Add Proxy scaling by percentage in "Create Proxy" dialogue box
Simply add an option to the proxy dialogue box where the user is able to type in a scale percentage instead of pixel dimensions for proxy generation. This will save the time of the user to generate aspect ratio locked proxies for media without having to consult look up tables for the values, or do the math. Maybe even adding in a "*****" window beside it to see the actual dimensions of the proxies you're generating. Being able to set scale percentage as in ingest, or proxy preset would also be extremely helpful.
create proxies for 3840x2160 media, you can either have an option to make 1280x720 proxies, or the option to make proxies at 25% scale of original, which is also 1280x720.
For example - RED Cine-X Pro has export size options including "quarter clip-res" or "half-clip res", just adapts to whatever aspect ratio the clip is. Works well.
Andy Mees commented
I'd also suggest that Ingest Presets created with Encoding Presets where Frame Size is 'Based on source' could and should be supported as Proxy creation ingest presets (effectively allowing a 100% frame size option, even if no other scaling options were supported) … at present, attempting to select an Ingest Preset that references a 'Match Source' encoding option for Proxy creation just gives an error.
MATT HOECKER commented
I would add to this the ability to set a desired horizontal resolution and have the vertical adjust to match the aspect ratio of the clip. I shoot in mostly DCI, but also sometimes shoot 4:3 on my GH5 (to be able to reframe vertically and use that extra vertical resolution) and sometimes if we get footage from another camera it's standard UHD 16:9. To create proxies for this media (especially if you haven't worked with that aspect ratio before) you have to go in and create a new ingest preset (which as many have brought up before, is a pain in and of itself.)
I just standardize all of my proxies to 1920x1080, 1920x1440 or 1920x900 for the three examples above. Now, I have these presets created on my primary computer so I only have to select the batch with the same aspect ratio and create the proxies, but if I'm working on a different computer, new version of Premiere etc, I have to go through the process of creating these again (which I'm getting pretty adept at the cumbersome process.)
What would make this so much easier is to have the option stated above, as well as a "standardize horizontal resolution to ___ and scale to maintain aspect ratio" option.
Then, you only need to choose your codec, and the rest is done for you. Either a percentage of the original, or a fixed width. You can also then just drop in a whole batch without worrying about what the aspect ratios are.
A document stating some of the preferred codecs (after some testing by Adobe engineers) would also be helpful.