Audio Sync - Drift Early
Audio sync with video becomes progressively earlier throughout program. For example, the audio is in sync at the beginning, 2-seconds early in middle, 5-seconds early by end).
This issue can be caused by conforming the audio to a video master that runs at a framerate different than the video that we hold.
For example, the video we have is 23.98fps (the videos native framerate), but the secondary audio you have been supplied is conformed to a 25fps master that was used/distributed to a PAL territory.
When processing Secondary Audio assets for Netflix always ensure that the final checks for sync are performed against the Netflix proxy that should be available within the Source Request on Backlot.
If the audio drifts early it is likely that you will have to perform a speed change and slow down the audio to bring it back in sync with the Netflix Proxy. Please note that doing so will reduce the pitch of the audio. If you are employing pitch correction ensure that no audio artifacts are introduced in the final deliverable.