uaudio0 -> audacity not recording

Russell L. Carter rcarter at
Wed Apr 22 20:34:45 UTC 2015

Hi Hans,

On 04/22/15 00:44, Hans Petter Selasky wrote:
> On 04/21/15 23:08, Russell L. Carter wrote:
>> Greetings,
>> I am going to take a stab at this again before giving up.
>> On 10/stable, I have a Behringer UCA202 that plays fine.


>> When I start up audacity, I see displayed:
>> OSS, /dev/dsp, 2(Stereo) Recording Channels, /dev/dsp
>> When I click on the monitor pane, I get level bars corresponding to
>> the monitor levels I'm hearing.  I hit the record button and I seem to
>> be seeing sensible record levels.  But when I hit the (re)play
>> button, I just hear a bunch of garbled noise, not very loud.  A
>> curiosity to me, but perhaps unimportant is that the audacity displays
>> /dev/dsp, but only /dev/dsp0.0 exists.
>> I build audacity using poudriere, and all options are set except
>> for lame and debug.
>> Could be a rookie mistake with audacity, or freebsd recording, or
>> something else.  Any ideas?  This setup works fine on linux.
> Hi,
> Are you running a -stable or -current kernel?

stable r281044

> Could you try to record using "sox", "play" and "rec" utilities instead?

Good idea:

rcarter at feyerabend> ls -lt /dev/dsp*
crw-rw-rw-  1 root  wheel  0xaf Apr 22 13:21 /dev/dsp0.0
rcarter at feyerabend> export AUDIODEV=/dev/dsp0.0
rcarter at feyerabend> rec  output.flac

Input File     : '/dev/dsp0.0' (ossdsp)
Channels       : 2
Sample Rate    : 48000
Precision      : 16-bit
Sample Encoding: 16-bit Signed Integer PCM

The cute little monitor line seems to be in sync with the audio I'm
hearing from the speakers being played through the UCA202.

On playback in play or mpv, I get the same sort of garbled noise,
not very loud, that I hear on playback in audacity.

There is no jackd or pulse, etc.  I'm trying to keep the setup
as simple as necessary.

It seems like I'm close...


> I have one of these audio adapters myself, and the problem is likely in
> the audio backend which audacity is using. See this PR for example,
> where hardcoded Linux OSS values are used:
> If you try to configure jackd to use 24-bit samples under FreeBSD you'll
> simply get a bunch of noise, because the wrong sample FMT is selected.
> --HPS

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