[alsa-devel] Which transfer mode to use

Clemens Ladisch clemens at ladisch.de
Wed Oct 14 16:44:44 CEST 2009


Till Crueger wrote:
> 1. Asynchronous callback:
> This method seems to be the best explained by all the tutorials I could
> find, so I am guessing this is the best choice for audio applications.

It's the worst choice; it isn't available on many devices, and the
asynchronous callback cannot do much because it might have interrupted
some non-reentrant function.

> 2. read/write:
> So far this seems the best choice.

Use it.

> For this however I would have to figure out after each polling, how
> much data can be written.

snd_pcm_avail()

> I found some concerns about differences in lattency between these
> three methods.

Those concerned have not measured; the latency is _exactly_ the same.


HTH
Clemens


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