D3+D4: export stage PCM16/24 + TPDF dither + noise shaping, resample 44.1/48/96k, normalize -1dBTP/-14LUFS, mono side/mid check; Export modal mastering options + /plugins/render options (test 9 case, 23 passed)

2026-08-23 07:47:27 +07:00
parent 35076f680b
commit 5d37c0683b
8 changed files with 372 additions and 16 deletions
@@ -0,0 +1,179 @@
+# -*- coding: utf-8 -*-
+"""D3: export stage — PCM_16/PCM_24 + TPDF dither + noise shaping, resample,
+normalize (-1dBTP / -14LUFS), mono-compat side/mid ratio.
+
+Không cần bridge: test track AUDIO thuần (không fx chain) → render thẳng qua
+PythonRenderEngine, chỉ động chạm khâu export stage.
+"""
+import os
+import sys
+
+import numpy as np
+import pytest
+
+REPO = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+sys.path.insert(0, REPO)
+
+SR = 44100
+
+
+def _write_wav(path, data, sr):
+    import soundfile as sf
+    sf.write(path, data.T, sr, subtype="FLOAT")
+
+
+def _audio_track(path):
+    return {
+        "id": "t1",
+        "type": "AUDIO",
+        "volume_db": 0.0,
+        "pan": 0.0,
+        "fx_chain": [],
+        "vst_fx_chain": [],
+        "vst_fx_bypass": False,
+        "items": [{
+            "type": "AUDIO_ITEM",
+            "start_bar": 0.0,
+            "duration_bars": 1.0,
+            "clip_start_offset_bars": 0.0,
+            "source_data": {"audio_file_url": path},
+        }],
+    }
+
+
+def _project(path):
+    return {
+        "metadata": {"bpm": 120.0, "time_signature_numerator": 4},
+        "main_session": {"length_bars": 1.0, "tracks": [_audio_track(path)]},
+        "section_store": {},
+    }
+
+
+def _render(engine, proj, out, **kw):
+    engine.render_project(proj, out, **kw)
+    import soundfile as sf
+    info = sf.info(out)
+    data, sr = sf.read(out, dtype="float32", always_2d=True)
+    return data.T, sr, info
+
+
+def _sine_audio(dbfs, sec=2.0, freq=1000.0, sr=SR):
+    t = np.arange(int(sr * sec)) / sr
+    x = (10 ** (dbfs / 20.0)) * np.sin(2 * np.pi * freq * t)
+    return np.stack([x, x]).astype(np.float32)
+
+
+# ── quantize ───────────────────────────────────────────────────────────────
+def test_quantize_pcm16_grid_exact():
+    from app.core.render_engine import _quantize_pcm
+    x = np.array([[0.0, 0.5, -0.5, 0.9999, 1.0, -1.0]])
+    q = _quantize_pcm(x, 16, False)
+    assert q.dtype == np.int16
+    assert q[0, 0] == 0
+    assert q[0, 1] == 16384      # 0.5*32768
+    assert q[0, 2] == -16384
+    assert q[0, 3] == 32765      # 0.9999*32768=32765.44 → 32765
+    assert q[0, 4] == 32767      # 1.0 clip
+    assert q[0, 5] == -32768
+
+
+def test_dither_tpdf_noise_on_constant():
+    """Hằng số 0: không dither → toàn 0; dither TPDF → nhiễu quanh 0 (≤1 LSB)."""
+    from app.core.render_engine import _quantize_pcm
+    x = np.zeros((2, 20000))
+    q_nodith = _quantize_pcm(x, 16, False)
+    assert np.all(q_nodith == 0)
+    q_dith = _quantize_pcm(x, 16, True)
+    assert np.std(q_dith.astype(np.float64)) > 0.0
+    assert np.max(np.abs(q_dith)) <= 1
+
+
+def test_quantize_pcm24_int32_shift():
+    """PCM_24: int32 << 8 (libsndfile lưu top-24-bit)."""
+    from app.core.render_engine import _quantize_pcm
+    x = np.array([[0.5, -0.25]])
+    q = _quantize_pcm(x, 24, False)
+    assert q.dtype == np.int32
+    assert q[0, 0] == 4194304 << 8  # 0.5*2^23 = 4194304, <<8 lên top-24-bit
+    assert q[0, 1] == -2097152 << 8
+    assert np.all(q % 256 == 0)
+
+
+# ── engine export stage ────────────────────────────────────────────────────
+def test_engine_pcm16_subtype_and_peak(tmp_path):
+    from app.core.render_engine import PythonRenderEngine
+    wav = str(tmp_path / "in.wav")
+    _write_wav(wav, _sine_audio(-20.0), SR)
+    out = str(tmp_path / "out16.wav")
+    data, sr, info = _render(PythonRenderEngine(), _project(wav), out, bit_depth=16)
+    assert info.subtype == "PCM_16"
+    assert sr == SR
+    import soundfile as sf
+    di, _ = sf.read(out, dtype="int16", always_2d=True)
+    assert di.dtype == np.int16
+    assert float(np.max(np.abs(di))) <= 32767
+    pk = float(np.max(np.abs(data)))
+    assert abs(20 * np.log10(pk) - (-20.0)) < 0.1
+
+
+def test_engine_pcm24_subtype(tmp_path):
+    from app.core.render_engine import PythonRenderEngine
+    wav = str(tmp_path / "in.wav")
+    _write_wav(wav, _sine_audio(-20.0), SR)
+    out = str(tmp_path / "out24.wav")
+    data, sr, info = _render(PythonRenderEngine(), _project(wav), out, bit_depth=24)
+    assert info.subtype == "PCM_24"
+    assert sr == SR
+    import soundfile as sf
+    di, _ = sf.read(out, dtype="int32", always_2d=True)
+    assert np.all(di % 256 == 0)
+    pk = float(np.max(np.abs(data)))
+    assert abs(20 * np.log10(pk) - (-20.0)) < 0.1
+
+
+def test_engine_resample_48k(tmp_path):
+    from app.core.render_engine import PythonRenderEngine
+    wav = str(tmp_path / "in.wav")
+    _write_wav(wav, _sine_audio(-20.0), SR)
+    out = str(tmp_path / "out48.wav")
+    data, sr, info = _render(PythonRenderEngine(), _project(wav), out,
+                             out_sample_rate=48000)
+    assert info.subtype == "FLOAT"
+    assert sr == 48000
+    # 1 bar @120bpm 4/4 = 2s: 88200 @44.1k → 96000 @48k
+    assert abs(data.shape[1] - 96000) <= 16
+
+
+def test_normalize_1dbtp(tmp_path):
+    from app.core.render_engine import PythonRenderEngine
+    from app.core import loudness
+    wav = str(tmp_path / "in.wav")
+    _write_wav(wav, _sine_audio(-20.0), SR)
+    out = str(tmp_path / "norm_tp.wav")
+    data, sr, _ = _render(PythonRenderEngine(), _project(wav), out,
+                          normalize=True, normalize_target="-1dbtp")
+    tp = loudness.true_peak_db(data, sr)
+    assert abs(tp - (-1.0)) < 0.15, f"dBTP {tp:.3f} != -1"
+
+
+def test_normalize_14lufs(tmp_path):
+    from app.core.render_engine import PythonRenderEngine
+    from app.core import loudness
+    wav = str(tmp_path / "in.wav")
+    _write_wav(wav, _sine_audio(-20.0), SR)
+    out = str(tmp_path / "norm_lufs.wav")
+    data, sr, _ = _render(PythonRenderEngine(), _project(wav), out,
+                          normalize=True, normalize_target="-14lufs")
+    lufs = loudness.integrated_lufs(data, sr)
+    assert abs(lufs - (-14.0)) < 0.5, f"LUFS {lufs:.3f} != -14"
+
+
+def test_mono_side_ratio():
+    from app.core import loudness
+    sr = 44100
+    t = np.arange(sr) / sr
+    mono = np.stack([0.5 * np.sin(2 * np.pi * 440 * t)] * 2)      # L==R
+    assert loudness.mono_side_ratio(mono) < 1e-9
+    wide = np.stack([0.5 * np.sin(2 * np.pi * 440 * t),
+                     -0.5 * np.sin(2 * np.pi * 440 * t)])          # side-only
+    assert loudness.mono_side_ratio(wide) > 100.0