I'm not sure what I did wrong, but for some reason when I render my video's, the result is just terrible. pixelated, blocky and just not watchable in the current quality.

But a few months ago, everything was still working fine. I'm using the latest release of kdenlive on a fully up to date arch-linux-lts system. Was there some update with kdenlive that requires a fix now?

mlt 6.20
kdenlive 20.04.3

I'm also getting this error with mp4 and mp3
Unsupported video codec: libx264
I mainly render in WebM so this isn't that big of an issue.


I recently switched from AMD gpu to a Nvidia gpu, does this have anything to do with this problem?

EDIT: When I put a rendering profile as favorite, the errors of missing codec for mp4 suddenly disappear. This must really be a bug I think, still, doesn't fix the bad rendering quality in both mp4 and webm :/

I recently ran into a similar problem in Slackware64-current + Plasma5.

It appeared after Slackware updated ffmpeg to 4.3.X (previously 4.2). The problem was not with kdenlive, but mlt which needed to be re-compiled against the new ffmpeg. However, be warned that mlt needs patching to build against qt-5.15 (patch on github).

Once mlt was recompiled, x264 and x265 re-appeared along with VP9 and mp3. Your mileage may vary depending on what codecs you have installed.

Hope this helps!

--
Pete