Re: Mplayer makes small popping/static sound when speed_set is used

On Sat, 15 Jul 2023 22:34:24 -0400
Brad Hermanson <[email protected]> wrote:

> Over the past two years I've developed a command-line front-end to
> MPlayer called Aletheia that features front-and-center pitch controls
> using music intervals (e.g. 1/12 of an interval for a semitone, but
> works with any EDO), and it utilizes speed_set to adjust. Everything
> works great; however, there is a slight clicking/popping/static sound
> on a speed_set change. It's not a big problem and I feel like it
> might be out of my control; perhaps even a symptom inherent to the
> audio frequency itself. I was wondering if anyone had any ideas on if
> this could be reduced or eliminated if it is something that can be
> fixed? It seems that even small increments produce the sound and I
> can't imagine it's my code as I'm just sending commands to a pipe to
> mplayer. I thought that perhaps mplayer itself could scale small
> increments to reduce the static, or perhaps another solution would be
> better. Aletheia is just a bash script, so the optimization would
> likely have to come from your end.
> 
> https://github.com/apeitheo/aletheia
> 
> Thank you in advance for any help or insight into this matter.

This is probably caused by a discontinuity in the wave form after your
adjustment.  Unless you are explicitly managing the output in order to
prevent this, it is almost certain to happen.  If you are familiar with
the audio editing program audacity, and can capture the audio when this
happens, you can look at the audio, and expand it until you see
individual samples.  There will be an abrupt change showing at the
point where the click happens; the waveform won't be smooth.