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aufklarer/Parakeet-TDT-v3-CoreML-INT8

sourceHugging Facecc-by-4.0updated 3mo agoView on Hugging Face
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Model Card

Parakeet TDT v3 — CoreML INT8

CoreML conversion of NVIDIA Parakeet-TDT 0.6B v2 with INT8-quantized encoder for Apple Neural Engine acceleration.

Models

ModelDescriptionComputeQuantization
encoder.mlmodelcFastConformer encoder (24L, 1024 hidden)CPU + Neural EngineINT8 palettized
decoder.mlmodelcLSTM prediction network (2L, 640 hidden)CPU + Neural EngineFP16
joint.mlmodelcTDT dual-head joint (token + duration logits)CPU + Neural EngineFP16

Additional Files

FileDescription
vocab.jsonSentencePiece vocabulary (1024 tokens)
config.jsonModel configuration

Notes

  • INT8 vs INT4: INT8 uses 8-bit palettization for the encoder, offering higher accuracy than INT4 at the cost of ~2x encoder weight size.
  • Mel preprocessing is done in Swift using Accelerate/vDSP (not CoreML) because torch.stft tracing bakes audio length as a constant, breaking per-feature normalization for variable-length inputs.
  • Encoder uses EnumeratedShapes (100–3000 mel frames, covering 1–30s audio) to avoid BNNS crashes with dynamic shapes.

Usage

Used by speech-swift ParakeetASR module:

swift
let model = try await ParakeetASRModel.fromPretrained(modelId: ParakeetASRModel.int8ModelId)
let text = try model.transcribeAudio(samples, sampleRate: 16000)