[pulseaudio-discuss] PulseAudio conference: Updated schedule

David Henningsson david.henningsson at canonical.com
Thu Nov 1 02:52:19 PDT 2012

Note: This schedule might still not be final. Apart from the six topic 
leaders, nobody has said that they depend on a specific topic at a 
specific time, so we reserve the possibility to shuffle things around, 
as well as start earlier on a topic if the previous one ended earlier. 
The time for each topic is quite hard to predict :-)


09.30 Conference start

Reserved time to organize chairs, make sure we have equipment, people, etc

09.45 PulseAudio - vision and mission

What do we want PulseAudio to be? What are we working for? How important 
is it for us to be the standard sound server in desktop/laptop as well 
as the embedded distributions? Other important use cases for PulseAudio? 
Are some distributions more important than others? Can we unify our 
visions for where we see PulseAudio in a few years time?

Topic leader: David Henningsson

10.30 Is there any way we can increase the patch review capacity?

The pile of unreviewed patches keeps growing. I don't have much ideas
for improving this beyond "just work harder", but maybe someone else

Topic leader: Tanu Kaskinen

10.45 Coffee break

11.00 Routing priority list infrastructure

A year ago or even more, Colin Guthrie had some ideas on how to improve 
the routing infrastructure in PulseAudio, but it is still not (fully) 
implemented. Until it's there, we're hacking around the current 
limitations with e g modules such as module-switch-on-port-available, 
have rerouting problems at suspend/resume, etc.

Also, Janos Kovacs and Jaska Uimonen has started implementing some kind 
of priority/policy infrastructure, which we will also be discussing.

Topic leaders: Janos Kovacs, Jaska Uimonen, Colin Guthrie

11.45 Improving low latency behaviour

Discussion about how we can make PulseAudio perform better in low 
latency scenarios, such as VOIP or gaming. In particular, the issue of 
latency increasing over time (as occasional underruns occur) should be 
somehow resolved.

12.15 Combining system-wide and per-user modes

I think the hardware should be accessed by a system-wide pulseaudio
instance. This would finally solve the issue that root/mpd/whatever
can't have sound while someone else is logged in. The drawbacks of the
system-wide mode can be avoided by having also per-user instances taking
care of the per-user stuff.

Topic leader: Tanu Kaskinen, Colin Guthrie

12.45 Misc minor things

  * Remove HAL?, Planning for a major bump?
  * Disable esound by default
  * Flash (specifically Recording)

Topic leader: Colin Guthrie

13.00 Lunch

14.00 Improving surround sound behaviour

More and more laptops have built in subwoofers; how can we handle/enable 
this in the best way?
Also; can we use jack detection to determine whether a certain profile 
should be available or not?

Topic leader: Arun Raghavan, David Henningsson, Colin Guthrie

14.45 Testing

I would like to see us adding more tests -- the amount of code/features 
that we add is much much larger that corresponding tests. Part of the 
problem is that there is still missing infrastructure to make this easy 
enough (we don't have an automated way to test that playback actually 
works, for example). Deng's work during the GSoC should make a lot of 
things a lot easier, so this would likely just be a small discussion 
about what kind of extensions we need, and maybe finding some way to tie 
that up into a CI system if possible.

Topic leader: Arun Raghavan

15.15 Unified ALSA config xdistro

It seems the different distros have different approaches here.
Automatic, semi-automatic etc. It would be nice to have a common
approach here. (I suspect I may lose my personal preference here, but I'd
rather go with consistency across distros than fight too hard for my own

Topic leader: Colin Guthrie

15.30 Base Volume options

It's just about how to handle the presentation and inclusion
of "base volumes" generally.

Topic leader: Colin Guthrie

15.45 Devices with dynamic capabilities (e g HDMI)

HDMI in particular can change its PCM capabilities, i e, maybe you first 
have one monitor connected that supports 5.1 LPCM, and you then unplug 
and plug in another one that only supports stereo. How do we 
update/reprobe/etc PulseAudio accordingly to support this? And how does 
it relate to the just pushed patches that can add profiles/ports 

Topic leader: David Henningsson

16.00 Coffee break

16.15 User experience

We've come a long way from in terms of being invisible to users (as we 
should be), but I still see a large number of people facing 
difficulties, often in "standard bugs". This includes programs grabbing 
the ALSA device, tsched=0 fixes, port switching, running mpd, and 
probably others that I can't remember. What I'd like to discuss is ways 
for us to deal with these sort of problems and help solve them quickly. 
My current thinking is some sort of program/script to help people 
quickly pin point problems and find solutions. This is really matter of 
automating the standard diagnostics we ask for on IRC, and documenting 
the standard solutions. (David pointed me to Ubuntu's diagnostic tool, 
which is a good starting point)

Topic leader: Arun Raghavan

16.45 Separate configuration for hw adaptation, core and policy

In the non-desktop world there is often a need to ship different
configuration files for different hardware, and also different UIs may
need different pulseaudio policy configuration (I think this latter
point potentially applies also to the desktop world). This can be solved
with some packaging tricks, but I would like to make things easier by
having the separation also in upstream.

Topic leader: Tanu Kaskinen

17.15 Better drain/underrun reporting behaviour

We more than once has got reports that 1) drains take seconds too long 
to complete 2) underruns are reported before all samples sent have been 
actually played back, and sometimes a audio glitch can be avoided even 
when an underrun has been reported to the client. Can we get almost 
sample accuracy on when we report back that underrun/drain has occurred?

Topic leader: David Henningsson

17.45 End of conference

David Henningsson, Canonical Ltd.

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