Python MJPEG 服务器
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【中文标题】Python MJPEG 服务器【英文标题】：Python MJPEG Server 【发布时间】：2017-02-03 05:25:29 【问题描述】：我正在尝试在树莓派上执行视觉处理并在图形界面上监控效果。使用 cv2.imshow 确实会降低帧速率，因此，我尝试将操作流式传输到 MPEG 本地服务器，然后从不同桌面上的 chrome 监视它。这是我开发的代码：
from http.server import BaseHTTPRequestHandler, HTTPServer
from socketserver import ThreadingMixIn
from threading import Thread
import imutils
import sys
class CamHandler(BaseHTTPRequestHandler):
def do_GET(self):
print(self.path)
if self.path.endswith('/stream.mjpg'):
self.send_response(20)
self.send_header('Content-type', 'multipart/x-mixed-replace; boundary=--jpgboundary')
self.end_headers()
while True:
try:
if(frame != None):
pass
r, buf = cv2.imencode(".jpg", frame)
self.wfile.write("--jpgboundary\r\n".encode())
self.end_headers()
self.wfile.write(bytearray(buf))
except KeyboardInterrupt:
break
return
if self.path.endswith('.html') or self.path == "/":
self.send_response(200)
self.send_header('Content-type', 'text/html')
self.end_headers()
self.wfile.write('<html><head></head><body>')
self.wfile.write('<img src="http://localhost:9090/stream.mjpg" />')
self.wfile.write('</body></html>')
return
class ThreadedHTTPServer(ThreadingMixIn, HTTPServer):
"""Handle requests in a separate thread."""
class WebcamVideoStream:
def __init__(self, src=0):
# initialize the video camera stream and read the first frame
# from the stream
self.stream = cv2.VideoCapture(src)
# self.stream.set(3, 1920)
# self.stream.set(4, 1080)
# self.stream.set(15,-100)
(self.grabbed, self.frame) = self.stream.read()
# initialize the variable used to indicate if the thread should
# be stopped
self.stopped = False
def start(self):
# start the thread to read frames from the video stream
Thread(target=self.update, args=()).start()
return self
def update(self):
# keep looping infinitely until the thread is stopped
while True:
# if the thread indicator variable is set, stop the thread
if self.stopped:
self.stream.release()
return
# otherwise, read the next frame from the stream
(self.grabbed, self.frame) = self.stream.read()
def read(self):
# return the frame most recently read
return self.frame
def stop(self):
# indicate that the thread should be stopped
self.stopped = True
def realmain():
global frame
ip = 'localhost'
try:
cap = WebcamVideoStream().start()
server = ThreadedHTTPServer((ip, 9090), CamHandler)
print("starting server")
target = Thread(target=server.serve_forever,args=())
i = 0
while True:
img = cap.read()
img1 = imutils.resize(img, width=600)
img2 = cv2.GaussianBlur(img1, (5, 5), 0)
#frame = cv2.cvtColor(img2, cv2.COLOR_BGR2HSV)
frame = cv2.Canny(img, 35, 125)
if(i == 0):
target.start()
i +=1
except KeyboardInterrupt:
sys.exit()
if __name__ == '__main__':
realmain()
现在，我可以从我的桌面运行服务器并在我的桌面上通过 chrome 查看 MPEG 的效果，但我无法从我的树莓派运行服务器，并通过输入以下 url 来访问它：http:/ /“RASPBERRY PI IP”：9090/stream.mjpg，在我的桌面上。当我这样做时，chrome 只是说该网页不可用。即使在 PI 上运行服务器，我也无法在 Epiphany 浏览器上查看 url，它只是下载图像。想知道是否有人对此问题有答案。
另外，在将 jpg 发送到服务器之前，有没有更快的方法来解压缩和重新压缩 jpg？
【问题讨论】：
你可以尝试用 ip = "" (空字符串) 代替 'localhost' 吗？ 谢谢，我实际上在我的手机 wifi 热点上尝试了服务器，我能够通过我的桌面连接。一定是有防火墙阻止了连接 【参考方案1】：您将服务器绑定到本地主机：
ip = 'localhost'
try:
cap = WebcamVideoStream().start()
server = ThreadedHTTPServer((ip, 9090), CamHandler)
尝试将'localhost' 更改为'0.0.0.0'。它将服务器绑定到所有网络接口。
【讨论】：
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