python - Bad timing when playing audio files with PyGame

Question

When I play a sound every 0.5 second with PyGame:

import pygame, time

pygame.mixer.init()
s = pygame.mixer.Sound("2.wav")

for i in range(8):
  pygame.mixer.Channel(i).play(s)
  time.sleep(0.5)

it doesn't respect the timing correctly at all.

It's like there are pause of 0.2 sec than 0.7 sec then 0.2 sec again, it's very irregular.

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Notes:

• I know that time.sleep() is not the most accurate in the world, but even with the more accurate solutions from here, the problem is still present

• Tested on a RaspberryPi

• The problem is still there if I play many different files s[i].play(), with i in a big range. So the problem doesn't come from the fact it tries to replay the same file

Answer 1

Here is the reason:

Even if we decrease the audio buffer to the minimum supported by the soundcard (1024 or 512 samples instead of pygame's default 4096), the differences will still be there, making irregulat what should be a "metronome beat".

I'll update with a working solution as soon as I find one. (I have a few ideas in this direction).