shairport-sync/ADVANCED TOPICS/Events.md

Events

Shairport Sync can run programs when certain "events" occur. The events are:

1. When Shairport Sync become active or inactive. Shairport Sync is normally in the inactive state when no audio is being played. When audio is sent to Shairport Sync, it will transition from inactive to active. When the audio stops, Shairport Sync will start a timer. If audio restarts before the timer reaches the value of the active_state_timeout configuration setting (10 seconds by default), Shairport Sync will stay active. However, if no more audio is received before the timer reaches the active_state_timeout value, Shairport Sync will transition to inactive. The overall effect of this is that Shairport Sync will go active when a track is played and will stay active in the interval between tracks, so long as the interval is less than the active_state_timeout. Shairport Sync can call an external program when it goes active and inactive.

2. When audio begins to play.

3. When audio stops playing.

4. When the volume is adjusted.

just before it starts to play an audio stream and just after it finishes. You specify them using the sessioncontrol group settings run_this_before_play_begins and run_this_after_play_ends. This is to facilitate situations where something has to be done before and after playing, e.g. switching on an amplifier beforehand and switching it off afterwards. Set the wait_for_completion value to "yes" for Shairport Sync to wait until the respective commands have been completed before continuing.

Note that the full path to the programs must be specified, and script files will not be executed unless they are marked as executable and have the appropriate shebang #!/bin/... as the first line. (This behaviour may be different from other Shairports.)

Shairport Sync can run a program whenever the volume is set or changed. You specify it using the general group setting run_this_when_volume_changes. This is to facilitate situations where something has to be done when the volume changes, e.g. adjust an external mixer value. Set the wait_for_completion value to "yes" for Shairport Sync to wait until the command has been completed before continuing. Again, please note that the full path to the program must be specified, and script files will not be executed unless they are marked as executable and have the appropriate shebang #!/bin/... as the first line.