UDP: Support push MPEG-TS over UDP to server.

[winlinvip]

Server listen at upd port, encoders push MPEG-TS over UDP to server.
Server then can remux the stream to RTMP/FLV/HLS/HDS etc.

The wiki:
https://github.com/ossrs/srs/wiki/v2_CN_Streamer
https://github.com/ossrs/srs/wiki/v2_EN_Streamer

[winlinvip]

For SRS, the UDP stream will remux to RTMP to rtmp://127.0.0.1/xxx.
While for Oryx, directly receive stream from UDP and convert to stream in memory. Then server will remux stream to other mux, for example, RTMP, FLV, HLS or HDS.