HDR

HDR: .\ffmpeg.exe -i "<infile>" -c:a copy -c:v libx265 , -ss 250 -t 5, and -ss -ss 30 -t 5.

https://superuser.com/questions/1280876/convert-youtube-hdr-vp9-2-video-to-hevc-hdr-with-ffmpeg

.\ffmpeg.exe -i "<infile>" -c:a copy -c:v libx265 -tag:v hvc1 -crf 22 -pix_fmt yuv420p10le -x265-params "colorprim=bt2020:transfer=smpte2084:colormatrix=bt2020nc" <outfile>

time 5 sec

A 5 second sample 250 seconds into the video.

-ss 250 -t 5

-ss -ss 30 -t 5