Has anyone worked with capturing video streams from IP cameras in MATLAB? For example to grab frames in MATLAB from rtsp://10.10.10.10:554/live.sdp (rtsp stream) or from http://x.x.x.x/axis-cgi/mjpg/video.cgi (mjpeg stream). MATLAB's Image Acquisition Toolbox does not currently support this. I found 2 options: 1) using mmread. However http stream reading is not supported under 64-bit MATLAB or 2) to write my own C++ function that grabs frames (I use OpenCV library) and then compile it into MATLAB MEX function. Any suggestions are appreciated.
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- 4FYI, this is the answer from MATLAB support."Unfortunately, you are correct that currently the Image Acquisition Toolbox does not support IP cameras. Regarding workarounds: 1. If mmread works for you, perhaps it is feasible for you to install a 32-bit MATLAB on your 64-bit machine. 2. Writing your own MEX driver should be a possible option. 3. IMREAD is able to obtain frames from IP cameras. It may be possible to utilize this capability and build a function that constructs the video stream. Although frame rate may be an issue."Alexey– Alexey2011-12-30 13:51:53 +00:00Commented Dec 30, 2011 at 13:51
- 1Frame rate is an issue with IMREAD function in MATLAB - it only grabs single images, but not a stream. I am going the route of compiling my OpenCV C++ code to Matlab mex function. Below is a link to collection and development kit of matlab mex functions for OpenCV library (thanks to Kota Yamaguchi): github.com/kyamagu/mexopencv.Alexey– Alexey2012-01-04 18:30:48 +00:00Commented Jan 4, 2012 at 18:30
- 1THANKs for the mexopencv link. I am using the videoio library since 2 years now and was quite pleased with it. It's great but compiling was a hassle. The mexopencv installation was straightforward. The examples are great und the mex library is done in an awesome way. I think I'll switch to mexopencv and opencv right now.georg– georg2012-12-03 21:42:19 +00:00Commented Dec 3, 2012 at 21:42
- I recommend you to post the solution you created as an answer, otherwise this question will remain open.Dennis Jaheruddin– Dennis Jaheruddin2012-12-18 12:39:39 +00:00Commented Dec 18, 2012 at 12:39
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2 Answers
This is the answer I got from MATLAB support:
Unfortunately, you are correct that currently the Image Acquisition Toolbox does not support IP cameras. Regarding workarounds: 1. If mmread works for you, perhaps it is feasible for you to install a 32-bit MATLAB on your 64-bit machine. 2. Writing your own MEX driver should be a possible option. 3. IMREAD is able to obtain frames from IP cameras. It may be possible to utilize this capability and build a function that constructs the video stream. Although frame rate may be an issue.
I suggest implementing your own Matlab mex function to grab video frames. Here are some pointers to do so:
- OpenCV library is used to capture video streams from network cameras, see OpenCV with Network Cameras. Each IP camera may have a different API for accessing video streams (i.e. URL address). For example,
http://10.10.10.10/axis-cgi/mjpg/video.cgi?resolution=800x600&.mjpg. Below is a link to collection and development kit of matlab mex functions for OpenCV library (thanks to Kota Yamaguchi): https://github.com/kyamagu/mexopencv. This library makes it easy to convert between OpenCV data types and mxArray. Here's an example:
#include "mexopencv.hpp" void mexFunction( int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[] ) { // Check arguments if (nlhs!=1 || nrhs!=1) mexErrMsgIdAndTxt("myfunc:invalidArgs", "Wrong number of arguments"); // Convert MxArray to cv::Mat cv::Mat mat = MxArray(prhs[0]).toMat(); // Do whatever you want // Convert cv::Mat back to mxArray* plhs[0] = MxArray(mat); }The application can be made asynchronous by using threads, where producer thread grabs frames from the camera and puts it into a circular buffer. Consumer thread, on the other hand, retrieves frames from the buffer and converts them into mxArray (matrix) output. See How to implement a circular buffer of cv::Mat objects (OpenCV)?. Circular buffer will need to be made thread safe, see Thread safe implementation of circular buffer.
2 Comments
Kyle Wright
Here I am exactly two years later trying to do the same thing. Were you ever able to accomplish this?
Shaked
@KyleWright I'm in the same position. Can anyone help me with this?
Since MATLAB R2015a it's become very easy with the function ipcam:
cam = ipcam('http://172.28.17.193/video.mjpeg', 'admin', 'password'); % preview the camera preview(cam); % close preview closepreview(cam); % Or get a snapshop... img = snapshot(cam); imshow(img); % release camera clear cam; The first time you call that function MATLAB may prompt you to download it. The good news is that solution doesn't even require a license to the camera acquisition toolbox.
