ffmpeg -hide_banner -i input.mkv 

ffmpeg -y -i input.avi -c:v libx265 -preset slow -b:v 2600k -x265-params pass=1 -an -f mp4 /dev/null && ffmpeg -i input.avi -c:v libx265 -preset slow -b:v 2600k -x265-params pass=2 -c:a copy -c:s copy output.mp4

ffmpeg -i ./input.mkv -map 0 -c:a copy -c:s copy -c:v libx264 output.mkv

ffmpeg -i "concat:input1.ts|input2.ts|input3.ts" -c copy output.ts

ffmpeg -i input1.mp4 -c copy -bsf:v h264_mp4toannexb -f mpegts intermediate1.ts
ffmpeg -i input2.mp4 -c copy -bsf:v h264_mp4toannexb -f mpegts intermediate2.ts
ffmpeg -i "concat:intermediate1.ts|intermediate2.ts" -c copy -bsf:a aac_adtstoasc output.mp4