[PD] ASIO

Michael Casey mkc at media.mit.edu
Wed Mar 20 18:44:25 CET 2002



Michael,

ASIO is double buffered and there is an additional latency of 60 samples
caused by the switchbuffers callback routine. This explains your input
latency of 7 ms instead of 5.8ms for a 256 sample buffer at 44.1kHz.

To explain the output latency, PortAudio doesn't tell you how many user
buffers are assigned for each device. There may be 4 buffers used for your
output channels, I believe the sound card makes such decisions and will
need to be configured for lower latency output.

-Michael Casey


On Wed, 20 Mar 2002, Michael Iber wrote:

> for all who are interested: PD test 14 runs on win98 and win2000 with
> Tascam428 very stable for input 1/2 (3/4 doesn't work, although recognized
> at startup).
> The only thing I do not understand: startup shows me, that the ASIO- and
> user-buffersize of 256 is accepted. Nevertheless the input latency is 7 ms
> and output 21 ms!!!!! Why????




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