[alsa-devel] ALSA default buffer sizes

Clemens Ladisch clemens at ladisch.de
Mon Aug 24 11:47:02 CEST 2009

Manuel Jander wrote:
> I'm somewhat upset because audacious does not work with my AU8830. The
> problem is that audacious never calls any function that would give any
> clue about the desired buffer size. So my AU8830 ends up with 32
> periods, 1 byte each.
> The question is, who is the entity deciding those default values ?

snd_pcm_hw_params_choose() in alsa-lib/src/pcm/pcm_params.c:
/* Choose one configuration from configuration space defined by PARAMS
   The configuration chosen is that obtained fixing in this order:
   first access
   first format
   first subformat
   min channels
   min rate
   min period time
   max buffer size
   min tick time

au88x0_pcm.c has period_bytes_min = 0x1 and periods_max = 32.

Is that periods_max an actual hardware limit?

Best regards,

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