Not gonna mention what the chosen alternative is? Ok...

ffmpeg, sadly. No other UI wrapper gave me what I needed. MeGUI is nice, but requires AviSynth and extracting audio and video, for which I no longer have the patience.

At least when I run it, I get options to select both x264 and x265 in 10 bit.

Yes, the option exists, but it is not a real 10 bit, because internally the pipeline is limited to 8 bit.

What does this mean? Once you've a decoded 10-bit raster, what's the limitation you're encountering?

What content comes in 10-bit in the first place? HDR is just becoming a thing and I'm pretty sure that's restricted to UHD Blu-rays.

A significant amount of content coming from a recording monitor for professional cameras, or in-camera itself, usually in ProRes/DNxHD form. Using an NLE for transcoding is miserable, and ffmpeg doesn’t have the most intuitive CLI syntax for people who just want quick buttons to press.

Pro-world also uses transcoders, and not everyone likes/is able to use Adobe for that.

I'm surprised people working with professional footage don't have better tools for that but fair enough.

Oh, there definitely are better tools out there, I’m just saying where the source material is coming from. Transcoding specific apps are relatively far and few between, so we end up having to use use other apps for this at times. Handbrake, ffmpeg, Apple’s Compression (is it still alive?), Adobe Media Encoder, etc. Having to use DaVinci Resolve, Premiere Pro, Medi Composer, etc to create proxies or flip between formats is overkill and time consuming.

>Apple’s Compression (is it still alive?)

Yes. Why wouldn't it be?

I haven’t been on Apple’s site in a long while (or on a Mac). Wasn’t sure how Compression and Motion were faring since FCPX came out.

FCPX has been going from strength to strength since the release, with a constant stream of big updates, and winning lots of hearts back from the FCPX backslash.

This is also interesting: https://offthetracksmovie.com/

(Interesting factoid: the same person spearheaded and designed all of FCP, FCPX, and Premiere)

In my experience, 10-bit also gives better results when transcoding, for instance smoother gradients and less banding.

From my understanding, if the raw material is 8-bit, simply using 10-bit won't help with banding unless you also use some de-banding or smoothing filters together.