Hello,
I want to do my kdenlive rendering but when I run it, it displays for 30 minutes, then 30 minutes later it displays for 1 hour even though the video is only 7 minutes long! Rendered as ‘Quick Sync Intel H264’. My project is in 4K, I wanted to set it to 1080p30fps but that moves all my clips and breaks my entire editing process. My PC consists of an Intel(R) Core™ i5-10400 CPU @ 2.90GHz processor, 16Gb of memory, and an Intel(R) UHD Graphics 630 on Windows 10. I tried several solutions such as rendering with github action, which retrieves my project via Google Drive, but in 4k it takes more than 6 hours and so github cuts the script. If I rescale, it takes 5 hours and upon arrival, my video with most of the clips not being in the right place and size. (My clips use the ‘transform’ effect). So I don’t know what to do.
Any response would be welcome, thank you!
Hi @Nonoylono7, and welcome to the forum and community.
What version and installation method of Kdenlive do you use?
Keep in mind that 4K sources is a lot to handle for any CPU, and the GPU is not used during the render process except for the encoding part.
Those specs are pretty weak for 4k, I’m surprised it would take an hour to render because I would have thought it be longer. Do you truly need 4k? Can you get by with 2k or even smaller 1080p?
I didn’t realize it when I did the editing and now I’m stuck in 4K. If I play back at 1080p 30fps, all my clips will be shifted. I don’t really feel like doing everything over
I recently installed kdenlive on Windows 10.
So I’m taking this as version 26.04.3 installed using the installer version.
You may want to try the standalone one.
It’s better ? It’s rendering more fast ?
That’s not what I’m saying. But perhaps the installer version is not working correctly to change the project from 4K to 1080p without changing shifting your clips.
Still, using 4K sources with your computer’s specs is asking for frustrating editing and rendering experience. So, I recommend using ffmpeg to bring your sources from 4K down to 2K.
So, would using the standalone version allow my project that uses the “transform” effect to go from 4K to 1080p without any problem? because if I use clips that are not in 4k, Kdenlive will transcode them, right?
I don’t know for sure because that may depend on a few things but using the standalone eliminates some possible reasons.
because if I use clips that are not in 4k, Kdenlive will transcode them, right?
These are different things. Kdenlive transcodes only video clips that have a variable FRAME rate, and only if the users agrees to it.
You can use mixed resolution and mixed dimension video clips in a single project without issues. Just keep in mind that when the project profile is 1920x1080 (2K) Kdenlive by default tries to fit any video clip into that frame, if you will. That means that a 4K video is scaled down to fit into the 2K frame; likewise, a 960x540 video clip is scaled up; and clips with a different aspect ratio (1920x1080 is 16:9) are scaled so that they fit the width or height, depending, and will therefore leave black areas on top/bottom or the left/right, depending.
In any case, Kdenlive will always use the original clip’s dimensions when it comes to rendering but a 4K clip has 4 times the number of pixels than a 2K clip. Therefore it has 4 times more data/information Kdenlive has to process. And it doesn’t make a difference whether you start with a 4K project profile and then scale it down to 2K in the rendering process, or start with a 2k project profile.
So, I recommend to use ffmpeg or other tools of your choice (Handbrake or Losslesscut, although the latter is not ideal for that purpose) to scale your 4K source videos to 2K before you edit your video. The videos will suffer a quality hit from the re-encoding them (unavoidable when scaling), and you have to define the trade-off between quality and speed of rendering.
My personal preference in a scenario like yours with a relatively weak system for 4K editing is to work with proxies (improves responsiveness during editing), use preview render for sections with heavy or lots of effects, and then let Kdenlive render overnight.
Okay, thanks a lot !