[Ffmpeg-devel] Extract audio from Nokia generated 3GP file

Barry barry
Tue Feb 21 14:54:34 CET 2006


I'm trying to extract the audio from a Nokia 6230 generated 3GP file 
using ffmpeg with the following command:

ffmpeg -y -i Video004.3gp -ac 1 -acodec mp3 -ar 22050 -f wav temp.mp3

I've built ffmpeg with the amr_float code (as described in amr.c) and 
with lame support but ffmpeg still core dumps. I don't think there's any 
problem with the build itself because I can extract the audio stream 
from another (non-Nokia) 3GP file OK.

The core dump seems to occur in a routine in the Speech_Decode_Frame() 
function in the amr_float code from 3gpp.org

One wierd thing I've found so far is that the Nokia file seems to 
contain the audio in one big frame (~20kb) while the OK file contains 
multiple small frames (320bytes) but beyond that my C gets a bit inadequate.

I've put the files here:

Nokia: http://www.zoidberg.nl/Video003.3gp
OK: http://www.zoidberg.nl/sample.3gp

Thanks for any help...

Regards, Barry.

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