ver0.1

tests/test_audio_wav_normalize.py

@@ -0,0 +1,45 @@
+"""PCM 归一化与 WAV 封装。"""
+
+from __future__ import annotations
+
+import array
+
+import pytest
+
+from app.services.audio_wav import (
+    WavDecodeError,
+    normalize_pcm_s16le_for_baidu,
+    pcm_s16le_to_wav_bytes,
+    wav_bytes_to_pcm16k_mono_s16le,
+)
+
+
+def test_normalize_boosts_quiet_pcm() -> None:
+    samples = array.array("h", [50, -80, 30] * 500)
+    pcm = samples.tobytes()
+    out = normalize_pcm_s16le_for_baidu(pcm)
+    arr = array.array("h")
+    arr.frombytes(out)
+    assert max(abs(x) for x in arr) > max(abs(x) for x in samples)
+
+
+def test_normalize_skips_loud_pcm() -> None:
+    samples = array.array("h", [15000, -14000])
+    pcm = samples.tobytes()
+    out = normalize_pcm_s16le_for_baidu(pcm)
+    assert out == pcm
+
+
+def test_pcm_wav_roundtrip_is_valid_wav() -> None:
+    pcm = array.array("h", [100, -200, 300] * 100).tobytes()
+    wav = pcm_s16le_to_wav_bytes(pcm)
+    back = wav_bytes_to_pcm16k_mono_s16le(wav)
+    assert len(back) == len(pcm)
+    assert max(abs(x) for x in array.array("h", back)) >= max(
+        abs(x) for x in array.array("h", pcm)
+    )
+
+
+def test_pcm_s16le_to_wav_empty_raises() -> None:
+    with pytest.raises(WavDecodeError):
+        pcm_s16le_to_wav_bytes(b"")