SYSTEM SPECS
CPU: i9-9900KF
GPU: AMD 9070 Radeon
32gb RAM
Mobo: Asus Z390 pro wifi
SSD that the data is being drawn from is an M.2 Drive with connection type NVME
OS: Linux Mint Cinnamon 22.3
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As you can see from the title, I’m having some issues with Kdenlive render speeds. After some research I can see that this is a common issue with many users, but many of those same users report some amount of render speed success by enabling “parallel processing” and maximizing the amount of threads the program is using. This, and using a hardware accelerated codec.
Even after doing both of those (16 threads, and VA API H264), it takes Kdenlive about 60+ minutes to render just 8 minutes of footage without “too many effects”.
I’ve made an 8 minute video with only about three video channels and two audio channels used, with each clip only containing a Transform effect as well as a Edge Crop effect. The audio has all previously been edited in Audacity, so there are no effects on the audio clips.
Can somebody advise? The render begins tremendously fast and reports that it will be able to render the entire video in only 4 minutes, but then rapidly becomes progressively more sluggish until it is only rendering at 1FPS at merely 10% or 15% completed.
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I feel you, Kdenlive performance is awful in general once you start using effects. 60 minutes export time for an 8 minute video sounds excessive though. I do 1080p/29.97fps with some effects and it takes usually 1x-2x of video length. What resolution and frame rate?
I’m using the exact same resolution and frame rate as you (1080p/29.97fps) unfortunately. I knew that it would take a while longer than say, Premiere pro or Davinci of course. But if 60 minutes seems excessive to you or anybody else in the community then there has to be some sort of work around or something I can do to optimize it?
I know that Kdenlive used to use a very large amount of RAM. I was making 30 minute long 4k 60 fps videos and they consumed like 48-50 GB of ram. So check how much RAM Kdenlive is using…?
I think they optimized the memory usage these days so its a bit better than it was, but its still pretty intensive.
Parallel processing comes with its own challenges in particular when effects need frame data from before and/or after.
The only HW support currently available is for the de- and encoding part by using the appropriate render profile (VAAPI or NVENC). Application of effects/filters, transitions and all compositing is currently done by the CPU only. Work is underway to use GPUs for effects, transitions and compositing during playback and rendering.
corrently i’m usign a 56 threads pc… (without using the GPU) High end CPUs used at 20/40% during rendering. (Windows and Linux) (#2099) · Issues · Multimedia / Kdenlive · GitLab
using other softwares to make conversions/deinterlacing (H264) i have to disable the hyperthreading to gain a little bit more from the CPU.. (from 56 threads to 28)
see also this: Too many threads when set to auto - Doom9's Forum
looks like H264.. ffmpeg…avisynth… etc etc are just not build for high number of threads.
Yeah, I noticed when upgrading my main workstation from a 5800X3D to a 5950X, Kdenlive didn’t really use that many more threads. The only real gains came from the slightly higher clock speeds of the 5950X.
When you say “Work is underway”, do you mean work in the underlying melt infrastructure? That’s been underway for many years. Do you know of any progress?
MLT uses the movit library for HW accelaration but it doesn’t work with/for Kdenlive and had to be disabled. We are working on GPU support but the team is very small, so it takes time …
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