Hacker News new | ask | show | jobs
by graue 5004 days ago
For audio at least, things are looking up. Opus, a new royalty-free codec backed by both Mozilla Foundation and Skype (Microsoft), has been standardized as an RFC[1], and will likely be mandatory in WebRTC[2]. So we should be seeing that across all major browsers in a year or two.

Opus beats almost all other codecs (MP3, AAC and HE-AAC, Vorbis) in subjective quality[3], so it's a good standard to have.

[1] https://tools.ietf.org/html/rfc6716

[2] http://jmspeex.livejournal.com/11042.html

[3] http://www.wired.co.uk/news/archive/2012-09/15/opus-codec, also http://people.xiph.org/~greg/opus/ha2011/

2 comments

The IETF is forming a new working group for an open video codec[1]. It is still a BoF and will be chartered in 3-6 months, which is when the real work will begin. More details on the charter can be found in this email [2].

As for the audio, WebRTC chose G.711 and Opus as mandatory to implement (MTI)[3]. The reason for G.711 is so that WebRTC can interoperate with legacy devices.

[1] http://www.ietf.org/mail-archive/web/video-codec/current/mai...

[2] http://www.ietf.org/mail-archive/web/video-codec/current/msg...

[3] http://www.ietf.org/mail-archive/web/rtcweb/current/msg05267...

Isn't Opus for speech?
Not solely. Opus is a hybrid of the SILK codec, which is more for speech, and CELT, which is more aimed at music. It can seamlessly switch between the two methods and use them simultaneously: https://wiki.xiph.org/OpusFAQ#Why_not_keep_the_SILK_and_CELT...

The main goal was streaming (of both music and speech), and hence, low latency. Matching or bettering high-latency codecs (like Vorbis) on quality was just a bonus, and I believe somewhat of a surprise to the developers when listening test results came out.

Apparently not

http://www.opus-codec.org/

> Opus is a totally open, royalty-free, highly versatile audio codec. Opus is unmatched for interactive speech and music transmission over the Internet, but also intended for storage and streaming applications