[FFmpeg-user] mpeg2 filesize reduction: reduce video, enhance audio, codec selection

Steve Boyer steveboyer85 at gmail.com
Wed May 7 17:15:15 CEST 2014

On Wed, May 7, 2014 at 10:11 AM, Beeblebrox <zaphod at berentweb.com> wrote:
> Sorry for the incomplete previous post.
> ffmpeg starts if I remove the "volume" flag:
> $ ffmpeg -i video1.mpg -c:a libfdk_aac -af
> 'compand=.3|.3:1|1:-90/-60|-60/-40|-40/-30|-20/-20:6:0:-90:0.2' -c:v
> libx264 -preset slow -crf 32 -f mp4 video1-out.mp4)

See my last e-mail: I think a comma was omitted.

> * How is "volume" combined with "compand"? Or should that not be done and
> volume should be increased on a second pass?
> * Syntax conversion question (compand 0.1,0.3
> -60,-60,-30,-15,-20,-12,-4,-8,-2,-7 -2) still open.

>From what I understand, the compand will compress frequency range's
volume. If you want to raise the volume over the entire video, you
should use the volume filter as well.


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