So I have a USB audio class device that supports only 16Bit/48KHz signal. I confirmed that by checking the hardware parameters with aplay -l. Windows also told me so.
When I start jackd on it with -r 44100, neither does it tell me that this rate can't be used with that device, nor does it report back the fact that it started the device with the only supported rate (48000):
[tom@localhost ~]$ jackd -d alsa -d hw:W2 -r 44100 -P
jackd 0.125.0
Copyright 2001-2009 Paul Davis, Stephane Letz, Jack O'Quinn, Torben Hohn and others.
jackd comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details
JACK compiled with System V SHM support.
loading driver ..
apparent rate = 44100
creating alsa driver ... hw:W2|-|1024|2|44100|0|0|nomon|swmeter|-|32bit
configuring for 44100Hz, period = 1024 frames (23.2 ms), buffer = 2 periods
ALSA: final selected sample format for playback: 16bit little-endian
ALSA: use 2 periods for playback
I once thought that maybe jack use libsamplerate or zita-resampler to resample the mix before sending it off to the device. But I read from an old issue that jack does not do that. Finally mpv showed me that I was wrong:
So I have a USB audio class device that supports only 16Bit/48KHz signal. I confirmed that by checking the hardware parameters with
aplay -l. Windows also told me so.When I start
jackdon it with-r 44100, neither does it tell me that this rate can't be used with that device, nor does it report back the fact that it started the device with the only supported rate (48000):I once thought that maybe jack use libsamplerate or zita-resampler to resample the mix before sending it off to the device. But I read from an old issue that jack does not do that. Finally
mpvshowed me that I was wrong:So
jackddid open the device with the rate 48000. It just didn't tell me that.