No official "Knox" variant exists in the x264 Git repository. If you encounter a binary labeled "Knox x264," treat it as a third-party compile. Always verify its integrity (VirusTotal, source reputation) before use.
x264 --preset slow --tune film --crf 18 --output-depth 10 \ --profile high10 --level 4.1 \ --ref 8 --bframes 8 --b-adapt 2 \ --direct auto --me umh --subme 10 --merange 24 \ --trellis 2 --no-fast-pskip \ --deblock -2:-2 --psy-rd 1.1:0.1 \ --aq-mode 3 --aq-strength 0.9 \ --sar 1:1 --colormatrix bt709 \ -o output.mkv input.yuv knox x264