Vegas handles MP4 file OK in V19, but not in VP21 or VP22

cbrillow wrote on 6/21/2025, 7:59 PM

I have an issue where Vegas is decoding and displaying an MP4 file correctly in 19, but not in 21 or 22. (I didn't upgrade to 20)

This anomaly appears in the preview window and is also encoded into rendered files. I've done a screen capture that illustrates the problem, as seen in the following link:

https://drive.google.com/file/d/1ZXnrmzoMmgkPlTR_18_FA2HxDjt7honu/view?usp=sharing

In the video, the same Vegas project is open in all three versions, with the same area looped 3 times and displayed in the preview window. The first set is shown in VP19, the second is VP21 and the third, VP22.

I've looked at a lot of the Preferences, with respect to video devices, and such, and they seem to be the same in all 3 versions. (I didn't compare every setting in every category.)

If anyone has an idea what could be causing this and/or suggestions on how to fix it, I'd appreciate it very much. I'm more than willing to supply more information, if requested.

Comments

Gid wrote on 6/21/2025, 8:06 PM

@cbrillow Try turning on Legacy AVC in Preferences - File IO.

You can upload pictures & video on here using the arrow button next to the smiley at the top of a new comment,

RogerS wrote on 6/21/2025, 8:14 PM

Could you share a link to download the actual media for testing?

cbrillow wrote on 6/21/2025, 8:46 PM

Thank you for the quick - and helpful! - response. I checked all 3 versions and it was turned off on all 3! VP19 had Experimental HEVC turned on, though. I kinda remember doing that several years ago,

They must've made some change in this area after 19, which I used for my last major project in the fall of 2202.

Obviously, I don't do a lot of work with Vegas these days. But I built a new computer last year and decided it was time for a lot of software upgrades, too, and I'm just starting to use them.

RogerS wrote on 6/21/2025, 8:50 PM

VP 21 build 300 and newer have a new decoder so the meaning of the checkboxes have changed. It would still be good to get VP 22 working- if you can provide a sample of the media (same format, short is fine) we can test it.

Gid wrote on 6/21/2025, 8:55 PM

@cbrillow In VP21 build (300) they introduced mxcompoundplug, turning Legacy AVC on makes VP use the former so4compoundplug (I'd have to restart VP to check that name but can't right now).

@RogerS or someone else would be able to explain what n why this is better than me.

Right click the event Properties, this is with Legacy AVC Off/unticked

cbrillow wrote on 6/21/2025, 9:42 PM

VP 21 build 300 and newer have a new decoder so the meaning of the checkboxes have changed. It would still be good to get VP 22 working- if you can provide a sample of the media (same format, short is fine) we can test it.

Well, 21 and 22 are working with the Legacy AVC Decoder enabled. Do you mean to get 22 working without having this function enabled? Is that even possible? If you still want a sample, I'll provide one tomorrow.