I am currently editing a recording of a musical - one wide cam and one close cam following the action. Both cameras and the audio are sync'd up properly in Premiere on the timeline (1920x1080 29.97), but when I export the video (using h.264 - match source - high bitrate) the first 3-5mins or so of the export are out of sync by about a second and then it fixes itself for the rest of the almost 2hr video.
Any ideas on how to fix this issue / what the problem might be? Let me know if you need more specifics.
Sorry about this. I would make absolutely sure that the Computer you are playing the file on has enough power to do so. It may be that your hard drive might be too slow or your video card, CPU, or both are not powerful enough to playback a 2 hour Long GOP H.264/HEVC file. I don't know anything about your system though. Can you give us any details?
There's also the possibilty that the source footage might contain a variable frame rate—if so, this kind of problem can arise. Which cameras were used to shoot this event?