v4l2videoenc: support force keyframe event in v4l2 encoder
Patch v4l2-encoder to handle keyframe requests on the fly. "Keyframe by request" feature is required for web-rtc (RTP) applications.
Details here: http://gstreamer-devel.230.s1.nabble.com/force-keyframe-ignored-v4l2h264enc-td4697066.html
Edited by Yuri Fedoseev