我正在尝试获得视频所示的结果(使用netcat的方法3)https://www.youtube.com/watch?v=sYGdge3T30o 它是将树莓派的视频流传输到PC并使用openCV和python处理它。
我使用命令
raspivid -vf -n -w 640 -h 480 -o - -t 0 -b 2000000 | nc 192.168.1.137 8000
将视频流式传输到我的PC,然后在PC上创建名称管道“ fifo”并重定向输出
nc -l -p 8000 -v > fifo
然后我正在尝试读取管道并将结果显示在python脚本中
import cv2
import subprocess as sp
import numpy
FFMPEG_BIN = "ffmpeg.exe"
command = [ FFMPEG_BIN,
'-i', 'fifo', # fifo is the named pipe
'-pix_fmt', 'bgr24', # opencv requires bgr24 pixel format.
'-vcodec', 'rawvideo',
'-an','-sn', # we want to disable audio processing (there is no audio)
'-f', 'image2pipe', '-']
pipe = sp.Popen(command, stdout = sp.PIPE, bufsize=10**8)
while True:
# Capture frame-by-frame
raw_image = pipe.stdout.read(640*480*3)
# transform the byte read into a numpy array
image = numpy.frombuffer(raw_image, dtype='uint8')
image = image.reshape((480,640,3)) # Notice how height is specified first and then width
if image is not None:
cv2.imshow('Video', image)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
pipe.stdout.flush()
cv2.destroyAllWindows()
但是我得到了这个错误:
Traceback (most recent call last):
File "C:\Users\Nick\Desktop\python video stream\stream.py", line 19, in <module>
image = image.reshape((480,640,3)) # Notice how height is specified first and then width
ValueError: cannot reshape array of size 0 into shape (480,640,3)
看来numpy数组是空的,所以有什么办法解决这个问题?
答案 0 :(得分:0)
图像数组为空。由于raw_image也为空,因此似乎未读取视频。确保视频已打开并可以阅读。