So as promised a year ago, I updated the libllsm repository to the latest version used by Moresampler.

There're quite some changes to the legacy version, in particular the two-layer representation of speech signal. The legacy libllsm is now called layer 0 LLSM, and there's a layer 1 model being added. The layer 1 model is an acoustic re-interpretation of the harmonic component in layer 0 and the conversion from layer 0 to layer 1 involves a new algorithm, which I prefer to call as Pseudo Glottal Inverse Filtering (PGIF), that approximately inverses the speech production process. All these changes are made in the direction that sticks to the principles of speech production, and enables more acoustically-meaningful modification of speech.

More details can be found in