sap:

[1] FFmpeg Protocols Documentation (2017-01-22 02:22:36 +09:00) <https://ffmpeg.org/ffmpeg-protocols.html#sap>

The syntax for a SAP url given to the muxer is:
sap://destination[:port][?options]
The RTP packets are sent to destination on port port, or to port 5004 if no port is specified. options is a &-separated list. The following options are supported:

[2] FFmpeg Protocols Documentation (2017-01-22 02:22:36 +09:00) <https://ffmpeg.org/ffmpeg-protocols.html#sap>

The syntax for a SAP url given to the demuxer is:
sap://[address][:port]
address is the multicast address to listen for announcements on, if omitted, the default 224.2.127.254 (sap.mcast.net) is used. port is the port that is listened on, 9875 if omitted.

[3] VLC command-line help - VideoLAN Wiki (2017-10-10 19:17:15 +09:00) <https://wiki.videolan.org/VLC_command-line_help/>

sap:// for the SDP to be announced via SAP.