Ethan Mick

Converting M4V to MP4 and WEBM with FFmpeg

Newer versions of FFmpeg are awesome. To make sure you have all the goodies for HTML 5 video (for OS X):

brew install ffmpeg --with-libvpx --with-libvorbis

or if you already had it installed:

brew reinstall ffmpeg --with-libvpx --with-libvorbis

Then, to convert a video to .mp4:

ffmpeg -i input.m4v out.mp4

or WebM:

ffmpeg -i input.m4v output.webm

So easy!

Of course, I had a lot of videos I wanted to convert. So I wrote up a little bash script.

for i in *.m4v;
do name=`echo $i | cut -d'.' -f1`;
echo $name;
ffmpeg -ss 00:00:05 -i "$i" -frames:v 1 "./output/$name.png"
ffmpeg -i "$i" "./output/$name.mp4";
ffmpeg -i "$i" "./output/$name.webm";

This requires there to be an output folder in the directory for the script to place the result in. This will not only convert every file to MP4 and WebM, but it also makes an image of the video at second 5. Why 5? Because sometimes the videos were black for the first few seconds, so I had to go into them a little bit. This can be great for using the new <video> element in HTML, and having a Poster image.

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