最终,这不是管道,平台或权限的结果。在RaspBerry Pi上生成并通过管道传输到python脚本的视频未得到正确处理。
我最终适应了这个picamera python食谱
在RaspBerry Pi上:(createStream.py)
import io
import socket
import struct
import time
import picamera
# Connect a client socket to my_server:8000 (change my_server to the
# hostname of your server)
client_socket = socket.socket()
client_socket.connect(('10.0.0.3', 777))
# Make a file-like object out of the connection
connection = client_socket.makefile('wb')
try:
with picamera.PiCamera() as camera:
camera.resolution = (1024, 768)
# Start a preview and let the camera warm up for 2 seconds
camera.start_preview()
time.sleep(2)
# Note the start time and construct a stream to hold image data
# temporarily (we Could write it directly to connection but in this
# case we want to find out the size of each capture first to keep
# our protocol simple)
start = time.time()
stream = io.BytesIO()
for foo in camera.capture_continuous(stream, 'jpeg', use_video_port=True):
# Write the length of the capture to the stream and flush to
# ensure it actually gets sent
connection.write(struct.pack('<L', stream.tell()))
connection.flush()
# Rewind the stream and send the image data over the wire
stream.seek(0)
connection.write(stream.read())
# Reset the stream for the next capture
stream.seek(0)
stream.truncate()
# Write a length of zero to the stream to signal we're done
connection.write(struct.pack('<L', 0))
finally:
connection.close()
client_socket.close()
在处理流的计算机上:(processStream.py)
import io
import socket
import struct
import cv2
import numpy as np
# Start a socket listening for connections on 0.0.0.0:8000 (0.0.0.0 means
# all interfaces)
server_socket = socket.socket()
server_socket.bind(('0.0.0.0', 777))
server_socket.listen(0)
# Accept a single connection and make a file-like object out of it
connection = server_socket.accept()[0].makefile('rb')
try:
while True:
# Read the length of the image as a 32-bit unsigned int. If the
# length is zero, quit the loop
image_len = struct.unpack('<L', connection.read(struct.calcsize('<L')))[0]
if not image_len:
break
# Construct a stream to hold the image data and read the image
# data from the connection
image_stream = io.BytesIO()
image_stream.write(connection.read(image_len))
# Rewind the stream, open it as an image with opencv and do some
# processing on it
image_stream.seek(0)
image = Image.open(image_stream)
data = np.fromstring(image_stream.getvalue(), dtype=np.uint8)
imagedisp = cv2.imdecode(data, 1)
cv2.imshow("Frame",imagedisp)
cv2.waitKey(1) #imshow will not output an image if you do not use waitKey
cv2.destroyAllWindows() #cleanup windows
finally:
connection.close()
server_socket.close()
这种解决方案的结果与我在原始问题中引用的视频类似。较大的分辨率帧会增加订阅源的延迟,但是对于我的应用程序而言,这是可以容忍的。
首先,您需要运行processStream.py,然后在RaspBerry Pi上执行createStream.py