Python 3.x 如何运行OpenCV VideoCapture';多线程类之外的读取函数?
我使用多线程技术从磁盘并行读取两个静态视频。下面修改的代码对我来说非常好:Python 3.x 如何运行OpenCV VideoCapture';多线程类之外的读取函数?,python-3.x,multithreading,opencv,python-multithreading,video-capture,Python 3.x,Multithreading,Opencv,Python Multithreading,Video Capture,我使用多线程技术从磁盘并行读取两个静态视频。下面修改的代码对我来说非常好: from threading import Thread import cv2, time class VideoStreamWidget(object): def __init__(self, src=0): self.capture = cv2.VideoCapture(src) # Start the thread to read frames from the vide
from threading import Thread
import cv2, time
class VideoStreamWidget(object):
def __init__(self, src=0):
self.capture = cv2.VideoCapture(src)
# Start the thread to read frames from the video stream
self.thread = Thread(target=self.update, args=())
self.thread.daemon = True
self.thread.start()
def update(self):
# Read the next frame from the stream in a different thread
while True:
if self.capture.isOpened():
(self.status, self.image) = self.capture.read()
self.frame = cv2.resize(self.image, (640, 480))
time.sleep(.01)
def show_frame(self, win_name='frame_1'):
# Display frames in main program
cv2.imshow(win_name, self.frame)
key = cv2.waitKey(1)
if key == ord('q'):
self.capture.release()
cv2.destroyAllWindows()
exit(1)
if __name__ == '__main__':
video_stream_widget1 = VideoStreamWidget(src=r'C:\Users\ab\Documents\Video\ch6.asf')
video_stream_widget2 = VideoStreamWidget(
src=r'C:\Users\ab\Documents\Video\ch4.asf')
while True:
try:
video_stream_widget1.show_frame('frame_1')
video_stream_widget2.show_frame('frame_2')
except AttributeError:
pass
现在,我正在尝试调整上述代码,因为我想在类外创建一个while循环,并从capture.read()函数中获取状态和图像,以便循环中的其他代码逐帧使用。但是,如果出现以下错误(断言fctx->async_lock在libavcodec/pthread_frame.c:155处失败),它甚至不能用于单个视频流。代码如下:
from threading import Thread
import cv2, time
class VideoStreamWidget(object):
def __init__(self, src=0):
self.capture = cv2.VideoCapture(src)
# Start the thread to read frames from the video stream
self.thread = Thread(target=self.update, args=())
self.thread.daemon = True
self.thread.start()
def update(self):
# Read the next frame from the stream in a different thread
while True:
if self.capture.isOpened():
(self.status, self.image) = self.capture.read()
self.frame = cv2.resize(self.image, (640, 480))
# time.sleep(.01)
# def show_frame(self, win_name='frame_1'):
# # Display frames in main program
# cv2.imshow(win_name, self.frame)
# key = cv2.waitKey(1)
# if key == ord('q'):
# self.capture.release()
# cv2.destroyAllWindows()
# exit(1)
if __name__ == '__main__':
video_stream_widget1 = VideoStreamWidget(src=r'C:\Users\ab\Documents\Video\ch6.asf')
# video_stream_widget2 = VideoStreamWidget(
# src=r'C:\Users\ab\Documents\Video\ch4.asf')
# while True:
# try:
# video_stream_widget1.show_frame('frame_1')
# video_stream_widget2.show_frame('frame_2')
# except AttributeError:
# pass
while True:
vflag, image_np = video_stream_widget1.status, video_stream_widget1.frame
print(image_np)
这是一个二传手-接受者问题吗?你能帮我指出哪里出了问题吗?在尝试了几种方法后,在init中添加self.status、self.image和self.frame解决了问题。由于它是多线程的,我们需要在构造函数中显式初始化这些变量