[FFmpeg-user] how to change ffmpeg configuration

[Lou]

On Wed, 11 Dec 2013 22:43:43 +0000
e-letter <inpost at gmail.com> wrote:

> Readers,
> 
> An attempt to convert flv to ogg failed:
> 
> ffmpeg -i file.flv file.ogg
> 
> FFmpeg version 0.6.5, Copyright (c) 2000-2010 the FFmpeg developers

This is old. Please compile from git master or use a recent build:

http://trac.ffmpeg.org/wiki/CompilationGuide
http://ffmpeg.org/download.html

>   built on May 15 2012 07:00:00 with gcc 4.4.3
>   configuration: --prefix=/usr --enable-shared --libdir=/usr/lib
> --shlibdir=/usr/lib --incdir=/usr/include --disable-stripping
> --enable-postproc --enable-gpl --enable-pthreads --enable-libtheora
> --enable-libvorbis --disable-encoder=vorbis --enable-x11grab
> --enable-runtime-cpudetect --enable-libdc1394 --enable-libschroedinger
> --disable-decoder=aac --disable-encoder=aac

Why --disable-decoder=aac --disable-encoder=aac? You disabled native
AAC decoding and encoding, but you are also not using an external AAC
library resulting in no AAC decoding or encoding capability.

--enable-pthreads and --enable-postproc are default (at least with
recent ffmpeg) so you don't need these.

> Input #0, flv, from '...':
>   Metadata:
>     duration        : ...
>     moovPosition    : ...
>     audiocodecid    : mp4a
>     aacaot          : 2
>     audiosamplerate : 22050
>     audiochannels   : 1
>   Duration: ..., start: 0.000000, bitrate: N/A
>     Stream #0.0: Audio: 0x0000, 22050 Hz, 1 channels

I'm guessing that this is AAC audio, but you disabled the AAC decoder.

> Is it correct to conclude that the configuration file needs to be
> changed, to enable the aac decoder?

You need to not use --disable-encoder=aac.

> Where is the configuration file to be found?

Changing the configure file will not change anything. You need to
re-compile ffmpeg without --disable-encoder=aac or use a recent build.