[alsa-devel] [PATCH] ALSA ymfpci - Add "Playback" to FM Legacy Volume control

Clemens Ladisch clemens at ladisch.de
Mon Sep 12 16:02:05 CEST 2011

Raymond Yau wrote:
> How accurate is the ymfpci timer ?

The period interrupts are not accurate at all.  The ymfpci hardware
internally uses fixed periods of 256 frames at 48 kHz; the driver
reports a period interrupt when the next hardware interrupt at or after
a period boundary occurs.  The current position reported by the hardware
is the position at the time of the last hardware interrupt.

> my ymf724f seem play quite well with alsa "hw" device but with bad
> noise with alsa-pulse plugin (e.g. aplay when not using default period
> times )  and it also occurrs on   benshee on ubuntu 11.4 live cd

It should be possible to increase accuracy by using the hardware period
parameters (48 kHz _and_ 256 frames/period).

TODO: implement support for the NORESAMPLE flag.


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