This is an ALSA-specific attempt to remove the annoying low-level clicking sounds that some output devices make just when they start processing audio and sometimes when they stop. Typically a faint click might be heard just before a play session starts or just before audio resumes after a pause. Similarly, a faint click can sometimes be heard just after a play session ends.
-It is extremely difficuly to remove these clicks completely from the hardware, so this new feature ensures that — once Shairport Sync has started — the output device avoids situations where these clicks might be generated by *always* playing audio. To accomplish this, if Shairport Sync isn't actually playing anything, audio frames consisting of silence are sent to the output device. Apart from the initial startup transition, the output device never stops playing, avoiding both starting and stopping transitions.
+It is extremely difficult to remove these clicks completely from the hardware, so this new feature ensures that — once Shairport Sync has started — the output device avoids situations where these clicks might be generated by *always* playing audio. To accomplish this, if Shairport Sync isn't actually playing anything, audio frames consisting of silence are sent to the output device. Apart from the initial startup transition, the output device never stops playing, avoiding both starting and stopping transitions.
To enable this feature, a new `alsa` group setting with the name `disable_standby_mode` is available. (If you do a full `$ sudo make install`, a new sample configuration file with this setting in it is installed at `/etc/shairport-sync.conf.sample` or `/usr/local/etc/shairport-sync.conf.sample`.) The default for the setting is `"no"`.