File size: 1,822 Bytes
a3c6c73 6c3b1c5 a3c6c73 6c3b1c5 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 | ---
license: mit
library_name: onnxruntime
pipeline_tag: audio-to-audio
tags:
- music-source-separation
- htdemucs
- demucs
- onnx
- onnxruntime-web
- webgpu
- stem-separation
---
# HTDemucs 6S for ONNX Runtime Web (Audisect build)
Browser-ready ONNX build of **HTDemucs 6S** (Hybrid Transformer Demucs, 6 sources), used by
[Audisect](https://audisect.funkz.app), a free stem splitter that runs entirely in the browser.
| File | Size | SHA-256 |
|---|---|---|
| `htdemucs_6s_web.onnx` | 142,808,361 bytes | `76d177e4cfd7da6aad46e540c5dc929a80f5e839d306a285265f9ec49a28a1ea` |
## Inputs and outputs
- **Input** `mix`: `float32 [1, 2, 343980]`, stereo, 44.1 kHz, 7.8 s, values in [-1, 1].
- **Output**: `float32 [1, 6, 2, 343980]`, stems in order `drums, bass, other, vocals, guitar, piano`.
Process longer audio in overlapping 7.8 s chunks and crossfade the results.
## How this file was made
It is derived from [`StemSplitio/htdemucs-6s-onnx`](https://huggingface.co/StemSplitio/htdemucs-6s-onnx)
(`htdemucs_6s_fp16weights.onnx`) with Audisect's `scripts/prepare_model.py`:
1. float64 constants in the iSTFT converted to float32 (ONNX Runtime Web has no float64 `ConstantOfShape`),
2. graph constant-folded with ONNX Runtime's basic optimisations (24,819 to 1,436 nodes),
3. weights stored as float16 with `Cast` nodes.
Checked against the source model on random input: relative RMS error about 3e-5.
## License and attribution
MIT, same as the upstream weights and export.
- Model: **HTDemucs** by Meta AI Research, [facebookresearch/demucs](https://github.com/facebookresearch/demucs) (MIT).
- Paper: Simon Rouard, Francisco Massa, Alexandre Défossez, *Hybrid Transformers for Music Source Separation*, ICASSP 2023.
- ONNX export: [StemSplit](https://github.com/StemSplit/demucs-onnx) (MIT).
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