I have noticed your profile and the description of your work/works.
I give first a short description about a proposed task. When you have read it, we can discuss further, and as you decide to accept it, I will give this task to you right then. The frame is between 100-250 USD, according to your judgement on the complexity.
Using the DirectX interface, the frames of the screen should be captured, upto 60 frame per second, with no loss. (The compression with H264 will be handled afterwards, with low CPU usage using the least expensive setting/preset).
There is an already written code in C++, which does the capturing through the DirectX interface. The encoding is handled by ffmpeg, so that part is all right, as written above.
But there are problems with the capturing, seems the frames are not captured as smoothly as planned. Relatively smooth, but seems something is not perfect.
As the encoder use minimal CPU resources, the perfect continuity of the frames should come from somewhere else.
I can give the whole code to you in advance, if you would like to take a look on the main parts, also the compiled file if you want a quick test.
Thank you. Awaiting your answer.