[pulseaudio-discuss] PulseConf report

[Arun Raghavan]

On Wed, 2012-11-07 at 14:59 -0600, Pierre-Louis Bossart wrote:
> > For those who aren't following the planet, thought I'd like you know
> > that I've put up notes from PulseConf up at:
> >
> > http://arunraghavan.net/2012/11/pulseconf-2012-report/
> 
> One comment on the low-latency case for desktop gaming with a 16ms 
> latency. I imagine this means trouble when sending data to the HDaudio 
> driver. With the PulseAudio sink architecture, you need the sink and 
> ring buffer to be of equal size (feature, not bug), which means you need 
> a ring buffer size of 8ms tops (neglecting the client-server buffer), 
> and events up to 4ms apart. Has anyone tried the changes we pushed 
> recently at the kernel level to properly handle the ring buffer pointer 
> and delay? I believe some of the underruns may be due to the ~1ms 
> inaccuracy that we had before these changes.  If your driver is already 
> giving you a 25% precision error no wonder things are broken?

Indeed. that likely is one of the problems. As David points out, there
seem to be a multitude of other, system-wide problems that are
collectively raising our minimum achievable latency.

And as he mentions, in the mean time, I'm trying to rework the playback
buffer attr fixup code. Should have an RFC out before too long,
hopefully.

-- Arun