Files
wyoming-parakeet-mlx/test/conftest.py
T
aharrison-fullerandClaude Opus 5 4286e88344 Wyoming speech-to-text server for Home Assistant using NVIDIA Parakeet
Loads parakeet-mlx in-process (no HTTP hop) and serves it over the Wyoming
protocol. On an M4 Mac mini this transcribes typical voice commands in ~110ms
versus ~1150ms for a whisper.cpp large-v3 setup, with identical accuracy on a
ten-command benchmark.

Two behaviours matter beyond speed: silence returns an empty string rather
than whisper's "Thank you." hallucination, and there is no decoder context
carried between requests.

Notable implementation details, all covered by mutation-checked regression
tests:

- MLX streams are thread-local, so the model is loaded and evaluated on a
  single dedicated worker thread. Splitting those raises
  "There is no Stream(cpu, 1) in current thread".
- parakeet_mlx.load_audio() shells out to ffmpeg, which is unnecessary here
  since Wyoming delivers 16kHz mono PCM. The mel is built directly via
  get_logmel(), whose input must be float32 -- it views the complex STFT
  output as the input dtype, so anything narrower doubles the mel bin count.
- Wyoming's run loop has no except clause, so an exception escaping
  handle_event closes the connection without sending a Transcript and Home
  Assistant waits indefinitely. Failures are caught and returned as an empty
  transcript instead.

Defaults to parakeet-tdt-0.6b-v2 rather than the newer multilingual v3
because v2 emits digits ("21 degrees") where v3 spells numbers out, and
Home Assistant's local intent matching expects digits.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-07-29 03:04:48 +01:00

13 lines
267 B
Python

import numpy as np
import pytest
@pytest.fixture
def pcm():
"""Build int16 mono PCM bytes of a given sample count."""
def _pcm(n_samples: int, value: int = 8192) -> bytes:
return np.full(n_samples, value, dtype=np.int16).tobytes()
return _pcm