[MPlayer-users] amr audio from a 3g2 video -> wav (or anything else)

[Eric S. Nagel]

I'm sure you've all seen this one before... I've seen it asked many
times, but never really answered.

I need to convert a 3g2 video to an mpeg.  No problem using ffmpeg... if
I ignore the sound.  After doing lots of reading, I've seen multiple
references to the fact that ffmpeg can't decode the amr soundtrack of
the 3g2 video file.

So I figure I'd convert the video, extract the sound from the original,
convert the sound, then put it back together.  Using mplayer, I'm
dumping the audio track:
/usr/local/bin/mplayer -ao pcm -vo null -vc dummy -dumpaudio -dumpfile
test.amr "0120060935.3g2"

Then trying to use a decoder from 3gpp.org to decode that into a format
I can use:
../3g2/decoder test.amr mytest.raw

However, I get back:
===================================================================
 TS 26.104                                                         
 R99   V3.5.0 2003-03                                              
 REL-4 V4.4.0 2003-03                                              
 3GPP AMR Floating-point Speech Decoder                            
===================================================================
Invalid magic number: ֙׆¨


I've taken this direction from
http://www.aquarionics.com/article/name/How_to_convert_AMR_files_to_MP3
And http://xa.bi/mms/

And, of course, I'm looking to do this all via the command-line, because
it's something that's going to be automated.


So while this isn't a direct question about mplayer, I was hoping
someone out there can help.

Thanks in advance,

Eric S. Nagel
eric at ericnagel.com
716.200.0922
 +44 (0) 20 8432 6139 (London, UK)
716.200.0923 fax