Trying to control lost frames with DVI2USB 3.0 card (working on Ubuntu with driver)

DVI2USB 3.0, SDI2USB 3.0 Setup, Kit, & Gear
1

Hello.

I am trying to record from an endoscopy video processor, Olympus’ CV-190 Evis Exera III.
It has a frame rate of 50/60 FPS. Working on Ubuntu 16.04 x86 64bit, I am using the driver vga2usb 3.30.2.10 for 4.4.0-57-generic to capture from the DVI2USB 3.0 card with a C++/OpenCV environment (cv::VideoCapture Class Reference). The point is that if the card frame rate (30 FPS for the 1920*1080 RGB24 images I use) is lower than the video processor’s I do not know which frames will be lost throughout the recording. Is there any way to know how many lost frames there are between the recorded ones?
I suspect the card sends the image from DVI input every ~33 ms (30 FPS), whatever the image is, and does not worry about the images that have been overwritten in the DVI input previously.
It would be great if I could order the card to record one out of every two images from the video processor, in order to achieve a 30 FPS frame rate, knowing thus the frames that are rejected.

Thank you and greetings.

2

Unfortunately there is no way to be absolutely certain which frame you get as you describe. As an alternate solution; if you request an I420 colourspace from the DVI2USB 3.0 instead of RGB24 you would be able to achieve 60fps capture at 1080p.

3

Fine. Thanks for the reply.