Last 5 years of my 7 years Linux experience I was regularly challenged by day-to-day video editing tasks. Main content was 720p/1080i/1080p in ts/m2ts/mp4/mov. The most useful instruments that produced a really nice results was combination of avidemux, kdenlive and VirtualDub (under Wine). As per my experience you are able to get excellent results with those tools but the problem is workflow really uncertain and not stable sometimes. Lack of features also has place. But the situation changes. Right now Kdenlive project is really nice. It has tons of features and stable enough for relatively serious editing/finishing. I am sure this won’t be too hard for any person interested to learn Kdenlive workflow. Otherwise this person is too lazy for Linux in general. You may find plenty of video lessons on ytube/vimeo.
Pierre, did you not see the mention of Blender??? It is GREAT for doing video. Yes, you do have to learn it but you want to do a good job right?? One thing to note. It is best in blender to turn the movie into a series of stills in the openEXR format. It is also important to go into settings and increase the buffer memory so that you get a much faster response as it loads much more movie at one time. Make sure to render the firm into its own director or you will have a LOT of picture files cluttering some other directory! Also more Ram mean better responsiveness and having a SSD drive is also a GREAT benefit. I would think this is true of any system.
Vidnami is an online video creator software (application) that helps you create fast, easy and professional-looking videos within minutes. It allows you to insert articles into the software and it automatically creates a good-looking video using the text from the article you inserted. It can also add great images, video backgrounds and even text to speech voices.