johnpattern/safenotes-sortformer-v2

Streaming Sortformer 4spk v2 (ONNX) for Safenotes

NVIDIA's Streaming Sortformer speaker-diarization model (up to 4 speakers) exported to ONNX with its streaming inputs (chunk, speaker cache, FIFO), plus the mel filterbank and window tables of its preprocessor.

This is a format conversion made by Safenotes (a local, on-device meeting notetaker) so the model runs on Intel hardware (ONNX Runtime / sherpa-onnx). It is not an official release of the original authors, who do not endorse it. All credit for the model goes to them.

Original model and attribution

• Streaming Sortformer 4spk v2 by NVIDIA: nvidia/diar_streaming_sortformer_4spk-v2 at revision 84edd514b8ef68004c10086918cd62f2148cbd59, licensed CC-BY-4.0 (model card metadata license: cc-by-4.0 and its Licence section at that revision). Note: the later v2.1 model is under the NVIDIA Open Model License and is NOT used here.

This repository is distributed under the same licence: Creative Commons Attribution 4.0 International (CC-BY-4.0). The full licence text is in LICENSE.

Changes made by Safenotes

own/sortformer-v2.onnx: the original .nemo checkpoint (sha256 b371afce2c49…) exported by Safenotes with torch.onnx (opset 18, fp32), with the streaming state as explicit inputs/outputs (the state update runs outside the graph, as in NeMo's forward_streaming). mel_fb.npy / mel_window.npy: the mel filterbank and window of the model's own preprocessor, saved as arrays. No retraining. Parity with NeMo 3.0.0 forward_streaming: 0 frames flipped.

How Safenotes uses it

Safenotes uses it for speaker labels during the call (ONNX Runtime on the CPU). The Safenotes app downloads the files below from a pinned revision of this repository and checks every file's sha256 before using it. Everything runs on the user's PC; no audio or text leaves it.

Files

3 files, 492,379,127 bytes.

file	bytes	sha256
mel_fb.npy	131,712	462cb0ddf0ee659b44e73eb67f06d1ebb4663a16d5a2fa98315ad875955424c1
mel_window.npy	1,728	39daf4ff0914631de0068adb484e81f390e8c053c836ad5ba92f76849bf334fd
own/sortformer-v2.onnx	492,245,687	a5974a8d8689bf5d7f03167bf290cd5a1a81081cb2b14a26ecae3fac418812f4

No warranty

Provided "as is", without warranties or conditions of any kind, express or implied, including fitness for a particular purpose and accuracy of the output (see the licence). Use at your own risk.