[FFmpeg-user] AAC conversion from 7.1 channel to 2 channel

[Carl Eugen Hoyos]

rohit a <rohit.tvm.86 <at> gmail.com> writes:

> For AAC conversion from 5.1 channels to 2 channels, the 
> equation used in surround_to_stereo() in 
> libavodec/resample.c is
> 
> *        l = av_clip_int16(fl + (0.5 * rl) + (0.7 * c));*
> *        r = av_clip_int16(fr + (0.5 * rr) + (0.7 * c));*

This does not exist in current FFmpeg.

As said, channel downmix happens in libswresample.
If you have any problems with it (if it does not 
work or if it does not work the way you expect) 
please report it here on the mailing list.

A typical test could be the following:
$ ffmpeg -i input.aac -ac 2 out.wav

Carl Eugen