48 lines
1.4 KiB
Python
48 lines
1.4 KiB
Python
import numpy as np
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import pytest
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scipy_signal = pytest.importorskip("scipy.signal")
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from client.audio import resample_24k_to_16k
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def test_length_and_dtype():
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frame = np.zeros(1920, dtype=np.int16)
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out = resample_24k_to_16k(frame)
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assert out.shape == (1280,)
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assert out.dtype == np.int16
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def test_constant_signal_stays_constant():
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frame = np.full(1920, 1000, dtype=np.int16)
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out = resample_24k_to_16k(frame)
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# poly resample of a constant is the same constant up to filter ringing
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assert np.abs(out.astype(int).mean() - 1000) < 5
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def test_silence_in_silence_out():
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frame = np.zeros(1920, dtype=np.int16)
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out = resample_24k_to_16k(frame)
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assert int(np.max(np.abs(out))) == 0
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def test_sine_peak_frequency_preserved():
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# 1 kHz sine at 24 kHz: 80 ms = 80 cycles.
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t = np.arange(1920) / 24_000.0
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sig = (8000 * np.sin(2 * np.pi * 1000 * t)).astype(np.int16)
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out = resample_24k_to_16k(sig)
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# 1 kHz in a 1280-sample 16 kHz window is bin (1000 / 16000) * 1280 = 80.
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spec = np.abs(np.fft.rfft(out.astype(np.float32)))
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peak = int(np.argmax(spec))
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assert abs(peak - 80) <= 1
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def test_zero_length_input_raises():
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with pytest.raises(ValueError):
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resample_24k_to_16k(np.zeros(0, dtype=np.int16))
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def test_wrong_dtype_rejected():
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with pytest.raises(TypeError):
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resample_24k_to_16k(np.zeros(1920, dtype=np.float32))
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