Close all frame grabbers.
The operator close_all_framegrabbers closes all frame grabbers. It is used to cope with deadlocks resulting from damaged frame grabber handles (in that case the use of close_framegrabber is impossible).
Since all frame grabbers are closed by close_all_framegrabbers all frame grabber handles become invalid.
If it is possible to close the frame grabbers the operator close_all_framegrabbers returns the value 2 (H_MSG_TRUE). Otherwise an exception handling is raised.
close_all_framegrabbers is local and processed completely exclusively without parallelization.
Foundation
