Turns out I was wrong about that, and it’s probably an issue with the reporting tool (Tautulli) reporting SDR. When I went in and manually ran ffprobe on the transcode session, I see Main 10, bt2020, and DOVI side data.
Example command with output:
$ cat "/tmp/plexmediaserver/Transcode/Sessions/plex-transcode-55406e9250c6872c-com-plexapp-android-ee9bf900-b76e-41b3-b663-56d283583cc4/header" "/tmp/plexmediaserver/Transcode/Sessions/plex-transcode-55406e9250c6872c-com-plexapp-android-ee9bf900-b76e-41b3-b663-56d2835
83cc4/media-00000.ts" | ffprobe -
ffprobe version 6.1.1-3ubuntu5+esm2 Copyright (c) 2007-2023 the FFmpeg developers
built with gcc 13 (Ubuntu 13.2.0-23ubuntu4)
configuration: --prefix=/usr --extra-version=3ubuntu5+esm2 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --disable-omx --enable-gnutls --enable-libaom --enable-libass --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libdav1d --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libglslang --enable-libgme --enable-libgsm --enable-libharfbuzz --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzimg --enable-openal --enable-opencl --enable-opengl --disable-sndio --enable-libvpl --disable-libmfx --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-ladspa --enable-libbluray --enable-libjack --enable-libpulse --enable-librabbitmq --enable-librist --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libx264 --enable-libzmq --enable-libzvbi --enable-lv2 --enable-sdl2 --enable-libplacebo --enable-librav1e --enable-pocketsphinx --enable-librsvg --enable-libjxl --enable-shared
libavutil 58. 29.100 / 58. 29.100
libavcodec 60. 31.102 / 60. 31.102
libavformat 60. 16.100 / 60. 16.100
libavdevice 60. 3.100 / 60. 3.100
libavfilter 9. 12.100 / 9. 12.100
libswscale 7. 5.100 / 7. 5.100
libswresample 4. 12.100 / 4. 12.100
libpostproc 57. 3.100 / 57. 3.100
Input #0, matroska,webm, from 'fd:':
Metadata:
ENCODER : Lavf59.20.101
Duration: N/A, start: 9.986000, bitrate: N/A
Stream #0:0: Video: hevc (Main 10), yuv420p10le(tv, bt2020nc/bt2020/smpte2084, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 23.98 fps, 23.98 tbr, 1k tbn
Metadata:
ENCODER : Lavc59.25.100 hevc_vaapi
Side data:
DOVI configuration record: version: 1.0, profile: 8, level: 6, rpu flag: 1, el flag: 0, bl flag: 1, compatibility id: 1
Stream #0:1(eng): Audio: opus, 48000 Hz, 5.1, fltp
Metadata:
ENCODER : Lavc59.25.100 libopus
The garbling issue for Android automatic quality still stands, but otherwise ignore me on the HDR side; that looks fine!