add codec info to manifest

Author: Gawor270

lib/ex_webrtc_recorder.ex

@@ -7,6 +7,10 @@ defmodule ExWebRTC.Recorder do
   Can optionally upload the saved files to S3-compatible storage.
   See `ExWebRTC.Recorder.S3` and `t:options/0` for more info.
   """
+  require Protocol
+  Protocol.derive(Jason.Encoder, ExWebRTC.RTPCodecParameters)
+  Protocol.derive(Jason.Encoder, ExSDP.Attribute.FMTP)
+  Protocol.derive(Jason.Encoder, ExSDP.Attribute.RTCPFeedback)
 
   alias ExWebRTC.MediaStreamTrack
   alias __MODULE__.S3
@@ -121,11 +125,12 @@ defmodule ExWebRTC.Recorder do
           recorder(),
           MediaStreamTrack.id(),
           MediaStreamTrack.rid() | nil,
+          ExWebRTC.RTPCodecParameters.t() | nil,
           ExRTP.Packet.t()
         ) :: :ok
-  def record(recorder, track_id, rid, %ExRTP.Packet{} = packet) do
+  def record(recorder, track_id, rid, codec, %ExRTP.Packet{} = packet) do
     recv_time = System.monotonic_time(:millisecond)
-    GenServer.cast(recorder, {:record, track_id, rid, recv_time, packet})
+    GenServer.cast(recorder, {:record, track_id, rid, codec, recv_time, packet})
   end
 
   @doc """
@@ -220,10 +225,12 @@ defmodule ExWebRTC.Recorder do
   end
 
   @impl true
-  def handle_cast({:record, track_id, rid, recv_time, packet}, state)
+  def handle_cast({:record, track_id, rid, codec, recv_time, packet}, state)
       when is_map_key(state.track_data, track_id) do
     %{file: file, rid_map: rid_map} = state.track_data[track_id]
 
+    state = if codec, do: update_codec(state, track_id, codec), else: state
+
     with {:ok, rid_idx} <- Map.fetch(rid_map, rid),
          false <- is_nil(file) do
       :ok = IO.binwrite(file, serialize_packet(packet, rid_idx, recv_time))
@@ -243,7 +250,7 @@ defmodule ExWebRTC.Recorder do
   end
 
   @impl true
-  def handle_cast({:record, track_id, _rid, _recv_time, _packet}, state) do
+  def handle_cast({:record, track_id, _rid, _codec, _recv_time, _packet}, state) do
     Logger.warning("""
     Tried to save packet for unknown track id. Ignoring. Track id: #{inspect(track_id)}.\
     """)
@@ -290,6 +297,7 @@ defmodule ExWebRTC.Recorder do
           start_time: start_time,
           kind: track.kind,
           streams: track.streams,
+          codec: nil,
           rid_map: (track.rids || [nil]) |> Enum.with_index() |> Map.new(),
           location: file_path,
           file: File.open!(file_path, [:write])
@@ -342,6 +350,20 @@ defmodule ExWebRTC.Recorder do
     end)
   end
 
+  defp update_codec(state, track_id, codec) do
+    case get_in(state, [:track_data, track_id, :codec]) do
+      nil ->
+        updated_track_data = Map.update!(state.track_data, track_id, &Map.put(&1, :codec, codec))
+        state = %{state | track_data: updated_track_data}
+        :ok = File.write!(state.manifest_path, state.track_data |> to_manifest |> Jason.encode!())
+        Logger.info("Updated manifest with codec info for track #{track_id}")
+        state
+
+      _ ->
+        state
+    end
+  end
+
   defp serialize_packet(packet, rid_idx, recv_time) do
     packet = ExRTP.Packet.encode(packet)
     packet_size = byte_size(packet)

lib/ex_webrtc_recorder/manifest.ex

@@ -20,6 +20,7 @@ defmodule ExWebRTC.Recorder.Manifest do
           kind: :video | :audio,
           streams: [MediaStreamTrack.stream_id()],
           rid_map: %{MediaStreamTrack.rid() => integer()},
+          codec: ExWebRTC.RTPCodecParameters.t() | nil,
           location: location()
         }
 
@@ -38,14 +39,16 @@ defmodule ExWebRTC.Recorder.Manifest do
          "kind" => kind,
          "streams" => streams,
          "rid_map" => rid_map,
+         "codec" => codec,
          "location" => location
        }) do
     %{
       streams: streams,
       location: location,
       start_time: parse_start_time(start_time),
       rid_map: parse_rid_map(rid_map),
-      kind: parse_kind(kind)
+      kind: parse_kind(kind),
+      codec: codec
     }
   end