I hadn't heard about this one 'till today when I saw this article talking about Google's new VP9 video codec which is to be released soon and used in YouTube and other popular platforms, like Skype. (Along with the WebM codec)

Then I reach to this line:
WebM will be updated to accommodate the new video codec and a new audio codec called Opus, too, said another Google employee, Lou Quillio.

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

Overview

Opus is a totally open, royalty-free, highly versatile audio codec. Opus is unmatched for interactive speech and music transmission over the Internet, but is also intended for storage and streaming applications. It is standardized by the Internet Engineering Task Force (IETF) as RFC 6716 which incorporated technology from Skype's SILK codec and Xiph.Org's CELT codec.

It is a codec designed for interactive usages, such as VoIP, telepresence, and remote jamming, that require very low latency. Opus can go as low as 5ms latency. Making a codec for low latency requires serious tradeoffs which reduce efficiency, so it might seem a bit strange to test it against a collection of state-of-the-art codecs which are completely unsuitable for these low-latency applications.

"When we started working on Opus (then known as CELT), we used the slogan "Why can't your telephone sound as good as your stereo?" and we weren't kidding. While we never expected in our wildest dreams to 'sound as good as your stereo' at the same bitrate, we tried to get as much efficiency as possible. When we exceeded the performance of MP3 (an older generation high-latency codec) in our first formal test several years ago we considered it a fantastic success, and we were later surprised when we found our low-bitrate result besting Vorbis. Now, these results demonstrate that Opus's performance against HE-AAC, one of the strongest (but highest-latency) codecs at this bitrate, are very strong, besting the quality of two of the most popular and respected encoders for the format on the majority of individual audio samples and receiving a higher average score overall.

Considering Opus's success in the tests, perhaps we should have asked "Why can't your stereo be as interactive as your telephone?" instead. This kind of convergence is already possible due to multimedia-ready web-browsers, mobile phones which are really mobile computers, and the expanding reach of high-speed Internet. Opus will provide the standardized royalty-free format needed to unleash the broad potential of low-delay, high-quality, multi-party audio."

Technology

Opus can handle a wide range of audio applications, including Voice over IP, videoconferencing, in-game chat, and even remote live music performances. It can scale from low bit-rate narrowband speech to very high quality stereo music. Supported features are:

- Bit-rates from 6 kb/s to 510 kb/s
- Sampling rates from 8 kHz (narrowband) to 48 kHz (fullband)
- Frame sizes from 2.5 ms to 60 ms
- Support for both constant bit-rate (CBR) and variable bit-rate (VBR)
- Audio bandwidth from narrowband to fullband
- Support for speech and music
- Support for mono and stereo
- Support for up to 255 channels (multistream frames)
- Dynamically adjustable bitrate, audio bandwidth, and frame size
- Good loss robustness and packet loss concealment (PLC)
- Floating point and fixed-point implementation

http://www.opus-codec.org/examples/
http://www.opus-codec.org/comparison/
http://people.xiph.org/~greg/opus/ha2011/



Those pages really got my interest. I think it sounds pretty decent considering most of those examples use an average bitrate of 64 kb/s. I tried it on a track myself and I can say it sounds better at 128kb/s compared to an mp3 of the same bitrate.

And a presentation:
https://www.youtube.com/watch?v=iaAD71h9gDU

Could be a serious candidate to replace ogg vorbis in games (not just real-time speech but also in-game sounds). I don't know if the same could apply to mp3 due to popularity and hardware limitations. But maybe in the future? FLAC has managed to sneak in some devices... Well, I thought this was of interest anyway.

 

thanks for the info on this

 

Opus has some great advantages for web applications, but it's not really useful for the same purposes as MP3, just because there is MP3.

Anyway, it's already supported by Rockbox.