digitaltrends.com has a interesting post about Opus, a royalty-free, open-source audio codec which is currently outperforming many industry standards (Mp3, Vorbis, AAC). The secret sauce to Opus is its ability to take advantage of audio channel redundancies through a hybrid architecture. Opus is able to dynamically use SILK and or CELT codecs depending on the frequency band that is being coded, typically speech or music. The end result is higher quality audio at lower bit-rates that is optimized for interactive audio applications. The video below is an in-depth presentation about the codec by Jean-Marc Valin. As Opus continues to gain ground as an online audio standard, the future definitely sounds good, even at at 64kb/s.
The Opus codec was developed by a consortium of researchers from Mozilla, Xiph.org, Skype, Microsoft, and Broadcomm. Previous audio codecs have been optimized for specific uses – MP3 for music, SILK for voice, and so on –– but Opus promisesbetter sound for everything, no matter how low your bitrate. Opus switches between different codecs based on how much bandwidth it detects, so it can reduce latency and drop-outs on any connection.