YouTube Audio-Video Sync Issues
If you’ve watched any of my recent YouTube videos (which most of you haven’t), you will have noticed a recurring problem with audio/video sync problems in which the video precedes the audio by nearly half a second. As a result the clips - despite the video quality - come across as severely disjointed and not very professional.
I haven’t been very happy about that and set out to locate the root cause of the problem. After a series of tests, each of which I’ve included below, I discovered it was all due to the codec I was using when making the recordings.
As a page in the YouTube support site entitled “The sound is out of sync on my video. How do I fix it?” indicates:
“Out-of-sync sound is usually the result of using an audio codec that our system doesn’t support. We’re always adding new ones, but if this happens to your video, you can try re-encoding it with a different audio compression. We recommend MP3 audio for best results.”
In the previous tests I had recorded the clips using the default QuickTime setting - Best (H.264). In the fourth test however I opted for the “Good (MPEG-4)” option to see if it improved things any. Lo and behold it did.
As a result I will now be able to start taking advantage of the better video quality I get from pre-recording clips prior to upload (rather than recording them directly to YouTube), while ensuring the audio and video are properly syncronised.
Changing the Settings:
To change the settings, go to QuickTime Player –> Preferences, select the recording tab and then choose Quality: Good (MPEG-4). You should then find the recordings created using this setting will play properly in YouTube.
Test Clips
In the interests of proper documentation, each of my 4 tests is included below:
Audio-Video Sync Issues Part 1 - Direct to YouTube
[youtube=http://www.youtube.com/watch?v=EbD8w3OcJ94]
Audio-Video Sync Issues Part 2 - MOV file upload
[youtube=http://www.youtube.com/watch?v=UwcKH8YhgFg]
Audio-Video Sync Issues Part 3 - Preliminary Findings
[youtube=http://www.youtube.com/watch?v=Vt7MTkJyMRU]
Audio-Video Sync Issues Part 4 - MOV upload (MPEG-4)
[youtube=http://www.youtube.com/watch?v=648tgmiu47I]
References:
- “The sound is out of sync on my video. How do I fix it?” YouTube Help Center, accessed 7 May 2008
May 9th, 2008 at 9:38 am
Why is video so freaking complicated? I think it is a conspiracy. Mpeg-4/DivX/Xvid is good enough for me - everyone should just use that from now on because I say so. (If you don’t like it then buy a smaller television like mine and you won’t notice a thing)
[Reply]
May 10th, 2008 at 8:48 pm
I guess the video guys I work with don’t call compression and post-production “the dark arts” for nothing. I tried getting one of them to explain codecs to me once and I thought my head was going to explode from information overload.
Truth be told, the workaround I’ve suggested above isn’t necessarily the best way to do it - I just personally think it’s the easiest.
The best way seems to be to suck in the content at the highest possible quality - in this case using the H.264 codec - then edit things and finally export to the final format before uploading.
For high quality stuff I think that’s definitely the way to go - especially when you’re using content that’s been planned, scripted and shot to good cameras. However in my case I’ll most likely be doing talking head shots straight to camera. So adjusting the recording quality in the QuickTime preferences is the quickest and least painful option.
Cheers,
Mike
[Reply]
May 13th, 2008 at 9:58 am
[...] movie, which is stored locally (in Movies/Vidnik) and then uploaded to YouTube. In light of my troubleshooting efforts late last week it’s conceivable that the issue lay with QuickTime rather than Vidnik, however this remains [...]