I've recently just upgraded my graphics card to a Nvidia Geforce 970 to speed up encoding but unfortunately I've not noticed any difference in time. I'm assuming that's because Kdenlive uses software rendering? Is there a way to put my new hardware to use and use it to speed encoding on Kdenlive? I was also hoping that performance during editing would have increased but the video previews still stagger very badly. I've selected to use proxy videos, but then it throws a 'cannot create proxy' error at me. I also cannot transcode videos. I don't know why all these errors have come up after a fresh 17.1 install. I was honestly expecting a smoother ride considering the hardware.

I've also noticed that the audio falls out of sync a lot. It never used to, but I've recently did a fresh Linux Mint 17.1 install with the Kdenlive repos and that's when it started. The audio thumbnails line up perfectly but when it comes to encoding, it's all over the place.

EDIT: I suspect some of these errors are because I'm having to use a beta version of Nvidia's drivers to support my card. Once the drivers become more stable I suspect the sync issue will stop.

Hi,

FFMpeg/LibAV (on which MLT is built and then Kdenlive) uses software x264 encoder.
(I remember old benchmarks showing x264 in multithread not slower than hardware, for better tunable quality, but filling your CPU of course)
If you are in a hurry and ready to relax file size you can adjust rendering settings with eg "-pre:v libx264-ultrafast" (jumping from 50fps to 100fps encoding but something like 20% greater file size in VBR).
GPU could speedup interaction&rendering only with some effects if we were using Movit, but this is not the case for the moment.

Sync issues occured recently in some mixs between LibAV and MLT versions, appearing in Ubuntu 14.04 so maybe on your Mint. Solutions then : upgrade MLT from a PPA (sunab:kdenlive-release), or use bundles from builds.meltytech.com/kdenlive, or pull LibAV/MLT stack from a newer distro release (using pinning ?).

So video drivers don't come to any point in the problem, don' bother about that.

For proxies, sorry but the default settings appear to fail with some framerates ; you can set them in Kdenlive preferences to :
parameters: -g 5 -s 640x480 -crf 25 -pre:v libx264-ultrafast
extension: mkv

Hope that helps.

There are virtually video editors on Linux where having a GPU, vs. integrated graphics will do anything for you. In lightworks there is a very minor difference in performance, but standard free software doesn't use the GPU for anything at all.

avidemux uses VDPAU which helps with decoding for playback, not encoding - but it is less of a real video editor, just for minor edits.