Treasured's Movie Repair Guide -- Audio Video sync strategies

Achieving a good synchronization of audio and video is one of the most challenging aspect of movie repairs.


The problems can be classified in 4 grand categories:

  1. Audio and Video are stored in separate blocks
  2. Audio blocks are difficult to identify. There is a small percentage of errors.
  3. Video frames do not all have the same duration
  4. Contiguous Audio and Video blocks can correspond to very different times. The difference varies randomly.


In the best case, for example a DV stream, none of those problems is present, since audio and video are synchronized right into the stream: each DV frame contains both audio and video.


When repairing through the Movie Repair Service, we try to achieve audio/video sync through automated methods, as described below. We can find many combinations of problems, from easy to very difficult:



Sometimes, some manual correction must be applied: See how to correct audio sync.