Add a distinct three-tone radio call ringtone for desktop and Android

tools/generate_radio_ringtone.py

@@ -0,0 +1,52 @@
+#!/usr/bin/env python3
+"""Создаёт общий рингтон рации для desktop и Android; нужен ffmpeg, без сторонних Python-модулей."""
+
+import array
+import math
+from pathlib import Path
+import shutil
+import subprocess
+import sys
+import tempfile
+import wave
+
+
+def main():
+    root = Path(__file__).resolve().parents[1]
+    rate = 48000
+    duration = 2.4
+    samples = array.array("h", [0]) * round(rate * duration)
+    # Три восходящих позывных с мягкими фронтами, затем пауза до следующего цикла.
+    for start, frequency in ((0.1, 660), (0.34, 880), (0.58, 1100)):
+        length = 0.16
+        for i in range(round(rate * length)):
+            t = i / rate
+            envelope = min(1.0, t / 0.008, (length - t) / 0.035)
+            phase = 2 * math.pi * frequency * t
+            signal = (math.sin(phase) + 0.15 * math.sin(2 * phase)) / 1.15
+            samples[round(start * rate) + i] = round(32767 * 0.42 * envelope * signal)
+    peak = max(abs(sample) for sample in samples) / 32767
+    if sys.byteorder != "little":
+        samples.byteswap()
+    destinations = (
+        root / "tools/chatgui/resources/sounds/radio_incoming.mp3",
+        root / "tools/chatgui-android/app/src/main/res/raw/radio_incoming.mp3",
+    )
+    with tempfile.TemporaryDirectory(prefix="utun-radio-ring-") as directory:
+        source = Path(directory) / "radio.wav"
+        encoded = Path(directory) / "radio.mp3"
+        with wave.open(str(source), "wb") as output:
+            output.setparams((1, 2, rate, 0, "NONE", "not compressed"))
+            output.writeframes(samples.tobytes())
+        subprocess.run(
+            ["ffmpeg", "-v", "error", "-y", "-i", str(source), "-codec:a", "libmp3lame", "-b:a", "96k", str(encoded)],
+            check=True,
+        )
+        for destination in destinations:
+            shutil.copyfile(encoded, destination)
+            print(destination.relative_to(root))
+    print(f"Radio ringtone: {duration}s, mono {rate}Hz, peak {20 * math.log10(peak):.1f} dBFS")
+
+
+if __name__ == "__main__":
+    main()