You have a couple of options. Probably the best coder available is x264, but it does not have a C # interface. You will need to define C-style interaction challenges in order to use it from a C # program.
SDK- MSFT, H264. , . , Mainconcept Dicas, #, .
- DirectShow.NET , directshow. , #, COM-, .
, YUV, , , -, RGB- - x264, Monogram YV12.