KDENLiVE choppy video playback
 

Hello, all. I'm not really sure if this is a hardware question or a software question, but I figured I'd start here and see what people think.

I had been running KDENLiVE using the on-board Radeon video driver in my Dell Inspiron under OpenSUSE 13.2. It worked, but the video playback was choppy, especially when any kind of filters were applied.

I decided to try and improve performance by installing an EVGA Hardware-accelerated NVidia graphics card. I installed the card, loaded the NVidia drivers (version 361.42) and made sure the libvdpau1 OpenSUSE package was installed. Now, if anything, the performance in KDENLiVE is even worse.

Do I have to go back and recompile KDENLiVE now that I have the new card and drivers installed? I checked on the NVidia web site and the card that I got (GeForce GT 610 with 2GB RAM) has the "C" rating for VDPAU capability, which says to me that it should play video like mercury on heated glass, but I'm getting choppy, slow playback even with no filters applied and almost EGA-level resolution.

Any suggestions would be greatly appreciated. Thank you!

Have you launched any resource monitors to check for other problems? For example, how much RAM do you have installed? I do not know a ton about your topic, but from what you say in your post I would assume it is not a graphics problem but some other. Try running dmesg to look for errors, or try launching Kdenlive from a terminal so you can get some output while it runs. Try running Htop, or Nmon, to check your CPU and RAM resources, as well as your harddrisk and other disk drive resource values.

In KDENlive configuration, you should see an option to use openGL. Make sure that is on.

Some questions:

What's the resolution of the video you're playing back?
What's the file size of the video (anything in the timeline is in RAM, so if you load a large video into a little bit of RAM...)
What codec? more compression == more decompressing for Kdenlive.


The effects problem is, as far as I can tell, a known issue, and unfortunately I have not heard of a solution yet. The problem is that any effect is being applied in realtime during playback, and that can really slow down playback. My current workaround is to save filters and effects until last, but if that doesn't work for your workflow then the other solution is to do a temporary render of the section of video with the filter on it, and then import that temp render back into your project. Not a very graceful process, but it's what other editors do behind your back, not always with seamless results, so it's not unheard of.

This temp render process is described here:
https://opensource.com/life/15/6/mas...eline-kdenlive (see the "Preview Renders" section)


You might also consider using proxy video for editing ("offline editing"). It's explained in detail here:
https://opensource.com/life/16/1/off...iting-kdenlive