Model card: family README with htdemucs_ft, license + attribution

README.md

@@ -1,3 +1,38 @@
----
-license: mit
----
+---
+license: mit
+tags:
+  - audio
+  - music-source-separation
+  - stem-separation
+  - onnx
+  - demucs
+---
+
+# HTDemucs — ONNX conversions
+
+ONNX conversions of the Demucs v4 (Hybrid Transformer) family, packaged for
+[SonicDemixer](https://smank.io) (on-device stem separation for macOS). All
+graphs share one contract: input `mix` `[1, 2, segmentSamples]` float32
+planar waveform → output `sources` `[1, numStems, 2, segmentSamples]`,
+opset 17, STFT/iSTFT embedded in the graph (no complex dtypes).
+
+| File | Stems | Notes |
+|---|---|---|
+| `htdemucs.onnx` | drums, bass, other, vocals | baseline 4-stem |
+| `htdemucs_6s.onnx` | + guitar, piano | 6-source variant |
+| `htdemucs_ft.onnx` | drums, bass, other, vocals | the fine-tuned bag's four per-source models fused into ONE graph — each submodel contributes its specialty stem (mapping verified against the bag weights). Higher quality, ~4× the compute. |
+
+Integrity: files are LFS-tracked; the LFS OID is the SHA-256 that consuming
+apps verify after download.
+
+## License & attribution
+
+MIT. These are derivative conversions of:
+
+- **Demucs / HTDemucs** — code and pretrained weights © Meta Platforms (FAIR),
+  MIT. https://github.com/facebookresearch/demucs
+- **ONNX-exportable HTDemucs + conv-based STFT/iSTFT** — Mixxx Development
+  Team demucs fork (GSoC 2025, Anmol Mishra), MIT.
+  https://github.com/mixxxdj/demucs
+
+Conversion scripts: `tools/model-conversion/` in the SonicDemixer repository.