Improving vision processing. This is an interface change where the us…

…er no longer calls start_vision_buffering but now just open_video and close_video

DroneVision.py

@@ -41,6 +41,11 @@ def __init__(self, drone_object, is_bebop, buffer_size=200):
         self.user_vision_thread = None
         self.vision_running = True
 
+        # the vision thread starts opencv on these files.  That will happen inside the other thread
+        # so here we just sent the image index to 1 ( to start)
+        self.image_index = 1
+
+
     def set_user_callback_function(self, user_callback_function=None, user_callback_args=None):
         """
         Set the (optional) user callback function for handling the new vision frames.  This is
@@ -99,9 +104,12 @@ def open_video(self):
             self.ffmpeg_process = \
                 subprocess.Popen("ffmpeg -i rtsp://192.168.99.1/media/stream2 -r 30 image_%03d.png &",
                                shell=True, cwd=self.imagePath, stderr=subprocess.PIPE, stdout=subprocess.PIPE)
-        print("Opening non-blocking readers")
 
+        # immediately start the vision buffering (before we even know if it succeeded since waiting puts us behind)
+        self._start_video_buffering()
+
         # open non-blocking readers to look for errors or success
+        print("Opening non-blocking readers")
         stderr_reader = NonBlockingStreamReader(self.ffmpeg_process.stderr)
         stdout_reader = NonBlockingStreamReader(self.ffmpeg_process.stdout)
 
@@ -143,14 +151,10 @@ def open_video(self):
         stdout_reader.finish_reader()
         stderr_reader.finish_reader()
 
-        # the second thread starts opencv on these files.  That will happen inside the other thread
-        # so here we just sent the image index to 1 ( to start)
-        self.image_index = 1
-
         # return whether or not it worked
         return success
 
-    def start_video_buffering(self):
+    def _start_video_buffering(self):
         """
         If the video capture was successfully opened, then start the thread to buffer the stream
 
@@ -232,11 +236,15 @@ def get_latest_valid_picture(self):
         """
         return self.buffer[self.buffer_index]
 
-    def stop_vision_buffering(self):
+    def close_video(self):
         """
-        Should stop the vision thread
+        Stop the vision processing and all its helper threads
         """
+
+        # the helper threads look for this variable to be true
         self.vision_running = False
+
+        # kill the ffmpeg subprocess
         self.ffmpeg_process.kill()
 
         # send the command to kill the vision stream (bebop only)

examples/demoBebopVision.py

@@ -39,7 +39,8 @@ def save_pictures(self, args):
 
     if (success):
         print("Vision successfully started!")
-        bebopVision.start_video_buffering()
+        #removed the user call to this function (it now happens in open_video())
+        #bebopVision.start_video_buffering()
 
         # skipping actually flying for safety purposes indoors - if you want
         # different pictures, move the bebop around by hand
@@ -50,7 +51,7 @@ def save_pictures(self, args):
         bebop.pan_tilt_camera_velocity(pan_velocity=0, tilt_velocity=-2, duration=4)
         bebop.smart_sleep(25)
         print("Finishing demo and stopping vision")
-        bebopVision.stop_vision_buffering()
+        bebopVision.close_video()
 
     # disconnect nicely so we don't need a reboot
     bebop.disconnect()

examples/demoMamboVision.py

@@ -23,7 +23,7 @@ def save_pictures(self, args):
         filename = "test_image_%06d.png" % self.index
         cv2.imwrite(filename, img)
         self.index +=1
-        #print(self.index)
+        print(self.index)
 
 
 
@@ -52,7 +52,8 @@ def save_pictures(self, args):
 
     if (success):
         print("Vision successfully started!")
-        mamboVision.start_video_buffering()
+        #removed the user call to this function (it now happens in open_video())
+        #mamboVision.start_video_buffering()
 
         if (testFlying):
             print("taking off!")
@@ -78,7 +79,7 @@ def save_pictures(self, args):
 
         # done doing vision demo
         print("Ending the sleep and vision")
-        mamboVision.stop_vision_buffering()
+        mamboVision.close_video()
 
         mambo.smart_sleep(5)