[opus] Opus 1.3 is out!

[Jean-Marc Valin]

Hi everyone,

I'm happy to announce that Opus 1.3 was just released. This major
release again brings quality improvements, new features, and bug fixes.
You can read all the details in this release demo page:
https://people.xiph.org/~jm/opus/opus-1.3/

Changes since 1.2.x include:
- Improvements to the VAD and speech/music classification using an RNN
- Support for ambisonics coding using channel mapping families 2 and 3
- Improvements to stereo speech coding at low bitrate
- Using wideband encoding down to 9 kb/s
- Making it possible to use SILK down to bitrates around 5 kb/s
- Minor quality improvement on tones
- Enabling the spec fixes in RFC 8251 by default
- Security/hardening improvements

Notable bug fixes include:
- Fixes to the CELT PLC
- Bandwidth detection fixes

Source code:
https://archive.mozilla.org/pub/opus/opus-1.3.tar.gz

Win32 binaries:
https://archive.mozilla.org/pub/opus/win32/opus-tools-0.2-opus-1.3.zip

Please report any problem you encounter.

Cheers,

	Jean-Marc