On Wed, Oct 11, 2006 at 08:50:32PM +0300, Jukka Marin wrote:
> On Wed, Oct 11, 2006 at 08:14:59PM +0300, Jukka Marin wrote:
> > I'm trying to bring a -current system into production use.  One of
> > the problems I'm seeing is that recording from Ensoniq AudioPCI
> > card produces 8 wrong samples at regular intervals which generates
> > a ticking background noise in the recorded audio.  The samples
> > seem to be part of the recorded audio signal, they just come from
> > a wrong place.  The number of wrong samples always seems to be 8.
> 
> It seems the problem is visible at 2400 sample intervals.  I checked
> the ai.blocksize in audio_info_t and it is 9600 (2400 samples * 2
> channels * 2 bytes/channel = 9600 bytes).  So, the problem occurs
> once per audio blocksize.

I tried changing the blocksize.  The maximum allowed by audio device
seems to be 21824 bytes.  With this value, I couldn't find any errors
on a 10 second recording made at 32000 samples/s.  With blocksize set
to 8192, 16384, or 20000 bytes, there were errors in the recorded
data.

  -jm