A Fix For YouTube’s A/V De-Sync Bug

Recently I uploaded some footage to video sharing giant YouTube.com. Once uploaded, I found that, due to the video to flash conversion, the audio / visual sync was out.

When uploaded, YouTube takes the submitted video and transcodes it - it decodes the original data into raw format, and then re-encodes it into Flash Video Format (FLV). During this process, the loss in A/V sync becomes apparent. A symptom that has been experienced many times by YouTube users. Whilst there are ideas around to fix the fault from the flash side, they don’t prove useful for fixing the bug when submitting media to YouTube.

My original video was ripped from a DVD VOB file (a recording using a Sony DVD Recorder) and exported via Adobe Premiere as an MPEG-1, with a single video and single audio track. As mentioned, once uploaded, the A/V was found to be out of sync.

To correct the problem I took the MPEG-1 format video, and ran it through a number of conversions, with which I had no luck. My salvation came soon with Windows Movie Maker. Whilst not a favourite application of mine, I imported the MPEG-1 video into the Microsoft application, checked the A/V sync was intact, then exported the video as a Windows Media Video (WMV) file. After checking the A/V sync again, I uploaded the new video format to YouTube.

The process took a little longer then the previous attempts, but after about 20 minutes the video was ready for streaming. Loading the URL, I watched the video through and found that the A/V was once again in perfect synchronisation.

I’ve posted this in case anyone else should find any sync problems with Video - FLV conversions, in the hope that, given a try, might fix them.