Aim & Conclusion

Test experimental support of MKV/WebM container mixing in-development video format VP9 and audio format Opus. As of today this is the best video-audio combo with royalty-free web formats with better quality/weight ratio than “classical” VP8-Vorbis.

Major browsers and players support both VP9 and Opus, but separately: Standalone Opus audio (MIME audio/opus) is well supported. WebM container is implying VP8+Vorbis or VP9-Vorbis, putting another audio format (WAV, FLAC, Speex, Opus) is unexpected. video/mkv isn't a recognized MIME by browsers.

I hope for a consensus about extending WebM format specs to VP9+Opus and push support for browsers, making it an efficient H.264+AAC killer before fighting the emerging H.265+HE-AAC.

Encoding

source: Quantum Ripples (AMV by Nostromo)

ffmpeg -i "Nostromo_-_Quantum_Ripples_720p@60_10b.mp4" -c:v libvpx-vp9 -c:a libopus -deadline best -crf 24 -b:v 300k -b:a 40k -threads 4 -y -ss 00:01:55.000 -t 13 "out.mkv"

original filesize: 168 MB
estimated filesize after full encoding: ~80 MB

Browser/player support

VLC 2.1.4:

<html>video/webm</html>
<html>VP9</html>
<html>Opus</html>
<html>MKV-fakeWebM [VP9+Opus]</html>
<html>can play (no sound: “audio undef”)</html>

Firefox 30:

<html>video/webm</html>
<html>VP9</html>
<html>Opus</html>
<html>MKV-fakeWebM [VP9+Opus]</html>
<html>WebM-Opus MIME incompatible</html>

Chromium 35:

<html>video/webm</html>
<html>VP9</html>
<html>Opus</html>
<html>MKV-fakeWebM [VP9+Opus]</html>
<html>can play</html>

Opera 12.16:

<html>video/webm</html>
<html>VP9</html>
<html>Opus</html>
<html>MKV-fakeWebM [VP9+Opus]</html>
<html>no VP9 support; WebM-Opus MIME incompatible</html>

Direct link

~~ BEGIN HTML5 PLAYER ~~

<html>

<video controls="">
<source src="./upload/test2-quantum-ripples-vp9-opus.mkv" type='video/webm; codecs="vp9, opus"'>
</video>

</html>

~~ EOF ~~