The Alliance for Open Media (the consortium behind the AV1 video codec) is developing OAC (Open Audio Codec) as a new open-source audio codec under the 3-Clause BSD license.
The project is available on GitHub and is in its very early stages, aiming to succeed Opus, the widely used format supporting WebRTC, streaming platforms, browsers, and many Linux audio systems.
It has served as the default open audio codec for over a decade, offering low-latency voice and high-quality music encoding. Opus is widely integrated into Linux desktops, browsers, conferencing tools, PipeWire systems, and streaming applications.
Project documentation states that OAC is experimental and not production-ready. There is no finalized specification, standardization timeline, or guarantee of backward compatibility. It is also important to note that OAC currently mirrors Opus capabilities, with no publicly documented functional advantages.
- Sampling rates from 8 to 48 kHz
- Bit-rates from 6 kb/s to 510 kb/s
- Support for both constant bit-rate (CBR) and variable bit-rate (VBR)
- Audio bandwidth from narrowband to full-band
- Support for speech and music
- Support for mono and stereo
- Support for multichannel (up to 255 channels)
- Frame sizes from 2.5 ms to 60 ms
- Good loss robustness and packet loss concealment (PLC)
- Floating-point and fixed-point implementation
In other words, at this stage, OAC appears to be just a development fork of Opus under the Alliance for Open Media’s governance. Whether it ultimately replaces Opus or evolves into a complementary format remains to be seen.
Hi, I’m trying to understand how codec transitions work across platforms like Android, iOS, browsers and apps such as WhatsApp Web and Discord. Opus had some support issues in older Android versions (5–9) and only became more stable in later versions. Now AOMedia is working on OAC (Open Audio Codec), which is intended to be a successor to Opus. My question is: If OAC becomes widely adopted in the future (for example in Android 20, future iOS versions, browsers, etc.), could Opus support eventually be removed? I understand that MP3 is still widely supported because it is universal and works everywhere. But Opus is newer and has had compatibility issues in some cases. Because of that, I’m worried that platforms might fully move to OAC and eventually stop caring about Opus, making it unsupported or less compatible over time. How do big platforms usually handle this kind of transition?
No matter how you look at it, this is reinventing the wheel. I don’t see anything new that it brings over Opus. It would have to be standardized from scratch, and besides, they could well dedicate that time and resources to direct optimizations and improvements to Opus.