Audio Mark Fade Out

Fades the audio overlay out to silence over the specified duration at the end of its window, in seconds.

audio-mark-fade-out defaults to 0.0 (no fade-out). The fade is measured relative to the overlay’s window end (audio-mark-end or the output end if no end is set). A fade-out of 3 seconds means the overlay ramps to silence over the last 3 seconds of its window.

If the combined audio-mark-fade-in and fade-out durations would exceed the window length, each is clamped to half the window so the result is never silent throughout.

Each layer takes its own [N] suffix: audio-mark-fade-out[1]=2.