Dec-19-2016, 09:07 AM
I've almost been successful in adapting a Python 2 code for video and html streaming to Python 3 (actually, the streaming works fine for html files). Unfortunately, I was unsuccessful in adapting the central part marked inside the following code, related to image streaming (I do not master the streaming modules). For these 10 lines, I'll greatly appreciate some help and advises (I'm new in this forum, hope that this is a valid question).
import cv2
from PIL import Image
from http.server import BaseHTTPRequestHandler, HTTPServer
from socketserver import ThreadingMixIn
import time
class CamHandler(BaseHTTPRequestHandler):
def do_GET(self):
#self.path handles the path of the request typed by the client in his browser or his other client program.
#For example, the client may have typed //127.0.0.1:8080/cam.mjpg or //127.0.0.1:8080/file.html.
#Here, we check only the suffix of the path to serve the client.
if self.path.endswith('.mjpg'):
self.send_response(200)
self.send_header('Content-type','multipart/x-mixed-replace; boundary=--jpgboundary')
self.end_headers()
while True:
try:
rc, img = capture.read()
if not rc:
continue
imgRGB = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
jpg = Image.fromarray(imgRGB)
#-----------------------------------------------------
#This is the fragment of code that does not work for Python 3:
#tmpFile = StringIO() #Python 2, don't work with Python3
#jpg.save(tmpFile, 'JPEG') #Python 2, replaced by next line (seems to work fine)
self.wfile.write(bytes('--jpgboundary', 'utf8'))
self.send_header('Content-type', 'image/jpeg') #this seems to work with python 3
#self.send_header('Content-length', str(tmpFile.len)) #Python 2, replaced by
self.send_header('Content-length', str(jpg.size[0]*jpg.size[1])) #don't know if this is the right replacement of the previous line
self.end_headers()
jpg.save(self.wfile, 'JPEG') #makes Python3 crashes
time.sleep(0.04)
#end of not working fragment
#-----------------------------------------------------
except KeyboardInterrupt:
break
return
if self.path.endswith('.html'): # The streaming here works for Python 3:
self.send_response(200)
self.send_header('Content-type','text/html')
self.end_headers()
self.wfile.write(bytes('<html><head>Hello world</head><body>', 'utf8'))
return
class ThreadedHTTPServer(ThreadingMixIn, HTTPServer):
"""Handle requests in a separate thread."""
def main():
global capture
capture = cv2.VideoCapture(0)
capture.set(cv2.CAP_PROP_FRAME_WIDTH, 320)
capture.set(cv2.CAP_PROP_FRAME_HEIGHT, 240)
capture.set(cv2.CAP_PROP_SATURATION, 0.2)
try:
server = ThreadedHTTPServer(('localhost', 8080), CamHandler)
print('server started', flush = True)
server.serve_forever()
except KeyboardInterrupt:
capture.release()
server.socket.close()
#----------------------------------------------------------------------------
if __name__ == '__main__':
main()
