Encode Video from Bitmap Frames one at a time

I have been looking into this for about an hour only being able to find how to encode a video once you have all the frames of a video. However this is using way too much ram. I discovered something called a Sink Writer but the only somewhat reproducible tutorial I could find was for c++ and would be very difficult to implement anyway.

The question is, with c# how could I encode a video one frame at a time without needing to have all the frames at once using ffmpeg or another encoder. (I get a frame, encode it and then free the memory before getting another frame). And then be able to save the video to a file when I am done. I also would like the ability to save audio samples to the video if possible

The bitmap frames are in the format of a byte[] with each pixel being stored by 3 bytes (one for each color) but I can convert the format if needed