Add rids field to MediaStreamTrack

elixir-webrtc · Jun 24, 2024 · 41ff049 · 41ff049
1 parent c65e1cb
commit 41ff049
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Showing 4 changed files with 29 additions and 6 deletions.
diff --git a/lib/ex_webrtc/media_stream_track.ex b/lib/ex_webrtc/media_stream_track.ex
@@ -3,26 +3,37 @@ defmodule ExWebRTC.MediaStreamTrack do
   Mimics [MediaStreamTrack](https://www.w3.org/TR/mediacapture-streams/#dom-mediastreamtrack).
   """
 
+  alias ExWebRTC.SDPUtils
   alias ExWebRTC.Utils
 
   @type id() :: integer()
   @type stream_id() :: String.t()
+  @type rid() :: String.t()
   @type kind() :: :audio | :video
 
   @type t() :: %__MODULE__{
           kind: kind(),
           id: id(),
-          streams: [stream_id()]
+          streams: [stream_id()],
+          rids: [rid()] | nil
         }
 
   @enforce_keys [:id, :kind]
-  defstruct @enforce_keys ++ [streams: []]
+  defstruct @enforce_keys ++ [streams: [], rids: nil]
 
-  @spec new(kind()) :: t()
+  @spec new(kind(), [stream_id()]) :: t()
   def new(kind, streams \\ []) when kind in [:audio, :video] do
     %__MODULE__{kind: kind, id: Utils.generate_id(), streams: streams}
   end
 
+  @doc false
+  @spec from_mline(ExSDP.Media.t()) :: t()
+  def from_mline(mline) do
+    streams = SDPUtils.get_stream_ids(mline)
+    rids = SDPUtils.get_rids(mline)
+    %__MODULE__{kind: mline.type, id: Utils.generate_id(), streams: streams, rids: rids}
+  end
+
   @spec generate_stream_id() :: stream_id()
   def generate_stream_id() do
     20

diff --git a/lib/ex_webrtc/rtp_transceiver.ex b/lib/ex_webrtc/rtp_transceiver.ex
@@ -182,8 +182,7 @@ defmodule ExWebRTC.RTPTransceiver do
     rtp_hdr_exts = get_rtp_hdr_extensions(mline, config)
     {:mid, mid} = ExSDP.get_attribute(mline, :mid)
 
-    stream_ids = SDPUtils.get_stream_ids(mline)
-    track = MediaStreamTrack.new(mline.type, stream_ids)
+    track = MediaStreamTrack.from_mline(mline)
     codec = get_codec(codecs)
     rtx_codec = get_rtx(codecs, codec)
 

diff --git a/lib/ex_webrtc/sdp_utils.ex b/lib/ex_webrtc/sdp_utils.ex
@@ -74,6 +74,18 @@ defmodule ExWebRTC.SDPUtils do
     end)
   end
 
+  @spec get_rids(ExSDP.Media.t()) :: [String.t()] | nil
+  def get_rids(media) do
+    Enum.flat_map(media.attributes, fn
+      %RID{direction: :send, id: id} -> [id]
+      _other -> []
+    end)
+    |> case do
+      [] -> nil
+      other -> other
+    end
+  end
+
   @spec reverse_simulcast(ExSDP.Media.t()) :: [ExSDP.Attribute.t()]
   def reverse_simulcast(media) do
     Enum.flat_map(media.attributes, fn

diff --git a/test/ex_webrtc/peer_connection_test.exs b/test/ex_webrtc/peer_connection_test.exs
@@ -1090,7 +1090,8 @@ defmodule ExWebRTC.PeerConnectionTest do
       assert %ExSDP.Attribute.Extmap{id: twcc_id} =
                Enum.find(transceiver.rtp_hdr_exts, &(&1.uri == @twcc_uri))
 
-      assert_receive {:ex_webrtc, ^pc2, {:track, %MediaStreamTrack{kind: :video, id: id2}}}
+      assert_receive {:ex_webrtc, ^pc2,
+                      {:track, %MediaStreamTrack{kind: :video, id: id2, rids: ^rids}}}
 
       rids
       |> Enum.with_index()