soniqo/Supertonic-3-LiteRT
SupertonicTTS-3 — LiteRT (.tflite, Android / Qualcomm NPU)
First-party LiteRT export of Supertonic-3's four non-autoregressive flow-matching graphs. Built by our own pipeline (speech-models/stmodels): weights lifted from the `Supertone/supertonic-3` ONNX initializers → PyTorch nn.Module → `litert_torch.convert` (torch.export → StableHLO → TFLite). This avoids the onnx2tf NCHW/ConvNeXt layout failures that block direct ONNX→TFLite for this model.
Graphs & parity (FP32, vs ONNX Runtime)
Shapes are fixed (T=128 text tokens; latent length L per graph) — litert_torch cannot lower the relpos attention + ConvNeXt stack with a symbolic L, so the latent axis ships in buckets: the base pair is L=64 (≈4.5 s of audio), and *_L128.tflite is the same two L-dependent graphs exported at L=128 (≈9 s). Pick the smallest bucket whose window holds a piece's predicted duration — short sentences run on the cheap L=64 pair, a long sentence is generated in one pass on L=128 instead of being split (speech-core's LiteRTSupertonicTts does this automatically and loads the L=128 pair on first use). The host runs the flow-matching ODE loop (vector_estimator ×total_steps). Assets to drive them: tts.json, unicode_indexer.json (G2P-free tokenizer), voice_styles/*.json.
Graph inputs are bound by tensor name (serving_default_args_N, N = signature position): the converter permutes input slots differently per toolchain version, so do not rely on slot order.
Running on Android / Qualcomm NPU
- CPU/GPU: LiteRT (
ai_edge_litert/ TFLite) interpreter with XNNPACK/GPU delegate. - Qualcomm HTP/NPU: the LiteRT QNN delegate at runtime, or compile to a QNN context binary via Qualcomm AI Hub (
qai_hub) from these graphs (static shapes are HTP-friendly). int8/int4 PTQ viaai-edge-quantizerfor full HTP residency is a follow-up.
Attribution & license
- Weights: derivative of `Supertone/supertonic-3` (commit
3cadd1ee6394adea1bd021217a0e650ede09a323), Supertone Inc., arXiv:2503.23108 — OpenRAIL-M (use-based restrictions carry over).
Other Supertonic-3 formats
- **Supertonic-3 — ONNX (INT8)** — server / desktop (ONNX Runtime).
- **Supertonic-3 — CoreML** — iOS / Apple Neural Engine (.mlpackage).
Ecosystem
- **soniqo.audio** — website / use-case explorer (transcription, voice cloning, live ASR, voice agents).
- **speech-core** — C++ orchestration library; Supertonic plugs in as a
TTSInterfaceLiteRT model. - **speech-swift** — Apple Silicon MLX + CoreML runtime.
- **speech-android** — Android SDK consuming on-device LiteRT bundles.
