| import unittest |
| import numpy as np |
| import os |
| import sys |
| import tempfile |
| import soundfile as sf |
|
|
| sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__)))) |
|
|
| from src.audio_utils import resample, load_and_resample, condition_audio |
|
|
|
|
| def tone(freq, sr, seconds=1.0, amp=0.5): |
| t = np.arange(int(sr * seconds)) / sr |
| return (amp * np.sin(2 * np.pi * freq * t)).astype(np.float32) |
|
|
|
|
| class TestResample(unittest.TestCase): |
| def test_removes_content_above_nyquist(self): |
| |
| out = resample(tone(10000, 48000), 48000, 16000) |
| self.assertLess(np.sqrt(np.mean(out[1000:-1000] ** 2)), 0.01) |
|
|
| def test_preserves_speech_band_tone(self): |
| out = resample(tone(1000, 44100), 44100, 16000) |
| self.assertEqual(len(out), 16000) |
| self.assertAlmostEqual(np.sqrt(np.mean(out[1000:-1000] ** 2)), 0.5 / np.sqrt(2), delta=0.02) |
|
|
| def test_upsample_8k(self): |
| out = resample(tone(1000, 8000), 8000, 16000) |
| self.assertEqual(len(out), 16000) |
| self.assertEqual(out.dtype, np.float32) |
|
|
| def test_16k_passthrough(self): |
| x = tone(1000, 16000) |
| self.assertTrue(np.array_equal(resample(x, 16000, 16000), x)) |
|
|
| def test_load_and_resample_uses_soxr(self): |
| stereo = np.stack([tone(10000, 48000), tone(10000, 48000)], axis=1) |
| with tempfile.NamedTemporaryFile(suffix=".wav", delete=False) as f: |
| path = f.name |
| try: |
| sf.write(path, stereo, 48000) |
| data, duration = load_and_resample(path) |
| finally: |
| os.remove(path) |
| self.assertEqual(data.ndim, 1) |
| self.assertEqual(data.dtype, np.float32) |
| self.assertAlmostEqual(duration, 1.0, places=3) |
| self.assertLess(np.sqrt(np.mean(data[1000:-1000] ** 2)), 0.01) |
|
|
|
|
| class TestConditionAudio(unittest.TestCase): |
| def test_removes_dc_normalizes_and_pads(self): |
| x = (0.1 * np.sin(2 * np.pi * 440 * np.arange(16000) / 16000) + 0.05).astype(np.float32) |
| out = condition_audio(x) |
| self.assertEqual(len(out), 16000 + 2 * 3200) |
| self.assertTrue(np.all(out[:3200] == 0) and np.all(out[-3200:] == 0)) |
| self.assertLess(abs(out[3200:-3200].mean()), 1e-3) |
| self.assertAlmostEqual(np.abs(out).max(), 0.9, delta=1e-3) |
|
|
| def test_all_zero_stays_zero(self): |
| out = condition_audio(np.zeros(1600, dtype=np.float32)) |
| self.assertFalse(np.isnan(out).any()) |
| self.assertEqual(np.abs(out).max(), 0.0) |
|
|
| def test_near_silent_gain_is_capped(self): |
| x = (0.001 * np.sin(2 * np.pi * 440 * np.arange(16000) / 16000)).astype(np.float32) |
| self.assertAlmostEqual(np.abs(condition_audio(x)).max(), 0.01, delta=1e-4) |
|
|
| def test_empty_input_returns_padding_only(self): |
| self.assertEqual(len(condition_audio(np.zeros(0, dtype=np.float32))), 6400) |
|
|
|
|
| if __name__ == "__main__": |
| unittest.main() |
|
|
