[Alsa-user] # of periods / input latency

[<ale...@gm...>]

Hi to all,

capturing the line in and measuring how long it takes I figured that the
whole latency is twice the blocking delay of the soundcard :

In case of using 48 kHz, 256 Samples/Frame I'm dealing with a blocking delay
of 5,6 ms. Processing audio internally I get exactly this value.

Capturing from line it gives me values of 11,2 ms.

In fact I used 2 periods because 1 results in tons of under/overruns.

My questions : Is there a way to reach capture values equal to the blocking
delay or is it alway twice of that ? Does this maybe depend on the soundcard
I'm using ? Is there a common way to process input signals in any soundcard
or do exist different approaches (i.e. doublebuffering) ?

Thanks in advance

-- A l e x 

-- 
Dipl.-Ing. Alexander Carôt
Email : Alexander@Carot.de
Tel.: +49 (0)177 5719797

phd-candidate at www.isnm.de

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