I was happily building my little Pygame project when suddenly my game blew up with an error I had never seen before.
The crash only happened when this line was active in my __init__ method:
self.pong = pygame.mixer.Sound("pingpong.wav")The moment I commented it out, my game ran fine. Leave it in?
Boom my console spit this monster at me:
*** Error in `python3': double free or corruption (top): ...And that was just the start it came with a ridiculously long C backtrace and a memory map that looked like the Matrix had exploded on my terminal.
What This Error Actually
This is not your typical Python exception. This is coming from deep inside the C libraries that Pygame wraps.
A “double free or corruption” means that something inside a native library tried to free memory that was already freed or corrupted. That’s why the traceback showed:
libSDL... -> libSDL_mixer... -> Mix_LoadWAV_RWYou can’t try/except this away it’s a process-killing crash.
From my digging (and plenty of frustrated coffee breaks), this usually means one of three things in Pygame:
- Old/buggy audio stack — especially SDL_mixer 1.2 with PulseAudio/ALSA on Linux.
- Weird/invalid WAV file — maybe it’s compressed, has an odd bit depth, or malformed header.
- Mixer misconfiguration — the audio format you’re initializing doesn’t match what the sound file or hardware expects.
If the file were missing, you’d see a clean Python error like “file not found.”
So, because it’s crashing inside Mix_LoadWAV_RW, my money was on #1 or #2.
Quick Ways I Stopped the Crash
I tried several fixes, and here’s what worked.
Upgrade to Pygame 2.x (SDL2)
Pygame 2 uses SDL2, which fixes a lot of ancient mixer issues.
python -m pip install --upgrade pygamePre Configure the Mixer Before pygame.init()
Set a safe, boring audio format that’s widely supported:
pygame.mixer.pre_init(44100, -16, 2, 512)
pygame.init()Re Encode the Sound File
My pingpong.wav turned out to be quirky.
I re-saved it as PCM 16-bit little-endian at 44.1kHz. Or better yet, I converted it to OGG:
ffmpeg -y -i pingpong.wav -ar 44100 -ac 2 -c:a libvorbis pingpong.oggTest Other Audio Driver
SDL_AUDIODRIVER=pulse python your_game.py
SDL_AUDIODRIVER=alsa python your_game.py
SDL_AUDIODRIVER=dummy python your_game.py
(dummy disables sound but helps confirm if the crash is audio-driver related.)
A Minimal Sound Sanity Check
Before diving back into my big game loop, I wrote this quick test:
import pygame, sys, pathlib
pygame.mixer.pre_init(44100, -16, 2, 512)
pygame.init()
try:
p = pathlib.Path("pingpong.wav")
print("Exists:", p.exists(), "Size:", p.stat().st_size if p.exists() else "N/A")
s = pygame.mixer.Sound(str(p))
s.play()
print("Loaded and played OK")
except Exception as e:
print("Python raised:", repr(e))
pygame.time.wait(500)
pygame.quit()
If this script also crashes, you know it’s not your main game logic it’s the file or mixer setup.
My Refactored Game
I took the chance to clean up my code and make it safer.
Here’s the complete single-file project:
import sys
import pygame
from pathlib import Path
ASSETS_DIR = Path(".")
SOUND_FILE = ASSETS_DIR / "pingpong.ogg" # use OGG or PCM16 WAV
class Game:
def __init__(self):
pygame.mixer.pre_init(44100, -16, 2, 512)
pygame.init()
pygame.font.init()
self.size = self.width, self.height = 700, 720
self.screen = pygame.display.set_mode(self.size)
pygame.display.set_caption("Ping-Pong Practice")
self.clock = pygame.time.Clock()
self.font = pygame.font.SysFont("Verdana", 24)
self.WHITE = (255, 255, 255)
self.BLACK = (0, 0, 0)
self.RED = (200, 0, 0)
self.play_area = pygame.Rect(0, 20, 700, 700)
self.paddle = pygame.Rect(350, 685, 50, 10)
self.ball_img = pygame.image.load("redball2.png").convert_alpha()
self.ball_rect = self.ball_img.get_rect(center=(350, 350))
self.speed = [-2, 1]
self.num_lives = 3
self.paused = False
self.sfx_enabled = True
self.volume = 0.7
self.pong = None
self._load_sound(SOUND_FILE)
def _load_sound(self, path: Path):
try:
if not path.exists():
raise FileNotFoundError(f"Missing sound: {path}")
self.pong = pygame.mixer.Sound(str(path))
self.pong.set_volume(self.volume)
except Exception as e:
print(f"[SFX] Could not load sound ({path}): {e}")
self.pong = None
self.sfx_enabled = False
def _play_pong(self):
if self.sfx_enabled and self.pong:
self.pong.play()
def _draw_hud(self, fps):
text = f"Lives: {self.num_lives} FPS: {fps:.0f} Vol: {int(self.volume*100)}% SFX: {'ON' if self.sfx_enabled else 'OFF'}"
label = self.font.render(text, True, self.BLACK, self.WHITE)
self.screen.blit(label, (10, 0))
if self.paused:
p = self.font.render("PAUSED (press C to continue)", True, self.WHITE, self.RED)
self.screen.blit(p, (160, 340))
def _update_ball(self):
self.ball_rect = self.ball_rect.move(self.speed)
if self.ball_rect.left < self.play_area.left or self.ball_rect.right > self.play_area.right:
self.speed[0] = -self.speed[0]
if self.ball_rect.top < self.play_area.top:
self.speed[1] = -self.speed[1]
if self.ball_rect.bottom > self.play_area.bottom:
self.num_lives -= 1
self.speed[1] = -abs(self.speed[1])
self.ball_rect.bottom = self.play_area.bottom - 1
def _handle_collision(self, change_dir=None):
if self.ball_rect.colliderect(self.paddle):
self._play_pong()
self.speed[1] = -abs(self.speed[1])
if change_dir == "right":
self.speed[0] = abs(self.speed[0]) + 1
elif change_dir == "left":
self.speed[0] = -abs(self.speed[0]) - 1
def _move_paddle(self, change_dir):
keys = pygame.key.get_pressed()
if keys[pygame.K_RIGHT]:
change_dir = "right"
self.paddle.x = min(self.play_area.right - self.paddle.width, self.paddle.x + 5)
if keys[pygame.K_LEFT]:
change_dir = "left"
self.paddle.x = max(self.play_area.left, self.paddle.x - 5)
return change_dir
def _handle_volume_keys(self, event):
if event.key == pygame.K_LEFTBRACKET:
self.volume = max(0.0, self.volume - 0.05)
elif event.key == pygame.K_RIGHTBRACKET:
self.volume = min(1.0, self.volume + 0.05)
elif event.key == pygame.K_m:
self.sfx_enabled = not self.sfx_enabled
if self.pong:
self.pong.set_volume(self.volume)
def run(self):
while True:
change_dir = None
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit(); sys.exit()
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_p:
self.paused = True
elif event.key == pygame.K_c:
self.paused = False
elif event.key == pygame.K_s:
self.sfx_enabled = not self.sfx_enabled
elif event.key in (pygame.K_LEFTBRACKET, pygame.K_RIGHTBRACKET, pygame.K_m):
self._handle_volume_keys(event)
elif event.key == pygame.K_SPACE:
self._play_pong()
if self.paused:
fps = self.clock.get_fps() or 60
self.screen.fill(self.WHITE)
self._draw_hud(fps)
pygame.display.flip()
self.clock.tick(60)
continue
change_dir = self._move_paddle(change_dir)
self._update_ball()
self._handle_collision(change_dir)
if self.num_lives <= 0:
self.num_lives = 3
self.ball_rect.center = (350, 350)
self.speed = [-2, 1]
self.screen.fill(self.WHITE)
pygame.draw.rect(self.screen, self.BLACK, self.play_area, 1)
self.screen.blit(self.ball_img, self.ball_rect)
pygame.draw.rect(self.screen, self.BLACK, self.paddle)
fps = self.clock.get_fps() or 60
self._draw_hud(fps)
pygame.display.flip()
self.clock.tick(60)
if __name__ == "__main__":
Game().run()
New “Practice” Controls
- Pause/Continue:
P/C - Volume:
[down,]up - Mute:
M - Toggle SFX:
S - Test Sound:
Space
Checklist to Keep the Mixer Happy
pygame.mixer.pre_init(44100, -16, 2, 512) before pygame.init()
Use OGG or PCM 16-bit LE WAV @ 44.1kHz
Stay on Pygame 2.x+
On Linux, try SDL_AUDIODRIVER=pulse or alsa if weirdness happens
To inspect a file:
ffprobe -hide_banner pingpong.wavMake sure it’s PCM S16LE or just convert to OGG.
Final Thought
In the end, the crash wasn’t “my” bug it was the native audio loader choking on an old/quirky WAV. Once I upgraded Pygame, pre-initialized the mixer with safe settings, and converted my sound file, the problem disappeared. And since I was already in there, I added some handy “practice” features volume control, SFX toggles, FPS display so my little game not only runs without crashing but is now more fun to tweak while playing.