when i last did the rendering i looked at how KDENLiVE used my graphics card and two CPU cores. one of the cores was utilized 100% at any time, the other one - in a broad range, and the graphics card wasn't used at all. is KDENLiVE supposed to utilize hardware that way? does it depend on anything?

okay, i found this video (https://www.youtube.com/watch?v=cip3MOjSfCs) which helped me understand that the Playback section in the settings isn't just about playback. so i enabled the GPU processing and the first thing i noticed after restart was that the system started to use almost half of the video memory whereas the usage was below 20% before. i applied 3 MoViT filters [saturation, lift-gamma-gain, white balance] to a short clip and the rendering took 3min28sec according to the job details. during the process GPU utilization jumped from 0 to 10% and the video memory was used almost fully [more than 90%]. i didn't see any noticeable changes in CPU or RAM usage. then i removed all the MoViT filters and applied their Frei0r counterparts to the same clip. this time the rendering took 4min29sec, and the video memory was again used almost fully although GPU utilization didn't exceed 5%. i saved the project and disabled the GPU processing. when i tried to re-open it after restart i was presented with a message saying that there were GPU effects in the project and asked if i wanted to use non-GPU ones instead. i canceled it and re-applied them manually. after that the rendering took 4min03sec and the graphics card wasn't used. i saved the project again and used it with the GPU processing enabled. this time it took 4min17sec and hardware usage was the same as it was for the same settings.

so, i guess i could say it's a step forward compared to what i had before and MoViT helps to reduce rendering time, but one thing still bothers me. the size of the output file i got with MoViT is much less than all the others. the video also looks darker. and all that might explain why the rendering with MoViT took less time, so i'm still in doubt. it seems to me that Frei0r and MoViT effects modify videos differently. it's especially noticeable in White Balance effect when i pick a neutral color. i need to do more comparisons before i can come to the final conclusion.

humanbeing wrote:does it depend on anything?

it mostly depends on hardware and it isn't just about GHz or GFLOPS. new hardware has integrated circuits such as nVidia's NVEnc and PureVideo, AMD's VCE and UVD and Intel's Quick Sync and Clear Video which can accelerate video rendering. unfortunately, my hardware is too old and only features PureVideo supported through VDPAU.