Useful ffmpeg commands

# useful ffmpeg cmds
brew install ffmpeg $(brew options ffmpeg | grep -vE '\s' | grep -- '--with-' | tr '\n' ' ')

# convert audio stream to mp3
ffmpeg -i input.mkv -map 0 -c copy -c:a libmp3lame -ac 2 output.mkv

# merge multiple AVIs to one
for f in $PWD/*.avi;do echo "file '$f'" >> mylist.txt; done
ffmpeg -f concat -i mylist.txt -c copy output.avi

# 2x normal speed (timelapse)
ffmpeg -i output.avi -r 16 -q:v 1 -filter:v "setpts=0.5*PTS" sped-upx2.avi
# 4x normal speed
ffmpeg -i output.avi -r 16 -q:v 1 -filter:v "setpts=0.25*PTS" sped-upx4.avi

# WebM conversion
ffmpeg -i IN -f webm -vcodec libvpx -acodec libvorbis -b:v 0 -crf 22 -s 640x360 OUT.webm
ffmpeg -i ./INPUT.avi -f webm -vcodec libvpx -acodec libvorbis -b:v 0 -crf 22 -s 640x360 OUTPUT.webm

# Master command from AVI to WebM/MP4 with speed x4
ffmpeg -i output.avi -r 16 -q:v 1 -filter:v "setpts=0.25*PTS" -f webm -vcodec libvpx -acodec libvorbis -b:v 0 -crf 22 -s 640x360 OUTPUT.webm
ffmpeg -i output.avi -r 16 -q:v 1 -filter:v "setpts=0.25*PTS" -profile:v baseline -vcodec libx264 -pix_fmt yuv420p -b:v 0 -crf 22 -s 640x360 OUTPUT.mp4