ffmpeg : 4K BluRay to 1080p x264

Question

I'm trying to encode a 1080p x264 from a 4K BluRay. The problem is that source has bit-depth : 10 bits and i want output bit-depth 8 bits ...

3840x2160 (input) ==> 3840x1600 (cropped to delete black bars) ==> 1920x800 (resized)

If i use x264 0.155.2901 7d0ff22 compiled with bit-depth=all

ffmpeg -y -i input4K.m2ts -c:v libx264 -preset slow -crf 18 -x264-params me=umh:merange=24:trellis=1:level=4.1:ref=5 -filter:v "crop=3840:1600:0:280, scale=1920:800" -an "1080_"$output.mkv

it works but the output file is not 8bit, Format profile : High [email protected]

how to get format profile = High @L4.1 ? (force 8 bits output)

If i usex264 compiled with bit-depth=8, it tells me it can't read source.

Answer 1

This should work:

ffmpeg -y -i input4K.m2ts -c:v libx264 -pix_fmt yuv420p -preset slow -crf 18 -x264-params me=umh:merange=24:trellis=1:level=4.1:ref=5 -filter:v "crop=3840:1600:0:280, scale=1920:800" -an "1080_"$output.mkv