I want to process mms video stream with OpenCV using Python. The stream comes from an IP camera I have no control over (traffic monitor). The stream is available as mms or mmst schemes -
mms://194.90.203.111/cam2
plays on both VLC and Windows Media Player.
mmst://194.90.203.111/cam2
works only on VLC. I've tried to change the scheme to HTTP by re-streaming with FFmpeg and VLC but it didn't work.
As far as I understand, mms is using Windows Media Video to encode the stream. No luck adding '.mjpeg' at the end of the URI. I've yet to find what types of streaming are accepted by OpenCV.
Here's my code -
import cv2, platform
#import numpy as np
cam = "mms://194.90.203.111/cam2"
#cam = 0 # Use local webcam.
cap = cv2.VideoCapture(cam)
if not cap:
print("!!! Failed VideoCapture: invalid parameter!")
while(True):
# Capture frame-by-frame
ret, current_frame = cap.read()
if type(current_frame) == type(None):
print("!!! Couldn't read frame!")
break
# Display the resulting frame
cv2.imshow('frame',current_frame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
# release the capture
cap.release()
cv2.destroyAllWindows()
The What am I missing? What type of video streams can OpenCV capture? Is there an elegant solution without scheme change or transcoding?
Thanks!
Python ver 2.7.8, OpenCV's ver 2.4.9, Both x86. Win7 x64
Solved using FFmpeg and FFserver. Note FFserver only works on Linux. The solution uses python code from here as suggested by Ryan.
Flow is as follows -
Run FFserver
ffserver -d -f /etc/ffserver.conf
On a second terminal run FFmpeg
ffmpeg -i mmst://194.90.203.111/cam2 http://localhost:8090/cam2.ffm
The Python code. In this case, the code will open a window with the video stream.
import cv2, platform
import numpy as np
import urllib
import os
cam2 = "http://localhost:8090/cam2.mjpeg"
stream=urllib.urlopen(cam2)
bytes=''
while True:
# to read mjpeg frame -
bytes+=stream.read(1024)
a = bytes.find('\xff\xd8')
b = bytes.find('\xff\xd9')
if a!=-1 and b!=-1:
jpg = bytes[a:b+2]
bytes= bytes[b+2:]
frame = cv2.imdecode(np.fromstring(jpg, dtype=np.uint8),cv2.CV_LOAD_IMAGE_COLOR)
# we now have frame stored in frame.
cv2.imshow('cam2',frame)
# Press 'q' to quit
if cv2.waitKey(1) & 0xFF == ord('q'):
break
cv2.destroyAllWindows()
ffserver.config -
Port 8090
BindAddress 0.0.0.0
MaxClients 10
MaxBandWidth 50000
CustomLog -
#NoDaemon
<Feed cam2.ffm>
File /tmp/cam2.ffm
FileMaxSize 1G
ACL allow 127.0.0.1
ACL allow localhost
</Feed>
<Stream cam2.mjpeg>
Feed cam2.ffm
Format mpjpeg
VideoFrameRate 25
VideoBitRate 10240
VideoBufferSize 20480
VideoSize 320x240
VideoQMin 3
VideoQMax 31
NoAudio
Strict -1
</Stream>
<Stream stat.html>
Format status
# Only allow local people to get the status
ACL allow localhost
ACL allow 192.168.0.0 192.168.255.255
</Stream>
<Redirect index.html>
URL http://www.ffmpeg.org/
</Redirect>
Note that this ffserver.config needs more fine tuning, but they work rather well and produce a frame very close to source with only a little frame freeze.