reviews

doc/py_tutorials/py_gui/py_video_display/py_video_display.markdown

@@ -25,27 +25,27 @@ import numpy as np
 import cv2 as cv
 
 cap = cv.VideoCapture(0)
-if not cap.isOpened:
-    print("Cannot open VideoCapture")
+if not cap.isOpened():
+    print("Cannot open camera")
     exit()
-while(True):
+while True:
     # Capture frame-by-frame
     ret, frame = cap.read()
 
     # if frame is read correctly ret is True
-    if ret:
-        # Our operations on the frame come here
-        gray = cv.cvtColor(frame, cv.COLOR_BGR2GRAY)
-
-        # Display the resulting frame
-        cv.imshow('frame',gray)
-    if cv.waitKey(1) & 0xFF == ord('q') or not ret:
+    if not ret:
+        print("Can't receive frame (stream end?). Exiting ...")
+        break
+    # Our operations on the frame come here
+    gray = cv.cvtColor(frame, cv.COLOR_BGR2GRAY)
+    # Display the resulting frame
+    cv.imshow('frame', gray)
+    if cv.waitKey(1) == ord('q'):
         break
 
 # When everything done, release the capture
 cap.release()
-cv.destroyAllWindows()
-@endcode
+cv.destroyAllWindows()@endcode
 `cap.read()` returns a bool (`True`/`False`). If frame is read correctly, it will be `True`. So you can
 check end of the video by checking this return value.