@solipp how can I control more than one external camera in pd?

@EEight @whale-av thank you so much for the advices! :-*

Hello!

How can I detect a presence in front of an external webcam and start a sound file when someone is detected?
I found this patch online : https://www.safaribooksonline.com/library/view/multimedia-programming-with/9781782164647/ch05s02.html

Can anybody help me? I have to say I am really new to pd.
You can even email me : patrobot@gmail.com