Audio Out Of Sync

AlanDogg wrote on 7/21/2017, 1:37 AM

Hi,
I have been creating a music video over the last month or so with help from all you guys in the forum and all has been great, I have been using the music video audio demo and yesterday I recieved the audio master which I have placed beside the original demo audio and lined them both up ( IE bang on sync with each other) I have muted the demo and have the new audio working great and in time with the video, However when I render the video the audio is slightly out of sync. Any ideas to what the issue may be?

Comments

Marco. wrote on 7/21/2017, 3:37 AM

Which version of Vegas Pro do you use and which build?

How about your render settings?

Is the "out of synch" static (same amount from first to last second) or is there a drift where it starts synchroniously and getting smoothly out of synch more and more?

AlanDogg wrote on 7/22/2017, 9:51 AM

Hi Marco,
Thanks for the reply. Details are as below

Vegas Pro Version 13 build 453
Render as MP4 XAVCS S Long 3840x2160-25
Yeah its static with audio lagging video

rraud wrote on 7/22/2017, 11:10 AM

Have you tried different players? Some players choke on hi res files or have issues with some codecs. Try a lower res render and/or a different codec.

 

Marco. wrote on 7/22/2017, 11:49 AM

I made a test render and at least in the rendered file the audio stream isn't shifted.

So either try what rraud suggested because maybe the player or the system you used just isn't as powerful enough for a good QFHD playback. Or try remuxing the rendered MP4 file.

rraud wrote on 7/22/2017, 12:13 PM

Yes, I was going to suggest muxing the components together. Typically, I render the A/V separately, Audio to a PCM (.wav) format for surgical clean ups and mastering (if needed), then encode to AAC (.m4a) using the Nero AAC encoder (@ 320kbs CBR) and mux the components w/ MeGUI.

AlanDogg wrote on 7/22/2017, 12:43 PM

Thanks guys but im a little confused as the original demo track worked fine in both playback and same with full render, The audio track is the only thing thats changed so surely player & codecs shouldnt be the issue? I have had a close look at both files which are wav but did notice the original demo was 24bit while the new master file is 16bit could that be the issue?

Marco. wrote on 7/22/2017, 1:34 PM

I tried to repro with a 24 bit source file. But again the rendered (16 bit) output file looks like being fine in synch, regarding the timing of the audio stream.

"The audio track is the only thing thats changed so surely player & codecs shouldnt be the issue?"

Do you mean you tested other render versions and these rendered ones were fine or did you just compare unrendered versions against that one out-of-synch rendered file?

AlanDogg wrote on 7/22/2017, 4:05 PM
 

Do you mean you tested other render versions and these rendered ones were fine or did you just compare unrendered versions against that one out-of-synch rendered file?

I have only got the 1 video I have been working on with this new pc build. I have rendered many versions as the video has progressed with the original demo 24 bit version. It has never been out of sync and the pc is only used for video editing. Nothing has changed IE no updates, no new programs etc etc. I added the new song version and synced it to the demo version and have muted the demo. everything is still the same and rendered in the same way with same players and previews are all fine except now when the new version is rendered using the new 16 bit audio the audio is slightly ahead of the video.