Should I render 59.94fps video at 60.00fps?

[porina]

My old problem has come back to haunt me.

 

I use Vegas 19 now. Source video is UHD 59.94fps, timeline set to same. I had a problem with an older version where sometimes it seems to skip frames in the rendered output. Moving to my current version seemed to resolve it, until it didn't. In a video I just made, I noticed an area looking "low fps" and if I advance one frame at a time, I can see for every 3 display frames, the 3rd one is a copy of the 2nd. The source file does not do that, and if I go frame by frame on my timeline it is fine too. That's the part I don't understand. Deinterlacing and resampling (frame rate adjustment) are explicitly turned off.

 

I tried messing around with various settings and what seemed to fix it, in that specific area at least, was to render that 59.94 timeline into 60.00 output. Of course, that is a slight mismatch in frame rates so I'm missing one every 2000, which is over half an hour. Longer than my video. I'm doing a full render of it now to see how it compares to the 59.94fps version I had the problem with.

 

So basically checking if this is a good idea. I haven't tried setting the timeline to 60fps, if that would be a good idea or not.

[Orbital_Aurora]

Have you done a mediainfo on your rendered and source media ? Maybe that could give a clue...

 

It's definitely not normal behaviour, and as a rule of thumb I would render media at the same frame rate as the timeline Wich should be the same as the source

 

Does it do that in a specific codec or in multiple ?

[porina]

7 minutes ago, Orbital_Aurora said:

Have you done a mediainfo on your rendered and source media ? Maybe that could give a clue...

I encountered a similar problem previously, where the source, timeline and render framerates were nominally identical yet I still had this problem. It seemed to go away when I updated to a newer version of Vegas and I didn't think of it again until it happened again recently. What I suspect might be happening are tiny variations in timing causing a mismatch in alignment somewhere. By ever so slightly increasing the output framerate it catches those variations. Like I said, the difference is like 1 frame in over 30 minutes so really insignificant.

 

7 minutes ago, Orbital_Aurora said:

Does it do that in a specific codec or in multiple ?

I mainly create for YouTube so only ever use H.264.

[Orbital_Aurora]

 Download media info and try it on both, and try a render in a different codec just for testing purposes when you have time.

 

Should at least narrow down where the issue comes from.

[porina]

5 minutes ago, Orbital_Aurora said:

 Download media info and try it on both, and try a render in a different codec just for testing purposes when you have time.

Source:

Frame rate mode                          : Constant
Frame rate                               : 59.940 (60000/1001) FPS
Original frame rate                      : 59.940 (59940/1000) FPS

 

Encoded version at 59.94 with stutter:

Frame rate mode                          : Constant
Frame rate                               : 59.940 (60000/1001) FPS

 

Encoded version at 60.00 without stutter:

Frame rate mode                          : Constant
Frame rate                               : 60.000 FPS

 

I'm not in a position to quickly re-render it right now with another codec. The source has two slightly different representations. Could that be it?