[alsa-devel] safe support for rewind in ALSA

Raymond Yau superquad.vortex2 at gmail.com
Tue Feb 23 03:44:22 CET 2010


2010/2/21 Kai Vehmanen <kvehmanen at eca.cx>

> Hi,
>
>
> On Mon, 15 Feb 2010, Raymond Yau wrote:
>
>  Even using a high resolution timer , the application still cannot achieve
>> latency better than the configured period size
>>
>> For USB case , the driver cannot give accurate hw pointer position , hw
>> pointer increase in steps for the current implementation, (i.e. the graph
>> is
>>
>
> ... but that's a real hardware limitation for the USB-driver, right? And
> even in the USB case, hw pointer is incremented in steps of URB transfer
> size, so even in this case, latency of a highres timer based application is
> not limited by the set period-size.
>
>
I guess alsa pulse plugin also has the same problem since the value returned
by pointer callback of the pulse device is also not accurate


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