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Valdaine's profile - activity

2014-07-27 13:44:26 -0600 answered a question highgui.VideoCapture buffer introducing lag

Dear all, I experienced the same problem as InakiE. Thanks to Tytan, I tried the solution to read several images in the buffer. I tried an enhancement by measuring the time it takes to capture the image. I remarked that it takes around 4ms to capture from the buffer and then around 30ms when buffer empty. I wrote the following code (I use Qt library but can be easily adapted):

   int delai=0;
   QTime h;
        {   h.start();//Start the chronometer
            cap>>AcquisitionFrame; //Declarations not included in this example
            delai=h.elapsed(); //Compute delay in ms since the start commande
            qDebug() << delai; //Display the delay for test 
                               // and measurement purposes in debug windows

With that config, the number of frame to loose is independant from the time it takes to process the image. We are "just in time".

If it can help others.