Video Streaming from IP Camera in Python Using OpenCV cv2.VideoCapture

Question

I am trying to get video stream in python from IP camera but i am getting an error. I am Using Pycharm IDE.

import cv2
scheme = '192.168.100.23'


host = scheme
cap = cv2.VideoCapture('http://admin:Ebmacs8485867@'+host+':81/web/admin.html')

while True:
    ret, frame = cap.read()

    # Place options to overlay on the video here.
    # I'll go over that later.

    cv2.imshow('Camera', frame)

    k = cv2.waitKey(0) & 0xFF
    if k == 27:  # esc key ends process
        cap.release()
        break
cv2.destroyAllWindows()

Error:
"E:\Digital Image Processing\python\ReadingAndDisplayingImages\venv\Scripts\python.exe" "E:/Digital Image Processing/python/ReadingAndDisplayingImages/ReadandDisplay.py"
Traceback (most recent call last):
  File "E:/Digital Image Processing/python/ReadingAndDisplayingImages/ReadandDisplay.py", line 14, in <module>
    cv2.imshow('Camera', frame)
cv2.error: OpenCV(4.0.1) C:\projects\opencv-python\opencv\modules\highgui\src\window.cpp:352: error: (-215:Assertion failed) size.width>0 && size.height>0 in function 'cv::imshow'

warning: Error opening file (/build/opencv/modules/videoio/src/cap_ffmpeg_impl.hpp:901)
warning: http://admin:[email protected]:81/web/admin.html (/build/opencv/modules/videoio/src/cap_ffmpeg_impl.hpp:902)

You try to check the frame is empty or not, probably the is empty. — Bahramdun Adil
That link is a webpage (html) you need the rtsp link... and this depends on the model of the camera. Also you should check if cap.isOpened() before the loop and if ret after the ret, frame = cap.read() line — api55

nathancy nathancy · Accepted Answer · 2019-04-24T21:12:00

You're most likely getting that error due to an invalid stream link. Insert your stream link into VLC player to confirm it is working. Here's a IP camera video streaming widget using OpenCV and cv2.VideoCapture.read(). This implementation uses threading for obtaining frames in a different thread since read() is a blocking operation. By putting this operation into a separate that that just focuses on obtaining frames, it improves performance by I/O latency reduction. I used my own IP camera RTSP stream link. Change stream_link to your own IP camera link.

Depending on your IP camera, your RTSP stream link will vary, here's an example of mine:

rtsp://username:[email protected]:554/cam/realmonitor?channel=1&subtype=0
rtsp://username:[email protected]/axis-media/media.amp

Code

from threading import Thread
import cv2

class VideoStreamWidget(object):
    def __init__(self, src=0):
        # Create a VideoCapture object
        self.capture = cv2.VideoCapture(src)

        # Start the thread to read frames from the video stream
        self.thread = Thread(target=self.update, args=())
        self.thread.daemon = True
        self.thread.start()

    def update(self):
        # Read the next frame from the stream in a different thread
        while True:
            if self.capture.isOpened():
                (self.status, self.frame) = self.capture.read()

    def show_frame(self):
        # Display frames in main program
        if self.status:
            self.frame = self.maintain_aspect_ratio_resize(self.frame, width=600)
            cv2.imshow('IP Camera Video Streaming', self.frame)

        # Press Q on keyboard to stop recording
        key = cv2.waitKey(1)
        if key == ord('q'):
            self.capture.release()
            cv2.destroyAllWindows()
            exit(1)

    # Resizes a image and maintains aspect ratio
    def maintain_aspect_ratio_resize(self, image, width=None, height=None, inter=cv2.INTER_AREA):
        # Grab the image size and initialize dimensions
        dim = None
        (h, w) = image.shape[:2]

        # Return original image if no need to resize
        if width is None and height is None:
            return image

        # We are resizing height if width is none
        if width is None:
            # Calculate the ratio of the height and construct the dimensions
            r = height / float(h)
            dim = (int(w * r), height)
        # We are resizing width if height is none
        else:
            # Calculate the ratio of the 0idth and construct the dimensions
            r = width / float(w)
            dim = (width, int(h * r))

        # Return the resized image
        return cv2.resize(image, dim, interpolation=inter)

if __name__ == '__main__':
    stream_link = 'your stream link!'
    video_stream_widget = VideoStreamWidget(stream_link)
    while True:
        try:
            video_stream_widget.show_frame()
        except AttributeError:
            pass

Video Streaming from IP Camera in Python Using OpenCV cv2.VideoCapture

1 Answers