Video and Audio Out of Sync

TheFireball100 wrote on 10/2/2015, 10:20 AM
Hi guys

I have always had a problem with Sony Vegas video and audio sync issues. When I have a separate audio and video source, they can be synced up perfectly to the sound waves, but when rendered are about 0.02 seconds off or so. Sometimes more. I know this sounds silly, but believe me, it's noticeable in my music videos. I play the guitar and the audio is slightly behind from when I plucked the string. This can happen with any separate audio sources other than in camera when I talking into a mic. I am rendering to MP4. What am I doing wrong? Please help.

I have always had to pull the audio back a little to compensate but it's not always working, especially for YouTube uploading with their compression rate. I need it in perfect sync.


musicvid10 wrote on 10/2/2015, 11:17 PM
What player(s) are you using?
What are the MediaInfo properties for your rendered files?
On what browser(s) are you viewing youtube?
What are your system specs?

Sync in the mp4 wrapper is not an exact science. We can only aim for an average that will work on most players. The sync delay can be tweaked in a utility such as Mp4Box. The sync is rarely the same on YouTube as on local machine playback.

TheFireball100 wrote on 10/6/2015, 9:50 AM
Using Windows Media Player.

Media Info of rendered video:
Data rate - 12395kbps
total bit rate - 12588kbps
frame rate - 24
audio is 192kbps at 44kHz

Using Chrome.

My system is an i7-4700MQ Quad core 2.4GHz.
RAM is 8 GB on a 64 bit system. Win 7.

So maybe people don't notice then. I guess only I do. I just don't know why it is not in sync when everything is lined up.

J. Bo wrote on 6/15/2016, 7:22 AM
Hi !

I think your problem is , that you are using 44kHz for audio. Its a normal problem.

Try using 48kHz for all audio, and you should be ok.


Fut2 wrote on 8/3/2016, 6:22 AM
What J.Bo said.
rraud wrote on 8/3/2016, 9:49 AM
Yes, typically 48kHz is the audio sample rate for video.. and sync issues often arise when audio is 44.1kHz.. though Vegas can have different sample rate audio events on the same timeline and/or track w/o issue.
musicvid10 wrote on 8/5/2016, 10:32 PM
3 things I can see that may contribute to your sync issue:

Overall bitrate is quite high - players lose sync when frames are dropped.
VBR audio perhaps?
Possibly sample rate as proposed.

MediaInfo is a utility that provides detailed information about your file.
You download it from Sourceforge, but take care not to install extra software.