Here's a few things that were posted in other threads to kick this off:
preserve wrote:if you output HEVC/H265 (the codec used by UHDs), Handbrake does retain the Rec. 2020 HDR color space.
preserve wrote:Although both have the WCG 2020 color space, the original MakeMKV file has a pixel matrix of yuv420p10 while the Handbrake-converted MKV has a pixel matrix of yuv420p.
Woodstock wrote:the internal work path is only 8-bit, even on the nightly builds with 10- and 12-bit output support.
preserve wrote:I was seeing bitrate spikes of 65+ on Passengers (someone else mentioned in another thread that they were seeing as high as 78). Those are the parts my laptop was stumbling on. At other times, the bitrates can be quite low.
For a 2-pass VBR encode, Handbrake's average bitrate setting does not enforce a maximum - even with a low average, those high spikes were still occuring.
I was getting smooth playback results by using 25000 as the average bitrate and then adding the following settings manually into the provided input box: "vbv-maxrate=30000:vbv-bufsize=40000"