On Thu, 14 Jan 2010, ANISH KUMAR wrote: >> mmap is supported by the Samsung drivers. > > Thanks for this information which i overlooked. >> This looks like the dmix data rates are getting out of sync with what >> the hardware is doing. Enabling CONFIG_SND_PCM_XRUN_DEBUG will produce >> more diagnostic information from the driver side > I got the problem and after doing the changes DMIX plugin is working > very fine. As you know XRUN was happening and this happening in > snd_pcm_update_hw_ptr_post function. This happened because > stop_threshold is increased suddenly(Is it done by dmix? If yes then why > ?) ?????? In normal condtions this would have been fine but in my code i > was multiplying it by some amount causing it to wrap > around(stop_threshold=0 );Causing XRUN.So i just removed this > multiplying factor. For dmix, the stop_threshold should be equal to boundary value, thus XRUN check should never be true. If you got xrun with dmix, something is wrong. > One more Rate conversion query: ./alsa_aplay -v > -D"plug:'dmix:RATE=44100'" bond.wav Playing WAVE 'bond.wav' : Unsigned 8 > bit, Rate 11025 Hz, Mono Plug PCM: Rate conversion PCM (44100, > sformat=U8) As you can see bond.wav is sampled at 11025k but when i am > playing with Plug PCM there is some noise in the song why????Is rate > conversion algoritm not able to resample it properly? The default linear resampler is not very good quality. You may use some sox resamplers from the alsa-plugins package, but they're more CPU intensive. Check google. Jaroslav ----- Jaroslav Kysela <perex@xxxxxxxx> Linux Kernel Sound Maintainer ALSA Project, Red Hat, Inc. _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
