[MPlayer-users] -af volume

[Alexander Roalter]

Media Streaming Services wrote:
> 
> It seems to work, thanks a lot!
> I have another question, if it reports the maximum volume, there must
> be a volume measurement taken on ~every frame...  is there any way to
> extract that info and use own statistics on the volume table?

I don't think volume measurement is done @ every frame, since with audio 
this is not how things are usually done. With a DVD input, sampling 
rates of 48kHz are usually applied, this means that 48,000 times per 
second the volume is measured (it's not *exactly* like that, since the 
points in the waveform do not actually represent the volume per se, but 
more an amalgamation of loudness, and frequency.

To create some statistics, one could average this over each second, or 
even at a finer grain, but you would only get what normal audio editor 
software shows (http://images.google.com/images?&q=waveform, first image 
comes handy). You could output the audio to PCM (-ao pcm) and apply one 
of the many other programs to do statistics on such a wave file.

-- 
cheers,
Alex