[FFmpeg-user] How to make the audio louder (at least "visually")?

[Gyan Doshi]

On 2023-04-15 10:20 pm, Marcin Borkowski wrote:
> Hi all,
>
> I am continuing my work involving waveforms.  So far it's great, and
> thanks for your help!  But I need one more thing.  I'd like to make the
> waveform better visible.  I noticed that most of the time, when the
> characters speak on a recording, they do not speak very loudly, so the
> bumps I can see (corresponding to syllables and words) have pretty low
> amplitude.  Is it possible to make them louder before generating the
> waveform so that they are better visible?  I don't care about any sound
> distortions, since I only want the waveform image.  Right now, this is
> what I am doing:
>
> ffmpeg -accurate_seek -ss ... -to ... -i ... -loglevel 0 \
> -filter_complex showwavespic=s=640x36:colors=white,negate \
> -frames:v 1 -c:v png -f image2 -
>
> I tried adding -filter:a "volume=4.0", but there seemed to be no effect.
>
> What was I doing wrong?

You have to add it before the showwavespic filter,

-filter_complex "volume=4.0,showwavespic=..."


Regards,
Gyan