使用具有多线程的 OpenCV python 运行两个视频

Question

我正在尝试同时使用 openCV 两个函数在 python 上运行。 一个功能应该显示本地视频，另一个应该显示来自我的网络摄像头的帧。 运行下面的代码时，两个窗口会冻结并变黑。 我在 Ubuntu 16.04 上运行它

import cv2
import numpy as np
from threading import Thread

def webcam_video(): 

  cap = cv2.VideoCapture(0)
  while(True):
    ret, frame = cap.read()
    if ret == True:
      cv2.imshow('frame',frame)
      if cv2.waitKey(1) & 0xFF == ord('q'):
        break
    else :
        break
  cap.release()
  cv2.destroyAllWindows()

def local_video(): 
  path = "video-1.mp4"
  cap = cv2.VideoCapture(path)
  while(True):
    ret, frame = cap.read()
    if ret == True:
     cv2.imshow('frame_2',frame)
     if cv2.waitKey(1) & 0xFF == ord('q'):
        break
    else :
        break     
  cap.release()
  cv2.destroyAllWindows()

t1= Thread(target = webcam_video)
t2= Thread(target = local_video)

t1.start() 
t2.start()

Answer 1

使用多处理对我有用！

import numpy as np
import cv2
from multiprocessing import Process

def webcam_video(): 

  cap = cv2.VideoCapture(0)
  while(True):
    ret, frame = cap.read()
    if ret == True:
      cv2.imshow('frame',frame)
      if cv2.waitKey(1) & 0xFF == ord('q'):
        break
    else :
        break
  cap.release()
  cv2.destroyAllWindows()

def local_video(): 
  path = r"C:\Users\bernad.peter\Downloads\Singapore Port.mp4"
  cap = cv2.VideoCapture(path)
  while(True):
    ret, frame = cap.read()
    if ret == True:
     cv2.imshow('frame_2',frame)
     if cv2.waitKey(1) & 0xFF == ord('q'):
        break
    else :
        break     
  cap.release()
  cv2.destroyAllWindows()


if __name__ == '__main__':
    p1= Process(target = local_video)
    p2= Process(target = webcam_video)
    p1.start() 
    p2.start()

    p1.join()
    p2.join()