RosettaCodeData/Task/Musical-scale/Python/musical-scale-2.py

49 lines
1.1 KiB
Python

import sys
import ctypes
import math
import time
import struct
import sdl2
import sdl2.sdlmixer as mixer
def create_sound(frequency, duration):
"""Create a buffer with sound at given frequency and duration"""
num_samples = int(48000 * duration)
wave = struct.pack(
f"<{num_samples}i",
*[
int(2**30 * math.sin(2 * math.pi * frequency / 48000 * t))
for t in range(num_samples)
]
)
length = num_samples * 4
sound_buffer = (ctypes.c_ubyte * length).from_buffer_copy(wave)
sound = mixer.Mix_QuickLoad_RAW(
ctypes.cast(sound_buffer, ctypes.POINTER(ctypes.c_ubyte)), length
)
return sound
def main():
"""Play sine wave"""
mixer.Mix_Init(0)
mixer.Mix_OpenAudioDevice(48000, sdl2.AUDIO_S32, 1, 2048, None, 0)
note = 261.63
semitone = math.pow(2, 1 / 12)
duration = 0.5 # seconds
for step in [0, 2, 2, 1, 2, 2, 2, 1]:
note *= semitone**step
sound = create_sound(note, duration)
mixer.Mix_PlayChannel(0, sound, 1)
time.sleep(duration)
return 0
if __name__ == "__main__":
sys.exit(main())