SDP (Session Description Protocol) Support

sip2json includes built-in parsing and serialization for application/sdp payload bodies.

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SDP Attribute Mapping

SDP lines (v=, o=, s=, c=, t=, m=, a=) are parsed into structured JSON objects inside b.sdp.

Media Lines (m=) and Attributes (a=)

{
  "v": 0,
  "o": {
    "user": "Alice",
    "t1": "2890844526",
    "t2": "2890844526",
    "type": "IN",
    "subtype": "IP4",
    "host": "10.0.0.5"
  },
  "s": "SIP Call",
  "c": {
    "type": "IN",
    "subtype": "IP4",
    "dn": "10.0.0.5"
  },
  "t": [0, 0],
  "m": "audio 49170 RTP/AVP 0 101",
  "a": {
    "rtpmap": [
      "0 PCMU/8000",
      "101 telephone-event/8000"
    ],
    "fmtp": "101 0-16",
    "sendrecv": true
  }
}

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Handling Multi-Line Attributes

• Flag attributes like a=sendrecv are stored as boolean true.
• Repeated attribute keys like a=rtpmap:... are accumulated into array values.
• Key-value attributes like a=fmtp:101 0-16 are separated into string mappings.