Re: tee-like function via virtual_oss

From: Hans Petter Selasky <hps_at_selasky.org>
Date: Sun, 03 Oct 2021 19:24:19 UTC
On 10/3/21 9:18 PM, Hans Petter Selasky wrote:
> On 10/3/21 5:47 PM, J P wrote:
>> Hi,
>> I need to record what is being played back from a play-only device:
>> pcm0: <ATI R6xx (HDMI)> (play) default
>>
>> I thought that virtual_oss might come at hand for this and function in a
>> "tee-like" fashion but I am unable to have it work.
>>
>> My config is as follows:
>> -T /dev/sndstat -C 2 -c 2 -r 48000 -b 24 -s 8.0ms -f /dev/null -d dsp5 -M
>> x,0,5,0,0,0
>>
>> What am I doing wrong?
>>
>> It seems that this configuration connects the input of dsp5 to the output
>> of dsp0, but I actually need the other way around.
>>
>> Thank you.
> 
> Hi,
> 
> Try this:
> 
> virtual_oss -T /dev/sndstat -C 2 -c 2 -r 48000 -b 24 -s 8.0ms -R 
> /dev/null -P /dev/dsp0 -d dsp9 -M x,0,0,0,0,0 -M x,1,1,0,0,0
> 
> You need two monitor filters, one for each channel.
> 
> --HPS
> 

Hi,

Maybe you want to add the -S option too, to support re-sampling.

Anyway, if you want the default audio device to behave like this, that 
what you play back can instantly be recorded, then replace "-d dsp9" 
with just "-d dsp".

--HPS