JP2002290895A - Optical disk reproducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly output a sub-picture signal such as subtitles when a special reproducing operation is shifted to the normal reproducing operation. SOLUTION: An optical disk reproducer reproduces a recording medium 1 which records video data, multiple kinds of sub-picture data being data related to then video data and control data which regulates a display period at each kind of sub-picture data. The reproducer reads at least one kind of sub-picture data at the predetermined time preceding the time when the normal reproduction of video data is started and reproduces the read sub-picture data together with the video data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DVD (Digital Ve
The present invention relates to an optical disc reproducing apparatus for reproducing an rsatile disc, etc., and particularly to an optical disc reproducing apparatus capable of shifting from a scanning operation such as a manual search and a special reproducing operation such as a slow reproduction and a double speed reproduction to a normal reproduction operation.

[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 periphery of the disc and a lead-out area (LO) recorded on the outermost periphery of the disc, during which video information and audio information are not stored. Multiple video title sets (V
TS) 4 (VTS # 1 to VTS # n). Here, VTS is related (specifications,
This is a term that indicates a group (set) of works (titles) with the same attributes. A video manager (VMG) 3 is recorded at the head of the area where the VTS 4 is recorded. The VMG 3 records information relating to the entirety of video information and audio information recorded on the DVD.

[0003] In one VTS 4, video title set information (VTSI) 5 in which common control information in a title is recorded is first recorded, and thereafter, reproduction data such as specific video and audio is recorded. Is done. That is, a video object set (VOBS) 6 for menus, a VOBS 7 for titles, and a VTSI 8 for backup are recorded. Note that the title VOBS 7 includes up to nine video objects (VOBs) 9.

Further, one VOB 9 has a plurality of cells (C
ELL) 10.

[0005] CELL is the minimum unit for normal reproduction. Here, one VOB 9 is composed of a plurality of CELLs 10.

[0006] 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, for example, a playback unit divided for each multi-scene, and
A BU is an information unit including video information, audio information, and sub-video information (sub-video such as subtitles in a movie).

One VOBU 11 includes a navigation pack 12 and a video pack 13 on which video data is recorded.
And an audio pack 14 in which audio is recorded, and a sub-picture pack 15 in which sub-pictures (sub-picture data) are recorded. According to the DVD standard, up to eight channels of audio data can be recorded on a DVD, and up to 32 types of sub-pictures (sub-picture data) are possible. According to the DVD standard, in one VOBU 11, the navigation pack 12 must always exist as recording data on the DVD. However, the video pack 13, the audio pack 14, and the sub-picture pack 15 are not necessarily required. The setting of the number and order is arbitrary.

[0008] A series of the video pack 13, the audio pack 14, and the sub-picture pack 15 is called a bit stream. The structure of these packs is MPEG (Moving Picture Image Coding Experts) which is an international standard.
Group) 2 system.

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

A unit for displaying a caption image is a sub-picture unit, which is composed of a maximum of 31 sub-picture packs. The configuration of the sub-picture unit is disclosed in Japanese Patent Application Laid-Open No. Hei 10-51741. The sub-picture unit is generated by accumulating a sub-picture pack having a pre-selected sub-stream ID in a sub-picture buffer, which will be described later, and performing decoding processing by a sub-picture decoder, which will be described later, as one sub-picture unit.

FIG. 4 shows the configuration of the sub-picture unit. The sub-picture unit includes a sub-picture unit header (SPUH) 20, pixel data (PXD)
21, a sub-picture display sequence control table (SPDCSQT) 22.
Each of the sub-picture packs includes a pack header 2
4, a packet header 25, a sub-stream ID 26, and sub-picture 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, PXD 21 and SPDCS.
The start address at which the display of the sub-picture generated by the QT 22 is started is entered. The PXD 21 performs run-length compression on the bitmap data in each horizontal line. The PXD 21 decompresses and extends the run-length compression to obtain the value of each pixel.

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

In the sub-picture unit, a presentation time stamp (PTS) which is time information for synchronizing the timing at which the data of the sub-picture unit is displayed with video data and audio data is defined. Is a basic unit of the decoding process.

FIG. 5 is a diagram showing a configuration of a conventional optical disk reproducing apparatus. Data recorded on the DVD 1 is read by the optical pickup 30, amplified by the amplifier 31, and subjected to waveform equalization by the equalizer 32. And D
The VD demodulation error correction section 33 performs demodulation processing and error correction processing, and inputs the result to the source decoder 45 as an MPEG bit stream.

The source decoder 45 uses the demultiplexer (DEMUX) unit 34 to determine the stream ID inserted in each of the packs, separates the data into video data, audio data, and sub-picture data. The signal is distributed to the decoding circuits of the picture decoder 39 and the audio decoder 40. In the processing of the sub-picture, the pack of the sub-stream ID specified by the host microcomputer 44 is separated and written into the memory 42, read from the memory 42 as necessary, and decoded by the sub-picture decoder 39.

In order for the user to select any subtitle and audio from subtitles in up to 32 languages and audio in up to eight languages, each circuit of the audio decoder 40 and the sub-picture decoder 39 uses the sub-stream ID existing in the sub-picture pack. Is used as an identification signal to select one subtitle stream and one audio stream. Then, the video data generated by the video decoder 38 and the sub-picture data generated by the sub-picture decoder 39 are synthesized by the synthesizing 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 one selected by the user in advance is discarded as unnecessary data when the sub-stream ID is detected.

The NTSC / PAL encoder 47 converts the video data and sub-picture data generated by the video decoder 38 and the sub-picture decoder 39 into N
The video signal is converted into a TSC video signal or a PAL video signal and output from a video signal output terminal.

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

The DVD reproducing apparatus has a fast forward button and a fast rewind button (not shown). The fast-forward button is a button for performing playback at a speed higher than usual by operation, and the fast-reverse button is a button for performing reverse playback at a speed faster than usual.

[0021]

A DVD in which video data, audio data and sub-picture data are multiplexed and recorded in a time-division manner as described above.
In reproducing the sub-picture data, if the sub-picture decoder 39 decodes data that has not yet been stored as a complete sub-picture unit in the sub-picture buffer 36, an accurate display cannot be obtained.

For example, in the case of a movie including subtitles created by sub-pictures, the sub-picture unit contains
A start address for displaying at the head of the scene and a time for displaying subtitles are set. A sub-picture displayed as a movie subtitle in a certain scene is multiplexed at the beginning of the scene or at a point earlier than the beginning of the scene.
Is stored in the sub-picture buffer 36, and the decoding process must be completed by the sub-picture decoder 39 as one sub-picture unit.

For this reason, in the DVD reproducing apparatus, when the operation is shifted from the operation of fast-forward and fast-reverse by the fast-forward button and the fast-reverse button to the normal reproduction by releasing the operation of the fast-forward and fast-reverse buttons, in most cases, the reproduction is performed. A sub-picture pack multiplexed before or at the beginning of a scene is not stored in the sub-picture buffer 36 as one sub-picture unit. For this reason, in the scene immediately after the normal reproduction operation, a phenomenon occurs in which the caption, that is, the sub-picture is not accurately displayed as an image. Since such a phenomenon that subtitles are not displayed does not occur in a VTR, a laser disk (registered trademark), or the like, the user may feel uncomfortable. Note that the subtitle display in the above case is accurately performed from the time when video, audio, and subtitles are synchronized after one sub-picture unit is stored in the sub-picture buffer.

The present invention has been made in view of the above-mentioned problems, and when a transition is made from a scanning operation such as a manual search or a special reproduction operation such as a slow reproduction or a double-speed reproduction to a normal reproduction operation, a sub picture signal is accurately outputted. It is an object of the present invention to provide an optical disc reproducing apparatus capable of outputting an optical disc.

[0025]

The present invention employs the following means in order to solve the above-mentioned problems.

In an optical disc reproducing apparatus for reproducing a recording medium on which video data, a plurality of sub-picture data as data related to the video data, and control data for defining a display period for each of the plurality of sub-picture data are recorded, The optical disk reproducing apparatus reads the at least one sub-picture data from a point in time that is set back from a start point of normal reproduction of the video data by a preset time when a transition is made from a special reproduction operation to a normal reproduction operation. The data is reproduced together with the video data. The set time is approximately 30.
Preferably, it is seconds.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an optical disc reproducing apparatus according to an embodiment of the present invention.

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

In the source decoder 45, the demultiplexer (DEMUX) section 34 determines the stream ID inserted in each pack, separates the stream ID into video data, audio data, and sub-picture data. The signal is distributed to the decoding circuits of the decoder 39 and the audio decoder 40. In the processing of the sub-picture, the pack of the sub-stream ID specified by the host microcomputer 44 is separated and taken out, written into the memory 42, read from the memory 42 as needed, and decoded by the sub-picture decoder 34.

The user operates the operation unit 50 to operate a maximum of 3
An arbitrary subtitle and audio are selected from subtitles in two languages and audio in up to eight languages. Each circuit of the audio decoder 40 and the sub-picture decoder 39 selects one subtitle stream and audio stream selected by the user using the sub-stream ID present in the sub-picture pack as an identification signal. The video data generated by the video decoder 38 and the sub-picture decoder 39
And the sub-picture data generated by the
And outputs the result to the NTSC / PAL encoder 47.

When a plurality of sub-picture streams are recorded on one DVD, a sub-stream I other than the sub-stream ID selected by the user through the operation unit is used.
The D sub-picture pack is discarded as unnecessary data when the sub-stream ID is detected.

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

As the audio data, only a bit stream selected from among MPEG audio, Dolby AC-3, and linear PCM is output to the D / A converter 48, and is converted into an audio signal by the D / A converter 48 to output an audio signal. Output from terminal.

The operation unit 50 outputs to the host microcomputer 44 a manual search instruction signal for instructing fast-forward playback for performing playback at a speed faster than normal playback and fast-backward playback for performing reverse playback at a faster speed. The host microcomputer 44 controls to read data recorded on the DVD 1 via a drive control unit (not shown) based on an instruction signal from the operation unit 50. The drive control unit controls the optical pickup 30 and a DVD rotation drive unit (not shown) under the control of the host microcomputer 44 so as to read data from the DVD1.

Further, when the manual search instruction signal from the operation unit 50 ends, the host microcomputer 44 suspends reproduction until a sub-picture control unit 52 outputs a reproduction start instruction signal. The sub-picture control unit 52 includes a microcomputer. When the sub-picture control unit 52 detects that the manual search instruction signal from the operation unit 50 has ended via the host microcomputer 44, the host microcomputer 44 attempts to start reproduction as described later. (When playback starts)
Then, the drive control unit is controlled to read the sub-picture data from DVD 1 up to a predetermined time, for example, 30 seconds before.

Under control of the sub-picture control unit 52, the sub-picture storage unit 53 stores sub-picture data from the start of reproduction read from the DVD 1 up to 30 seconds before. Further, the sub-picture control unit 52 controls the sub-picture decoder 39 to decode the data stored in the sub-picture storage unit 53. At this time, the sub-picture control unit 52 determines whether or not a sub-picture unit is generated by the sub-picture decoder 39, and outputs the sub-picture unit decoded by the sub-picture decoder 39 when the sub-picture unit is generated. Control.

Next, using the flowchart shown in FIG.
An example of a display operation for displaying sub-picture data will be described.

First, when the manual search by the operation unit 50 is completed (step S1), the reproduction is temporarily stopped until a reproduction start instruction signal is output from the sub-picture control unit 52, and the reproduction is started. (Reproduction start time) is detected (step S2). Then, the sub-picture control unit 52 reads the sub-picture data up to 30 seconds before the reproduction start time from the DVD 1, and stores the read sub-picture data in the sub-picture storage unit 53 (step S3).

Next, the sub-picture control unit 52 uses the sub-picture decoder 39 to
The decoding process of the sub-picture data stored in No. 3 is started (step 4), and it is determined whether or not one sub-picture unit is completely stored (step S5).

When it is determined that the data is stored (YES)
Detects the display start time and the display time for displaying the display data of the sub-picture unit U (step S
6).

Next, the sub-picture control unit 52 determines whether or not the display start time of the sub-picture unit U has passed (step S7). It is determined whether the display end time of the picture unit U has passed (step S).
8).

If it is determined that the display end time has not passed (NO), the sub-picture control unit 52 controls the host microcomputer 44 to start outputting video data, sub-picture data and audio data. At this time, the host microcomputer 44 starts outputting the video data decoded by the video decoder 38, the sub-picture data decoded by the sub-picture decoder 39, and the audio data decoded by the audio decoder 40. Synthesizer 4
6 synthesizes the video data output from the video decoder 38 and the sub-picture data output from the sub-picture decoder 39, and generates an NTSC / PAL encoder 4.
7 is output. The NTSC / PAL 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 the video signal from a video signal output terminal (not shown). (Step S9). If it is determined in step S8 that the display end time has passed (YES), the host microcomputer 44 controls to erase the display data of the sub-picture unit U, and returns to step S5 (step S9).

According to the present embodiment, when shifting from the manual search operation to the normal reproduction operation, a sub-picture unit is generated retroactively for a predetermined period from an arbitrary reproduction start time, and the generated sub-picture unit is sent to the sub-picture decoder 39. Since the output can be performed, sub-pictures such as subtitles can be reliably displayed after the manual search operation.

Next, when generating the sub-picture unit, a "predetermined period" to be traced back from the reproduction start point
Will be described.

A typical moving picture for reproducing subtitles together with moving pictures is a movie with subtitles. A movie with captions is displayed while updating certain captions at substantially constant intervals. The subtitle update interval is within 15 seconds in most cases. Assuming that the interval from the update of the subtitle to the update of the next subtitle is one scene, the sub picture decoder 39
It is necessary to decode the sub-picture data for one scene recorded in the sub-picture data, that is, the sub-picture data from the point at which a new subtitle is to be displayed to 15 seconds before, in synchronization with the moving image before the display.

Therefore, a DV recording a movie with subtitles
When normal playback is started after performing a manual search for D, the sub-picture control unit 52 stores the sub-picture data up to 30 seconds before the playback start time in the sub-picture storage unit 53, thereby starting playback. Regardless of the time point, one or more sub-picture units can always be generated. Therefore, subtitles of most subtitled movies can be displayed accurately regardless of the reproduction start point.

Assuming that the period of reading back from the reproduction start time is longer than 30 seconds, the interval of one scene is 15 seconds.
It can handle movies with subtitles of more than a second. However, it takes a long time to read the sub-picture data retroactively from the reproduction start time. As a result, the amount of sub-picture data read from the DVD increases.
The time from the end of the manual search operation to the start of the reproduction becomes long. Therefore, it is preferable that the period be approximately 30 seconds.

It is to be noted that a time setting unit for setting the period can be provided, and the period can be arbitrarily set by the time setting unit. The time setting unit is, for example, 30 seconds, 20
By selecting and setting an arbitrary time from seconds or 10 seconds, an instruction signal of the set time is output to the sub-picture control unit 52. Sub-picture control unit 52
Is configured to read sub-picture data before the reproduction start point from the DVD 1 in response to an instruction signal of a set time. As a result, the time from when the manual search operation is completed to when the sub-picture control unit 52 completes reading the sub-picture data from the DVD 1 can be reduced.

[0049]

As described above, according to the present invention, it is possible to provide an optical disk reproducing apparatus capable of accurately outputting a sub-picture signal such as a subtitle when shifting from a special reproduction operation to a normal reproduction operation. Can be.

[Brief description of the drawings]

FIG. 1 is a diagram showing an optical disk reproducing device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of the optical disc reproducing apparatus according to the embodiment of the present invention.

FIG. 3 is a diagram showing a physical recording format on a DVD.

FIG. 4 is a diagram illustrating a configuration of a sub-picture unit.

FIG. 5 is a diagram showing a configuration of a conventional optical disc reproducing apparatus.

[Explanation of symbols]

 Reference Signs List 1 DVD 30 optical pickup 31 amplifier 32 equalizer 33 DVD demodulation error correction unit 34 DEMUX 35 video buffer 36 sub-picture buffer 37 audio buffer 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 Synthesis unit 47 NTSC / PAL encoder 48 D / A converter 50 Operation unit 52 Sub-picture control unit 53 Sub-picture storage unit

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) H04N 7/03 7/035 F term (reference) 5C052 AA02 AC01 CC11 DD10 5C053 FA24 FA30 GA11 GB06 GB38 HA21 JA16 KA01 KA16 KA22 KA24 LA06 5C063 AB07 AC01 CA12 DA03 DA07 5D044 BC03 CC06 DE03 DE12 DE17 DE23 DE29 FG19 5D077 AA23 BA30 DC03

Claims (3)

[Claims] 1. An optical disk reproducing apparatus for reproducing a recording medium on which video data, a plurality of sub-picture data as data related to the video data, and control data for defining a display period for each of the plurality of sub-picture data are recorded. In the optical disc playback apparatus, when the normal playback operation is shifted from the special playback operation, the at least one sub-picture data is read and read from a point in time that is set back from a start time of the normal playback of the video data by a preset time. An optical disc reproducing apparatus for reproducing sub picture data together with the video data. 2. An optical disc reproducing apparatus according to claim 1, further comprising a setting section for setting a time period retroactive to said normal reproduction start time. 3. The optical disk reproducing apparatus according to claim 1, wherein the preset time is approximately 30 seconds.