I can't render my video.. any ideas??
I have no clue which part of the video is crashing it..

Rendering of /home/Videos/untitled.mp4 crashed

[mp4 @ 0x7fea20200f00]
Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.
[mp4 @ 0x7fea20200f00]
Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.

the rendering is progressive... looking at progress bar you can (hopefully) find the clip that make the error.
if the rendering time is too high, switch to low quality rendering to speed up this thing... if the error is not appearing on low quality (this happens to me sometimes) try to switch to a different codec for final rendering.

you can also select a "ZONE" (rendering selection) to identify the clip.

P.S. on past i fixed this issue on a project moving clip alternatively from Track1 to Track2 (if these non have compositions)
https://invent.kde.org/kde/kdenlive/issues/189

are you using AUTO-MASK?

I seem to have fixed it. I had a composite and transform without having two clips on top of each other, and I also had a wipe that wiped into nothing, ..
Not sure if that should crash it but I fixed those two and it rendered..

But the rendering is insanely CPU intensive, and I'm using stills.. Pictures only. It worked much better when I had multiple videos. It makes no sense why stills would have worse performance. It feels as if it's re-sizing the image on every frame or something, even though the frames are identical.. it probably has no idea the image is identical for a good 10 seconds sometimes. The images are big, sometimes 6000pixels wide jpegs, so they have to be re-sized for sure.. but I would think it would do one resize and cache it (position and zoom) ..
It's using about 10GB of ram for a 2 minute video of only stills.. almost ran out of ram on my 12GB machine. Without closing all programs, it ran out and crashed the entire computer (Ubuntu), swap got filled completely too.