Waveform display and scrubbing bug with Sample Delay
The video from my camera is usually out of sync with the audio from my mic. It's generally around the same duration of delay, so I have made a preset using the Apple AUSampleDelay to apply to all my audio layers that have the sync issue.
But when I use this filter, the waveform display in the timeline shrinks as if it were getting quieter when in fact it should just be shifted in time. Eventually the waveform disappears altogether and, even weirder, the sound level when scrubbing also disappears. When I hit play, everything is still full volume, just delayed (as I need it to be)
Because I cannot see or hear the audio other than in real-time playback, I'm unable to sync it up accurately eg using a clapperboard. Syncing the audio accurately is of course the entire point of adding the delay.
This bug has been around since at least v9, I believe.
Steve Kirby said:
Eventually the waveform disappears altogether and, even weirder,
Thanks for reporting. It's a known issue and we're working on the fix. It happens with a number of audio filters. Investigation FLOW-11186