[alsa-devel] Backported sbxfi driver, possible fix

Takashi Iwai tiwai at suse.de
Sun Oct 26 09:21:46 CET 2008

At Sat, 25 Oct 2008 23:57:53 +0200,
Bjoern Olausson wrote:
> > Latest unstable (25Oct 19:57) works from command line with mplayer,
> > without the proc oss fix.
> >
> Confirmed.
> The stuttering got better, but is still present.

Hm.  The probme like stuttering is a bit hard to analyze.
In most cases, it comes from the inaccurate PCM hwptr (i.e. the value
calculated in PCM pointer callback is wrong), but not always like

> Xine works flawless.
> > aplay still works but only with dmix.
> >
> Samplingrate 11025Hz and 8000Hz do not play a clear sinus, sounds a
> bit scratchy..

To be sure - this symptom is only on sbxfi, right?

> All other common samplingrates work flawless. Could someone confirm that?
> http://tmp.olausson.de/30days/0_16_s_8000.wav
> http://tmp.olausson.de/30days/0_16_s_11025.wav
> http://tmp.olausson.de/30days/0_16_s_96000.wav
> Just using "aplay file.wav"
> More noticable ist it when using mplayer. Crackles a lot with 8000Hz and 11025Hz
> "mplayer file.wav"
> mmh, xine crackles too. Please someone confirm, otherwise the files may be bad.

Yes, please...

> > Now also almost working in gnome with pulse, sound is recognisable but
> > with lots of interference/corruption.
> >
> No pulseaudio on my machine. Sry.
> > Machine did not crash at any point!
> >
> Just observed a X crash when using smplayer to play a avi. When I
> closed smplayer while the movie was playing X crashed. (But could be
> unrelated to audio, I could not reproduce it)

I'm not sure whether this is really related with sbxfi.
For checking that, you can load snd-dummy driver instead, and run
smplayer with it.

> But no crash or freez so far.
> > This was running on 2.6.26... is this a problem? SUPPORTED_KERNELS says
> > 2.6.25 or earlier?
> >
> I am using vanilla
> Thanks for you awesome work!
> By the way, what's next on your plan when stereo output and recording
> is working flawless?

A few important features are in my mind:
- continuous rate support
- multi-channel playback
- multi-stream playback

Not sure whether I can achieve any of them without a document,



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