python-mss speedup grab until 60fps

Question

I have this simple multiprocessing script which:

• I define grabber process with using mss module to get screenshot
• I define displayer process with using pygame module to display current screenshot (current frame)

Even though I'm applying multiprocessing for pipelining I still only get 30 FPS, but the weirdly is rarely I got 60 FPS. Is this because my laptop specification or what? My laptop spec is 8 GB RAM with AMD Ryzen 5 4500U. My monitor size is (1366 * 768)

Here is my code:

SCR_SIZE = (640, 480)

def grabber(queue, isRunning):
  from mss import mss
  from time import time
  global SCR_SIZE
  with mss() as sct:
    while isRunning.value:
      t0 = time()
      # queue.put(cvtColor(resize(asarray(sct.grab(sct.monitors[1])), SCR_SIZE), COLOR_BGRA2BGR))
      queue.put(sct.grab(sct.monitors[1]))
      print(time() - t0)
  print('P1 Finished!')

def displayer(queue, isRunning):
  from numpy import asarray
  from cv2 import resize, cvtColor, COLOR_BGRA2BGR
  import pygame
  import pygame.display
  import pygame.image
  import pygame.time
  import pygame.font
  import pygame.event
  from pygame.locals import DOUBLEBUF
  global SCR_SIZE
  pygame.init()
  SCR = pygame.display.set_mode(SCR_SIZE, DOUBLEBUF)
  SCR.set_alpha(None)
  clock = pygame.time.Clock()
  FONT_COMIC = pygame.font.SysFont('Cambria Math', 20)
  while isRunning.value:
    for EVENT in pygame.event.get():
      if EVENT.type == pygame.QUIT:
        print('Quit')
        isRunning.value = 0
    currentFrame = cvtColor(resize(asarray(queue.get()), SCR_SIZE), COLOR_BGRA2BGR)
    if currentFrame is not None:
      SCR.blit(pygame.image.frombuffer(currentFrame, SCR_SIZE, 'BGR'), (0,0))
    else:
      break
    clock.tick(60)
    SCR.blit(FONT_COMIC.render('FPS:'+str(clock.get_fps())[:5], False, (0,255,0)),(10,10))
    SCR.blit(FONT_COMIC.render('QUEUE:'+str(queue.qsize())[:5], False, (0,255,0)),(10,20))
    pygame.display.update()
  print('P2 Finished!')


if __name__ == "__main__":
  from multiprocessing import Process, Queue, Value
  from time import sleep
  queue = Queue()
  isGameRunning = Value('i', 1)
  p1 = Process(target=grabber, args=(queue,isGameRunning, ))
  p2 = Process(target=displayer, args=(queue,isGameRunning, ))
  p1.start()
  p2.start()
  while isGameRunning.value:
    sleep(5)
  p1.terminate()
  p2.terminate()

and this is the console output

0.04599404335021973
0.028006553649902344
0.03400731086730957
0.03400993347167969
0.032022953033447266
0.033005475997924805
0.03300619125366211
0.03402543067932129
0.03399157524108887
0.03502368927001953
0.0309908390045166
0.032007694244384766
0.02500629425048828
0.0290069580078125
0.03200531005859375
0.03400683403015137
pygame 2.0.1 (SDL 2.0.14, Python 3.9.5)
Hello from the pygame community. https://www.pygame.org/contribute.html
0.033006906509399414
0.03300976753234863
0.029005050659179688
0.03700971603393555
0.030007123947143555
0.03400850296020508
0.05001020431518555
0.028904199600219727
0.03100895881652832
0.03200721740722656
0.03300642967224121
0.03300762176513672
0.03302264213562012
0.033007144927978516
0.03400921821594238
0.03200793266296387
0.03400754928588867
0.031007051467895508
0.022005081176757812
0.03300762176513672
0.032007694244384766
0.03300929069519043
0.03300738334655762
0.043009042739868164
0.028005599975585938
0.03400611877441406
0.03500843048095703
0.0400087833404541
0.03300905227661133
0.031008243560791016
0.03300738334655762
0.032007455825805664
0.03200960159301758
0.03501081466674805
0.029006004333496094
0.03200674057006836
0.03200793266296387
0.03500723838806152
0.031007766723632812
0.033010244369506836
0.032006263732910156
0.03300762176513672
0.03400826454162598
0.031005859375
0.03600883483886719
0.033008575439453125
0.0490117073059082
0.03500771522521973
0.049012184143066406
0.037007808685302734
0.027006864547729492
0.04201197624206543
0.04100990295410156
0.038008928298950195
0.039008378982543945
0.03801131248474121
0.03300738334655762
0.03400778770446777
0.0400080680847168
0.032006025314331055
0.03400874137878418
0.0360109806060791
0.03200650215148926
0.025002241134643555
0.03700685501098633
0.04300880432128906
0.0380094051361084
0.0360112190246582
0.03300881385803223
0.02500605583190918
0.03200531005859375
0.0380096435546875
0.04001021385192871
0.04001045227050781
0.02600717544555664
0.026006460189819336
0.0380101203918457
0.023005247116088867
0.030007362365722656
0.02600717544555664
0.027008533477783203
0.029008150100708008
0.02601027488708496
0.02800750732421875
0.028006792068481445
0.0269925594329834
0.028009414672851562
0.027006864547729492
0.02800726890563965
0.028005599975585938
0.028008222579956055
0.02700638771057129
0.02800750732421875
0.027006149291992188
0.0270082950592041
0.029009580612182617
0.027008771896362305
0.028006792068481445
0.02800774574279785
0.049011945724487305
0.027006864547729492
0.020006895065307617
0.02300715446472168
0.028006792068481445
0.028008222579956055
0.02700638771057129
0.02700662612915039
0.03000664710998535
0.03100872039794922
0.03200507164001465
0.036008358001708984
0.038010597229003906
0.027007102966308594
0.023005008697509766
0.0340113639831543
0.023008346557617188
0.02800607681274414
0.027008056640625
0.027008771896362305
0.027006864547729492
0.028007984161376953
0.02700519561767578
0.027004241943359375
0.027006864547729492
0.02800750732421875
0.02800583839416504
0.027007341384887695
0.02800583839416504
0.02900862693786621
0.02601003646850586
0.03600716590881348
0.031005859375
0.03300642967224121
0.04101252555847168
0.0290071964263916
0.024007797241210938
0.03100132942199707
0.022005319595336914
0.024549484252929688
0.02600884437561035
0.02700638771057129
0.029021024703979492
0.02703118324279785
0.02802300453186035
0.027024507522583008
0.028046846389770508
0.028011083602905273
0.029011964797973633
0.02800774574279785
0.02800893783569336
0.02802586555480957
0.02800917625427246
0.0250399112701416
0.02556896209716797
0.027019500732421875
0.02600550651550293
0.026027679443359375
0.02702021598815918
0.028985261917114258
0.02600860595703125
0.028020620346069336
0.028008460998535156
0.028006553649902344
0.02802276611328125
0.02799224853515625
0.026992082595825195
0.02502274513244629
0.025006532669067383
0.02600693702697754
0.027026891708374023
0.027007102966308594
0.026021718978881836
0.027024030685424805
0.027007341384887695
0.025989294052124023
0.028009653091430664
0.027990341186523438
0.028003454208374023
0.026990175247192383
0.02799081802368164
0.026991844177246094
0.027007341384887695
0.028992414474487305
0.025006532669067383
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0.04300951957702637
0.026005268096923828
0.029010534286499023
0.02800607681274414
0.026005983352661133
0.028006553649902344
0.027023792266845703
0.027024030685424805
0.026023149490356445
0.0270230770111084
0.031009674072265625
0.02799248695373535
0.0269927978515625
0.027005910873413086
0.028020620346069336
0.027993202209472656
0.027297496795654297
0.028006315231323242
0.027024507522583008
0.0270235538482666
0.02602362632751465
0.0270235538482666
0.02800917625427246
0.027018308639526367
0.028023958206176758
0.027004718780517578
0.02902507781982422
0.029009580612182617
0.027008056640625
0.027992725372314453
0.02799057960510254
0.026519775390625
0.02800774574279785
0.02802586555480957
0.02400660514831543
0.02600693702697754
0.026007890701293945
0.02700662612915039
0.028023958206176758
0.027006149291992188
0.027007102966308594
0.026988506317138672
0.027007579803466797
0.02799057960510254
0.027005672454833984
0.028009414672851562
0.027008056640625
0.0270235538482666
0.028009414672851562
0.02700972557067871
0.028011322021484375
0.02500605583190918
0.02600860595703125
0.027007341384887695
0.027006149291992188
0.027006864547729492
0.027004718780517578
0.026005029678344727
0.028005599975585938
0.028991222381591797
0.02700972557067871
0.026992321014404297
0.027990102767944336
0.02700638771057129
0.028324127197265625
0.02798748016357422
0.025006532669067383
0.027005434036254883
0.027005910873413086
0.02600693702697754
0.025532007217407227
0.0270233154296875
0.027006149291992188
0.028005123138427734
0.02702474594116211
0.02802562713623047
0.028010129928588867
0.02801990509033203
0.027988433837890625
0.028007984161376953
0.02701115608215332
0.027019977569580078
0.027994871139526367
0.0270082950592041
0.02800917625427246
0.03199338912963867
0.029006481170654297
0.020004749298095703
0.029005765914916992
0.02800774574279785
0.02800607681274414
0.02600693702697754
0.02700638771057129
0.028023242950439453
0.026040077209472656
0.0250241756439209
0.025023221969604492
0.028006553649902344
0.027988433837890625
0.028023242950439453
0.028002500534057617
0.028006553649902344
0.028020143508911133
0.02799224853515625
0.02703118324279785
0.027036666870117188
0.02902054786682129
0.026038408279418945
0.02801060676574707
0.026019811630249023
0.027007102966308594
0.0290067195892334
0.026072025299072266
Quit
P2 Finished!
0.038007497787475586
P1 Finished!

As you see if you averaging the delay between two point it will give you about 0.0333 which it's 1/0.0333 = 30 FPS

Answer 1

Solved, just keep using multiprocessing with separate two process grabbing, one for top half screen and one else for down half screen.

Also update top half screen and down half screen if they are exist only no need update entire screen.

SCR_SIZE = (640, 480)
HALFED_HEIGHT_SCR = SCR_SIZE[1] // 2
HALFED_SCR = (SCR_SIZE[0], HALFED_HEIGHT_SCR)
MON_SIZE= (1366, 768)
HALFED_SIZE_MON = (1366, 384)
TOP_GRAB = {'left':0, 'top': 0, 'width': HALFED_SIZE_MON[0], 'height':HALFED_SIZE_MON[1]}
DOWN_GRAB = {'left':0, 'top': HALFED_SIZE_MON[1], 'width': HALFED_SIZE_MON[0], 'height':HALFED_SIZE_MON[1]}

def grabber_top(queueTop, isRunning):
  from mss import mss
  from cv2 import resize, cvtColor, COLOR_BGRA2BGR
  from numpy import asarray
  global TOP_GRAB, SCR_SIZE
  with mss() as sct:
    while isRunning.value:
      queueTop.put(cvtColor(resize(asarray(sct.grab(TOP_GRAB)),(SCR_SIZE[0], SCR_SIZE[1]//2)), COLOR_BGRA2BGR))
  print('Top Grabber Finished!')

def grabber_down(queueDown, isRunning):
  from mss import mss
  from cv2 import resize, cvtColor, COLOR_BGRA2BGR
  from numpy import asarray
  global DOWN_GRAB, SCR_SIZE
  with mss() as sct:
    while isRunning.value:
      queueDown.put(cvtColor(resize(asarray(sct.grab(DOWN_GRAB)),(SCR_SIZE[0], SCR_SIZE[1]//2)), COLOR_BGRA2BGR))
  print('Down Grabber Finished!')

def displayer(queueTop, queueDown, isRunning):
  import pygame
  import pygame.display
  import pygame.image
  import pygame.time
  import pygame.font
  import pygame.event
  from pygame.locals import DOUBLEBUF
  global SCR_SIZE, HALFED_SIZE_MON, HALFED_SCR
  pygame.init()
  SCR = pygame.display.set_mode(SCR_SIZE, DOUBLEBUF)
  SCR.set_alpha(None)
  clock = pygame.time.Clock()
  FONT_COMIC = pygame.font.SysFont('Cambria Math', 20)
  topFrame = None
  downFrame = None
  while isRunning.value:
    clock.tick(60)
    for EVENT in pygame.event.get():
      if EVENT.type == pygame.QUIT:
        print('Quit Game')
        isRunning.value = 0

    if not queueTop.empty():
      topFrame = queueTop.get_nowait()
      SCR.blit(pygame.image.frombuffer(topFrame, HALFED_SCR, 'BGR'), (0,0))
      SCR.blit(FONT_COMIC.render(f'FPS: {str(clock.get_fps())[:5]}', False, (0,255,0)),(10,10))
      SCR.blit(FONT_COMIC.render(f'QUEUE: {str(queueTop.qsize())[:5]}, {str(queueDown.qsize())[:5]}', False, (0,255,0)),(10,30))
      pygame.display.update(0, 0,SCR_SIZE[0], HALFED_HEIGHT_SCR)
    if not queueDown.empty():
      downFrame = queueDown.get_nowait()
      SCR.blit(pygame.image.frombuffer(downFrame, HALFED_SCR, 'BGR'), (0,HALFED_HEIGHT_SCR))
      pygame.display.update(0, HALFED_HEIGHT_SCR, SCR_SIZE[0], HALFED_HEIGHT_SCR)
  print('Displayer Finished!')

if __name__ == "__main__":
  from multiprocessing import Process, Queue, Value
  from time import sleep
  queueTop = Queue(maxsize=5)
  queueDown = Queue(maxsize=5)
  isGameRunning = Value('i', 1)
  p1 = Process(target=grabber_top, args=(queueTop,isGameRunning, ))
  p2 = Process(target=grabber_down, args=(queueDown,isGameRunning, ))
  p3 = Process(target=displayer, args=(queueTop, queueDown,isGameRunning, ))
  p1.start()
  p2.start()
  p3.start()
  while isGameRunning.value:
    sleep(5)
  p1.terminate()
  p2.terminate()
  p3.terminate()
  print('All process terminated!')
  

Now I got 60 FPS :)