[pulseaudio-discuss] [ANNOUNCE] PulseAudio 0.9.11
lennart at poettering.net
Thu Jul 24 06:16:25 PDT 2008
I just released PulseAudio 0.9.11:
It's a major new release, a big step forward. It's such a big step
forward that this release *will* break software that sits on top of
PA, and triggers bugs previously unknown in the software below PA. Due
to this this version is not a version packagers should be pushing into
any 'LTS' release or suchlike. If you want a solid release that you
can build a house on it is probably a good idea to wait for 0.9.12.
To make PA work 0.9.11 you need the newest ALSA (1.0.17) in both
userspace and kernel. Also, on top of that these three patches need
You also need a very recent kernel. The buffering parameters in PA are
chosen in a way that they work fine on standard kernels which are
optimized for low-latency behaviour (HZ=1000, preemptive ...). The
Fedora kernel is a very good choice. If you run PA on other kernels,
especially those with a lot of latency-inducing closed source drivers
(Ubuntu...), you might need to alter the default buffering
metrics. The glicht-free feature mentioned below will only be enabled
if the kernel supports high-resolution timers (hrtimers).
So, what new does this version bring that it justifies this breakage?
Quite a lot, actually. Here are the most important changes:
- the best new feature, although not directly visible from the outside
and often enough not enabled due to artificial limitations on the
hardware buffer size of ALSA is time-scheduled playback (aka
'glitch-free'). See http://0pointer.de/blog/projects/pulse-glitch-free.html
- The PA client libraries now interpolate timing information in a more
sophisticated fashion, to avoid roundtrips.
- Arbitrary properties can be attached to streams, devices, clients in
PA, such as icons, program names, X11 windows
- a new PA startup scheme that should make PA compatible with multiple
simultaneous logins by the same user and console applications.
- "Spatial" event sounds, i.e. sound events from UI elements are
positioned in space, according to where they were triggered on the
screen (click on a button on the left side of the screen and audio
comes from the left speaksers, ...) To make use of these features
clients need to use the libcanberra event sound library.
- The startup logic has been rewritten to allow file-based
capababilites (CAP_SYS_NICE) instead of suid root for acquiring
- Fix RTP client to adapt to the speed of the sender
- A new module 'module-always-sink' to make sure there is always at
least one sink defined, and it it is a null sink.
- A new switch --start to start PA only if it is not running yet
- Add peak detection monitor/record streams
- Optimize memory consumption
- Lots of other additions, and fixes.
Lennart Poettering Red Hat, Inc.
lennart [at] poettering [dot] net ICQ# 11060553
http://0pointer.net/lennart/ GnuPG 0x1A015CC4
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