Since I installed Kdenlive video editor in my laptop I couldn’ t render videos to H.264 and other formats with different codecs. After reading countless forums, uninstall and reinstall Kdenlive and ffmpeg from Debian and Debian-Multimedia’s repositories with the same results, I tried the option Settings > Run Config Wizard and I found out that the MLT engine was out of date.
MTL is a multimedia framework used by Kdenlive to transcode videos. If you need to upgrade it follow these steps:
aptitude purge libmlt++3
This will remove MTL completely and everything that depends on it, like Kdenlive. Then you must type this:
aptitude clean aptitude update aptitude install kdenlive
Once you have done this the wizard should show MTL upgraded, and the render file option will be available.