Audio/Video

increase volume with ffmpeg

ffmpeg -i input.mkv -filter:a "volume=4.0" output.mkv

Convert all .avi files to .mkv

for i in *.avi; do ffmpeg -i "$i" "${i%.*}.mkv"; done

Re-encode a directory tree to H265 recursively

find /path/to/media -iname '*.mkv' -exec ffmpeg -n -i '{}' -map 0 -map_metadata 0 -c:v libx265 -crf 24 -preset veryslow -c:a libopus -scodec copy '{}'.h265 \;