Hallo, Josh Steiner hat gesagt: // Josh Steiner wrote:
weird... why?
Because USB audio is delivered in frames of which there are 1000 frames per second. Running at 44.1 kHz means, that you have to pack 44.1 samples into one such frame. But there is no fractional sample so you pack 44 samples for 9 frames, then 45 sample for one frame, repeat ad infinitum.
This is not really compliant with how ALSA and Jack access the hardware, which is with a constant period size that, per requirement of Jack, also needs to be a power of two. With 44.1 kHz samplerate the driver has to do lots of buffering to emulate the changing frame fill which leads to masses of latency. For example, using 44.1 kHz on I never got the old Quattro running with anything less than 3 periods each with size 2024. Using 48 kHz samplerate this can be much lower. In fact with my current USB card, I can gow as low as "-n 3 -p 256"
Just try it, you will see yourself.
ciao
Frank Barknecht _ ______footils.org__