Am using version 24.12. After finishing a lengthy project in 1080p, I was surprised to see Interpolation and Deinterlace settings active in the Render Custom window. No option to deactivate them! Or are they ignored when rendering progressive? I normally render at 23 slower. But as the rendered file seems quite a bit larger for similar running time am wondering if Interpolation/Deinterlace are causing this.
Interpolation controls how scaling is performed if your source frames are a different size to what is rendered, Deinterlacing is how to handle any interlaced source files you might have. IIRC, that one is/should be disabled if you have no interlaced source files, but detecting that is a little imprecise so it may sometimes be ‘enabled’ even if it’s not actually used.
Both are really more about how to read your source files than how the output is rendered though, so they alone won’t generally make a lot of difference to the output bitrate beyond determining how complex the source is and how well it can be compressed for a given quality.
You’re going to need to be a bit more specific about what you’re really doing if you want guesses about what is making your output “larger” - but that’s always possible when you’re transcoding files, and especially so if you’ve edited them to add effects or other visual complexity etc. Mostly it’s just a function of how your originals were encoded vs how you’re encoding what you render, things like VFR can have a notable effect on bitrate if your originals used that, as can some other options, but interpolation and deinterlacing probably aren’t your smoking guns here if they are otherwise set correctly for what you’re trying to do.
Many thanks for your reply Ron. Version 24.12 is the first one I’ve seen with this window. I never came across it before. As I’m not scaling and I always shoot progressive non interlaced footage, both settings are not needed. I don’t understand why they can’t be turned off by something like a “none” option in the menu. I upload to Vimeo which has never had problems with my 1080p before. But this latest upload is constantly buffering unless I switch the viewer to 720p. Of course it could be a network problem and many say Vimeo is going down the tubes. So who knows! Thanks again.
It might be nice to grey them out if we really can know they won’t be used, as a UI polish thing, but that might not always be trivial to know at the point that dialog is displayed.
A user selected ‘none’ option though would fall into the anti-pattern of “trick questions the user can only ever get wrong”. If they really aren’t needed in practice, then it already doesn’t matter what you selected there, they still won’t be used. But if they really are, and you selected ‘none’, then the result won’t be something that you’d want. So it doesn’t make a lot of sense to add a choice that at best does nothing, and if it doesn’t do nothing, only ever does Something Bad.
Which isn’t to say that nothing has changed since whatever kdenlive version you updated from - and something may have increased the bitrate of your rendered videos - just that these two options aren’t the villains you’re looking for to explain or fix that.
It could be the content of them, it could be a change to the encoder, or it could be some other bug, but there isn’t enough information about them and what changed here yet to speculate on what may have caused that.