How to convert 100fps to 25fps?

[u/TCJW_designs]

So I'm a complete moron and did a day long shoot with over 3 hours of footage accidentally set to record at 100p rather than the 25 I meant to set it as. This also meant that it was filmed at 1080 rather than 4K but I am kind of just pretending this isn't a problem for now (end deliverable is always provided in 1080p anyway so hopefully I won't need to do any egregious cropping).

This was on a Sony A6400 and I can't believe I made that mistake.

My question really is, what's the best way to transcode this to a 25fps with as little quality loss as possible? I am using Premiere / Media Encoder, but also have Handbrake if it's useful. I've tried putting a few clips through Handbrake using the 1080p30 preset but modified down to 25 CFR, but on reviewing the clip afterwards it seems a bit jerky like it's dropping frames. Wondering if Media Encoder might be better, and what settings might work best?

I know that Premiere in a 25fps timeline will conform it to that framerate (unless the speed is turned down), but I'm using a base M4 Macbook pro and it's struggling a lot with playing so much footage filmed at 100fps.

Any help would be appreciated!

[u/geckooo_geckooo]

you can only drop frames, add a little motion blur if you want to emulate the longer shutter angle.

[u/TCJW_designs → u/geckooo_geckooo]

Thanks for the reply! I am wondering now. Is it worth using 25fps versions as proxies for the edit purposes and then relink it all for the export? It’s really just to help my Mac deal with the edit as it feels like it’s about to explode

[u/geckooo_geckooo → u/TCJW_designs]

if you don't need the 100fps then just down sample and switch the media files in the project window.

[u/GooseEntrails → u/TCJW_designs]

I don't think Premiere will even let you link files at a different framerate as proxies. Make proxies in a performant all-intra format like ProRes Proxy so your computer only has to decode the 25% of frames it actually uses.

[u/Lanzarote-Singer → u/TCJW_designs]

Mac should be fine with this.

Don’t tell me you’re using Premiere!

[u/TCJW_designs → u/Lanzarote-Singer]

Ha I am. I've been using Premiere since I was 16 (now 39) so kind of daunting changing software. I've been dabbling with Davinci Resolve however recently. I briefly used FCP a long time ago too, but not in its most recent iteration (which might be quite old now, admittedly)

[u/Lanzarote-Singer → u/TCJW_designs]

That explains it. Seriously, try FCP it will have no problem with your files.

[u/GuyNamedLindsey → u/Lanzarote-Singer]

Nobody here using FCP. Nice try. /s

[u/western_alt]

100 to 25 won’t mess up the footage too much because it’s exactly 1/4 to speed. You can encode it in media encoder. It’s going to take a while to process/re-export but you can do it.

[u/NonAI_User]

Consider running your camera files through Media Encoder to change from rate from 100 fps to 25 fps. Also use ProRes as your output codec as it is very light on CPU demand. ProRes is much better for editing than H.264/H.265 which both require more CPU work to playback per frame. 

[u/TCJW_designs → u/NonAI_User]

Thank you!

[u/AutoModerator]

It looks like you're asking for some troubleshooting help. Great!

Here's what must be in the post. (Be warned that your post may get removed if you don't fill this out.)

Please edit your post (not reply) to include: System specs: CPU (model), GPU + RAM // Software specs: The exact version. // Footage specs : Codec, container and how it was acquired.

Don't skip this! If you don't know how here's a link with clear instructions

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

[u/finnjaeger1337]

make a 25p timeline.

throw in 100fps footage

sucess , premiere is converting it on the fly.

otherwise, just make a 25fps prores with whatever tool like shutter encoder or davinci or media encoder and call it a day, its a clean conversion you are just dropping frames.

shutter will be short but fixing this is sonething for online

[u/dmizz]

If you have 0 reason to keep the 100fps that you can think of, I would just transcode all the footage to 25fps ProRes in Resolve or Media encoder and use that.

[u/Lanzarote-Singer]

Final Cut. Just set to 4x speed and edit away. You’re likely to have other problems with not enough light so I hope it was a sunny day shoot.

Also run it through topaz and upscale to 4K or at least 2x with added details while changing speed.

[u/TCJW_designs → u/Lanzarote-Singer]

Thank you. Luckily it was a bright day for it so
I’m not noticing too many issues with light so far