[Ffmpeg-devel] AAC support in ffmpeg

[parag arole]

Hi Michel,
   Thank you so much for your reply.. it is indeed libfaad2 that is
used for decoding AAC in ffmpeg :-).
   For encoding AAC from AMR audio files, I had also tried using m4a
as the output format, like you suggested. That didn't work. However,
it does work for extracting audio from MPG , MOV and WMV files.
Thanks again for your help.
Parag

>> Hi, I am trying to decode AAC-LC audio and save it as amr(nb) from an
>> MP4 (also tried MOV ) file using ffmpeg, as follows -
>> ./ffmpeg -i ./test.mp4 -acodec amr_nb -ar 8000 -ac 1 -ab 12 -y -vn out.amr
>> 
>> This is the ffmpeg's response-
>>  
>>          ffmpeg version 0.4.9-pre1, build 4747, Copyright (c)
>> 2000-2004 Fabrice Bellard
>>          configuration:  --enable-faac --enable-amr_nb --enable-amr_nb-fixed 
>>          built on Apr 21 2005 15:58:19, gcc: 3.2.3 20030502 (Red Hat
>> Linux 3.2.3-52)
>> 
>>         Input #0, mov,mp4,m4a,3gp,3g2, from './Picnic.mp4':
>>         Duration: 00:00:40.6, start: 0.000000, bitrate: 107 kb/s
>>         Stream #0.0: Video: mpeg4, 192x144, 15.01 fps
>>         Stream #0.1: Audio: 0x6134706d, 44100 Hz, mono
>> 
>>         Unsupported codec (id=86018) for input stream #0.1
>> 
>> I have installed libfaac and built ffmpeg with faac and amr_nb
>> enabled, as can be seen above. 

>Isnt faad (delta) the one you need for decoding?

>> The AMR encoding works for MP2 and
>> Windows media audio codecs.
>> Also, I confirmed using mp4UI that the input audio stream is AAC LC.
>> 
>> I also tried to convert AMR audio files to ACC as - 
>>        ffmpeg -i ./out.amr -acodec aac -y -vn out.aac
>> But this does not work either.
>> 
>> ffmpeg returns the following -
>> 
>>       Stream #0.0: Audio: amr_nb, 8000 Hz, mono
>>       Unable for find a suitable output format for 'out.aac'
>
>Maybe ffmpeg is right and there is no aac format, only an aac codec? Try 
>  out.m4a.

>> 
>> I would really appreciate any help in understanding why AAC audio
>> decoding/encoding is not working.
>> Thanks and regards,
>> Parag Arole
>> 
>-- 
>Michel Bardiaux
>Peaktime Belgium S.A.  Bd. du Souverain, 191  B-1160 Bruxelles
>Tel : +32 2 790.29.41