lou
103 lines
3.2 KiB
Python
103 lines
3.2 KiB
Python
"""32 段 EQ + 总音量 —— pipe 插件载荷(单声道块进, 单声道块出)。
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参数实时来自共享内存(dsp/common.py): 32 段增益(dB) + 总音量(dB)。
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做法: 每段一个 peaking biquad, 32 段级联成二阶节(sos), 用 scipy.signal.sosfilt
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逐块滤波(C 实现, 保留滤波状态, 无额外延迟), 末级乘总音量。
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"""
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from __future__ import annotations
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import math
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import os
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import sys
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import numpy as np
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from scipy.signal import sosfilt
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sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
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import common # noqa: E402
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RATE = int(os.environ.get("CX_RATE", "96000"))
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BLOCK_BYTES = 4096
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N = BLOCK_BYTES // 4 # 每块样本数(1024)
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Q = 4.318 # 1/3 倍频程
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def design_peaking(freq: float, gain_db: float, fs: int, q: float) -> list[float]:
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"""RBJ cookbook 的 peaking biquad, 返回一行 sos [b0 b1 b2 1 a1 a2]。
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gain_db = 0 时结果恰好是单位传递函数, 所以 32 段可以一直挂着(不必增删节点)。
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"""
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amp = 10.0 ** (gain_db / 40.0)
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w0 = 2.0 * math.pi * freq / fs
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alpha = math.sin(w0) / (2.0 * q)
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cos_w0 = math.cos(w0)
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b0 = 1.0 + alpha * amp
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b1 = -2.0 * cos_w0
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b2 = 1.0 - alpha * amp
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a0 = 1.0 + alpha / amp
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a1 = -2.0 * cos_w0
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a2 = 1.0 - alpha / amp
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return [b0 / a0, b1 / a0, b2 / a0, 1.0, a1 / a0, a2 / a0]
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def build_sos(gains: list[float], fs: int) -> np.ndarray:
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"""32 段增益 -> sos 矩阵(32 x 6)。"""
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return np.array([design_peaking(freq, gain, fs, Q)
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for freq, gain in zip(common.EQ_FREQS, gains)], dtype=np.float64)
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def level_db(block: np.ndarray) -> tuple[float, float]:
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"""返回 (RMS dBFS, 峰值 dBFS)。"""
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if block.size == 0:
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return -120.0, -120.0
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rms = float(np.sqrt(np.mean(block * block)))
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peak = float(np.max(np.abs(block)))
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rms_db = 20.0 * math.log10(rms) if rms > 1e-9 else -120.0
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peak_db = 20.0 * math.log10(peak) if peak > 1e-9 else -120.0
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return rms_db, peak_db
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def main() -> None:
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store = common.open_store()
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stdin = sys.stdin.buffer
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stdout = sys.stdout.buffer
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version = -1
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sos = build_sos(common.defaults()[0], RATE)
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zi = np.zeros((sos.shape[0], 2), dtype=np.float64)
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volume = 1.0
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volume_db = 0.0
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while True:
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raw = stdin.read(BLOCK_BYTES)
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if not raw:
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break
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if len(raw) % 4:
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raw = raw[: len(raw) - (len(raw) % 4)]
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gains, want_volume_db, new_version = common.read_params(store)
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if new_version != version:
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version = new_version
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sos = build_sos(gains, RATE)
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volume_db = want_volume_db
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volume = 10.0 ** (volume_db / 20.0)
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x = np.frombuffer(raw, dtype="<f4").astype(np.float64)
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if x.size != N:
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x = np.resize(x, N)
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y, zi = sosfilt(sos, x, zi=zi)
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out = y * volume
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in_rms, in_peak = level_db(x)
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out_rms, out_peak = level_db(np.clip(out, -1.0, 1.0))
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common.write_state(store, in_rms, in_peak, out_rms, out_peak, volume_db)
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stdout.write(np.clip(out, -1.0, 1.0).astype("<f4").tobytes())
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stdout.flush()
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if __name__ == "__main__":
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main()
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