[alsa-devel] pointer callback question
tiwai at suse.de
Thu Feb 12 18:54:40 CET 2009
At Thu, 12 Feb 2009 18:50:45 +0100,
Tim Blechmann wrote:
> hi all,
> one question about the pointer callback.
> the docs say:
> > This callback is called when the PCM middle layer inquires the current
> > hardware position on the buffer. The position must be returned in
> > ranging from 0 to buffer_size - 1.
> i am using a ringbuffer to communicate with my audio device. but when
> the position is reset to 0, alsa requests to stop the stream
> 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.
> stream_pointer at 0
> after returning 0, a stop is requested.
> am i missing something?
> thanks, tim
> tim at klingt.org
> Contrary to general belief, an artist is never ahead of his time but
> most people are far behind theirs.
> Edgar Varèse
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