From 2b1721fcb1142437df54b2891ec05af1ec0c4fb5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micka=C3=ABl=20Schoentgen?= <contact@tiger-222.fr>
Date: Sat, 15 Dec 2018 18:04:02 +0100
Subject: [PATCH] Update 09_grab_screen_multiprocessing.py

Do you see better results with those changes?
Also, keep in mind to move the OpenCV preview window outside the recorded area. And the smaller the captured aea, the faster.
---
 .../09_grab_screen_multiprocessing.py         | 70 ++++++++++---------
 1 file changed, 36 insertions(+), 34 deletions(-)

diff --git a/9_part grab screen multiprocessing/09_grab_screen_multiprocessing.py b/9_part grab screen multiprocessing/09_grab_screen_multiprocessing.py
index e5f8be6..6c97fc7 100644
--- a/9_part grab screen multiprocessing/09_grab_screen_multiprocessing.py	
+++ b/9_part grab screen multiprocessing/09_grab_screen_multiprocessing.py	
@@ -1,49 +1,51 @@
 import multiprocessing
+from queue import Empty
 import time
 import cv2
 import mss
 import numpy
-
-title = "FPS benchmark"
-start_time = time.time()
-display_time = 2 # displays the frame rate every 2 second
-fps = 0
-sct = mss.mss()
-# Set monitor size to capture
-monitor = {"top": 40, "left": 0, "width": 800, "height": 640}
+import sys
 
 
 def GRABMSS_screen(q):
-    while True:
-        # Get raw pixels from the screen, save it to a Numpy array
-        img = numpy.array(sct.grab(monitor))
-        # To get real color we do this:
-        #img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
-        q.put_nowait(img)
-        q.join()
+    # Set monitor size to capture
+    monitor = {"top": 40, "left": 0, "width": 800, "height": 640}
+
+    with mss.mss() as sct:
+        while True:
+            # Get raw pixels from the screen, save it to a Numpy array
+            img = numpy.array(sct.grab(monitor))
+            q.put(img)
 
 def SHOWMSS_screen(q):
-    global fps, start_time
+    title = "FPS benchmark"
+    start_time = time.time()
+    display_time = 2 # displays the frame rate every 2 second
+    fps = 0
+
     while True:
-        if not q.empty():
+        try:
             img = q.get_nowait()
-            q.task_done()
-            # To get real color we do this:
-            img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
-            # Display the picture
-            cv2.imshow(title, cv2.cvtColor(img, cv2.COLOR_BGR2RGB))
-            # Display the picture in grayscale
-            fps+=1
-            TIME = time.time() - start_time
-            if (TIME) >= display_time :
-                print("FPS: ", fps / (TIME))
-                fps = 0
-                start_time = time.time()
-            # Press "q" to quit
-            if cv2.waitKey(25) & 0xFF == ord("q"):
-                cv2.destroyAllWindows()
-                break
-    
+        except Empty:
+            continue
+            
+        # Display the picture
+        cv2.imshow(title, img)
+
+        # Display the picture
+        fps += 1
+        TIME = time.time() - start_time
+        if TIME >= display_time :
+            print("FPS:", fps / TIME)
+            fps = 0
+            start_time = time.time()
+
+        # Press "q" to quit
+        if cv2.waitKey(25) & 0xFF == ord("q"):
+            cv2.destroyAllWindows()
+            break
+
+
 if __name__=="__main__":
     # Queue
     q = multiprocessing.JoinableQueue()