ffmpeg - very slow conversion

Question

I create web app in JavaEE which displays many video formats. I use ffmpeg solution to convert videos to formats which is supported natively by main browsers.

According to : http://www.jwplayer.com/html5/formats/ I convert to WEBM container (VP8/VORBIS or VP9/OPUS). But conversion is very slow, bit rate equals to ~ 200kbits/s. To convert I execute following command

ffmpeg -i file.mov -c:v libvpx -preset ultrafast result.webm How to speed up conversion to natively supported formats by main browsers?

Answer 1

Use the -speed number (e.g. 8), not the -preset setting (e.g. ultrafast). The latter is for x264/x265 encoding.

A Higher number means faster encoding, so ultrafast would map to 8 or so. Very slow/placebo maps to 0, and values in between map accordingly. 1-2 still gives reasonably good results and settings like 4-5 tend to be relatively fast but not entirely crap quality.