Rhythmbox stutters over very light system load

[Manu Cornet]

Rhythmbox stutters whenever I ask my system to do something else when an mp3 is
playing, like opening a new nautilus window (or any other program), or get my
mails. I searched for an option to make rhythmbox process priority (nice)
higher, but didn't find one. Since this is a serious bug, I guess it must quite
local, but it's very annoying nonetheless...

A funny thing is that the sound doesn't stutter at all when I perform a search
with Synaptic (and since I have universe and multiverse packages activated, it
takes a few seconds).

The rhythbox process remains at about 5% CPU and 5% memory all the time.

This seems to happen with mp3 files as well as with OGG files. Packages are (I
believe) gstreamer0.8-vorbis and gstreamer0.8-lame.

I am running an up-to-date breezy (freshly installed) and the rhythmbox process
shows a "nice" value equal to 0 (I guess this is normal). I don't believe this
is a "your computer is too old" issue : my CPU is rather recent (more than 2
GHz) and I have 512 Mo RAM.

[Sebastien Bacher (seb128)]

Thanks for your bug. What version of Ubuntu do you use? What sinks are
configured with the multimedia selector? Do you have the issue if you play your
file with 'gst-launch-0.8 playbin uri="file://...."'?

[Manu Cornet (lmanul)]

I use an up-to-date Breezy Badger (including today's rhythbox upgrade).

ii rhythmbox 0.9.1-1ubuntu3~breezy1

The default sink is esd, the default source is OSS (I guess these are the
default settings).

I tried playing a file (MP3) with gst-launch-0.8 playbin uri="file://...." and
the result is even weirder : the sound doesn't just stutters... How to say that.
Well, using rhythmbox, the sound often pauses, maybe two or three times per
second, when the system is a little loaded, when it pauses, it's just silence
for a very, very short time. Using playbin, it still stutters, but it seems that
instead of the silence, it plays another part of the sound, maybe one second
ahead or behind, thus giving the impression of always jumping from here to
there, several times per second, and even withtout any system load. Weird :)

My soundcard is a SoundBlaster Live 24, seen by lspci as :

0000:00:0e.0 Multimedia audio controller: Creative Labs SB Audigy LS

[Sebastien Bacher (seb128)]

does that happen with an alsasink?

[Manu Cornet (lmanul)]

Yes, and it is worse (the stuttering is stronger, and happens even without any
system load at all)...

But when I select "Alsa" as the default sink and try to test that (from the
multimedia system selector), an error tells me that the pipeline couldn't be
built... But I do have sound (system sounds, for example, are perfectly normal).

Should we just say that this problem comes from my sound system and drop this
bug, or transfer it somewhere else ? Has anybody else experienced this on a
default breezy installation ?

[Manu Cornet (lmanul)]

Some additionnal info : it turns out that this doesn't happen with an OSS sink
(huh, maybe that was predictable ? I don't know anything about sound systems).
With OSS, the sound is smooth all the time, even on quite heavy system load
(expanding a 100M tar.gz file). (Still up-to-date breezy)

[Sebastien Bacher (seb128)]

Ok, so this bug is a summary of the audio world under linux:
- oss works usually fine but doesn't do sampling, you are limited to one sound
at time (ie: no sound effect while you play some music, can't open totem while
listening to some ogg)
- esound has synchronization issues, can be laggy, etc but work on every
configuration and allow to play different sounds in the same time
- alsa/dmix works fine and allow to play from different sources but doesn't work
fine with all the souncards (and that's why we don't use it by default)

Manu, I'm marking this bug as duplicate of #15438, feel free to reopen if you
disagree

This bug has been marked as a duplicate of bug 21661.

[Jasper Frumau (jfrumau)]

Well the current state of PA/ALSA in combination with Rhythmbox has not changed. It still stutters a lot when I do other tasks. Can't really point out the main sources of the stuttering. I thought it was Skype. But as I am typing this message in Firefox with Keepassx and Evolution open it happens as well. I wil leave it at this, as this appears to be a duplicate bug. But the tittle of it just connects well to my issue.