JPH10322661A - Image decoder and image decoding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image decoder or the like which outputs smooth video data at the time of special reproduction such as fast forward and reverse reproduction. SOLUTION: Data in a VOBU (video object unit) unit is intermittently supplied to a video decoder of a DVD reproducing device at the time of fast forward or reverse reproduction. Only three I or P pictures (intra-frame coding image data or inter-frame forward predictive coding image data) from the first of each VOBU are decoded. The decoder outputs I or P pictures which are decoded to memory for more than three based on the control of a controller. In the case of fast forward reproduction, it outputs in order of time, and in the case of reverse reproduction, it outputs in order that is opposite to decoding order. Also, it measures the time when the VOBU passes through a demultiplexer that is on a preceding stage, balances the output interval of each picture and outputs. That is, because three pictures are outputted to each VOBU, a picture is outputted every 1/3 time of a mean passing time of the VOBU.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image decoding apparatus and an image decoding method for intermittently decoding compressed image data using a correlation in a time axis direction over a plurality of frames.

[0002]

2. Description of the Related Art In a conventional DVD (digital video disk: DVD-VIDEO), when performing special reproduction such as high-speed reproduction in the forward direction or high-speed reproduction in the reverse direction, MPEG2 (M
Only one intra-frame coded image data (I-Picture: IntraCoded Picture) in the oving Picture Experts G2) system is used.

[0003]

However, when the special reproduction is performed using only the I-Picture, the amount of information is reduced, and the reproduced image is displayed as a slide at high speed. In addition, the amount of information becomes very small as compared with high-speed reproduction such as a VTR.
The display interval is sparse because it is affected by the decoding time and the like, which causes a problem of giving a sense of incongruity.

The present invention has been made in view of such circumstances, and has an image decoding apparatus and an image decoding apparatus for outputting image data with smooth images during special reproduction such as high-speed reproduction in a forward direction or a reverse direction. It is an object to provide a decoding method.

[0005]

In order to solve the above-mentioned problems, an image decoding apparatus according to the present invention provides an image decoding apparatus which compresses image data compressed over a plurality of frames using a correlation in a time axis direction. Decoding means for supplying video object units (VOBU: Video Object Unit) comprising image data units, expanding the compressed image data to generate video data, and outputting the expanded video data; VOBU search information (VOBU_SRI: VOBU Search) indicating time information between VOBUs included in the VOBU
Information) (NV_PCK: Navi
and a control means for controlling the VOBU to be supplied to the decoding means based on the VOBU_SRI. The control means intermittently supplies the VOBU to the decoding means and measures the time of the intermittent interval. Then, the average time of the intermittent interval is obtained, and the decoding means sets the first three intra-frame coded image data (I-Picture: Int) in the VOBU.
ra Coded Picture) or inter-frame forward prediction coded image data (P-Picture: Predictive Coded Picture) to generate video data, and expand the three I-pictures.
Picture data of Picture or P-Picture is output one screen at a time at an interval of 1/3 of the average time.

In the image decoding apparatus according to the present invention, the control means measures the time of the intermittent interval to determine the average time of the intermittent interval, and the decoding means sets the first three I-pictures in the VOBU. Alternatively, P-Picture is decompressed to generate video data, and the decompressed three IP
image or P-Picture video data,
It outputs one screen at a time interval of 1/3 of the average time.

Further, in the image decoding method according to the present invention, the image data compressed using the correlation in the time axis direction over a plurality of frames is used for each video object unit (VOBU) composed of a plurality of frames of image data. And the navigation pack (NV_ included in the VOBU)
Based on the VOBU search information (VOBU_SRI) indicating the time information between the VOBUs of the PCK), the supplied VOBU is intermittently selected, the time of the supplied VOBU is measured, and the average of the intermittent intervals is measured. The time is obtained, and the first three intra-frame predictive coded image data (I-Picture) or the inter-frame forward predictive coded image data (P-Picture) in the intermittently selected VOBU are decompressed to obtain a video. Data is generated, and the expanded three I-Picture or P-Picture video data are divided by 1 / the average time.
It is characterized in that one screen is output at a time interval of three.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a DVD-Video disk reproducing apparatus (hereinafter referred to as a DVD reproducing apparatus) to which the present invention is applied will be described as an embodiment with reference to the drawings.

FIG. 1 is a block diagram of a DVD reproducing apparatus.

The DVD reproducing apparatus 100 includes a pickup 2 for reproducing an RF signal from a recording medium 1, an RF circuit 3 to which an RF signal reproduced by the pickup 2 is supplied and performs a binarization process of the RF signal, and the like. A data decoder 4 to which reproduction data is supplied from the RF circuit 3 to perform decoding processing such as error correction, and a data decoder that distributes the reproduction data decoded by the data decoder 4 to main video compression data, sub-video compression data, and audio compression data. And a multiplexer 5.

The DVD reproducing apparatus 100 includes a video decoder 6 for expanding the main video compressed data, a sub-video decoder 7 for expanding the sub-video compressed data and synthesizing it with the main video data, And a digital / NT converter which supplies video data obtained by combining main video data and sub-video data from the sub-video decoder 7 and converts the video data into an NTSC signal or a PAL signal.
An SC / PAL conversion circuit (hereinafter simply referred to as an NTSC conversion circuit) 9 and a digital / analog conversion circuit (hereinafter simply referred to as a D / A conversion circuit) to which audio data is supplied from an audio decoder 8 and converted into an analog signal.
10 is provided.

The DVD reproducing apparatus 100 includes a pickup 2, an RF circuit 3, a data decoder 4, a demultiplexer 5, a video decoder 6, a sub-picture decoder 7, an audio decoder 8, an NTSC conversion circuit 9, and a D / A conversion circuit. The controller 11 includes a controller 11 that controls the controller 10, a user interface 12 that mediates operation inputs of the controller 11 and a user, and a memory 13 that serves as a data storage unit of the controller 11.

The DVD reproducing apparatus 100 reproduces, as the recording medium 1, a read-only, write-once, rewritable, etc. DVD disk and DVD-Video disk.

The pickup 2 reproduces an RF signal from the recording medium 1 and supplies the RF signal to the RF circuit 3.

The RF circuit 3 performs waveform equalization and binarization of the RF signal to generate digital data and a synchronization signal thereof. Digital data and the like generated by the RF circuit 3 are supplied to a data decoder 4.

The data decoder 4 performs processes such as data demodulation and error correction based on the digital data generated by the RF circuit 3. Digital data demodulated by the data decoder 4 is supplied to a demultiplexer 5.

In the data decoder 4, the MPE
Parameter information included in the system header and pack header in the G2 format, and the navigation pack (NV_PCK: Navigation P
ack) is detected. The detected parameter information and the like are supplied from the data decoder 4 to the controller 11.

The data decoder 4 has a track buffer 4a at the output stage of digital data.
The difference in processing speed between the data decoder 4 and the demultiplexer 5 is absorbed by the track buffer 4a.

The demultiplexer 5 includes a data decoder 4
To divide the digital data subjected to the error correction decoding processing into compressed main video data, compressed sub-video data, and compressed audio data.

Here, the compressed main video data is MPEG data.
Video data compressed in two formats, for example, Video streams in a DVD format. The sub-picture compressed data is data such as a caption image to be combined with the main picture, and is, for example, Sub-picture streams in the DVD format. The audio compression data is audio data compressed by a method such as MPEG2, and is audio streams in a DVD format.

The demultiplexer 5 supplies the main video compression data to the video decoder 6, supplies the sub video compression data to the sub video decoder 7, and supplies the audio compression data to the audio decoder 8.

The video decoder 6 decodes the compressed main video data and generates expanded main video data by this decoding process. The video decoder 6 has a memory for three screens for performing a decoding process. That is, intra-frame coded image data (I-Picture: Intra Coded Picture) and inter-frame forward prediction coded image data (P-Picture: Predict
ive Coded Picture) and bidirectional predictive coded image data (B
-Picture: Bidirectionally predictive_codedpicture)
Is decoded and stored in the memory of the video decoder 6, and each decoded picture is output from this memory. This memory is not limited to three screens, and may have a larger capacity. The video decoder 6 supplies the generated main video data to the sub video decoder 7.

The sub-picture decoder 7 decodes the compressed sub-picture data, and combines the decoded sub-picture data with the main picture data supplied from the video decoder 6 to generate video data. That is, the sub-picture decoder 7 combines a subtitle image or the like reproduced as sub-picture data with the main video. When there is no sub video data, the sub video decoder 7 outputs the main video data as it is as video data. The sub-video decoder 7 supplies the generated video data to the NTSC conversion circuit 9.

The audio decoder 8 performs a decoding process on the compressed audio data to generate expanded audio data. That is, the audio decoder 8 determines that the audio compression data is M
If the data is compressed in the PEG2 format, the audio data is generated by performing a corresponding expansion process. In addition,
If the audio data is encoded in a format such as PCM in addition to the MPEG2 format, a decoding process corresponding to this is performed. The audio decoder 8 supplies the generated audio data to the D / A conversion circuit 10.

The NTSC conversion circuit 9 converts video data from digital data into a television signal of the NTSC system or the PAL system and outputs the same. By supplying this output to a monitor or the like, the user can view the video reproduced from the recording medium 1.

The D / A converter circuit 10 converts digital audio data into analog audio data and outputs the analog audio data. By supplying this output to a speaker or the like, the user can view the sound reproduced from the recording medium 1.

The controller 11 includes a pickup 2, R
It controls the F circuit 3, data decoder 4, demultiplexer 5, video decoder 6, sub-picture decoder 7, audio decoder 8, NTSC conversion circuit 9, and D / A conversion circuit 10.

The controller 11 receives an operation input through an operation panel or a user interface 12 which is a remote controller.
Controls each circuit based on this operation input.

The controller 11 stores control data and the like in the memory 13 and controls each circuit based on the data stored in the memory 13.

The DVD reproducing apparatus 100 can perform special reproduction processing such as high-speed reproduction of a video signal in a forward direction or a reverse direction. FIG. 2 is a conceptual diagram for explaining a data decoding method when compressed main video data is supplied to a video decoder to which the present invention is applied. With reference to FIG. 2, a description will be given of the high-speed reproduction process in the forward direction or the reverse direction of the DVD reproducing apparatus 100.

The video decoder 6 includes, for example, an MPEG
Group of Pictures (GOP: Group
Of Pictures) are sequentially supplied. Note that the unit of the video supplied to the video decoder 6 is not limited to the GOP,
It may be a video object unit (VOBU) in the format of a DVD-VIDEO disc. The details of this VOBU will be described later.

In the case of high-speed reproduction in the forward direction, the main video compressed data supplied to the video decoder 6 is skipped by a predetermined number of GOPs in the time axis direction as shown in FIG. And is supplied to the video decoder 6 intermittently. This intermittent interval varies depending on the speed of high-speed reproduction, and is controlled by the controller 11 based on a user operation. Of course, depending on the reproduction speed, one GOP may be sequentially supplied to the video decoder 6 without skipping one GOP.

When the GOP is supplied, the video decoder 6
As shown in FIG. 2B, the first three intra-frame coded image data (I-Picture: Intra Coded)
Picture) or inter-frame forward prediction coded image data
(P-Picture: Predictive CodedPicture) is decoded. That is, the main video compressed data decoded by the video decoder 6 is the I-Pictu from the beginning of the GOP data stream.
If three consecutive res, these three I-Pictures
And two I-Pictures and a P-Pictur
If one e continues, the two I-Pictures and one P-Picture, and the I-Picture
If one is followed by two P-Pictures, this 1
One I-Picture and two P-Pictures. Also, three or more I-Pictures in a GOP
If there is no P-Picture or P-Picture, only one or two I-Pictures are decoded.

The video decoder 6 has 3
The I-Picture or P-Picture is decoded, and the decoded video data is stored in the memory in the video decoder 6. Then, the remaining data in the GOP is discarded. The G supplied to the video decoder 6
OP data is stored in advance with management data such as a header in the first 3
The data may include only the I-Picture or P-Picture data. That is, unnecessary data may be discarded before being supplied to the video decoder 6. For example, based on the control of the controller 11, a process of discarding unnecessary data may be performed by the data decoder 4 provided before the video decoder 6 or the demultiplexer 5 that divides audio data and the like.

The video decoder 6 sequentially outputs the decoded I-Picture and P-Picture on the memory in chronological order under the control of the controller 11.
At this time, the video decoder 6 outputs video data by averaging the output intervals based on the supplied GOP intervals. For example, as shown in FIG.
If each interval with the OP is t ₁ , t ₂ , t ₃ , and t ₄ , respectively, three I-Pi corresponding to the GOP supplied first.
the output interval such as cture to t _1/3. The output interval of each I-Picture or the like corresponding to the second GOP is ((t ₁ + t ₂ /) // 3. The output interval of the I-Picture or the like corresponding to the third GOP is ( (t ₁ +
t ₂ + t ₃ ) / 3) / 3. And the fourth GOP
The output interval of the I-Picture or the like corresponding to ((t ₁
+ T ₂ + t ₃ + t ₄ ) / 4) / 3.

That is, the intervals of the supplied GOPs are not equal due to various factors such as the compression ratio of the image, the type of the image, the access time from the recording medium 1, and the decoding time of the video decoder 6. Different for each image. Therefore, if output processing is immediately performed from the decoded data, the output intervals become sparse, and an image that causes a sense of incongruity is displayed. Therefore, the video decoder 6 detects the intervals of the supplied GOPs and averages the speed of the output data. The averaging process is performed by sampling intervals between a plurality of GOPs.
The processing may be performed such that the number of samples is made constant for the past 30 GOPs and old samples are discarded.

The intermittent intervals of the GOPs detected for averaging are determined by the timing at which the data decoder 4 supplies the GOPs to the demultiplexer 5, and the demultiplexer 5
The timing at which the OP is acquired or the timing at which the demultiplexer 5 supplies the GOP to the video decoder 6 may be detected, and this timing may be measured.

On the other hand, when high-speed reproduction in the reverse direction is performed, GOPs are skipped by a predetermined number in the direction opposite to the time axis direction and supplied intermittently to the video decoder 6.

When decoding the GOP supplied in the direction opposite to the time axis, the video decoder 6 decodes from the beginning of the GOP in the same manner as in the forward reproduction. Three I-Picts decoded from the beginning of this GOP
ure and P-Picture are stored in the memory of the video decoder 6.

When the video decoder 6 stores the three I-pictures in one GOP in the memory,
This time, output is performed in the direction opposite to the time axis, that is, from the last decoded picture. At the time of this output, the video decoder 6 performs averaging in the same manner as in the case of the forward reproduction described above.

By the way, when performing special reproduction processing such as high-speed reproduction of the video signal in the forward direction and the reverse direction as described above, there is a case where the GOP supplied to the video decoder 6 does not include the video compression data. This is a case where a so-called video gap occurs, for example, when still images are continuously output. During this video gap,
The video decoder 6 has three I-Pictures or P-pictures.
-Picture cannot be decoded.

In such a case, in the forward high-speed reproduction, the video decoder 6 decodes the main video compressed data up to the image immediately before the video is interrupted, and re-encodes the video data until it comes back to the GOP where the video data exists. Continue to output. In the high-speed playback in the reverse direction, the main video compressed data of the GOP in which the image immediately before the video in which the video data exists next is present is decoded, and the image immediately before the video is interrupted is output to this GOP. Allow time to reach.

Next, in the DVD reproducing apparatus 100, when the recording medium is a DVD-VIDEO disc, high-speed reproduction in the forward direction (hereinafter referred to as FWD-Scan (Forward Scan)) and high-speed reproduction in the reverse direction (hereinafter referred to as BWD). -Scan (Backward Sc
an). )), Specifically, this DV
Description will be made using the format of a D-Video disk.

First, before describing the contents of this processing, a brief description of the format of this DVD-VIDEO disc and management information, attributes, search information, and the like used in FWD-Scan and BWD-Scan will be described.

As shown in FIG. 3, a DVD-Video disk has a video object set (VOBS: Video Ob
The main video data, the sub video data, and the audio data are managed in units of (Jet Set). The VOBS is a unit of one movie or the like, for example. This VOBS is composed of a plurality of video objects (VOBs). This VOB is a unit in which each data is recorded as one group on the disk. The VOBS is composed of a plurality of cells. The Cell is a unit of one scene or one cut in a movie, for example.
Cell is a unit of time from several minutes to ten and several minutes.
In addition, the DVD has a function of skipping educationally unfavorable scenes such as a multi-story format in which one movie can be viewed in a plurality of story developments and a violent scene called a so-called parental lock. Such a function is provided by this Cell
Created by the combination of

The Cell is composed of a plurality of Video Object Units (VOBUs).

This VOBU is 0.4 to 1.
A unit of 2 seconds, a plurality of group of pictures (GOP: GOP) in the MPEG2 format are included in this VOBU.
roupOf Pictures). This VOB
U is a pack having management information of this VOBU, N
V_PCK and V_PCK which is a pack having a main video
And A_PCK, which is a pack having audio data, and SP_PCK, which is a pack having sub-picture data. This V_PCK, A_PCK, SP_
The PCK is recorded on the recording medium 1 after being compressed in a format such as MPEG2.

In the DVD-VIDEO disk format, each data having the above-described structure is managed by various management information. The controller 11
When reproducing video data or the like from the recording medium 1, this management information is obtained from the recording medium 1 and stored in the memory 13,
Controls data reproduction and the like.

For example, each Cell is managed in a management unit called a program chain (PGC). The PGC management information includes the PGCI shown in FIG.
(Program Chain Information). PGCI Pr
The eCommand includes the management information of the previous PGC, and the PostCommand includes the post-PGC.
C management information is included. The PGCI contains information such as the playback order of the cells managed by the PGC. When playing a movie or the like, the controller 11 reads the PGCI from the recording medium 1 in advance and stores the PGCI in the memory 13. Then, the controller 11 controls each unit based on the information of the PGCI, and sequentially reproduces the designated Cell.

As shown in FIG. 5, the PGCI has a program chain general information (PGC_
GI), Program Chain Command Table (PGC_CMDT), Pr
ogram Chain Program Table (PGC_PGMAT) and Cell Play b
ack Information Table (C_PBIT) and Cell Position Info
It has management information such as rmation Table (C_POSIT).

The PGC_GI contains information on the entire PGC. For example, the information content of this PGC and the PG
Time information and the like of the entire C. The PGC_CMDT includes information indicating the relationship between the PGC and the PGC before and after the PGC. For example, the above-mentioned PreCommand and Pos
Information such as tCommand. PGC_PGMAT
Contains the starting Cell number of each program and the like. C_PBIT contains information such as the playback time of each Cell. C_POSIT contains V of each Cell.
An ID number, which is a continuation number in the OB, is included.

In particular, as shown in FIG. 6, the C_PBIT includes management information (C_PBI: Cell Playback Information) such as the reproduction time in each Cell constituting the PGC. As shown in FIG. 7, the C_PBI of each Cell includes C_CAT as management information and C_PBT as management information.
M, C_FVOBU_SA, and C_FILVU_EA
, C_LVOBU_SA, and C_LVOBU_EA. C_CAT shows the category information of this Cell. C_PBTM contains this Ce
11 shows the total playback time and the like. C_FVOB
U_SA indicates the start address of the first VOBU of this Cell. C_FILVU_EA contains the last interleaved VOB of this Cell
The end address of U is shown. C_LVOBU_
The SA indicates the start address of the last VOBU of the cell. C_LVOBU_EA indicates the end address of the last VOBU of this Cell.

The management of each VOBU is performed based on a management pack called a navigation pack (NV_PCK: Navigation Pack). This NV_PCK is at the head of each VOBU as shown in FIG. Controller 11
Is used in advance when playing back a movie or the like.
Is obtained via the data decoder 4 and the demultiplexer 5 and stored in the memory 13.
Reproduction is performed based on K management information.

This NV_PCK is shown in FIG. 8 (a) and FIG.
As shown in (a), control information for displaying video data (PC
PC containing (I: Presentation Control Information)
I packet and search information of each data (DSI: Data Search
Information) is included.

As shown in FIG. 8B, the PCI of NV_PCK contains management information (PCI_GI: General In) of PCI in general.
formation) and angle switching information for non-seamless (NSML_AGL: IAngle Information for non-seamless)
And information for highlighting a predetermined area when displaying a sub-picture or the like (HLT: Highlight Information), and recording information (RECI: Recording Information) of main picture data, sub-picture data, and audio data. include.

In particular, as shown in FIG. 8C, the PCI_GI includes NV_PCK_LBN and VOBU_CAT.
, VOBU_UOP_CTL, and VOBU_S_PT
M, VOBU_E_PTM, and VOBU_SE_E_
PTM and C_ELTM are included.

NV_PCK_LBN includes NV_P
The address of CK is shown. VOBU_CAT indicates the category of this VOBU. VOBU
_UOP_CTL indicates control information of the user operation. VOBU_S_PTM contains this V
The start time of the display of the first GOP in the OBU is shown. VOBU_E_PTM indicates the display end time of the last GOP in this VOBU. VOB
U_SE_E_PTM indicates that the main video data is interrupted in this VOBU. In C_ELTM,
The elapsed time from the beginning of the Cell including the VOBU is shown. The elapsed time and the like can be displayed on the display based on the C_ELTM.

As shown in FIG. 9B, the DSI of the NV_PCK contains management information (DSI_GI: DSI Genera) for the entire DSI.
l Information) and playback management information (S
ML_PBI: Seamless Playback Information) and angle information in the case of seamless (SML_AGLI: Angle In)
formation for seamless) and VOBU search information (VOBU_SRI: VOBU Search Informatio
n) and synchronous information (SYICI: Synchronous Information) indicating temporal coincidence with audio data and sub-video data.

In particular, as shown in FIG. 9C, NV_PCK_SCR and NV_PCK_L are included in DSI_GI.
BN, VOBU_EA, and VOBU_1STREF_
EA, VOBU_2NDREF_EA, and VOBU_
3RDREF_EA, VOBU_VOB_IDN,
VOBU_C_IDN and C_ELTM are included.

NV_PCK_SCR indicates the reference of the system clock. NV_PCK_LBN indicates the address of this NV_PCK. VO
BU_EA indicates the end address of this VOBU. VOBU_1STREF_EA includes this V
The end address of the first I-Picture of the OBU is shown. When there is no I-Picture in the VOBU, this data is 0. VOBU_2
NDREF_EA indicates the end address of the second to the first I-Picture or P-Picture of the VOBU. In addition, two I-
If there is no Picture or P-Picture, this data is 0. VOBU_3RDREF
_EA includes the third I-Pi from the beginning of this VOBU.
The end address of the C.ture or P-Picture is shown. It should be noted that three I-Pictu are added to the VOBU.
If there is no re or P-Picture, this data is 0. VOBU_VOB_IDN indicates the ID number of this VOBU. VOBU_C_I
The DN indicates the ID number of the Cell containing this VOBU. In C_ELTM, like PCI,
The elapsed time from the beginning of the Cell including the VOBU is shown.

The VOBU_SRI of this DSI is
As shown in FIG. 10, information indicating a time difference between the current VOBU and another VOBU in the Cell is included.
In the VOBU_SRI, for example, the address of the VOBU 0.5 seconds ahead of this VOBU is shown in FWD1, and the address of the VOBU 7.5 seconds ahead is shown in FWD15. Similarly, V 0.5 seconds before this VOBU
The address of the OBU is shown in BWD1, and the address of the VOBU 2.5 seconds before is shown in BWD5. That is, in order to perform FWD-Scan or BWD-Scan, the controller 11 needs to detect the information of the VOBU_SRI and control the reproduction information.

The VOBU_SRI includes, specifically,
As shown in FIG. 11, FWDNext and FWDIn
, FWDIVideo, BWDprev, and BWD
In and BWD Video are included.

FWDIn indicates the address of the VOBU preceding this VOBU in the time axis direction. Here, the subscript n represents time, and in actuality, nx
The unit is 0.5 seconds. That is, the address of the VOBU 30 seconds ahead is indicated in the FWDI 60. Similarly, B
WDIn includes the previous VO in the time axis direction from this VOBU.
The address of the BU is shown. Subscript n is FWD
Same as I. If there is no VOBU after the predetermined time or before the predetermined time in the same Cell, the lower 30 bits of the data indicating this address are all 1 (the data indicating the address of this VOBU is 4 bits).
Byte. ). For example, if the first VOBU of the Cell, the VOBU before that
The data indicating the address of each BWDI is 3FFFFFFFF because it is not indicated in OBU_SRI. Also, C
If it is the last VOBU in the cell, the data indicating the address of each FWDI is 3FFFFFFF.

FWDINext indicates the address of the next VOBU in time of this VOBU. Also,
BWDIPrev indicates the address of the VOBU immediately before this VOBU in time.

FWDIVideo indicates the address of a VOBU having the next main video data stream. For example, in the case of a so-called video gap in which VOBUs in which no main video data exists continue, the address of the VOBU in which the next main video data exists is shown. BWDIVideo indicates the address of the VOBU immediately before the main video data stream is interrupted. For example, if the VOBU before this VOBU is followed by a VOBU in which no main video data exists, the last VOBU has the address of the VOBU in which the main video data exists.

The data of each FDWIn is shown in FIG.
As shown in (a), FDWA indicating address data
, V_FWD_Exist1, and V_FWD_Exi
st2. As described above, the address data indicates the address of the VOBU a predetermined time ahead, and is 30-bit data. V_FWD_Exi
st1 indicates whether or not the main video data exists in the VOBU a predetermined time later, and is 0 if it does not exist and 1 if it exists. Also, V_FWD_Exis
t2 is a VOBU that is a predetermined time ahead, and V
This indicates whether main video data exists between the previous VOBU and the previous VOBU in the OBU SRI step, and is 1 if video data exists and 0 if no video data exists. For example, FWDI 14 and FWD in FIG.
If a VOBU exists between I15 and video data exists in the VOBU between FWDI14 and FWD15,
V_FWD_Exist2 of the FWDI 15 becomes 1.

The data of each BWDIn is shown in FIG.
As shown in (b), address data and V_BWD
_Exist1 and V_BWD_Exist2. As described above, the address data indicates the address of the VOBU before a predetermined time. V_BW
D_Exist1 indicates whether or not the main video data exists in the VOBU before the predetermined time, and is 0 if it does not exist and 1 if it exists. Also, V_FWD
_Exist2 is a VOBU that is a predetermined time ahead and a VOBU that is one step before in the SRI step of the VOBU that is a predetermined time ahead.
This indicates whether or not main video data exists between the BU and the BU. The value is 1 if video data exists and 0 if video data does not exist.

The address of VOBU_SRI described above is a relative address indicating the distance from the head of VOBU. That is, when acquiring the data of the VOBU at the address indicated by the VOBU_SRI, the address of the VOBU including the VOBU_SRI (N
For example, FWDIn is added to (V_PCK_LBN).

The format of the DVD-Video disk has been briefly described above.
In the case of performing the FWD-Scan or BWD-Scan processing at 00, the information of the packet header of the MPEG format in the V_PCK as shown in FIG. 13 is also used. In this packet header, a decoding time stamp (DTS: Decoding) serving as time management information when decoding video compressed data, and a sequence end code (Sequence End Code) indicating the end of the video data stream
It is included.

Next, the FWD-S of the DVD player 100
The processing method of can and BWD-Scan will be described using a flowchart.

In the DVD reproducing apparatus 100, the controller 11 controls the data decoder 4 to determine the VOBU to be supplied to the video decoder 6, and supplies the necessary VOBU data to the demultiplexer 5. Then, the controller 11 controls the video decoder 6, and the video decoder 6 controls the FWD-Scan and the BWD-Scan.
The decoding process of the main video compression data required for n is performed. Further, the video decoder 6 outputs the decoded video data. Here, in the data decoder 4 and the video decoder 6, there is a time difference between the respective processes because data is supplied via the track buffer 4a, the demultiplexer 5, and the like. From this,
The controller 11 controls the data decoder 4 and the video decoder 6 independently. Hereinafter, FWD-Sca
The processing of n and BWD-Scan will be described separately by the data decoder 4 and the video decoder 6.

First, the FWD-Scan process performed by the controller 11 of the DVD reproducing device 100 will be described.

FIGS. 14 and 15 are flowcharts showing a process of supplying data from the data decoder 4 to the demultiplexer 5 during FWD-Scan.

The controller 11 controls steps S101 to S114 shown in FIG.
Set. Here, SA is a relative address indicating the distance from the head of VOBS. The scan interval is n. The scan interval n is determined, for example, by a user's operation input, and the intermittent interval of the VOBU supplied to the demultiplexer 5 is determined based on the scan interval n. This value is the same unit as VOBU_SRI included in NV_PCK, where n is an integer and one step is 0.5 seconds. The scan interval n corresponds to the high-speed reproduction speed in FWD-Scan.

In the DVD reproducing apparatus 100, when a user's operation input or the like is performed, step S shown in FIG.
The process from 101 is started.

At step S101, the controller 11 sets the NV_PCK_LBN and C_LVOBU_SA
(Cn) is determined to be the same. That is, the address of the NV_PCK of the current VOBU is compared with the address of the last VOBU of the Cell, and the current VOB is compared.
It is determined whether U is the last VOBU of Cell. If the current VOBU is the last VOBU of the Cell, the process proceeds to step S102, and the last VOBU of the Cell
If not, the process proceeds to step S105.

In step S102, it is determined whether or not the current Cell is the last Cell to be reproduced by referring to the PGCI stored in the memory 13, and the last Cell is determined.
If it is 1, the process ends. If the cell is not the last cell, the cell number is updated to the cell to be reproduced next in step S103. Then, in step S104, the address SA of the VOBU from which data is to be obtained next is changed to the address C_FVO of the first VOBU of the updated Cell.
Set to BU_SA (Cn).

Therefore, by setting the first VOBU of the next cell as SA in step S104, the first VOBU of the cell can always be reproduced when reproducing a portion where the cell changes during FWD-Scan.

On the other hand, in step S105, it is determined whether or not the scan destination VOBU exists in the current Cell by referring to the VOBU_SRI in the NV_PCK of the current VOBU. That is, VOBU_S
If the lower 30 bits of RI FWDIn are all 1,
The VOBU does not exist in the Cell. If the scan destination VOBU is not in the current Cell, step S
Proceeding to 106, if the VOBU is in the current Cell, proceeding to step S107.

In step S106, the address SA of the VOBU from which data is to be obtained next is set to C_LVOBU_SA. That is, the last VO in the current Cell
Set to BU.

Therefore, by setting the last VOBU of the cell as SA in step S106, F
When reproducing a portion where the cell changes during WD-Scan, the last VOBU of the cell can always be reproduced.

On the other hand, in step S107, the V of the VOBU_SRI in the NV_PCK of the current VOBU is
_FWD_Exist1 and scan destination VO
It is determined whether video data exists in the BU. That is, V_FWD_E of FWDIn of VOBU_SRI
If xist1 is 1, video data exists in the VOBU. If there is video data in the scan destination VOBU, the process proceeds to step S108, and if there is no video data, the process proceeds to step S109.

In step S108, FWDA (FW) is assigned to NV_PCK_LBN, which is the current VOBU address, as the address SA of the next VOBU from which data is to be obtained.
DIn) is set. That is, a VOBU ahead of a distance corresponding to the scan interval n is set. Here, the address is added because the address indicated in VOBU_SRI is a relative address from the head of VOBU.

Therefore, by setting a VOBU with a scan interval n in time as SA in step S108, the VOBU for each scan interval n can be set during FWD-Scan.
BU can be played.

On the other hand, in step S109, the value of n is substituted for m, and the value of n is temporarily stored.

In step S110, it is determined whether the address of the scan destination VOBU is the same as the address of the VOBU next to the current VOBU. That is,
Scan destination VOBU address and VOBU_SRI
Is compared with the address of FWDINext shown in FIG. If the address of the scan destination VOBU is the same as the address of the VOBU next to the current VOBU, the process proceeds to step S113, and if different, the process proceeds to step S111.

In step S111, VOBU_S
The RI refers to the scan destination V_FWD_Exist2, and the scan destination VOBU and the scan destination V
It is determined whether video data exists between the OBU and the immediately preceding VOBU on the SRI of the VOBU. That is, V_FWD_ of FWDIn of VOBU_SRI
If Exist2 is 1, video data exists in the intervening VOBU. Scan destination VOBU and its SR
If there is video data between the previous VOBUs on I, the process proceeds to step S114, and if there is no video data, the process proceeds to step S112.

In step S112, 1 is subtracted from n, and the processing from step S110 is repeated. That is, in the loop processing from step S110 to step S112, it is determined whether or not video data exists between the VOBU of the scan destination and the current VOBU.

In the loop of steps S110 to S112, if there is no video data even if n is sequentially reduced by one step, FWDA (FWDI
(n)) = FWDA (FWDINext), and the process exits the loop from step S110 and proceeds to step S113.
In step S113, the temporarily stored n is obtained, and the flow advances to step S108 to set the SA.

Therefore, when there is no video data, that is, during the video gap (not at the beginning and end of the video gap), a VOBU having no video data is set.

Also, in steps S110 to S112
In the loop of n, if n is moved down by one step and video data exists, V_FWD_Exist2
(FWDI (n)) = 1, and the process exits the loop from step S111 and proceeds to step S114.
At 1, subtract 1 from n and proceed to step S108.
Set A. At this time, since n fluctuates, this scan interval is reset to the first scan interval n in step S108.

Therefore, when video data exists, that is, when a video gap starts, the video data immediately before the start of the video gap is obtained. It should be noted that the VOBU_SRI has a VOBU during the step.
If video data is interrupted in the VOBU during this period, the address of the VOBU immediately before the video data is interrupted in the processing loop from the next step S201 is set as SA.

The controller 11 executes the above step S1
When the control from 01 to S114 is performed to set the SA which is the address of the VOBU from which data is to be obtained next, the processing from step S201 shown in FIG. 15 is started.

In step S201, the controller 11 causes the data decoder 4 to read the data of the VOBU at the specified address SA from the recording medium 1.
Then, in step S202, NV_PCK of the VOBU of the specified address is obtained.

When NV_PCK is obtained, step S2
03, the number of I-Pictures or P-Pic in the current VOBU read by the data decoder 4
Determine whether there is a cure. Here, this I-Pic
The number of the “pure” or “P-Picture” in the VOBU can be determined by referring to VOBU_1STREF_EA, VOBU.
BU_2NDREF_EA and VOBU_3RDREF
The information indicated by _EA is detected and determined. First, VOBU
When _3RDREF_EA is other than 0, I-Pict
ure etc. are three or more. Second, VOBU_3RDRE
When F_EA is 0 and VOBU_2NDREF_EA is other than 0, there are two I-Pictures and the like. Third, V
OBU_3RDREF_EA and VOBU_2NDRE
When F_EA is 0 and VOBU_1STREF_EA is other than 0, there is one I-Picture. And
In cases other than the first to third cases, IP
No picture and no P-Picture.

In the VOBU, I-Picture or P-
If there is no picture, step S204
To step S2 if there is at least one sheet
Go to 05.

In step S204, it is determined that the main video data does not exist in the VOBU and NV_PCK
Is supplied to the demultiplexer 5 only. That is, when there is no main video data, there is no need to perform video data decoding processing in the video decoder 6, so other data is discarded in advance and only necessary management data is supplied. If there is audio data or the like that is not the main video data, this audio data may be supplied to the demultiplexer 5 together with NV_PCK.

Therefore, unnecessary data is not supplied to the video decoder 6 by the processing in step S204, so that the video decoder 6 can perform efficient decoding processing and can perform processing at high speed.

On the other hand, in step S205, this V
It is determined whether or not the main video is interrupted in the middle of the OBU. That is, it is determined whether a so-called video gap is generated from the VOBU. This is performed by detecting VOBU_SE_E_PTM of PCI of NV_PCK or sequence-end-code in MPEG. If it is determined that the main video data is interrupted in the middle of the VOBU, the process proceeds to step S206, and if the main video data is
If it is determined that there is no interruption during the BU, step S2
Proceed to 07.

In step S206, this VOBU
Is supplied to the demultiplexer 5 up to VOBU_SE_E_PTM. That is, this is to enable the video decoder 6 to output the video up to just before the main video data is interrupted.

Therefore, when the main video is interrupted in step S206, the main video data is supplied to the demultiplexer 5 to the end. Therefore, when a so-called video gap occurs, the immediately preceding video is displayed and the FWD-video is displayed.
You can scan.

In step S207, VOBU 1
Up to 3 I-Picture or P-Pictur
e is supplied to the demultiplexer 5. That is, when it is determined in step S203 that there is only one I-Picture in the VOBU, one I-Picture
The data of e is supplied to the demultiplexer 5, and the other data is discarded. In step S203, 2 is set in the VOBU.
When it is determined that there is only one I-Picture or P-Picture, data such as two I-Pictures is supplied to the demultiplexer 5 and the other data is discarded. In step S203, three or more I-Pictures or P-Picturs are stored in the VOBU.
If it is determined that there is e, three pieces of data such as I-pictures from the beginning of the VOBU are supplied to the demultiplexer 5, and the other data is discarded. The demultiplexer 5 has the above-described VOBU_1STREF_E
A, VOBU_2NDREF_EA and VOBU_3R
Supply up to the address indicated by DREF_EA.

Therefore, the necessary 3 in FWD-Scan
I-Picture and P-Picture up to the number of sheets
Is supplied to the demultiplexer 5, so that the video decoder 6 can perform an efficient decoding process.

If there is audio data that is not the main video data, this audio data may be supplied to the demultiplexer 5 together with NV_PCK.

As described above, when data is supplied to the demultiplexer 5 in steps S204, S206, and S207, the above-described processing from step S101 in FIG. 14 is repeated to acquire the next VOBU data.

Next, the control contents of the decoding process in the video decoder 6 will be described with reference to the flowchart of FIG.

The controller 11 includes the demultiplexer 5
When the VOBU is supplied to the video decoder 6 from, the processing from step S301 is started.

In step S301, NV_PCK of the VOBU supplied to the video decoder 6 is obtained.
Note that NV_PC
K is obtained, and at the stage of processing by the video decoder 6, N
The reason why V_PCK is acquired again is that the controller 11 performs the parallel processing because a time difference occurs between the data decoder 4 and the video decoder 6. N
After acquiring V_PCK, the process proceeds to step S302.

In step S302, this VOBU
How many I-Picture or P-Pictur
e is determined. The processing in step S302 is performed in step S20 in the data decoder 4 described above.
3 is the same as the process of FIG. I-Pictur in VOBU
If there is no e or P-Picture, the process proceeds to step S303, and if there is at least one, the process proceeds to step S304. In step S303, N
The C_ELTM of V_PCK is detected and the time code is updated. In this step S303, no new decoding processing of the video data is performed, but the video data output (or displayed) from the video decoder 6 is
At this time, since the image output in the previous process in time is output, the display image is a still image. That is, in a so-called video gap state where no video data exists, only the time information is updated while the video immediately before the video is interrupted is output.

On the other hand, in step S304, VO
Find the first GOP in the BU. That is, since a VOBU includes a plurality of GOPs, it is necessary to find the first GOP among them. In this step S304, DTS ≧ (VOBU_S_PTM−3 × Ts1Fi)
eld) and DTS ≦ (VOBU_S_PTM−2 × T
The DTS is updated until the condition of (s1Field) is satisfied. Here, Ts1Field is one field time, which is 1/60 second in NTSC and 1/50 second in PAL.

That is, when the difference between the decoding start time and the display start time reaches the time difference of two to three fields, VOBU
Starts decoding as the first GOP of. This is because there is a gap from the start of decoding to the output of the video decoder 6 for one field, and in the DVD-VIDEO format, video data of two to three fields may be included in one picture.

When the first GOP of the VOBU is found, in step S305, one to three I-Pictures and P-Picturs obtained in step S302 are obtained.
e is decoded and stored in the memory of the video decoder 6.

Further, the video decoder 6 determines in step S3
At step 06, three images are decoded into the memory and video data is output to display the video. At this time,
The output processing is performed in parallel with the decoding processing, and the decoded images are sequentially output. The output processing (display processing) will be described later in detail.

In step S305, the controller 11 sets the VOBU_SE_E_PT of NV_PCK.
M is obtained, and it is determined whether or not the video is interrupted by this VOBU. That is, it is determined whether a video gap is generated from this VOBU. VOBU_SE_E_P
If the TM determines that the main video is interrupted, decoding is performed up to the image immediately before the main video is interrupted. Then, the decoded image is stored in a memory and output processing is performed. Therefore, in this step S305, up to the video data immediately before the main video is interrupted is decoded, so that when a so-called video gap occurs, the video immediately before that is displayed and the FWD is displayed.
-Scan.

When the decoded video data is stored in the memory, in step S307, the above-described step S3
The time code is updated in the same manner as 03.

When the time code is updated in steps S303 and S307, NV_PCK of the next VOBU is updated.
Is repeated to repeat the processing from step S301.

Next, the BWD-Scan processing performed by the controller 11 of the DVD reproducing apparatus 100 will be described.
Note that a detailed description of the same processing as the above-described FWD-Scan processing is omitted.

FIGS. 17 and 18 are flowcharts showing a process of supplying data from the data decoder 4 to the demultiplexer 5 during BWD-Scan.

The controller 11 controls steps S401 to S417 shown in FIG.
Set. The scan interval is n. The scan interval n is determined, for example, by a user's operation input, and the intermittent interval of the VOBU supplied to the demultiplexer 5 is determined based on the scan interval n. That is, the scan interval n corresponds to the speed of high-speed reproduction in the direction opposite to the time axis in BWD-Scan. The difference from the above-described FWD-Scan is that a VOBU is searched for in the direction opposite to the time axis at this scan interval. Therefore, BWD-Sc
The scan interval n of “an” has a different direction from that of FWD-Scan.

In the DVD reproducing apparatus 100, when a user's operation input or the like is performed, step S shown in FIG.
Processing from 401 is started.

In step S401, the controller 11 determines whether Gap is 1. This G
ap is a variable used in BWD-Scan, and is used when reproducing a VOBU in a so-called video gap where video data is interrupted in the middle. This setting of Gap is set in step S415 described later, and is set to 0 at the time of initial setting. When this Gap is 1, that is, when the current VOBU is the VOBU of the video gap portion, the process proceeds to step S402,
If p is not 1, the process proceeds to step S403.

In step S402, Gap is set to 0, and SA is set to BSA. Here, BSA is
This is set in step S415 as in the case of Gap.

On the other hand, in step S403, NV_
It is determined whether PCK_LBN and C_FVOBU_SA (Cn) are the same. That is, this NV_PCK
Is compared with the first address of the current Cell, and the current VOBU is the first VOBU of the current Cell.
Is determined. Current VOBU is Cell
If it is the first VOBU, the process proceeds to step S404, and C
If it is not the first VOBU of the cell, the process proceeds to step S407.

In step S404, it is determined whether or not the current Cell is the cell for which reproduction has been completed by referring to the PGCI stored in the memory 13, and the cell for which reproduction has been completed.
If it is 1, the process ends. Here, the end of reproduction indicates the end of reproduction in the case of BWD-Scan. For example, in the case of a movie or the like, the cell is the cell at the start of the movie.
If the cell has not been reproduced, the cell number is updated to the cell to be reproduced next in step S405.
Then, in step S406, the address SA of the VOBU from which data is to be obtained next is set to the address C_LVOBU_SA (Cn) of the last VOBU of the updated Cell.

Accordingly, by setting the last VOBU of the next cell as SA in step S404, when reproducing a portion where the cell changes during BWD-Scan, the cell can always be reproduced from the end of the cell.

On the other hand, in step S407, it is determined whether or not the scan destination VOBU exists in the current Cell by referring to the VOBU_SRI in the NV_PCK of the current VOBU. That is, VOBU_S
If the lower 30 bits of RI's BWDIn are all 1,
The VOBU does not exist in the Cell. If the scan destination VOBU is not in the Cell, step S408
Proceeds to step S4 if the VOBU is in the Cell.
Go to 09.

In step S408, the address SA of the VOBU from which data is to be obtained next is set to C_FVOBU_SA. That is, the first VO in the current Cell
Set to BU.

Therefore, by setting the first VOBU of Cell as SA in step S408, B
When reproducing a portion where the cell changes during WD-Scan, the beginning of the cell can always be reproduced.

On the other hand, in step S409, it is determined with reference to the VOBU_SRI in the NV_PCK of the current VOBU whether video data exists in the VOBU of the scan destination. That is, B of VOBU_SRI
If V_BWD_Exist1 of WDIn is 1, video data exists in the VOBU. Scan destination VO
If there is video data in the BU, the process proceeds to step S410,
If there is no video data, the process proceeds to step S411.

In step S410, BWDA (BWW) is assigned to NV_PCK_LBN, which is the current VOBU address, as the address SA of the next VOBU from which data is to be obtained.
DIn) is set. That is, a VOBU ahead of a distance corresponding to the scan interval n is set.

Accordingly, by setting a VOBU with a scan interval n in time as SA in step S410, the VOBU for each scan interval n can be set during BWD-Scan.
BU can be played.

On the other hand, in step S411, the value of n is substituted for m, and the value of n is temporarily stored.

In step S412, the address of the scan destination VOBU is the VOBU immediately before the current VOBU.
Is determined to be the same as the address. That is, the address of the scan destination VOBU and the VOBU_S
It is compared with the address of BWDIPrev indicated in RI to determine whether or not the address is the same. Scan destination VOBU
If the address is the same as the address of the VOBU immediately before the current VOBU, the process proceeds to step S415, and if different, the process proceeds to step S413.

In step S413, VOBU_S
The scan destination VOBU and the scan destination VO are referred to by the RI with reference to the scan destination V_BWD_Exist2.
VOBU after one step on BU's VOBU_SRI
It is determined whether or not video data exists.
That is, V_BWD of BWDIn of VOBU_SRI
If _Exist2 is 1, video data exists in the VOBU that is present. Scan destination VOBU and its S
If there is video data between the VOBU after one step on the RI, the process proceeds to step S416, and if there is no video data, the process proceeds to step S414.

In step S414, 1 is subtracted from n, and the processing from step S412 is repeated. That is, in the loop processing from step S412 to step S414, it is determined whether or not video data exists between the scan destination VOBU and the current VOBU.

In the loop processing from step S412 to step S414, if there is no video data even if n is sequentially reduced by one step, BWDA (B
WDI (n)) = BWDA (BWDIPrev), and the process exits the loop from step S412 and proceeds to step S415. In step S415, n temporarily stored is acquired and the SA is set.

At this time, in step S415, BW
The address immediately before the start of the video gap is acquired with reference to DIVideo, and SA is set as the address immediately before the start of the video gap. Gap is set to 1. And, from NV_PCK_LBN as BSA
Set the value obtained by subtracting WDA (BWDI (m)). The values set in step S415 are the same as those in step S4 described above.
02.

In addition, steps S412 to S414
In the loop of n, if n is moved down by one step and video data exists, V_BWD_Exist2
(BWDI (n)) = 1, the process exits the loop from step S413, proceeds to step S416, and proceeds to step S416.
At 1, subtract 1 from n and proceed to step S417.
Set A. At this time, since n fluctuates, this scan interval n is reset to the first scan interval n in step S401.

In step S417, BWDA (BWW) is added to NV_PCK_LBN, which is the current VOBU address, as the address SA of the next VOBU from which data is to be obtained.
DIn) is set. That is, a VOBU ahead of a distance corresponding to the scan interval n is set.

Therefore, when video data exists, that is, when the video gap ends, the video data immediately after the end of the video gap is obtained.
It should be noted that the VOB during the steps in VOBU_SRI
If U is present and video data is interrupted in the VOBU during this time, the address of the VOBU immediately before the video data is interrupted in the processing loop from the next step S401 is set as SA.

The controller 11 executes the above-described step S4
When the control from step 01 to step S417 is performed to set the SA which is the address of the VOBU from which data is to be obtained next, the processing from step S501 shown in FIG. 18 starts.

In step S501, the controller 11 causes the data decoder 4 to read the data of the VOBU at the set designated address SA. Then, in step S502, the NV of the VOBU of the specified address
Get _PCK.

When NV_PCK is obtained, step S5
At 03, it is determined whether or not Gap is 1.
If Gap is 1, the process proceeds to step S504, and if Gap is not 1, the process proceeds to step S506.

In step S504, this VOBU
Is supplied to the demultiplexer 5 up to VOBU_SE_E_PTM. That is, this is to enable the video decoder 6 to output the video up to just before the main video data is interrupted.

Therefore, when the main video is interrupted in step S504, this main video data is supplied to the demultiplexer 5 to the end. When a so-called video gap occurs, the video immediately before that is displayed and the BWD-video is displayed.
You can scan.

Then, in step S505, the fact that this VOBU is the VOBU at the start of the gap is notified.

On the other hand, in step S506, it is determined how many I-Pictures or P-Pictures are present in the read VOBU. Here, this I-Picture or P-Picture is a VOBU.
VOBU_1STREF_
EA, VOBU_2 NDREF_EA and VOBU_3
The information shown in RDREF_EA is detected and determined. This determination is the same as step S203 described above.

[0148] I-Picture or P-
If there is no picture, step S507
Proceeds to step S5 if there is at least one sheet.
Proceed to 08.

At step S507, it is determined that no main video data exists in the VOBU, and NV_PCK
Is supplied to the demultiplexer 5 only. That is, when there is no main video data, there is no need to perform video data decoding processing in the video decoder 6, so other data is discarded in advance and only necessary management data is supplied. If there is audio data or the like that is not the main video data, this audio data may be supplied to the demultiplexer 5 together with NV_PCK.

Therefore, unnecessary data is not supplied to the video decoder 6 in step S507, so that the video decoder 6 can perform efficient decoding processing and can perform processing at high speed.

In step S508, VOBU 1
Up to 3 I-Picture or P-Pictur
e is supplied to the demultiplexer 5. That is, when it is determined in step S506 that there is only one I-Picture in the VOBU, one I-Picture
The data of e is supplied to the demultiplexer 5, and the other data is discarded. In step S506, 2 is stored in the VOBU.
When it is determined that there is only one I-Picture or P-Picture, data such as two I-Pictures is supplied to the demultiplexer 5 and the other data is discarded. In step S506, three or more I-Pictures or P-Picturs are stored in the VOBU.
If it is determined that there is e, three pieces of data such as I-pictures from the beginning of the VOBU are supplied to the demultiplexer 5, and the other data is discarded.

Therefore, the necessary 3 in BWD-Scan
I-Picture and P-Picture up to the number of sheets
Is supplied to the demultiplexer 5, so that the video decoder 6 can perform an efficient decoding process.

As described above, when data is supplied to the demultiplexer 5 in steps S505, S507, and S508, the processing from step S401 in FIG. 14 described above is repeated to acquire the next VOBU data.

Next, the control content of the decoding process in the video decoder 6 in the BWD-Scan will be described with reference to the flowchart in FIG.

The controller 11 includes the demultiplexer 5
When the VOBU is supplied to the video decoder 6 from, the processing from step S601 is started.

In step S601, NV_PCK of the VOBU supplied to the video decoder 6 is obtained.
Upon acquiring NV_PCK, the process proceeds to step S602.

In step S602, the first GOP in the VOBU is found. This processing is the same as the processing in step S304 described above. The first GO of VOBU
If P is found, the process proceeds to step S603.

In step S603, this VOBU
How many I-Picture or P-Pictur
e is determined. The processing in step S603 is performed in step S20 in the data decoder 4 described above.
3 is the same as the process of FIG. I-Pictur in VOBU
If there is no e or P-Picture, the process proceeds to step S604, and if there is at least one, the process proceeds to step S605. In step S604, N
The C_ELTM of V_PCK is detected and the time code is updated. In this step S604, no new decoding processing of the video data is performed, but the video data output (or displayed) from the video decoder 6 is
At this time, since the image output in the previous process in time is output, the display image is a still image. That is, in a so-called video gap state where no video data exists, only the time information is updated while the video immediately before the video is interrupted is output.

When the time code is updated in step S604, the process from step S601 is repeated to obtain the NV_PCK of the next VOBU.

On the other hand, in step S605, NV_
The VOBU_SE_E_PTM of the PCK is obtained, and it is determined whether or not the video is interrupted by this VOBU. That is, it is determined whether a video gap is generated from this VOBU. If it is determined that the main video is interrupted by VOBU_SE_E_PTM, the process proceeds to step S608,
If it is determined that the main video is not interrupted, step S60
Proceed to 6.

In step S606, step S6
1-3 I-Pictures and Ps acquired at 03
Decode the Picture and store it in the memory of the video decoder 6;

The video decoder 6 determines in step S6
At 09, three images are decoded into the memory and video data is output to display the video. At this time,
The output processing is performed in parallel with the decoding processing, and the decoded images are sequentially output. The output processing (display processing) will be described later in detail.

When the time code is updated in step S607, the processing from step S601 is repeated to obtain the NV_PCK of the next VOBU.

On the other hand, in step S608, decoding is performed up to the image immediately before the main video is interrupted. Then, the decoded image is stored in the memory, and output processing is performed in step S609. Therefore, this step S608
Since the video data is decoded up to the video data immediately before the main video is interrupted, when a so-called video gap occurs, the video immediately before the video gap can be displayed and FWD-Scan can be performed.

When the decoding is completed in step S608, the processing from step S601 is repeated to obtain the NV_PCK of the next VOBU.

By performing the above-described processing, the DVD reproducing apparatus 100 obtains the first three IP cards in the VOBU.
picture and P-Picture to FWD-Sca
n and BWD-Scan. Accordingly, a smooth display can be performed even in the case of FWD-Scan and BWD-Scan.

When the cell changes at any scan interval, the first and last VOBUs of the cell are reproduced, thereby making it easy to search when the scene is switched.

When a so-called video gap in which video data is interrupted in the middle occurs, an image immediately before the interruption is output, so that a display similar to a normal reproduction output is performed and FWD-Scan and BWD-Scan are output.
n processing can be performed. Further, in the case of a so-called video gap in which the video data is interrupted on the way, FWD-Scan and BWD-Scan processing for updating only the time code can be performed.

Next, display processing from the video decoder 6 in FWD-Scan and BWD-Scan processing performed by the controller 11 of the DVD reproducing apparatus 100 will be described. Note that, in the DVD playback device 100, to be precise,
The video data can be displayed by outputting the video data from the NTSC conversion circuit 9, but the display timing depends on the output timing from the video decoder 6. Is sometimes referred to as “display”.

Video decoder 6 of DVD reproducing apparatus 100
Are the I-Picture and P-Pictu which are decoded on the memory at the time of FWD-Scan and BWD-Scan.
re are sequentially output in chronological order under the control of the controller 11. At this time, the video decoder 6
Three I-Pictures and P-Pic from the beginning of U
Output only the "ture". The controller 11 detects the passage time of the VOBU including the I-Picture or the like output from the video decoder 6, and averages the output intervals to display the video data.

More specifically, as shown in FIG. 20, averaging is performed by detecting the time when NV_PCK passes through the demultiplexer 5. The first NV_PCK (NV ₁ ) and the second N
When the time difference between passage through V_PCK (NV ₂ ) is t ₁ , each picture (D ₁₁ , D ₁₁₎ corresponding to the first NV_PCK
D _12, the display interval of D ₁₃₎ averages the t _1/3.

Further, the second NV_PCK (NV ₂ ) and the third NV_PCK (NV ₂ )
When the time difference between the passage of the second NV_PCK and the NV_PCK (NV ₃ ) is t ₂ , each picture (D
_21, the display interval of D _22, D ₂₃₎ is averaged _{((t 1 + t 2)} / 2) / 3. Further, the third NV_PCK (NV ₃ ) and the fourth
When the time difference between the passage of NV_PCK (NV ₄ ) and the corresponding NV_PCK (NV ₄ ) is t ₃ , each picture (D
_31, the display interval of D _32, D ₃₃₎ is _{((t 1 + t 2 +} t 3) / 3) /
Average to 3.

That is, each image to be displayed is averaged sequentially, and display is performed in accordance with the processing speed of reproduction, decoding, and the like. The number of past VOBU samples to be averaged is set to a certain value, and old samples are sequentially discarded.

FIG. 21 shows that NV_P
It is a flowchart which shows the process which measures the time which CK passed.

The controller 11 receives the FW from the user.
When an operation input of D-Scan or BWD-Scan is performed, the processing from step S701 is started.

At step S701, NV_PCK
Set each sample of the transit time to the initial value. here,
Each sample is set for 1 second.

When each sample is set to the initial value, in step S702, the process waits until the first NV_PCK passes through the demultiplexer 5, and starts measuring time when the first NV_PCK passes.

When the measurement is started, in step S703, the process waits until the next NV_PCK passes, and
When V_PCK passes, the time measurement is stopped. And
Of the samples, the oldest sample is discarded, and the measured time is set as the newest sample.

Then, in step S704, each sample is summed, and the sum is divided by the number of samples.
The passing average time of the BU demultiplexer 5 is determined.

When the average time is obtained, in step S705, the time measurement is restarted, and the processing from step S703 is repeated.

Further, based on the average VOBU passage time obtained in the above steps S701 to S705, display processing of the decoded video data in the memory of the video decoder 6 is performed.

The flowchart shown in FIG.
Video decoder 6 for Scan and BWD-Scan
I-Picture and P-Pi decoded on the memory of
9 is a flowchart illustrating processing contents for displaying the C.T. The display is controlled by the controller 11.

The controller 11 receives the FW from the user.
When an operation input of D-Scan or BWD-Scan is performed, the processing from step S801 is started.

In step S801, the video decoder 6 sets the first one I-Picture or P-Pic
It is determined whether or not “Ture” has been decoded, and the process waits in step S801 until the first one is decoded. In the case of FWD-Scan, the first one is the leading I-Picture on the stream in the VOBU,
In the case of BWD-Scan, the last Pi on the stream among the three I-Pictures or P-Pictures
cture. This is because, in the case of BWD-Scan, the video in the VOBU is played back in the time axis direction.

When the first picture is decoded, in step S802, the first picture that has been decoded is displayed, and the flow advances to step S803.

In step S803, a timer provided in the controller 11 is started. When the timer is started, in step S804, step S701 in FIG.
Average passage time / 3 obtained in step S705
Has elapsed, whether the memory of the video decoder 6 has no area for proceeding with the decoding process, and whether the decoded Pictur has been stored in the memory of the video decoder 6.
It is determined whether or not e is gone.

If the time of passage average time / 3 has elapsed and there is a decoded Picture in the memory of the video decoder 6, or if there is an area for the memory of the video decoder 6 to proceed with the decoding processing, the flow advances to step S805. Waits in this step S804.

In step S805, the next Pict
ure is displayed. This step S8
05 is performed in FWD-Scan and BWD-Scan.
Different. In the case of FWD-Scan, each Pictur is processed in the order in which decoding processing is performed in order to reproduce in the forward direction in the time axis direction.
e is displayed. In the case of BWD-Scan, reproduction is performed in the reverse direction in the time direction, so that display is performed in the reverse order of decoding. When the next Picture is displayed, the process proceeds to step S806.

In step S806, the timer is reset and the processing from step S803 is repeated.

As described above, this DVD reproducing apparatus 100
In FWD-Scan and BWD-Scan, a smooth display screen can be output by averaging the display intervals of each Picture to be reproduced, thereby facilitating viewer search.

[0191]

In the image decoding apparatus according to the present invention, the control means measures the time of the intermittent interval and obtains the average time of the intermittent interval, and the decoding means determines the first three times in the VOBU.
The I-Picture or P-Picture is expanded to generate video data, and the expanded three I-Pictures or P-Pictures
By outputting the picture data of the Picture or P-Picture one screen at a time at an interval of 1/3 of the average time, it is possible to average the display intervals of each Picture to be reproduced during intermittent reproduction. It can output a smooth display screen.

In the image decoding method according to the present invention, the time of the intermittent interval is measured, and the average time of the intermittent interval is obtained.
First three I-Pictures or P-Pi in BU
image data is generated by decompressing the I-Picture or the P-Pictur.
e, by outputting the video data one screen at a time at an interval of 1/3 of the average time, the display intervals of each Picture to be reproduced can be averaged during intermittent reproduction, and a smooth display screen can be obtained. Can be output.

[Brief description of the drawings]

FIG. 1 is a block diagram of a DVD reproducing apparatus to which the present invention is applied.

FIG. 2 is a conceptual diagram for explaining a data decoding method when compressed main video data is supplied to a video decoder to which the present invention is applied.

FIG. 3 is an explanatory diagram of a DVD-Video format.

FIG. 4 is an explanatory diagram of a DVD-Video format.

FIG. 5 is an explanatory diagram of a DVD-Video format.

FIG. 6 is an explanatory diagram of a DVD-Video format.

FIG. 7 is an explanatory diagram of a DVD-Video format.

FIG. 8 is an explanatory diagram of a DVD-Video format.

FIG. 9 is an explanatory diagram of a DVD-Video format.

FIG. 10 is an explanatory diagram of a DVD-Video format.

FIG. 11 is an explanatory diagram of a DVD-Video format.

FIG. 12 is an explanatory diagram of a DVD-Video format.

FIG. 13 is an explanatory diagram of an MPEG-2 format.

FIG. 14 shows a FWD- of the DVD reproducing apparatus to which the present invention is applied.
9 is a flowchart illustrating Scan processing.

FIG. 15 shows a FWD- of the DVD reproducing apparatus to which the present invention is applied.
9 is a flowchart illustrating Scan processing.

FIG. 16 shows a FWD- of the DVD reproducing apparatus to which the present invention is applied.
9 is a flowchart illustrating Scan processing.

FIG. 17 shows a BWD- of the DVD reproducing apparatus to which the present invention is applied.
9 is a flowchart illustrating Scan processing.

FIG. 18 shows a BWD- of a DVD reproducing apparatus to which the present invention is applied.
9 is a flowchart illustrating Scan processing.

FIG. 19 shows a BWD- of a DVD reproducing apparatus to which the present invention is applied.
9 is a flowchart illustrating Scan processing.

FIG. 20 shows a FWD- of the DVD reproducing apparatus to which the present invention is applied.
FIG. 9 is an explanatory diagram of a method of a video output process in Scan and BWD-Scan.

FIG. 21 is a flowchart showing a process for measuring the elapsed time of a VOBU passing through a demultiplexer of a DVD playback device to which the present invention has been applied.

FIG. 22 shows a FWD- of a DVD reproducing apparatus to which the present invention is applied.
9 is a flowchart illustrating a video output process in Scan and BWD-Scan.

[Explanation of symbols]

1 recording medium, 2 pickup, 3 RF circuit, 4
Data decoder, 5 demultiplexer, 6 video decoder, 7 sub-picture decoder, 8 audio decoder,
9 NTSC conversion circuit, 10 D / A conversion circuit, 11
Controller, 12 user interface, 13
memory

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takayuki Ishida 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation

Claims (4)

[Claims] An image data compressed using a correlation in a time axis direction over a plurality of frames is supplied for each video object unit (VOBU) composed of a plurality of frames of image data. Decoding means for decompressing the compressed image data to generate video data and outputting the decompressed video data;
VO indicating time information between VOBUs included in BU
A navigation pack (NV_PCK: Navigation Pack) including BU search information (VOBU_SRI: VOBU Search Information) is supplied, and control means for controlling a VOBU to be supplied to the decoding means based on the VOBU_SRI is provided. Is intermittently supplied to the decoding means, the time of the intermittent interval is measured to determine the average time of the intermittent interval, and the decoding means sets the first three intra-frame coded image data (I- Picture: Intra Coded P
picture) or inter-frame forward prediction coded image data (P
-Picture: Predictive Coded Picture) to generate video data, and expand the three I-Pictues.
An image decoding apparatus for outputting video data of re or P-Picture one screen at a time at an interval of 1/3 of the average time. 2. The image decoding apparatus according to claim 1, wherein the compressed image data supplied to said decoding means is image data reproduced from a DVD disk. 3. An image data compressed over a plurality of frames by utilizing a correlation in a time axis direction is supplied for each video object unit (VOBU) composed of a plurality of frames of image data. Navigation pack included in VOBU (NV_PCK:
VOBU search information (VOBU_SRI: VOBU Search Information) indicating time information between VOBUs in Navigation Pack)
The intermittently selects the supplied VOBU based on the VOBU, measures the time of the intermittent interval of the supplied VOBU, finds the average time of the intermittent interval, and selects the first three VOBUs in the intermittently selected VOBU. In-frame coded image data (I-Picture: Intra Coded Pictur
e) or inter-frame forward prediction coded image data (P-Pict
ure: Predictive Coded Picture) to generate video data, and expand the three I-Pictures or PPs
An image decoding method characterized by outputting picture data of a single picture at a time interval of 1/3 of the average time. 4. The supplied compressed image data is D
4. The image decoding method according to claim 3, wherein the image data is image data reproduced from a VD disk.