[pulseaudio-discuss] PulseAudio for Embedded System

Lennart Poettering lennart at poettering.net
Mon May 28 15:42:11 PDT 2007

On Mon, 14.05.07 09:47, keith preston (keithpre at gmail.com) wrote:

> libspeex resampling patch.   I have this working in certain cases.  Most
> notably the embedded case, which is S16_LE audio in 1 or 2 channels.   I
> haven't really followed up with the libspeex guys, but I was going to wait
> for the resampling code API to stabilize in libspeex and be released, before
> I added a patch with a dependency to it.

Awesome! This has been on my TODO list as well.

> software volume/mixing (sample-utils.c)   I've been looking and thinking
> about how to rewrite this for efficiency.  I found on my embedded device CPU
> Utilization for from 5% to 100% whenever I have two streams with software
> volumes.   As a temporary measure for myself, my embedded platform has some
> proprietary audio mixing code I am using, but this code should be cleaned up
> a bit.

Any chance for better liboil usage?

> Audio Class Policy,  this is really the big one and I'm sure you'll be
> interested in with the gsmartmix stuff.   I've added the concept of audio
> class to all the internal streams in pulseaudio and have a module that
> arbitrates between streams actively preempting streams, changing volume and
> such.   It is working pretty well right now.   I can have my music turn down
> when sound events happen that need my attention, I can block all audio when
> a VOIP call comes in, etc...

This sounds very good. As soon has you have something useful or maybe
even mergable, please ping me. This kind of overlaps with what I have
on my TODO list. I am very happy to see that someone else is doing
this work for me ;-).

Thank you,


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

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