SUMMARY When trying to render to mp4, the UI claims that libx264 isn't available. When generating a mlt-script and hacking it, I can still render using libx264. STEPS TO REPRODUCE 1. Create video project 2. Select render 3. Attempt to render to mp4 OBSERVED RESULT "Unsupported video codec: libx264" EXPECTED RESULT No warnings or errors. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Debian testing, dist-upgraded today (available in About System) KDE Plasma Version: 5.17.5 KDE Frameworks Version: 5.70.0 Qt Version: 5.14.2 ADDITIONAL INFORMATION As mentioned, I can hack the mlt file and run it as a script, it just works. It would be nice to either have this fixed, or to being able to override this warning and just run melt even though kdenlive thinks there will be issues.
Please try with the current Kdenlive AppImage version 20.04.1b to see if there are any packaging issues https://files.kde.org/kdenlive/release/ If the problem/issue doesn't occur when using the AppImage, then it's your configuration or packaging.
It works after doing a dist-upgrade today (with the distro release). I suspect it has to do with the ffmpeg update made this week.