IndexTTS-2 (MLX, fp16)
MLX conversion of IndexTeam/IndexTTS-2 —
zero-shot voice-cloning TTS with decoupled emotion control and duration control
(22.05 kHz output). Consolidated single-repo weight set for the Swift-MLX port
xocialize/mlx-indextts2-swift
(an MLXEngine tts package; also loadable by
solar2ain/mlx-indextts, whose conversion
lineage these weights follow — thanks to vanch007/mlx-indextts2-standard-fp16).
Contents
| File | Component | Dtype |
|---|---|---|
gpt.safetensors | UnifiedVoice v2 GPT AR (text→semantic) + conformer/perceiver conditioners | fp16 |
s2mel.safetensors | S2Mel flow-matching (DiT/WaveNet/length-regulator) | fp16 |
bigvgan.safetensors | BigVGAN v2 vocoder | fp16 |
vq2emb.safetensors | Semantic-code embedding | fp16 |
model.safetensors | w2v-BERT 2.0 conditioning front-end | fp32 (as upstream) |
semantic_codec/model.safetensors | MaskGCT RepCodec semantic codec | fp32 |
campplus.safetensors | CampPlus DTDNN speaker embedding (192-d) | fp32 |
emotion_matrices.safetensors | 8-emotion preset matrices (emo_matrix 73×1280, spk_matrix 73×192) | fp32 |
tokenizer.model / config.yaml / config.json | SentencePiece Unigram (12k) + resolved config | — |
int8/int4 tiers are produced in-memory by the Swift package (GPT transformer Linears, group 64) — no separate quantized repos.
Parity
The Swift port is phase-gated against a captured oracle: tokenizer bit-exact; GPT latent
cos 0.9999995; conditioners ≥0.999999; CFM mel 0.9999999; vocoder at the reference's own
CPU↔Metal precision floor; end-to-end waveform reproduces the reference render (spectral
cos 0.9998, −23.0 dBFS vs −23.2). Emotion (emoAlpha) and exact targetDuration were
validated live through MLXServeEngine.
License
Weights: NonCommercial — the INDEX_MODEL_LICENSE requires written authorization from bilibili for commercial use. Port/inference code is Apache-2.0 / MIT (see the source repos).