Vegas cannot render seamless audio loops, drops audio in final frames

NightHawkInLight wrote on 8/11/2023, 3:44 PM

FIXED! Changed encode mode on rendering from NV encoder to Mainconcept AVC and everything went smoothly.

I've shared a video of this issue in this post on reddit:

I'm using Vegas pro 19.

I've tried changing a number of settings in preferences/audio device to no avail. I've also tried dropping my project into a new timeline. I've also dragged the length of my audio to expand past the selected render area. No change. The error is not with my playback software, but also appears in social media playback and in Vegas itself if I drag the rendered clip back in.

I found another post from 8 years ago reporting the same issue with no resolution:

Anyone have a fix for this?



john_dennis wrote on 8/11/2023, 5:26 PM


  • Do you have Quantize to Frames turned on?
  • Does the audio end point land exactly at a frame boundary?
  • What is the project frame?
  • What is the frame rate of the render template?

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mark-y wrote on 8/11/2023, 5:33 PM

Using .mp4 AVC format for looping is a big problem. Depending on the Long-GOP encoder settings, anywhere from 1 to 4 frames will be dropped at the loop point before playback resumes. It seems reasonable the NVENC hardware encoder will be at the upper end of those figures. With Baseline Profile ( no B-Frames, no CABAC, Web Optimized enabled), the drop can be reduced to one frame, which many people won't notice.

The only 100% seamless solution I know of is to record your loops in an Intraframe format, such as AVI / PCM. Or do it all in HTML5, which limits your delivery options.

Here's an old Tip on the topic:

fr0sty wrote on 8/11/2023, 5:39 PM

FIXED! Changed encode mode on rendering from NV encoder to Mainconcept AVC and everything went smoothly.

Reposting in the form of a reply so that I can mark it as a solution.