Release Notes: This version fixes two minor bugs with 0.11 that affect the bit-stream. The quality should improve (very) slightly, but not enough to be noticeable in most cases. Several Opus-related bugs have also been fixed.
Release Notes: This release brings many quality improvements, mostly through better bit allocation. It also fixes many bugs and regressions, most notably with VBR support. The bit-stream is not compatible with version 0.9.x.
Release Notes: This release fixes the PLC that was broken in 0.9.0. No other changes were made beyond that. The bit-stream is compatible with 0.9.0.
Release Notes: This release mainly focuses on quality improvements. The transient handling code has been greatly improved and high-frequency artifacts have been reduced. There have also been lots of small improvements from better tuning of various parameters.
Release Notes: This release fixes some bugs introduced in 0.8.0. The bit-stream remains compatible with 0.8.0, with the caveat that CELT no longer supports frame sizes that have prime factors larger than 5. This should not affect any reasonable application.
Release Notes: This release brings quality improvements for high bit-rates and for transients in general. It also adds the ability to change the frame size dynamically, which requires a minor change in the API. The new PLC algorithm from 0.7.1 is now enabled for the fixed-point builds as well. As is typical for CELT, this release is not compatible with previous releases.
Release Notes: This release improves the quality of the packet loss concealment (PLC), but does not change the rest of the codec. For this reason, it is the first release not to break bit-stream compatibility with the previous release (0.7.0). However, the next release will likely break compatibility once again. Note that the PLC improvements have not been completely converted to fixed-point yet, so the fixed-point still uses the old PLC. The default name of the library was changed to libcelt0.so.
Release Notes: This release improves the stereo quality, reduces artefacts at low bitrates (birdies and speech roughness), and fixes many bugs. In addition to the usual bitstream incompatibilities, the API has also changed in this release.
Release Notes: This release improves stereo quality, especially at lower bit rates. This breaks bit-stream compatibility again, but only for stereo this time.
Release Notes: This release brings in many quality improvements, including better stereo coupling, better handling of transients, and better handling of highly tonal signals. In addition, packet loss robustness has been improved through the optional use of independent (intra) frames. CELT now supports a larger dynamic range, suitable for encoding 24-bit audio (float version only). There is also a very early VBR implementation.