title: process video stream from memory buffer
body: <p>I need to parse a video stream (mpeg ts) from proprietary network protocol (which I already know how to do) and then I would like to use OpenCV to process the video stream into frames.  I know how to use cv::VideoCapture from a file or from a standard URL, but I would like to setup OpenCV to read from a buffer(s) in memory where I can store the video stream data until it is needed.  Is there a way to setup a call back method (or any other interfrace) so that I can still use the cv::VideoCapture object?  Is there a better way to accomplish processing the video with out writing it out to a file and then re-reading it.  I would also entertain using FFMPEG directly if that is a better choice.  I think I can convert AVFrames to Mat if needed.</p>