Question about using 'video device in' with 'blobtrack' to cue the audio to play?

Hi everyone, I am a very new beginner of TD and have a problem in controlling the audio with motion tracking.

I have created ‘blobtrack’ that when there is a motion detected with the cam, a rectangle will be tracked and moved along the motion. Then I want that when there is a motion detected, the audio in the ‘audio file in’ can be played, just like the rectangle is being tracked.

Which nodes should the ‘audio file in’ and the ‘audio file out’ be connected to? What should be inserted in between to extract the info/data for controlling the audio with ‘blob track’? How can I cue the audio to play, which mean when i move, the rectangle move and the audio play at the same time?

Also, an extra question.
After I have save the file and quit, when I open it again, the ‘video device in’ does not work and just give a black background. I have tried to reopen the file, turn the active button off and on again, check the ‘library’ and ‘device’ setting in the ‘video device in’ is correct, also confirm the privacy preferences that TD is allowed to access the camera. However, it is still not working. Any way that I can fix this problem?

Sorry for bunch of questions, hope I explain it clear. Thank you very much!!

The question is more “how to extract information from blobtrack” and you need to be more precise about what do you want to trigger? Start the file, go to cue, change speed?
To analyse the blobtrack, you need an Info Chop and with the “u” info, you can put a delay, substract the 2 signals, have the absolute value and then logic to obtain a trigger. I join a quick example.
Concerning the camera, we need more infos, which camera, which driver etc. My kinect start normaly when I start the project.
blobTrack.toe (4.2 KB)

I do not use kinect. I just use the webcam from the computer. I am using MacBook Pro. Here is the version and the detail of it.

Also I have tried your file, and the audio do match with the movement of the rectangle. For the camera problem, I copied the node from your file and pasted it on mine, and then it works :joy:

Thank you so much for you help!