ffmpeg [options] input_file output_file

ffmpeg -i input.mkv \ -map 0:v -map 0:a:0 -map 0:s? \ -c:v libx265 \ -preset slow \ -crf 18 \ -pix_fmt yuv420p10le \ -x265-params "aq-mode=3:no-sao=1:deblock=-2,-2" \ -c:a flac \ -compression_level 8 \ -c:s copy \ -metadata title="Game of Thrones - S01E01 - Winter Is Coming" \ -movflags +faststart \ output_s01e01.mkv