play sound if object is detected

Question

I'm working on an object detection model using raspberry Pi. I've used Google's Object Detection API to detect models, My question is how to play sound when an object of a specific class(say human (ie 'id' : 22))is detected.

I've tried a little and the code I came to is this,

if 22 in classes:
    threading.Thread(play_sound()).start()
def play_sound():
    pygame.init()
    pygame.mixer.music.load("")
    pygame.mixer.music.play(1,0.0)
    pygame.time.wait(5000)
    pygame.mixer.stop()

In this code, the problem I'm getting is

1. Sound starts playing even before the object is detected, I tried debugging but don't know why.
2. I'm starting the same thread again
3. If I use different threads, the pi runs out of resources and the whole execution stops

Is there any way to get this to work?

Thanks in advance

Answer 1

Don't use threads (you don't need them), don't use pygame.time.wait , and don't use pygame.mixer.music if you don't want to use it for background music.

Use a Sound object (and maybe provide a maxtime if you want to it's play function).

So your code should look more like this:

pygame.init()
detected_sound = pygame.mixer.Sound('filename')

...
    if 22 in classes:
        # use loops=-1 if the sound's length is less than 5 seconds
        # so it's repeated until we hit the maxtime of 5000ms
        detected_sound.play(loops=-1, maxtime=5000)
...