Opus is a lossy audio coding format developed by the Internet Engineering Task Force (IETF). It is suitable for interactive real-time applications over the Internet. Opus format was finalized in 2012.
- Opus can be adjusted seamlessly between high and low bitrates.
- Opus has a low latency delay which allow lipsync at live broadcasts.
- It is a standardize open format.
- It competes favorably with MP3, Vorbis, HE-AAC at similar bitrates. Some say it is better that MP3.
- One of the newest format for use with Video formats in multi-media use
SoundCloud has ditched 128kbps MP3 files for 64kbps Opus files and the company itself is claiming no change to audio quality. The smaller bitrate means using way less bandwidth, leading to faster start-up times (less delay between hitting play and hearing tunes), better reliability on poor-quality or slower connections, like cellular service and fewer monetary charges (a possible bonus for SoundCloud users in the States where the repeal of net neutrality means internet providers can start hiking up prices for subscribers who use more data). For SoundCloud itself, cutting its bandwidth use in half will significantly lower its in-house costs and saving money is likely a priority.