[pulseaudio-discuss] volume ramping

Lennart Poettering lennart at poettering.net
Thu Dec 11 10:04:44 PST 2008

On Thu, 11.12.08 09:56, Baek Chang (baeksan at ccrma.stanford.edu) wrote:

> What is the proper way to do volume ramping in pulse audio to avoid clicking
> when changed the volume?  I wrote a module to callback and change the volume
> in small incremental steps, but it seems that pulse seems to apply the
> volume changes on the audio buffer as a whole.  Does pulseaudio take a
> volume command, and then process the one audio buffer with that set volume?
> I'm using a buffer size of 4096 at 44100Hz, so it is about 10mS. So how
> would I go about ramping the volume, in say about 15 mS?

Volumes are applied block-by-block. The Block size is variable and
depends on the sound device and the application used.

I wrote some code to implement volume "envelopes" for this. The code
is there, it's even included in the tarball.  But it's not hooked
up. And until I finish that I fear, no: we cannot do volume ramping.



Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net         ICQ# 11060553
http://0pointer.net/lennart/           GnuPG 0x1A015CC4

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