Playout Development & Testing

Testing with virtual audio devices

It is possible to do testing with purely virtual audio devices. This comes in handy if testing on hosts without any audio hardware is required. There are different options for virtual audio devices that can be enabled through the .env file of aura-playout. Setting them to 1 enables them, commenting them out or setting them to 0 disabled them.

AURA_ENGINE_VIRTUAL_OUTPUT

If enabled creates a pipewire null-audio-sink virtual_line_out_0 which is automatically linked to engine-cores output.

AURA_ENGINE_VIRTUAL_OUTPUT_LINK_AURA_RECORDER

If enabled links the virtual_line_out_0 to engine-recorder allowing purely virtual block recordings. This requires engine-recorder to use jack as source_format in engine-recorder.yaml. In addition pipewire needs to be enable for engine-recorder by using the pipewire docker-compose overwrite:

COMPOSE_FILE=docker-compose.yml:docker-compose.pipewire.yml

AURA_ENGINE_VIRTUAL_INPUTS

If enabled 5 virtual line-in pipewire null-audio-sinks virtual_line_in_0,1,2,3,4 are created and linked to engine-cores line-in channels. It is then possible to play audio to these line-in channels using pw-play --target virtual_line_in_0,1,2,3,4 or similar commands.

AURA_ENGINE_VIRTUAL_INPUTS_PLAY_TEST_AUDIO

If enabled test audio is played in a loop on each virtual line in. The audio is a voice saying “This is line-in X”.