Quoting Hans Petter Selasky <h...@selasky.org> (from Sun, 8 Oct 2017 13:19:19 +0200):

On 10/08/17 12:56, Alexander Leidinger wrote:


attached are the config descriptors and the device dump of two uaudio devices. Both exhibit distorted audio output. It sounds a little bit like clipping / not feeding enough samples fast enough...

I played around with dev.pcm.2.bitperfect=1, dev.pcm.2.play.vchans=0, dev.pcm.2.play.vchanrate and hw.snd.latency=1...10.

At some point vchanrate doesn't work anymore, it always stays at 4.0 audio, even when trying to go back to 2.0. I have to usbconfig reset the device.

Sometimes (rarely) when playing around I get clear audio output, but when I try to reproduce it (going back to default value for the last sysctl setting and then going back again to the same setting again), the audio is distorted again.

To me it sounds like some kind of buffer is not big enough or the data is not delivered fast enough to the uaudio device. But this is a dual-socket system with:     CPU: Intel(R) Xeon(R) CPU           E5620  @ 2.40GHz (2133.36-MHz K8-class CPU)
    FreeBSD/SMP: Multiprocessor System Detected: 16 CPUs
    FreeBSD/SMP: 2 package(s) x 4 core(s) x 2 hardware threads
And while playing around with uaudio the system has a load of around 1, so I would expect CPU/RAM is not an issue here.


What version of FreeBSD is this?

current as of r323636

Try to enable hw.usb.uaudio.debug=16 during playback.

No such sysctl, only hw.usb.debug....
I did the hw.usb.debug=16, but no output in dmesg nor /var/log/console.log nor /var/log/messages, where do I need to look?


http://www.Leidinger.net alexan...@leidinger.net: PGP 0x8F31830F9F2772BF
http://www.FreeBSD.org    netch...@freebsd.org  : PGP 0x8F31830F9F2772BF

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