如何减慢用cv2捕获的视频？
我的代码的问题是，保存视频后，它会大量加速，我注意到如果我更改cv2.waitkey（）中的整数值，视频会改变速度，但是即使我将其设置为1仍在加速
import pyautogui
import os, cv2, threading
import numpy
import time
#paths
path_videos = os.chdir('C:/Users/mypcname/Desktop/screenrec/videos')
codec = cv2.VideoWriter_fourcc(\*XVID')
video_file = cv2.VideoWriter(os.getcwd()+ '\\' + 'VIDEO2' + '.avi', codec, 23.976, (1920, 1080))
def rec_loop():
global rec, path_videos, path_frames, frame_number, codec, video_file
while True:
#takes BGR screenshot and makes it in a NumPy array
capture = pyautogui.screenshot()
frame = numpy.array(capture)
#converts BGR screenshot into RGB
frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
#shows the recording screen live
cv2.imshow('REC', frame)
video_file.write(frame)
#cancel recording
if cv2.waitKey(250) == ord('Q'):
break
cv2.destroyAllWindows()
video_file.release()
rec_thread = threading.Thread(target=rec_loop)
rec_thread.start()
问题来源：stackoverflow
写回答
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几件事...
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You seem to start a new thread and then do nothing in parallel, so that is ostensibly not very sensible.
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You will probably find that ` pyautogui ` can only capture around 2-3 frames per second, so you will only be passing them at that rate to videowriter, so they will appear speeded up. You could capture 2-10 frames before creating your output file and calculate the rate you achieve and pass that in.
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You will be able to achieve a better framerate with ` ffmpeg ` , if that's what you want.
回答来源：stackoverflow
2020-03-24 20:31:41赞同 展开评论 打赏 -
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