Bug in ffmpeg duration

[dersh]

There seems to be a bug in the way that ffmpegX calculates the duration of a .VOB file.
I have had the same problem with both versions 0.0.9p and q.
I tried to convert a VOB file and the progress went to 100% and then kept going to well beyond that number (a few thousand % I believe).
So I tried to narrow down the problem (and because I was trying to extract just part of a movie).
I started doing some testing at the command line by using the same hour long VOB file and ffmpeg, from inside of ffmpegX package.

If I do this at the command line:
>ffmpeg -i VTS_01_1.VOB test.mov
ffmpeg version 0.4.9-pre1, build 4731, Copyright (c) 2000-2004 Fabrice Bellard
configuration: --enable-mp3lame --enable-gpl --disable-vhook --enable-ffplay --disable-ffserver --enable-a52 --enable-xvid --enable-faac --enable-faad --enable-amr_nb --enable-pthreads
built on Nov 21 2004 19:41:49, gcc: 3.3 20030304 (Apple Computer, Inc. build 1666)
Input #0, mpeg, from 'VTS_01_1.VOB':
Duration: 00:00:29.5, start: 0.236100, bitrate: 288957 kb/s
Stream #0.0: Video: mpeg2video, 720x480, 29.97 fps
Stream #0.1: Audio: ac3, 48000 Hz, stereo, 256 kb/s
Output #0, mov, to 'test.mov':
Stream #0.0: Video: mpeg4, 720x480, 29.97 fps, q=2-31, 200 kb/s
Stream #0.1: Audio: aac, 48000 Hz, stereo, 64 kb/s
Stream mapping:
Stream #0.0 -> #0.0
Stream #0.1 -> #0.1
Press [q] to stop encoding

Note that it says that the duration aove is 29.5 seconds, when the actual video is perhaps an hour. It, and ffmpegX, will correctly convert the whole file however.

The real problem that I have run into is that I wanted to skip part of the video. Since I could not see a way to do this using ffmpegX I went to the command line.
If I use a value of -ss of greater than 29 seconds I get a bus error:

>ffmpeg -ss 40 -i VTS_01_1.VOB test.mov
ffmpeg version 0.4.9-pre1, build 4731, Copyright (c) 2000-2004 Fabrice Bellard
configuration: --enable-mp3lame --enable-gpl --disable-vhook --enable-ffplay --disable-ffserver --enable-a52 --enable-xvid --enable-faac --enable-faad --enable-amr_nb --enable-pthreads
built on Nov 21 2004 19:41:49, gcc: 3.3 20030304 (Apple Computer, Inc. build 1666)
[mpeg @ 0x376034]read_seek: 0 3621249
[mpeg @ 0x376034]using cached pos_min=0x3fa2180e dts_min=2681968
[mpeg @ 0x376034]pos_min=0x3fa2180e pos_max=0x3fa5800e dts_min=2681968 dts_max=2718004
[mpeg @ 0x376034]0 1067587598 0 / 1067810830 0 1067810830 target:0 limit:2681968 start:0 noc:2718004
[mpeg @ 0x376034]pos=0x3fa5800e 2718004<=3621249<=-9223372036854775808
Input #0, mpeg, from 'VTS_01_1.VOB':
Duration: 00:00:29.5, start: 0.236100, bitrate: 288957 kb/s
Stream #0.0: Video: mpeg2video, 720x480, 29.97 fps
Stream #0.1: Audio: ac3, 48000 Hz, stereo, 256 kb/s
File 'test.mov' already exists. Overwrite ? [y/N] y
Output #0, mov, to 'test.mov':
Stream #0.0: Video: mpeg4, 720x480, 29.97 fps, q=2-31, 200 kb/s
Stream #0.1: Audio: aac, 48000 Hz, stereo, 64 kb/s
Stream mapping:
Stream #0.0 -> #0.0
Stream #0.1 -> #0.1
Press [q] to stop encoding
Bus error

So it appears that both of the above things are due to problems in how ffmpeg deals with the duration of .VOB files.
If anyone has a fix, or knows of how to work around this, please let me know.

Thanks,

--Adam

[dnix71]

Way beyond 100% was something I noticed, too. I converted a ripped vob as a test and the progress was quick, but it would be nice to know exactly where you really are