This forum is dedicated to basic help and support :
Ask here your questions about basic installation and usage of Mageia. For example you may post here all your questions about getting Mageia isos and installing it, configuring your printer, using your word processor etc.
Try to ask your questions in the right sub-forum with as much details as you can gather. the more precise the question will be, the more likely you are to get a useful answer
first : i've updated ffmpeg to tainted 5 days ago second: after a triple chek on kdenlive, cos you were saying that it must be ok, i finally found the webm rendering: it was not at the previous version's place, that's all. thanks anyway.