The
Opus Codec is known to have better quality at a lower size than legacy codecs such as MP3, WMA, Vorbis, Speex, and AAC. See our
sound test discussion. Opus within
MKV is still missing a few things and not supported everywhere, but support at the moment is still pretty good.
Since support is pretty good, we should start switching to it shortly.
Opus audio tools:
http://www.opus-codec.org/downloads/
MKV creating with Opus can be done using mkvmerge from
mkvtoolnix (
Windows).
Media file information:
http://mediaarea.net/en/MediaInfo
If you're on Debian Linux, note that Debian takes a while to upgrade some packages, and furthermore, due to licensing, doesn't compile a lot of features into the packages they build. Therefore one of the Debian multimedia maintainers have a separate repository with more up to date and fully featured packages.
http://www.deb-multimedia.org/
Some tools can encode audio, video, and mux into a container file all at the same time and support MKV with Opus:
FFMPEG (
Windows).
MEncoder (
Windows) (Part of MPlayer).
MPV (
Windows).
File to test Opus in MKV:
http://ilari.tasvideos.org/kirbyglitched.opus-10bit444.mkv
Players which support Opus in MKV:
MPlayer (
Windows).
MPV (
Windows).
ffplay from
FFMPEG (
Windows).
Official
SMplayer builds.
K-Lite Mega Codec Pack for Windows- provides up to date versions of Media Player Classic Homecinema, LAV Video, and ffdshow. I did not test out the individual versions of each of these applications, or the versions floating around on other build sites, but the versions and default settings in this package do the trick.
Tools which DO NOT (but should!) support Opus in MKV:
Libav (
Windows) - The avconv and avplay converter and player.
MPlayer2 (
Windows).
VLC.
I tested everything enumerated here using latest versions in Debian repositories, and Windows builds from the various sites for Windows XP.
For Debian Linux Encoding+Muxing, there are 3/4 applications. For Windows, 3/4.
For Debian Linux playback, there are 4/7 applications. For Windows, 5/8.
All in all, it looks like there's enough support that we can move ahead.
Encoders, please weigh in.
(All information is only up to date at the time of this writing - September 22 2013)
Edit: Added MPV for Windows. Thanks you turska.
Edit: MPlayer/MEncoder on Debian has been updated, and now supports Opus in MKV.