I'm shooting GoPro footage in 4K and since my computer isn't the fastest and gets quite choppy with 4K footage, I create ProRes proxies files and use those for editing. I'm working with a 1920x1080 sequence. What I notice with the ProRes files is that when I scale the image down to 50% to fit in the 1920x1080 window, the scaling starts to go crazy and when I use the slider to get it to 50%, it jumps back and forth to 24% and other random size. When I manually type in 50% it works but as soon as I start to playback the video it zooms in again to 100% while the video is playing and back to 50% when I pause it.
I tried the Cineform codec and this codec seems to work without any issues. Has anyone else experienced this with ProRes?
Yeah, interpret the footage to fit in your sequence. What are you going for in your output resolution?
Did you transcode the camera footage to a new filetype? Prores or AVC intra? This will make it easier on the playback engine, and you can export both a full quality and proxy quality. Start by creating a sequence with full quality version.
If you create a 4k sequence from your main video, then unlink and relink to your proxy file and interpret the footage to fit, you won't have so much trouble with this, and your proxy can be 720 for all the editor cares. Just remember to unlink and relink to the full format when you are ready to output your movie. If you aren't fast, go to full format first (prores or avc full format) then compress that file (takes a lot less time than applying edits while compressing).
The reason the file dances around is that you need to place a KeyMark in the effect controls at the beginning and at the end of your resizing. Set both to be at your desired zoom, then render the work area. Your video should play just fine after that, and for every 3-5 small effects, drag the work area bar around them only and render effects in work area (shorter than rendering the whole thing and same effect on playback--speeds it right up so you can see the true effect). I always have my previews set to iframe only mpeg.