124 lines
3.4 KiB
Python

from __future__ import annotations
from pathlib import Path
import numpy as np
import pytest
import soundfile as sf
from level_1.level_1 import aac_coder_1, i_aac_coder_1
# Helper "fixtures" for aac_coder_1 / i_aac_coder_1
# -----------------------------------------------------------------------------
def _snr_db(x_ref: np.ndarray, x_hat: np.ndarray) -> float:
"""
Compute overall SNR (dB) over all samples and channels after aligning lengths.
"""
x_ref = np.asarray(x_ref, dtype=np.float64)
x_hat = np.asarray(x_hat, dtype=np.float64)
if x_ref.ndim == 1:
x_ref = x_ref.reshape(-1, 1)
if x_hat.ndim == 1:
x_hat = x_hat.reshape(-1, 1)
n = min(x_ref.shape[0], x_hat.shape[0])
c = min(x_ref.shape[1], x_hat.shape[1])
x_ref = x_ref[:n, :c]
x_hat = x_hat[:n, :c]
err = x_ref - x_hat
ps = float(np.sum(x_ref * x_ref))
pn = float(np.sum(err * err))
if pn <= 0.0:
return float("inf")
if ps <= 0.0:
return -float("inf")
return float(10.0 * np.log10(ps / pn))
@pytest.fixture()
def tmp_stereo_wav(tmp_path: Path) -> Path:
"""
Create a temporary 48 kHz stereo WAV with random samples.
"""
rng = np.random.default_rng(123)
fs = 48000
# ~1 second of audio, keep small for test speed
n = fs
x = rng.normal(size=(n, 2)).astype(np.float64)
wav_path = tmp_path / "in.wav"
sf.write(str(wav_path), x, fs)
return wav_path
def test_aac_coder_seq_schema_and_shapes(tmp_stereo_wav: Path) -> None:
"""
Module-level contract test:
Ensure aac_seq_1 follows the expected schema and per-frame shapes.
"""
aac_seq = aac_coder_1(tmp_stereo_wav)
assert isinstance(aac_seq, list)
assert len(aac_seq) > 0
for fr in aac_seq:
assert isinstance(fr, dict)
# Required keys
assert "frame_type" in fr
assert "win_type" in fr
assert "chl" in fr
assert "chr" in fr
frame_type = fr["frame_type"]
win_type = fr["win_type"]
assert frame_type in ("OLS", "LSS", "ESH", "LPS")
assert win_type in ("SIN", "KBD")
assert isinstance(fr["chl"], dict)
assert isinstance(fr["chr"], dict)
assert "frame_F" in fr["chl"]
assert "frame_F" in fr["chr"]
chl_f = np.asarray(fr["chl"]["frame_F"])
chr_f = np.asarray(fr["chr"]["frame_F"])
if frame_type == "ESH":
assert chl_f.shape == (128, 8)
assert chr_f.shape == (128, 8)
else:
assert chl_f.shape == (1024, 1)
assert chr_f.shape == (1024, 1)
def test_end_to_end_aac_coder_decoder_high_snr(tmp_stereo_wav: Path, tmp_path: Path) -> None:
"""
End-to-end module test:
Encode + decode and check SNR is very high (numerical-noise only).
Threshold is intentionally loose to avoid fragility.
"""
x_ref, fs = sf.read(str(tmp_stereo_wav), always_2d=True)
assert fs == 48000
out_wav = tmp_path / "out.wav"
aac_seq = aac_coder_1(tmp_stereo_wav)
x_hat = i_aac_coder_1(aac_seq, out_wav)
# Basic sanity: output file exists and is readable
assert out_wav.exists()
x_hat_file, fs_hat = sf.read(str(out_wav), always_2d=True)
assert fs_hat == 48000
# SNR computed against the array returned by i_aac_coder_1 (should match file, but not required)
snr = _snr_db(x_ref, x_hat)
assert snr > 80.0