[FFmpeg-user] VOB error

[Benoit]

Hello,

Goal
----
I've saved a VOB file from a DVD. It contains a VHS rip made by a
"conversion professional".

I'd like to convert it and make some cutting.

ffplay
------
ffplay refuses to read it:
$ ffplay VTS_01_1.VOB
[...]
VTS_01_1.VOB: Invalid data found when processing input

I forced it:
$ ffplay -f mpegvideo VTS_01_1.VOB

I get a lot of error on console:
[...]
[mpeg2video @ 0x18d4010]invalid cbp at 21 11
[mpeg2video @ 0x18d4010]concealing 550 DC, 550 AC, 550 MV errors
 736.21 A-V:  0.000 s:0.0 aq=    0KB vq=   12KB sq=    0B f=12/638   
[...]

Display is split in 2 parts, with some small portions of image.

ffmpeg
------
$ ffmpeg -f mpegvideo -i VTS_01_1.VOB
[...]
[mpeg1video @ 0x167ea00]mpeg_decode_postinit() failure
    Last message repeated 5 times
[mpeg1video @ 0x167ea00]ac-tex damaged at 24 4
[mpeg1video @ 0x167ea00]Warning MVs not available
[mpeg1video @ 0x167ea00]concealing 1440 DC, 1440 AC, 1440 MV errors
[mpegvideo @ 0x16756b0]max_analyze_duration reached
[mpegvideo @ 0x16756b0]Estimating duration from bitrate, this may be inaccurate

Seems stream 0 codec frame rate differs from container frame rate: 50.00 (50/1) -> 50.00 (50/1)
Input #0, mpegvideo, from 'VTS_01_1.VOB':
  Duration: 00:20:26.67, bitrate: 2713 kb/s
    Stream #0.0: Video: mpeg2video, yuv420p, 720x576 [PAR 16:15 DAR 4:3], 2713 kb/s, 54.60 fps, 50 tbr, 1200k tbn, 50 tbc
At least one output file must be specified

xine
----
Xine manages to read it more or less correctly (with errors on console).
Therefore the file is not totally corrupted. 

avidemux
--------
Avidemux manages to open it, and after reindexing, shows two parts
(horizontally), with correct images. The console output is verbose, I
don't paste it here. I think the interesant message is:

[...]
The video codec has some extradata (40 bytes)
 0000 : ...³-.@#.À#...µ  00 00 01 b3 2d 02 40 23 16 c0 23 80 00 00 01 b5
 0010 : ........µ#....B  14 8a 00 01 00 00 00 00 01 b5 23 05 05 06 0b 42
 0020 : ........  12 00 00 00 00 00 00 00
Deleting post proc
Initializing postproc
Deleting post proc
updating post proc
Enabled type:3 strength:3
[Editor] Duration in seconds: 5298, in samples: 254338544
 Decoder FCC: MPEG (4745504D)
Searching decoder (720 x 576, extradataSize:40)...
[lavc] Build: 3430145
[lavc] Decoder init: CODEC_ID_MPEG2VIDEO video decoder initialized!
 checking for B-Frames...
 scanning 125 frames
[lavc] warning: first frame is no keyframe
[lavc] warning: first frame is no keyframe
[...]


Any idea?

Thanks,
Benoit