[pulseaudio-discuss] Optimize PA for mobile usage

[Paul Menzel]

Dear Andreas,


Am Freitag, den 07.10.2011, 17:03 +0200 schrieb Andreas Bauer:

> First a big thank you for a quality piece of software. I am a first
> time user and am amazed at the flexiblity that PA provides. I
> installed PA because I wanted to have better integration of my
> Bluetooth headset and works perfectly.

thank you for such positive feed back. I guess developers (not me)
should get that more often.

> Running Debian Squeeze (stable) with Kernel 3.0.1

Is the PA version 0.9.21-3+squeeze1 [1]? I guess the ALSA version is
quite old then too. PA 1.0 was released recently.

Could you somehow test a more recent version. I am not sure if there is
a live CD for that purpose or if you have a spare storage medium where
you can try Debian Sid/unstable.

> Now I have three issues which I hope someone can point me to a
> possible solution.
> 
> On my Lenovo X201 laptop with Intel HDA I do see a heavy increase in
> power consumption when I activate pulseaudio. The system is already
> optimised so without pulseaudio it will idle at 6-9W with wifi on,
> with pulseaudio started it will jump to 13W. No pulseaudio client
> connected (no sound played)
> 
> Averaged battery reading every 5s 
> 
> 1267000
> 1311000
> 1330000
> 1347000 <- here pa-suspender is started
> 1192000
> 1091000
> 986000
> 952000
> 943000
> 988000
> 970000
> 943000
> 
> I have already optimised the PA setup for my needs (e.g. low quality
> resampling-method), so I investigated further:
> 
> From top:
> 
> 8816 ab         9 -11  211m 3832 2832 S    0  0.1   0:00.06 pulseaudio
> 
> From powertop:
> 
>            695,7 µs/s      13,6
> Process        /usr/bin/pulseaudio --start --log-target=syslog
> 
> So it is not about CPU consumption, pulseaudio is economical with CPU
> as is.
> 
> The same thing (also drawing about the same amount of extra juice)
> happens with this:
> 
> root at charly:~# mv /etc/asound.conf /etc/asound.pulse
> root at charly:~# aplay -d front /boot/vmlinuz-*
> Wiedergabe: Rohdaten '/boot/vmlinuz-3.0.1' : Unsigned 8 bit, Rate:
> 8000 Hz, mono
> 
> So clearly, it is the power consumption of the sound chip. I suspect
> that pulseaudio activates the sound chip even when no sound is being
> played. Is there any way to have it only access the hardware when at
> minimum one client is connected (e.g. audio playing)?

I am not sure. 4 W power consumption of a sound chip sounds quite a lot
to me. Additionally as written above please try a newer version.

> I was not successful with this shot (old syntax?):
> 
> add-autoload-sink alsa_sink module-alsa-sink device="hw:0"
> add-autoload-source alsa_source module-alsa-source device="hw:0"

You can also take a look at the ALSA Wiki [2] and provide the output of
`alsa-info.sh` which should give a lot of useful information to the
developers.

> Second issue: I have one application (Zoiper) which can only access
> ALSA at the moment (because it will not allow me to input non-hardware
> ALSA device names like pcm.pulse). Is there some hack/workaround to
> get such applications to talk to pulseaudio?

Please open a new thread by sending a new message with an appropriate
subject line for this topic.


Thanks,

Paul


[1] http://packages.debian.org/squeeze/pulseaudio
[2] http://alsa-project.org/main/index.php/Help_To_Debug
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