How to create a WebM video file?

Question

After looking around the web, I found no way to generate a WebM video. I see drivers for Windows and QuickTime, but no evidence that the most common utility FFmpeg is being supported.

Is there any open source converter that produces WebM?

Answer 1

You can use ffmpeg to convert to WebM. Make sure to compile it with the --enable-libvpx and --enable-libvorbis flags (see FFmpeg compile guides), or visit the FFmpeg Download page for links to builds that include support. After that, you can use the following command (I'm using input.flv as my example input file):

ffmpeg -i input.flv -vcodec libvpx -acodec libvorbis output.webm 

For additional information, see the FFmpeg vpx (WebM) Encoding Guide.

Answer 2

ffmpeg -i input.mp4 -c:v libvpx -crf 10 -b:v 1M -c:a libvorbis output.webm 

By default the CRF value can be from 4–63, and 10 is a good starting point. Lower values mean better quality.