XMediaLib.SDP.Parser (xmedialib v0.3.0)

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Line-oriented SDP parser.

What problem this solves

Incoming SDP arrives as a multiline string from SIP INVITE bodies or trickle ICE updates. Turning that into structs requires walking session and media lines in order and promoting WebRTC attributes into typed fields. This module is the line-oriented parser behind XMediaLib.SDP.parse/1.

Walks CRLF- or LF-separated lines, building %XMediaLib.SDP{} and nested media structs. Session lines (v=, o=, s=, c=, t=, session a=) update the root struct. Each m= starts a new %XMediaLib.SDP.Media{}; following lines until the next m= belong to that section.

Well-known WebRTC attributes are promoted to typed fields via XMediaLib.SDP.Parser.Helpers. By default, unrecognized non-a= lines are skipped; :strict mode surfaces them as errors instead.

Prefer XMediaLib.SDP.parse/1 at application boundaries; use this module when you need parser-specific options or tests.

RFCs

Summary

Types

parse_result()

SDP parse result: {:ok, %SDP{}} or {:error, reason}.

Functions

parse(raw_sdp)

Parses an SDP binary into %XMediaLib.SDP{}.

parse(raw_sdp, opts)

Parses an SDP binary with options.

Types

parse_result()

@type parse_result() :: {:ok, XMediaLib.SDP.t()} | {:error, term()}

SDP parse result: {:ok, %SDP{}} or {:error, reason}.

Functions

parse(raw_sdp)

@spec parse(binary()) :: parse_result()

Parses an SDP binary into %XMediaLib.SDP{}.

Equivalent to parse/2 with default options (non-strict).

Examples

iex> {:ok, sdp} = XMediaLib.SDP.Parser.parse("v=0\r\no=- 0 0 IN IP4 127.0.0.1\r\ns=-\r\nt=0 0\r\n")
iex> sdp.version
0

parse(raw_sdp, opts)

@spec parse(
  binary(),
  keyword()
) :: parse_result()

Parses an SDP binary with options.

Options:

  • :strict - when true, unknown non-a= lines return {:error, {:unsupported_line, line}} instead of being skipped

Malformed numeric fields or invalid promoted attributes raise internally and surface as {:error, :parse_failed}.

Examples

iex> raw = "v=0\r\no=- 0 0 IN IP4 127.0.0.1\r\ns=-\r\nt=0 0\r\nz=bad\r\n"
iex> {:error, {:unsupported_line, "z=bad"}} = XMediaLib.SDP.Parser.parse(raw, strict: true)