Format of an SDP file for ancillary data - AWS Elemental Live

Format of an SDP file for ancillary data

v=0
o=- 1443716955 1443716955 IN IP4 10.xx.xxx.236
s=st2110 0-9-0
t=0 0
m=video 20000 RTP/AVP 100
c=IN IP4 239.x.x.xx/64
a=source-filter: incl IN IP4 239.x.x.xx 10.xx.xxx.236
a=rtpmap:100 smpte291/90000
a=fmtp:100 VPID_Code=133;
a=mediaclk:direct=0 rate=90000
a=ts-refclk:ptp=IEEE1588-2008:04-5c-6c-ff-fe-0a-53-70:127

Following is information about the data in this example:

  • o= This line identifies the source IP for the stream

  • m= The combination of m=video and smpte291 (in the a=rtpmap: line) identifies this file as an ancillary data file. 20000 is the port of the stream. This line must occur before the a lines.

  • c= identifies the destination IP address. This is a unicast or multicast address.

  • a=source-filter identifies a filter. This line is optional.

    In a file for an input to Elemental Live:

    • If the line is included, Elemental Live will listen only to the source IP (10.xx.xxx.236) for packets.

    • If the line isn't included, Elemental Live will listen to any packets on the destination IP address (239.x.x.x).

    In a file for an output: Elemental Live always includes this line in any SDP file that it creates.