sudo apt-get install qt5-default libopenjp2-7-dev libpulse-dev libv4l-dev libasound2-dev libgtk-3-dev libfftw3-dev
sudo apt-get install hamlib-dev
sudo apt-get install pavucontrol
sudo apt-get install qsstv
# start qsstv
qsstv
# load a PulseAudio model called ” module-null-sink” and name it virtual-cable.return pactl model ID.
pactl load-module module-null-sink sink_name=virtual-cable
# start pavucontrol
pavucontrol
qsstv->Options->Configration->Sound->PulseAudio
pavucontrol->Recoring->Monitor of Null Output & All Streams
# play video
paplay -d virtual-cable youraudiofile.wav