How to use Webread and analyze video

Hi there,

I am trying to perform webread using the following link,

httpsUrl = 'https://upload.wikimedia.org/wikipedia/en/transcoded/4/4c/Green_and_cyan-green_demonstration_of_frame_rate_control_FRC_4K60.webm/Green_and_cyan-green_demonstration_of_frame_rate_control_FRC_4K60.webm.160p.webm';
imageUrl = strcat(httpsUrl, '/assets/computerVision.jpg');
rgb = webread(imageUrl);

Error using matlab.internal.webservices.HTTPConnector/copyContentToByteArray
The server returned the status 404 with message "Not Found" in response to the request to URL https://upload.wikimedia.org/wikipedia/en/transcoded/4/4c/Green_and_cyan-green_demonstration_of_frame_rate_control_FRC_4K60.webm/Green_and_cyan-green_demonstration_of_frame_rate_control_FRC_4K60.webm.160p.webm/assets/computerVision.jpg.

Error in readContentFromWebService (line 46)
byteArray = copyContentToByteArray(connection);

Error in webread (line 125)
[varargout{1:nargout}] = readContentFromWebService(connection, options);

whos rgb

I'd like to analyse the video provided in the link, and I'd like to know whether there is a better way to do it than the existing one.

Thank you

Answer 1

[Piyush Patil]

Hello,

You can follow these steps to perform "webread" and analyze the video from the given link -

1. Download video data from the link using "webread

videoData = webread('https://upload.wikimedia.org/wikipedia/en/transcoded/4/4c/Green_and_cyan-green_demonstration_of_frame_rate_control_FRC_4K60.webm/Green_and_cyan-green_demonstration_of_frame_rate_control_FRC_4K60.webm.160p.webm');

2. Write video data to a file using "fwrite"

fid = fopen('vid_file_name.mp4', 'w');
fwrite(fid, videoData);
fclose(fid);

3. Read the video from the file using "VideoReader"

videoObj = VideoReader('vid_file_name.mp4');

4. Capture and display the video frames using a loop that iterates over all frames in the video

while hasFrame(videoObj)
    frame = readFrame(videoObj);
    imshow(frame);
end

5. Now you can analyze the frames as needed

Here is the example code -

% Download the video data
videoData = webread('https://upload.wikimedia.org/wikipedia/en/transcoded/4/4c/Green_and_cyan-green_demonstration_of_frame_rate_control_FRC_4K60.webm/Green_and_cyan-green_demonstration_of_frame_rate_control_FRC_4K60.webm.160p.webm');

% Write the video data to a file
fid = fopen('vid_file_name.mp4', 'w');
fwrite(fid, videoData);
fclose(fid);

% Read the video from the file
videoObj = VideoReader('vid_file_name.mp4');

% Capture and display the video frames
while hasFrame(videoObj)
    frame = readFrame(videoObj);
    imshow(frame);
    % Analyze the frames as needed
end

Hope this helps!

[Life is Wonderful]

@Piyush Patil, Excellent and Nice writeup. Thank you very much.