alsa_loopback - loop back the first two channels of a alsa device to another device

playdev
              ALSA playback device (e.g.: hw:0)

       captdev
              ALSA capture device (e.g.: hw:0)

       fsamp  Sample rate (e.g.: 48000)

       frsize Period size (e.g.: 256)

       nfrags Number of fragments (e.g.: 2)

       zita-alsa-pcmi was written by Fons Adriaensen <fons@linuxaudio.org>.

       This manual page was written by IOhannes m zmoelnig <zmoelnig@iem.at> for the Debian project (but may  be
       used by others).

                                                    July 2013                                  zita-alsa-pcmi(1)

       This tool is mainly for testing whether a given soundcard works with the zita-alsa-pcmi library.  It will
       send  the  1st  two  channels  of  the  given  capture device to the playback device, using the specified
       settings.

       Note, that this might give massive (ear and equipment  damaging)  feedback  if  your  capture  device  is
       connected to a microphone near some speakers connected to the playback device.

       This  will  loopback  the  1st two channels of hw:0 to hw:1 using 48kHz samplerate, and 10 fragments each
       2048 samples.
         alsa_loopback hw:0 hw:1 48000 2048 10

       alsa_loopback - loop back the first two channels of a alsa device to another device

alsa_loopback playdev captdev fsamp frsize nfrags