manzoloandClaude Opus 5.5
7f0584f0fc
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_018ks2K99uqCZjAxvy7Rdj1R
76 lines
3.5 KiB
Python
76 lines
3.5 KiB
Python
#!/usr/bin/env python3
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"""La musica dentro la Pieve (assets/audio/pieve.mp3), sintetizzata da zero: un organo morbido (canne di flauto,
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poche armoniche) con una melodia lenta originale sopra otto accordi in fa maggiore. Dura un giro intero e ricomincia
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sullo stesso accordo, così il loop non si sente; il riverbero della chiesa lo aggiunge ffmpeg.
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python3 tools/organo.py # scrive assets/audio/pieve.mp3 (serve ffmpeg)
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"""
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import math
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import subprocess
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import tempfile
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import wave
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from array import array
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from pathlib import Path
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SR = 22050
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BEAT = 3.0 # secondi per nota della melodia: due note per accordo
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CHORD = 2 * BEAT
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OUT = Path(__file__).resolve().parent.parent / "assets" / "audio" / "pieve.mp3"
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# Accordi (basso + tre voci) e melodia, due note per accordo. Il giro chiude su fa, come comincia.
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CHORDS = [
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("F2", ["F3", "A3", "C4"]), ("D2", ["D3", "F3", "A3"]), ("Bb1", ["Bb2", "D3", "F3"]), ("C2", ["C3", "E3", "G3"]),
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("A1", ["F3", "A3", "C4"]), ("G2", ["G3", "Bb3", "D4"]), ("C2", ["C3", "F3", "G3"]), ("F2", ["F3", "A3", "C4"]),
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]
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MELODY = ["A4", "C5", "D5", "C5", "Bb4", "A4", "G4", "G4", "A4", "C5", "D5", "Bb4", "A4", "G4", "F4", "F4"]
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DUR = CHORD * len(CHORDS)
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buf = [0.0] * int(SR * DUR)
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def hz(note: str) -> float:
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names = {"C": 0, "D": 2, "E": 4, "F": 5, "G": 7, "A": 9, "B": 11}
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semis = names[note[0]] + (1 if "#" in note else -1 if note[1] == "b" else 0)
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return 440 * 2 ** ((semis + 12 * (int(note[-1]) + 1) - 69) / 12)
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def pipe(start: float, length: float, freq: float, vol: float, attack: float, release: float,
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partials=((1, 1.0), (2, 0.35), (3, 0.12), (4, 0.06)), vibrato: float = 0.0, wrap: bool = False) -> None:
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"""Una canna d'organo: poche armoniche, attacco e rilascio lenti. Con `wrap` la coda che esce dalla fine
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rientra all'inizio: il loop resta continuo."""
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n0, n = int(start * SR), int((length + release) * SR)
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for i in range(n):
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t = i / SR
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env = min(1.0, t / attack) if t < length else max(0.0, 1 - (t - length) / release)
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if env <= 0:
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continue
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f = freq * (1 + vibrato * math.sin(2 * math.pi * 5.2 * t))
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s = sum(a * math.sin(2 * math.pi * f * k * t) for k, a in partials)
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j = n0 + i
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if j >= len(buf):
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if not wrap:
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break
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j -= len(buf)
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buf[j] += vol * env * s
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for c, (bass, voices) in enumerate(CHORDS):
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at = c * CHORD
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pipe(at, CHORD, hz(bass), 0.10, 1.0, 1.6, partials=((1, 1.0), (2, 0.5), (3, 0.15)), wrap=True)
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for v in voices:
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pipe(at, CHORD, hz(v), 0.045, 1.2, 1.8, wrap=True)
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for m, note in enumerate(MELODY):
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# La melodia su un flauto un po' più chiaro, con un vibrato appena accennato.
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pipe(m * BEAT, BEAT * 0.92, hz(note), 0.055, 0.35, 0.9, partials=((1, 1.0), (2, 0.18), (3, 0.05)), vibrato=0.004, wrap=True)
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peak = max(abs(x) for x in buf) or 1
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with tempfile.TemporaryDirectory() as tmp:
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w = Path(tmp) / "pieve.wav"
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with wave.open(str(w), "wb") as f:
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f.setnchannels(1)
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f.setsampwidth(2)
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f.setframerate(SR)
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f.writeframes(array("h", (int(x / peak * 0.8 * 32767) for x in buf)).tobytes())
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# Il riverbero della navata: echi lunghi e morbidi, senza alti.
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af = "aecho=0.8:0.75:140|310|520|830:0.35|0.26|0.18|0.12,lowpass=f=5000,volume=1.45"
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subprocess.run(["ffmpeg", "-loglevel", "error", "-y", "-i", str(w), "-af", af, "-c:a", "libmp3lame", "-b:a", "96k", str(OUT)], check=True)
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print(f"-> {OUT} ({DUR:.0f} s)")
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