[alsa-devel] [PATCH] Two patches for Alsa-plugins (pulse)

Raymond Yau superquad.vortex2 at gmail.com
Tue Jul 13 07:08:39 CEST 2010

2010/7/10 David Henningsson <launchpad.web at epost.diwic.se>

> > PA developer often complain the driver did not provide accurate playback
> > position by the pcm_pointer callback
> >
> > Did the pulse_pointer callback also provide accurate position of the
> pulse
> > device ?
> Yes, but it provides the pointer to the fake ring buffer (the alsa-lib
> plugin system expects that all pcm plugins are ring buffers, which seems
> to me like a design flaw).
This mean that pulse_pointer jump suddenly when PA wake up from sleep and
write audio to sound card until the ring buffer is empty, Those "0 bytes in
queue " message is the result of PA server flush the ring buffer.

Did alsa-lib regard this condition as underrun, since the application
pointer and hardware pointer of the pulse device  seem at the same point ?

Is this the reason why alsa-time-test.c fail on the pulse device ?

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