opencv VideoCapture very slow with high resolution videos

Question

I am trying to read a high resolution video using OpenCV VideoCapture and it seems to be extremely slow. I read somewhere changing the buffer sizes might help, but I tried setting all kinds of buffer sizes and its still slow. Any help here on what settings can help improve reading high resolution videos for java opencv is really appreciated

I am using VideoCapture to read a video from disk. I am using Mac OSX. Here is a snippet of my code:

while(camera.read(frame))
{
    BufferedImage bufferedImage = MatToBufferedImage(frame);
    BufferedImage scaledImage = (BufferedImage)getScaledImage(bufferedImage, frameWidth, frameHeight);
    ImageIcon icon = new ImageIcon(scaledImage);
    publish(icon);

}

I am using swingworker and doing this in the background thread. I am not explicitly setting any openCV properties. Should I be setting any explicit properties is something I am not sure of.

Here is what I observe: My video starts off well and then around 50th frame or so, i see some lag and then again at around 120th frame and it almost completely stops at frame number 190ish.

Answer 1

Have you tried resizing the individual frames?

while(camera.read(frame))
{
resize(frame,frame,Size(640,360));
imshow("frame",frame);
}