[FFmpeg-user] Audio filter: removesilence doesn't appear to do anything

[Quinn Wood]

I thought I'd extracted the video by simply using the m4a extension-
that's not the way that works and I should have noticed that. I bet
the audio has been truncated but the video remains the full length.
Let me strip out the video and try it.

On Mon, Sep 25, 2017 at 12:59 AM, Quinn Wood <mtcjayne at gmail.com> wrote:
> I have used the following command
>     ffmpeg -i input.m4a -af silenceremove=0:0:0:-1:0.5:-20dB output.m4a
>
> on a file. When I use another tool (Audacity) to truncate periods over
> 0.5 seconds of under -20dB volume it removes upwards of an hour from
> the input file. When I run this command ffmpeg doesn't remove a single
> second. I have tried numerous variations of the command and numerous
> input files, and am simply unable to replicate the effect Audacity is
> producing.
>
> The input files have a period of silence at the beginning that is
> predictable, intermittent periods of silence throughout the file of
> unknown quantity and length, and a period of silence at the end that
> is predictable.