PulseAudio performance test (Karmic?)

[onemyndseye]

I ran some tests tonight and stumbled on some interesting results...

First, I noticed my FPS has really suffered lately. So i started looking into it. And I found that turning RO's internal volume control all the way down make a HUGE difference. Not just 10-20fps. But LARGE jumps in FPS.

So I starting thinking ... hrmm.. I wonder if PulseAudio is bottle-necking RO..?

Testing was simple enough: Launch RO and turn in a circle until FPS stabilize and take a screen. Repeat bypassing PulseAudio (of sorts)

Test1 (Normal Launch):

onemyndseye@onemyndsmobile:~/regnum$ ./rolauncher

Result:

Test2 (Launch with OSS):

onemyndseye@onemyndsmobile:~/regnum$ aoss ./rolauncher

Result:


WOW! O.O


These results are in no way conclusive or even 100% consistent (so far I would say 80% consistent) and I will continue to test, but the results were so surprising I wanted to share and get a discussion started on this topic.

[Myxir]

Interesting.
I'm not sure but isn't openal a very old implementation?
I'm using a fresh karmic install with pulseaudio of course.
When I want to start it with aoss it just segfaults when selecting "enter gameworld".

I'll try to make it work with aoss as well :/

[DkySven]

I use a fresh install of ubuntu 9.10 and when playing games the sound will crash after a while, which will also cause the game to freeze when trying to exit it. This only happens with games, all other sound on my system keeps working. It looks like this is PulseAudio-related.

[onemyndseye]

yes - tried this on a different machine and got the segfault you mentioned..

OpenAL has been replaced by OpenAL Soft which is a much better implentation and is very well maintained unlike the older "OpenAL"

aoss tells RO to use the alsa-oss layer instead of pulse in either case still routes through OpenAL-Soft best of my understanding.

[Myxir]

Originally Posted by onemyndseye

aoss tells RO to use the alsa-oss layer instead of pulse in either case still routes through OpenAL-Soft best of my understanding.

Yes, I know how aoss works. But I did not know about OpenAL soft. Thanks about that.

[surak]

I've been noticing some nasty problems in with openal+pulseaudio in Karmic. (game freezes, and i can hear the music badly distorted). Anyone else having similar issues?

[DkySven]

Originally Posted by surak

I've been noticing some nasty problems in with openal+pulseaudio in Karmic. (game freezes, and i can hear the music badly distorted). Anyone else having similar issues?

Ah, I was trying to report that. Yes, I have those issues too.

[Ertial]

Originally Posted by surak

I've been noticing some nasty problems in with openal+pulseaudio in Karmic. (game freezes, and i can hear the music badly distorted). Anyone else having similar issues?

I haven't tested for performance decreases, but I do sometimes suffer from sound that starts to be malformed after a bit, but in Karmic this has actually improved; when it happens now it often just occurs for a short period of time.

EDIT: By the way, is libopenal1 still needed? Or do you include a library with the game?

[Myxir]

Originally Posted by surak

I've been noticing some nasty problems in with openal+pulseaudio in Karmic. (game freezes, and i can hear the music badly distorted). Anyone else having similar issues?

In generally I have sound completely disabled in RO. Though I have constant system freezes after 40-50 minutes of gameplay. I am not sure yet what causes this problem.
Do you just get game freeze or is it the whole system?

[onemyndseye]

After some testing the following settings put into ~/.alsoftrc works very well even though I am using surround sound mixing.

# Option and block names are case-insenstive. The supplied values are only
# hints and may not be honored (though generally it'll try to get as close as
# possible). These are the current available settings:

## format:
#  Sets the output format. Can be one of:
#  AL_FORMAT_MONO8    (8-bit mono)
#  AL_FORMAT_STEREO8  (8-bit stereo)
#  AL_FORMAT_QUAD8    (8-bit 4-channel)
#  AL_FORMAT_51CHN8   (8-bit 5.1 output)
#  AL_FORMAT_61CHN8   (8-bit 6.1 output)
#  AL_FORMAT_71CHN8   (8-bit 7.1 output)
#  AL_FORMAT_MONO16   (16-bit mono)
#  AL_FORMAT_STEREO16 (16-bit stereo)
#  AL_FORMAT_QUAD16   (16-bit 4-channel)
#  AL_FORMAT_51CHN16  (16-bit 5.1 output)
#  AL_FORMAT_61CHN16  (16-bit 6.1 output)
#  AL_FORMAT_71CHN16  (16-bit 7.1 output)
#format = AL_FORMAT_QUAD16
format = AL_FORMAT_51CHN16


## refresh:
#  Sets the buffer size, in frames. Note that the actual granularity may or may
#  not be less than this.
refresh = 6144

## sources:
#  Sets the maximum number of allocatable sources. Lower values may help for
#  systems with apps that try to play more sounds than the CPU can handle.
#sources = 256

## stereodup:
#  Sets whether to duplicate stereo sounds on the rear and side speakers for 4+
#  channel output. This can make stereo sources substantially louder than mono
#  or even 4+ channel sources, but provides a "fuller" playback quality. True,
#  yes, on, and non-0 values will duplicate stereo sources. 0 and anything else
#  will cause stereo sounds to only play out the front speakers.
stereodup = True

## drivers:
#  Sets the backend driver list order, comma-seperated. Unknown backends and
#  duplicated names are ignored, and unlisted backends won't be considered for
#  use. An empty list means the default.
#drivers = alsa,oss,solaris,dsound,winmm,port,pulse,wave
#drivers = alsa,oss,pulse   ### These good for linux
drivers = alsa


##
## ALSA backend stuff
##
[alsa]

## device:
#  Sets the device name for the default playback device.
device = surround51  # Comment this to use default alsa device

## periods:
#  Sets the number of update buffers for playback. A value of 0 means auto-
#  select.
#periods = 0

## mmap:
#  Sets whether to try using mmap mode (helps reduce latencies and CPU
#  consumption). If mmap isn't available, it will automatically fall back to
#  non-mmap mode. True, yes, on, and non-0 values will attempt to use mmap. 0
#  and anything else will force mmap off.
mmap = true

some settings I have left as their default I am still testing to see if they make a performance impact. I.e. buffers, number of voices etc etc.