iMovie 4K resolution to Keynote - apparent loss of resolution

[SuzuBell]

I exported a 4k resolution video from iMovie on my MacBookPro. I imported it into Keynote in order to crop it. I noticed that upon exporting from Keynote, the resolution of the video was markedly reduced.

In Keynote, I had exported the cropped video using File --> Export To --> Movie. Upon export, the resolution field only gave me "720p", "1080p", and "Custom". I clicked on "Custom". This gave me three "compression types" ("H.264", "Apple ProRes 422", and "Apple ProRes 4444"). I tried saving the cropped video using each of these three options. However, in each case, the video appeared to be reduced in quality (presumably resolution).

My question is: How can I crop a 4K video in Keynote and export it without reducing quality/resolution?

 

[nicho]

I exported a 4k resolution video from iMovie on my MacBookPro. I imported it into Keynote in order to crop it. I noticed that upon exporting from Keynote, the resolution of the video was markedly reduced.

In Keynote, I had exported the cropped video using File --> Export To --> Movie. Upon export, the resolution field only gave me "720p", "1080p", and "Custom". I clicked on "Custom". This gave me three "compression types" ("H.264", "Apple ProRes 422", and "Apple ProRes 4444"). I tried saving the cropped video using each of these three options. However, in each case, the video appeared to be reduced in quality (presumably resolution).

My question is: How can I crop a 4K video in Keynote and export it without reducing quality/resolution?

Why would you crop a video in keynote rather than doing it in imovie?

iMovie for Mac: Crop a clip

Also, you can't crop a video without reducing its resolution. You're literally removing pixels from the video.

 

[SuzuBell]

Thanks for the suggestion about cropping in iMovie. Unfortunately, it seems iMovie is restricted to cropping in only one size (16:9). I am uploading this video to Instagram, which supposedly works best (does least compression) for a 5:4 sized video.

 

[nicho]

Thanks for the suggestion about cropping in iMovie. Unfortunately, it seems iMovie is restricted to cropping in only one size (16:9). I am uploading this video to Instagram, which supposedly works best (does least compression) for a 5:4 sized video.

I see now! So your desired video file is still 2160p high, it's just not in a 16:9 ratio. In that case there's no need to be losing quality. Try using handbrake instead. https://handbrake.fr/docs/en/latest/advanced/resizing-video.html