snd_uaudio monitor recording

[Hans Petter Selasky]

On 07/26/17 18:18, Marcel Bonnet wrote:
> On 25 July 2017 at 14:18, Hans Petter Selasky <hps at selasky.org> wrote:
>>
>> On 07/25/17 17:00, Marcel Bonnet wrote:
>>>
>>> Hi.
>>>
>>> I'd like to record to a file whatever the sound card is actually playing,
>>> essentially when I am not using jackd server.
>>> I don't know if I just did not figure how to do it, or if depends on a new
>>> driver functionality ?
>>> Thanks in advance,
>>>
>>
>> You'd need to use virtual_oss to do that.
> Thanks. But, I didn't understand how to use it. Can you help me, please?
> 
> I tried an example from the man page (I changed the sample rate,
> because my USB Fast Track Pro is set to 44100 Hz):
> 
> [@machine tmp]$  virtual_oss -C 2 -c 2 -r 44100 -b 16 -s 1024 -f
> /dev/dsp3.0 -w dsp.wav -d dsp
>                           hw.snd.basename_clone: 1
> sysctl: hw.snd.basename_clone=0: Operation not permitted
> virtual_oss: Could not create CUSE DSP device
> 
> So, I tried with sudo:
> 
> [@machine tmp]$  sudo  virtual_oss -C 2 -c 2 -r 44100 -b 16 -s 1024 -f
> /dev/dsp3.0 -w dsp.wav -d dsp
> hw.snd.basename_clone: 1 -> 0
> virtual_oss: Could not open DSP device '/dev/dsp3.0': Device busy
> virtual_oss: Could not open DSP device '/dev/dsp3.0': Device busy
> virtual_oss: Could not open DSP device '/dev/dsp3.0': Device busy
> virtual_oss: Could not open DSP device '/dev/dsp3.0': Device busy
> virtual_oss: Could not open DSP device '/dev/dsp3.0': Device busy
> virtual_oss: Could not open DSP device '/dev/dsp3.0': Device busy
> virtual_oss: Could not open DSP device '/dev/dsp3.0': Device busy
> virtual_oss: Could not open DSP device '/dev/dsp3.0': Device busy
> virtual_oss: Could not open DSP device '/dev/dsp3.0': Device busy
> virtual_oss: Could not open DSP device '/dev/dsp3.0': Device busy
> virtual_oss: Could not open DSP device '/dev/dsp3.0': Device busy
> virtual_oss: Could not open DSP device '/dev/dsp3.0': Device busy
> virtual_oss: Could not open DSP device '/dev/dsp3.0': Device busy
> virtual_oss: Could not open DSP device '/dev/dsp3.0': Device busy
> 
> I never know why I have so much /dev/dsp3.x units. When using jack
> server, I always attach to the first one (3.0) and it is ok. I tried
> the other 3.x units, with no success.
> 
> Thanks in advance.
> 
> My environment:
> 
> [@machine tmp]$  ls /dev/dsp* ; cat /dev/sndstat ; sysctl hw.snd.default_unit
> 
> /dev/dsp0.1  /dev/dsp1.1  /dev/dsp2.1  /dev/dsp3.0  /dev/dsp3.1
> /dev/dsp3.2  /dev/dsp3.3
> 
> FreeBSD Audio Driver (64bit 2009061500/amd64)
> Installed devices:
> pcm0: <Realtek ALC269 (Analog)> on hdaa0  (1p:2v/1r:1v)
> pcm1: <Realtek ALC269 (Analog)> on hdaa0  (1p:1v/1r:1v)
> pcm2: <Intel Panther Point (HDMI/DP 8ch)> on hdaa1  (1p:1v/0r:0v)
> pcm3: <USB audio> at ? kld snd_uaudio (1p:2v/1r:1v) default
> No devices installed from userspace.
> 
> hw.snd.default_unit: 3
> 
> [@machine tmp]$  sysctl dev.pcm.3
> dev.pcm.3.feedback_rate: 0
> dev.pcm.3.bitperfect: 0
> dev.pcm.3.buffersize: 0
> dev.pcm.3.rec.vchanformat: s16le:2.0
> dev.pcm.3.rec.vchanrate: 44100
> dev.pcm.3.rec.vchanmode: fixed
> dev.pcm.3.rec.vchans: 1
> dev.pcm.3.play.vchanformat: s16le:2.0
> dev.pcm.3.play.vchanrate: 44100
> dev.pcm.3.play.vchanmode: fixed
> dev.pcm.3.play.vchans: 2
> dev.pcm.3.hwvol_mixer: vol
> dev.pcm.3.hwvol_step: 5
> dev.pcm.3.%parent: uaudio0
> dev.pcm.3.%pnpinfo:
> dev.pcm.3.%location:
> dev.pcm.3.%driver: pcm
> dev.pcm.3.%desc: USB audio
>>
>> --HPS
> 

Hi,

Try this:

sudo virtual_oss -S -C 2 -c 2 -r 44100 -b 16 -s 1024 \
   -f /dev/dsp3 -d dsp -w dsp.rec.wav -l dsp.rec


Then either:

dd if=/dev/dsp.rec.wav of=myfile.wav bs=1024

Or use a program like audacity (not sox, due to reading one and one 
sample) to record from /dev/dsp.rec .

--HPS