OpenCV how the frame is grabbed out from WebCam?

asked 2017-06-15 09:20:14 -0600

hongyuanlu gravatar image

updated 2017-06-15 13:05:34 -0600

LBerger gravatar image

I am wondering in a single frame grab

cap >> frame

If I am using Logitech C920 which has its own hardware encoder, and I am grabbing 720p image, Am I getting 1280 * 720 * 3=921600 * 3=2700000 bytes from the USB port directly?

Or I am getting a compressed image out first and decode it into 2700000bytes?

edit retag flag offensive close merge delete

Comments

idk about your logicam, but most webcams send compressed data over the wire (the usb bus is the bottleneck here)

yuv422 is a popular format here (3 color bytes compressed into one)

berak gravatar imageberak ( 2017-06-15 09:33:24 -0600 )edit
add a comment