Hi all,

Running a performance Dell laptop with Ubuntu 16.04 and Kdenlive. never got the GPU support working and a few days ago something broke Kdenlive (crashed by just starting) and I had to reinstall/compile MLT etc to get it running again.

I'm planning to re-install my computer with a fresh distribution. Does 17.04 normally enable GPU support when installed? Are there any other distros that comes with the GPU support without all the extra work?

Hello,
As long as Movit is packaged by the distro & MLT built with it, it should be available in Kdenlive (I believe it is the case in Debian/Ubuntu/OpenSuse).
However it is no more enabled it by default in Kdenlive, and there are discussions about disabling it everywhere: its integration in MLT is not reliable in several cases, and the speed improvement is null as soon as you apply CPU effects/transitions...

vpinon wrote:Hello,
As long as Movit is packaged by the distro & MLT built with it, it should be available in Kdenlive (I believe it is the case in Debian/Ubuntu/OpenSuse).
However it is no more enabled it by default in Kdenlive, and there are discussions about disabling it everywhere: its integration in MLT is not reliable in several cases, and the speed improvement is null as soon as you apply CPU effects/transitions...

Ok, good to know. I've noticed the not so very stable behaviors when GPU has been enabled, a lot of hangs and crashes for me so I took it away. But I expected it to be a cause of my home brew compilations, seems to not be the case though.

My problem right now is that I can edit a clip and it is all fine. As soon as I add a filter, like Sharpen for example, the preview lags and hacks aaaa lot. Doesn't matter if I use proxy clips, I must add all filters in the end right before I render. Which is kind of surprising as I have a powerful laptop.

You know you can use "preview rendering" to save in cache the rendered effect?

vpinon wrote:You know you can use "preview rendering" to save in cache the rendered effect?

Yes sort of, but haven't got a good grasp on how to use it. What is the best procedure, preview the entire timeline or just small chunks?

The preview will be reset and recalculated on any change in the zone, so it's not a good idea to do it on whole timeline, but only in zones where you have heavy effects, properly set and not evolving much anymore... (my own understanding)

vpinon wrote:The preview will be reset and recalculated on any change in the zone, so it's not a good idea to do it on whole timeline, but only in zones where you have heavy effects, properly set and not evolving much anymore... (my own understanding)

If I have the entire timeline of a 2 min video rendered and change a transition between two clips it seems only those blocks covering the change is re-rendered?

you can preview render what you have marked before, this implies all the effects etc.. . then when you edit parts within this preview rendering you will see that they are marked red, indicating that preview rendering wont take place in these parts anymore and you can preview render again. it is a very handy feature for more cpu heavy effects. though i have some problems with it sometimes (color changes, etc) i use it all of the time. just try it out on a short edit to get used to it..

Will try preview more. Thanks for all the input!