glitches with mixed 24p/23.976p

Former user wrote on 6/7/2020, 7:59 PM

I have original UHD footage that is either in true 24p film .MOV files created by JVC GY LS-300 which has true 24p (vs. 23.976), or 23.976 p .MP4 files from some other cameras. I have been getting pixelated glitches when rendering to any format except still image sequences. I know it is not in the original as I've examined the same spots and they are clean, so it is being generated by Vegas probably because of the differing frame rates (?) I have the project properties set for 23.976p and disable resample. I was going to render to jpg sequences, then render back to .mov intermediate, which works, but that is incredibly awkward and laborious! Is there an easier solution???

Comments

Musicvid wrote on 6/7/2020, 8:27 PM

I don't believe the common nomenclature discrepancy is responsible for your glitches. The product page for your camera says it is not true 30p, but NTSC.

http://pro.jvc.com/prof/attributes/specs.jsp?model_id=MDL102318&feature_id=03

Former user wrote on 6/7/2020, 8:39 PM

I have two of these cameras, and have been using them for the last three years. and so I am quite familiar with them. This was on a feature film project, and it was 24p - not 30p.

Also, the camera allows one to select between 24p, or 23.976p in its menu. This obviously indicates there is a difference. So it is true film 24p. Also looking at the media in Vegas it clearly states 24p on these files, but 23.976 on the others. So I am not doing the common mistake of thinking 23.976 is 24p. However I did make the mistake of using true 24p on this film. These are the only project files I have this problem with in Vegas.

Musicvid wrote on 6/8/2020, 12:17 AM

Regardless, the very worst thing that could happen in Vegas (and you can type in 24.000 if you want), is that it would dupe, drop, or blend one out of every 1001 frames.

If that's what you're seeing momentarily once every 41.7 seconds of video, I'd be hard pressed to call it a glitch. Like I said though, you can type in the numbers, but usually just turning off Resampling is enough to keep it out of my way.

If you can upload a screenshot of your glitch and your MediaInfo properties, it will help us to help you. Experiment.

https://www.vegascreativesoftware.info/us/forum/faq-how-to-post-mediainfo-and-vegas-pro-file-properties--104561/

 

3POINT wrote on 6/8/2020, 12:26 AM

Leave your project settings at 23,976p and import your 24p media at project framerate to the timeline. Doing this by rightmousebutton clicking 24p media in project media folder and select "add at project framerate". ( no need to disable resampling). Here in my example I import 25p media into a 23,976p project.

Last changed by 3POINT on 6/8/2020, 12:30 AM, changed a total of 1 times.

3POINT, Theo Houben, Vegasuser since version 5 and co-founder and moderator of the Dutch Vegasforum https://vegasvideoforum.nl/index.php

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john_dennis wrote on 6/8/2020, 2:59 AM

If you've already added your clips to the project:

  •  "add at project frame rate" as 3 POINT suggests in a new project at the delivery frame rate.
  • Save the new project as clipname.veg
  • Replace the clips in your main project with clipname.veg
  • Repeat for all clips with frame rate not equal to your delivery frame rate.

You will likely have to tweak the clips in the main project because of the length difference, but you won't have to redo the whole project.

Former user wrote on 6/8/2020, 7:20 AM

Hey, thanks a lot guys - I will give that a try.

Former user wrote on 6/9/2020, 9:16 PM

None of these solutions worked very well. I rendered to jpeg stills at the same UHD resolution, then rendered to .mov and it is fine. One way to deal with problems due to differing frame rates - simply create a separate still for each frame. What a concept. Like film. Remember that? Since I am at a resolution way higher than the delivery format it doesn't matter if there was another layer of codec that one has to cater to.

 

By the way - the JVC GY LS-300 has frame rates that are both 23.976, and 24.000p, selectable. Vegas recognizes the difference as well as the camera menu. And so the information posted here by the first response stating it does not have those frame rates is completely wrong.

john_dennis wrote on 6/9/2020, 9:30 PM

@Former user

“... simply create a still from each frame...”

I’ve described this in the past as the “nuclear option”.

https://www.vegascreativesoftware.info/us/forum/24p-to-25p--99136/#ca605760

EricLNZ wrote on 6/9/2020, 11:32 PM

I'm surprised that 3POINT's suggestion didn't work for you. It suggests that differing framerates may not be the cause of your problem?

3POINT wrote on 6/9/2020, 11:54 PM

I'm surprised that 3POINT's suggestion didn't work for you. It suggests that differing framerates may not be the cause of your problem?

Me too, because this is exactly the same as what you get with the "creating separate stills" method. Only that the last method also only needs an extra audio treatment.

Former user wrote on 6/10/2020, 12:22 AM

Thanks for the suggestion, it may have worked. It was going to play back the clips at .999 playback speed. But I just decided to use the stills because I had done that in an animation project recently and it was a perfect way of making some varying video clips all at different frame rates match animation still sequences, so I got used to doing it.

Former user wrote on 6/13/2020, 10:55 AM

I thought I would add I found a solution through trial and error for this problem. None of these worked (though thanks anyway for the suggestions):

conform clip to project frame rate (glitches still there)

render to stills then re-render to video (glitches still there)

change overall project frame rate (all cuts are messed up)

What DID work I found accidentally: in checking the original video clips to see if they had glitches to begin with (which they did not) I opened a new project which auto-conformed to the clip. So the overall project frame rate was the same as the clip - 24.000. I thought of re-rendering the 24.000 clips there to 23.976 clips. That works. Those clips then import into the 23.976 project files with no glitches or editing problems.

 

3POINT wrote on 6/13/2020, 11:32 AM

Makes no sense at all. Rendering 24fps in a 24fps project to 23.976fps is the same as putting 24fps in a 23.976fps project.

At the moment I'm wondering what kind of glitches you have seen. Probably the jumps you get when disabling resampling.

Former user wrote on 6/13/2020, 12:18 PM

No, disabling or enabling resampling had no effect. Also they were not "jumps" - they were distorted pixelated areas of the image. And when the clip was made to conform to project frame rate -resulting in a playback rate of .999 it had the EXACT SAME glitch. Also - I have absolutely none of these glitches in any other project including another feature film. It only happened after combining these fractionally differing frame rates which of course I won't be doing again.