Hi,

• When I call the bindVideoBackground(), the camera take a picture, then analyze it, and return the pose ? Or does the capture beeing done in a separate loop ?

the bindVideoBackground() simply binds the current OpenGL video background texture corresponding to the current QCAR State, but it does not trigger any specific process; the video frame capture and processing (which results in determining the Trackable Pose) is done asynchronously.

• Where can I get the exact timestamp when the picture associated to the pose whas taken?

You can use the getTimeStamp() method of the QCAR::Frame class:

https://developer.vuforia.com/resources/api/class_q_c_a_r_1_1_frame

So, you can first retrieve the latest camera Frame from the QCAR State (using state.getFrame()) and then call frame.getTimeStamp()

See also:

https://developer.vuforia.com/forum/faq/android-how-can-i-access-camera-image