CODEWITHSUNDEEP
pythonwindowpywin32screen-capture
kalaiyarasi Uma
kalaiyarasi Uma

Reputation: 51

Python windows screen capture - Continuous streaming issue

I'm trying to do an exercise of an application windows capture using pywin32, so that I get the exact mirror image of the window(like a video game) The issue is - the below code keep capturing/ keep returning only the first frame/old frame of the window and not the current frame of the window. So there is no change reflecting in the mirror image. I tried changing the pywin32 different version but same problem. Please help is there any issue with the lines of code

Python Version== 3.8.10 pywin32 == 227 Windows 10

import cv2 as cv  
import numpy as np  
from time import time  
import win32gui, win32ui, win32con  

def get_screenshot(win_name):
    
    hwnd = win32gui.FindWindow(None, win_name)
    print('hwnd',hwnd)
    window_rect = win32gui.GetWindowRect(hwnd)
    print('window_rec',window_rect)
    w = window_rect[2] - window_rect[0]
    h = window_rect[3] - window_rect[1]

    wDC = win32gui.GetWindowDC(hwnd)
    print('wDC',wDC)
    dcObj = win32ui.CreateDCFromHandle(wDC)
    print('dcObj',dcObj)
    cDC = dcObj.CreateCompatibleDC()
    print('cDC',cDC)
    dataBitMap = win32ui.CreateBitmap()
    print('dataBitMap',dataBitMap)
    dataBitMap.CreateCompatibleBitmap(dcObj, w, h)
    
    cDC.SelectObject(dataBitMap)
    cDC.BitBlt((0, 0), (w, h), dcObj, (0,0), win32con.SRCCOPY)

    signedIntsArray = dataBitMap.GetBitmapBits(True)
    img = np.fromstring(signedIntsArray, dtype='uint8')

    img.shape = (h, w, 4)
    
    dcObj.DeleteDC()
    cDC.DeleteDC()
    win32gui.ReleaseDC(hwnd, wDC)
    win32gui.DeleteObject(dataBitMap.GetHandle())


    img = img[...,:3]

    return img

loop_time = time()
while(True):

    # get an updated image of the window
    frame = get_screenshot("<<Window Name>>") 
    cv.imshow('Computer Vision', frame)
    # debug the loop rate
    #print('FPS {}'.format(1 / (time() - loop_time)))
    loop_time = time()

    # press 'q' with the output window focused to exit.
    # waits 1 ms every loop to process key presses
    if cv.waitKey(1) == ord('q'):
        cv.destroyAllWindows()
        break

Upvotes: 2

Views: 1343

Answers (1)

DaveNate
DaveNate

Reputation: 11

I had the same issue, following the same online tutorial. He covers this issue in the 5th video. see here: https://www.youtube.com/watch?v=7k4j-uL8WSQ&list=PL1m2M8LQlzfKtkKq2lK5xko4X-8EZzFPI&index=5

Instead of:

hwnd = win32gui.FindWindow()

use:

hwnd = win32gui.GetDesktopWindow()

Which unfortunately has the side effect of capturing the whole desktop window, but functions great still.

Upvotes: 1

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