When setting delay, audio output flushing and picture drops can happen and lead to unpleasant result, like stuttering, on both outputs.
Since the delay was set by an input command, demux could send a bit of data to play before the delay was really applied, leading to this effect even when starting the playback.
This commit alone doesn't fix the issue, but it ensures that delay is synchronously set before the start of the input when it's not running yet, mimicking the other input methods allowing to apply a control synchronously when the input is not yet running.
Refs #27918
Co-authored-by: Thomas Guillem thomas@gllm.fr
VideoLAN code repository instance