[alsa-devel] pointer callback question

Takashi Iwai tiwai at suse.de
Thu Feb 12 18:58:02 CET 2009


At Thu, 12 Feb 2009 18:55:49 +0100,
Tim Blechmann wrote:
> 
> >> the brief log is (4 periods of 64 frames):
> >> stream_pointer at 64
> >> stream_pointer at 128
> >> stream_pointer at 192
> >> stream_pointer at 256
> > 
> > This is invalid.  The pointer callback must return 0 in this case.
> > The value the pointer callback returns is between 0 and buffer_size-1.
> 
> sry, typo, 5 periods of 64 frames

Then it must be OK.  If the stream is stopped, it's likely by the
buffer underrun detection or so...

BTW, you should be sure that the buffer size is aligned to the period 
size if such a design is assumed.  Without the extra constraint, it
could be unaligned as default.


Takashi


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