[Ffmpeg-devel] Subject: -acodec 'copy' fails

[Michael Niedermayer]

Hi

On Sunday 31 July 2005 13:06, Bastian Suess wrote:
> Hi,
>
> I am trying to convert a multi-language VOB-file (from DVD)
> to a single-language VOB-file (only german).
>
> => ffmpeg crashes
>
> => my command line:
> > ffmpeg -i HARRY_POTTER_PHILOSOPHERS_STON1-1.vob \
>
>   -vcodec copy -acodec copy -f vob harryff13.vob -map 0.0 -map 0.3
>
> => Output:
> ffmpeg version CVS, build 4759, Copyright (c) 2000-2004 Fabrice Bellard
>   configuration:
>   built on Jul 28 2005 20:06:50, gcc: 3.3.3 (SuSE Linux)
> Input #0, mpeg, from 'HARRY_POTTER_PHILOSOPHERS_STON1-1.vob':
>   Duration: 00:42:39.7, start: 0.052000, bitrate: 6711 kb/s
>   Stream #0.0[0x1e0]: Video: mpeg2video, yuv420p, 720x576, 25.00
> fps, 7500 kb/s
>   Stream #0.1[0x80]: Audio: 0x0000
>   Stream #0.2[0x82]: Audio: 0x0000
>   Stream #0.3[0x81]: Audio: 0x0000
> Output #0, vob, to 'harryff13a.vob':
>   Stream #0.0: Video: mpeg2video, 720x576, 25.00 fps, q=2-31, 7500 kb/s
>   Stream #0.1: Audio: ac3
> Stream mapping:
>   Stream #0.0 -> #0.0
>   Stream #0.3 -> #0.1
> Gleitkomma-Ausnahme
> (german translation of floating point execption)
>
> =>I found, that
>
> 1) The call-path
> " main() => av_encode() => av_write_header() => av_frac_init() "
> causes in av_frac_init() that
> 	st->time_base.num and st->codec->sample_rate are both zero !
> So an Division by zero occures.
>
> 2) Something similar happens in
> " main() => av_encode() => output_packet() "
> ist->st->codec->sample_rate and ist->st->codec->channels
> are also both zero.
>
> Simple patching the code to avoid the division by zero
> keeps the progam running, but it works only with audio-channel-mapping
> to 0.1.
>
>
> Does everybody knows how to fix it the rigt way?

./configure --enable-a52 --enable-gpl should fix this

[...]
-- 
Michael