Fix simulcast issues

lib/ex_webrtc/peer_connection.ex

@@ -1040,21 +1040,22 @@ defmodule ExWebRTC.PeerConnection do
 
   @impl true
   def handle_cast({:send_pli, track_id, rid}, state) do
-    receiver =
-      state.transceivers
-      |> Enum.find_value(fn
-        %{receiver: %{track: %{id: ^track_id}} = receiver} -> receiver
-        _ -> nil
-      end)
+    state.transceivers
+    |> Enum.find(fn tr -> tr.receiver.track.id == track_id end)
+    |> case do
+      %{receiver: %{layers: %{^rid => %{ssrc: ssrc}}}} when ssrc != nil ->
+        encoded =
+          %ExRTCP.Packet.PayloadFeedback.PLI{sender_ssrc: 1, media_ssrc: ssrc}
+          |> ExRTCP.Packet.encode()
+
+        :ok = DTLSTransport.send_rtcp(state.dtls_transport, encoded)
 
-    if receiver[rid] != nil and receiver[rid].ssrc != nil do
-      encoded =
-        %ExRTCP.Packet.PayloadFeedback.PLI{sender_ssrc: 1, media_ssrc: receiver.ssrc}
-        |> ExRTCP.Packet.encode()
+      nil ->
+        Logger.warning("Attempted to send PLI for non existent track #{inspect(track_id)}")
 
-      :ok = DTLSTransport.send_rtcp(state.dtls_transport, encoded)
-    else
-      Logger.warning("Attempted to send PLI for non existent track")
+      other ->
+        dbg(other)
+        Logger.warning("Unable to send PLI for track #{inspect(track_id)}, rid #{rid}")
     end
 
     {:noreply, state}

lib/ex_webrtc/rtp_receiver.ex

@@ -65,7 +65,7 @@ defmodule ExWebRTC.RTPReceiver do
       track: track,
       codec: codec,
       simulcast_demuxer: SimulcastDemuxer.new(rtp_hdr_exts),
-      layers: %{nil => init_layer(codec)}
+      layers: %{}
     }
   end
 
@@ -213,8 +213,10 @@ defmodule ExWebRTC.RTPReceiver do
   @spec get_stats(receiver(), non_neg_integer()) :: [map()]
   def get_stats(receiver, timestamp) do
     Enum.map(receiver.layers, fn {rid, layer} ->
+      id = if(rid == nil, do: receiver.track.id, else: "#{receiver.track.id}, rid: #{rid}")
+
       %{
-        id: receiver.track.id,
+        id: id,
         rid: rid,
         type: :inbound_rtp,
         timestamp: timestamp,

test/ex_webrtc/rtp_receiver_test.exs

@@ -13,18 +13,7 @@ defmodule ExWebRTC.RTPReceiverTest do
     track = MediaStreamTrack.new(:audio)
     receiver = RTPReceiver.new(track, @codec, [])
 
-    assert [
-             %{
-               id: receiver.track.id,
-               rid: nil,
-               type: :inbound_rtp,
-               timestamp: timestamp,
-               ssrc: nil,
-               bytes_received: 0,
-               packets_received: 0,
-               markers_received: 0
-             }
-           ] == RTPReceiver.get_stats(receiver, timestamp)
+    assert [] == RTPReceiver.get_stats(receiver, timestamp)
 
     packet1 = Packet.new(payload, ssrc: 1234)
     raw_packet1 = Packet.encode(packet1)