tap property
Per-filter PCM tap — emits PcmFrames captured at the chosen
TapSide of filter's slot in the af chain. Use
TapSide.pre for "input signal" overlays, TapSide.post for
"output signal" overlays in a per-filter editor.
The tap is lazy: the engine activates the matching hook in
the audio chain only while at least one listener is attached,
and tears down on the last cancel. Multiple subscribers to the
same (filter, side) share a single underlying tap.
filter is one of the typed AudioEffect values — the same
86 filters surfaced as *Settings fields on AudioEffects, so
every reachable filter is named at compile time. Live streams
without an active af chain emit no frames; the stream is silent
(no error) when the loaded libmpv does not expose the
filter-tap property.
Implementation
final Stream<PcmFrame> Function(
AudioEffect filter, {
required TapSide side,
}) tap;