Am using video input from an external Logitech Webcam HD Pro C920 to a Mac via usb.
I am noticing a full second of latency on the video, yet if I switch to the internal computer’s webcam, I experience almost no latency.
Is this due to the limited video bandwidth when using usb?
Does anyone know how to reduce this latency?
i have used those cams before on mac book pro, mac mini and mac pro at half HD res and the latency was find. at full HD latency was less than the full seconds you see but the fps was low.
I’ve had similar experience, but not a full second unless I was running something like CoreImage face detection or some heave OpenCV stuff on the video.
I was able to swap out a MacMini with an i5 processor to a model with an i7 and I saw a big difference. I’ve always been able to get at least 30 fps with my 2 year old Macbook Pro - with both the C920 and C930e.
USB2 could be the culprit. Are you able to try USB3 instead?
Further testing reveals it isn’t the actual webcam connection but some additional processing I was doing to crop the video.
Instead of cropping simply ran full HD and layered my other app on top with a later draw call.