-codecs # list codecs
-c:v # video codec (-vcodec) - 'copy' to copy stream
-c:a # audio codec (-acodec)
-fs SIZE # limit file size (bytes)
ffmpeg -i foo.mp3 -ac 1 -ab 128000 -f mp4 -acodec libfaac -y target.m4r
# no audio
ffmpeg -i input.mov -vcodec h264 -an -strict -2 output.mp4
ffmpeg -i input.mov -vcodec libvpx -an output.webm
ffmpeg -i input.mov -vcodec h264 -acodec aac -strict -2 output.mp4
ffmpeg -i input.mov -vcodec libvpx -acodec libvorbis output.webm
<video width="320" height="240" controls>
<source src="movie.mp4" type='video/mp4'></source>
<source src="movie.webm" type='video/ogg'></source>
</video>