not shown). In the embodiment, the reason why the sub-picture control unit 50 of the optical disk reproducing apparatus sets the time (retroactive time) for reading back from the repeat reproduction start time point A, that is, the predetermined time to 30 seconds will be described.

A movie with subtitles can be considered as a typical moving image that reproduces subtitles at the same time as a moving image. In this movie with subtitles, a certain subtitle is displayed while being updated at substantially regular intervals. This subtitle update interval is within 15 seconds for most movies with subtitles. Assuming that the interval from the subtitle update to the next subtitle is one scene, in order for the subpicture decoder 39 to decode the subpicture data for one scene recorded on the DVDl, a new subtitle should be displayed. The sub-picture data from 15 seconds before is required.

In such a movie with subtitles, when the signal for instructing repeat reproduction is output, the sub-picture data from 30 seconds before the reproduction start time is stored in the sub-picture storage unit 51. As a result, one or more sub-picture units can be surely generated at any point of the repeat reproduction start point A. Therefore, the subtitles can be accurately displayed in most movies with subtitles at any time when the reproduction starts.

By controlling the sub-picture data from the playback start time to the time exceeding 30 seconds so as to be read from the DVD 1, it is possible to cope with a movie with a subtitle interval of 15 seconds or more. However, as the time to read back from the start of repeat playback increases,
Since the amount of sub-picture data read from the DVD 1 is large, the time from the output of the signal instructing repeat reproduction from the operation unit 49 to the start of repeat reproduction becomes long. Therefore, the predetermined time is 3
About 0 seconds is preferable.

A time setting unit for arbitrarily setting the predetermined time is provided in, for example, the operation unit 49, and the predetermined time (retroactive time) is arbitrarily set by the time setting unit (for example, 30 seconds, 20 seconds or Can be set to 10 seconds). In this case, the signal for instructing repeat reproduction is the operation unit 4
It is possible to shorten the time from the output from 9 to the reading of the sub-picture data.

[0044]

As described above, according to the present invention, it is possible to provide an optical disk reproducing apparatus capable of generating an accurate sub-picture signal even when repeat reproduction is performed.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an optical disc reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a physical recording format on a DVD.

FIG. 3 is a diagram showing a configuration of a sub-picture unit.

FIG. 4 is a diagram showing a configuration of a conventional optical disc reproducing apparatus.

[Explanation of symbols]

1 DVD 30 optical pickup 31 amplifier 32 Equalizer 33 DVD demodulation error correction unit 34 De Multixa 35 video buffer 36 sub-picture buffer 37 audio buffers 38 Video Decoder 39 Sub-picture decoder 40 audio decoder 41 Memory controller 42 memory 43 Host interface 44 Host microcomputer 45 source decoder 46 Composition Department 47 NTSC / PAL encoder 48 D / A converter 49 Operation part 50 Sub-picture control unit 51 Sub-picture storage

Continued front page    F-term (reference) 5C052 AA02 AB03 AB04 AC01 CC06                       DD04                 5C053 FA24 HA21 HA33 KA04 LA06                       LA11                 5D044 AB05 AB07 BC02 CC04 DE18                       DE39 FG19 FG23 GK08 GK12                 5D077 AA23 BA01 CA02 DC03 GA10

Claims (3)

[Claims] 1. An optical disk reproducing apparatus for reproducing a recording medium on which video data, a plurality of sub-picture data which are data related to the video data, and control data which defines a display period for each of the plurality of sub-picture data are recorded. When the optical disk reproducing apparatus receives a repeat reproduction instruction of a designated section, the optical disk reproducing apparatus starts from the start of the repeated reproduction of the video data by a predetermined time and then returns to the at least 1
An optical disk reproducing apparatus, which reads data constituting one sub-picture unit, stores the data in a storage unit, and reproduces the stored data of the sub-picture unit together with the video data. 2. The optical disk reproducing apparatus according to claim 1, wherein the predetermined time is about 30 seconds. 3. The optical disk reproducing apparatus according to claim 1, further comprising a time setting unit that variably sets the predetermined time.