opencv2 capture using retrieve() does not work but read() works
After reading the docs and performing many tests, I realized the I had not grabbed a frame before calling retrieve(). My thought was that the USB driver would automatically tick in the web cameras image into a buffer. Then, at any time, I could read that video frame's memory with having to wait.
I am using opencv2. I am able to capture frames from my web cam using cap.read() but not with cap.retrieve(). I like retrieve() because it does not block so my frame speed is faster. My retrieve() used to work but it stopped and now returns a black screen. both functions return true in the return status. I must have installed something like a different usb driver. I am using Ubuntu linux on a pcduino2.