How to cleanly stop a blocking capture?
When using the capture policy DC1394_CAPTURE_POLICY_WAIT, the capture function will lock the program (or thread) until a frame is grabbed. If the camera is not sending frames (e.g. no external trigger, etc…), then the progam will be locked. One solution is to use the polling policy DC1394_CAPTURE_POLICY_POLL but it may be impractical for other reasons. If your kernel is new enough (2.6.20?), you can use the dc1394_capture_get_fileno() function to get a file descriptor for the capture process. After that, you can use the normal Unix mechanisms of select() and poll() to determine when it’s time to call dc1394_capture_dequeue and know that it won’t block. If your kernel is too old, you will find that select() and poll() will always return immediately.
