first working

Author: brzep

lib/ex_webrtc/rtp/depayloader.ex

@@ -36,6 +36,7 @@ defmodule ExWebRTC.RTP.Depayloader do
   defp to_depayloader_module(mime_type) do
     case String.downcase(mime_type) do
       "video/vp8" -> {:ok, ExWebRTC.RTP.Depayloader.VP8}
+      "video/h264" -> {:ok, ExWebRTC.RTP.Depayloader.H264}
       "audio/opus" -> {:ok, ExWebRTC.RTP.Depayloader.Opus}
       "audio/pcma" -> {:ok, ExWebRTC.RTP.Depayloader.G711}
       "audio/pcmu" -> {:ok, ExWebRTC.RTP.Depayloader.G711}

lib/ex_webrtc/rtp/h264/depayloader.ex

@@ -12,27 +12,20 @@ defmodule ExWebRTC.RTP.Depayloader.H264 do
 
   alias ExWebRTC.RTP.H264.{FU, NAL, StapA}
 
-  @frame_prefix <<1::32>>
-  @annexb_prefix <<1::4>>
-
-  defmodule State do
-    @moduledoc false
-    defstruct parser_acc: nil
-  end
+  @annexb_prefix <<1::32>>
 
   @type t() :: %__MODULE__{
-          current_nal: nil,
-          current_timestamp: nil
+          current_timestamp: nil,
+          fu_parser_acc: nil
         }
 
-  defstruct [:current_nal, :current_timestamp]
+  defstruct [:current_timestamp, :fu_parser_acc]
 
   @impl true
   def new() do
     %__MODULE__{}
   end
 
-  # TODO: handle timestamps
   @impl true
   def depayload(depayloader, packet)
 
@@ -41,8 +34,9 @@ defmodule ExWebRTC.RTP.Depayloader.H264 do
   def depayload(depayloader, packet) do
     with {:ok, {header, _payload} = nal} <- NAL.Header.parse_unit_header(packet.payload),
          unit_type = NAL.Header.decode_type(header),
-         {:ok, {nalu, depayloader}} <- handle_unit_type(unit_type, depayloader, packet, nal) do
-      {nalu, depayloader}
+         {:ok, {nal, depayloader}} <-
+           handle_unit_type(unit_type, depayloader, packet, nal) do
+      {nal, depayloader}
     else
       {:error, reason} ->
         Logger.warning("""
@@ -54,18 +48,18 @@ defmodule ExWebRTC.RTP.Depayloader.H264 do
     end
   end
 
-  defp handle_unit_type(:single_nalu, _depayloader, _packet, nal) do
-    {header, payload} = nal
-    {:ok, {prefix_annexb(payload), depayloader}}
+  defp handle_unit_type(:single_nalu, depayloader, packet, {_header, payload}) do
+    {:ok,
+     {prefix_annexb(payload), %__MODULE__{depayloader | current_timestamp: packet.timestamp}}}
   end
 
   defp handle_unit_type(
          :fu_a,
-         {current_nal, current_timestamp} = depayloader,
+         %{current_timestamp: current_timestamp, fu_parser_acc: fu_parser_acc},
          packet,
-         {header, payload} = nal
+         {header, payload}
        ) do
-    if current_nal != nil and current_timestamp != packet.timestamp do
+    if fu_parser_acc != nil and current_timestamp != packet.timestamp do
       {:error, "fu-a colliding rtp timestamps"}
 
       Logger.debug("""
@@ -74,25 +68,37 @@ defmodule ExWebRTC.RTP.Depayloader.H264 do
       """)
     end
 
-    case FU.parse(payload, current_nal) do
-      {:ok, {payload, type}} ->
-        {:ok, result}
+    case FU.parse(payload, fu_parser_acc || %FU{}) do
+      {:ok, {data, type}} ->
+        data = NAL.Header.add_header(data, 0, header.nal_ref_idc, type)
+
+        {:ok,
+         {prefix_annexb(data),
+          %__MODULE__{current_timestamp: packet.timestamp, fu_parser_acc: nil}}}
 
-      {:incomplete, tmp} ->
-        {:ok, {nil, %{depayloader | current_nal: curent_nal <> tmp}}}
+      {:incomplete, fu} ->
+        {:ok, {nil, %__MODULE__{fu_parser_acc: fu}}}
 
       {:error, _reason} = error ->
         error
     end
   end
 
-  defp handle_unit_type(:stap_a, depayloader, {_header, data}, buffer, state) do
-    with {:ok, result} <- StapA.parse(data) do
+  defp handle_unit_type(:stap_a, depayloader, packet, {_header, payload}) do
+    with {:ok, result} <- StapA.parse(payload) do
       nals = Enum.reduce(result, <<>>, fn nal, acc -> acc <> prefix_annexb(nal) end)
-      {:ok, {nals, depayloader}}
+      {:ok, {nals, %__MODULE__{depayloader | current_timestamp: packet.timestamp}}}
     end
   end
 
+  defp handle_unit_type(unsupported_type, _depayloader, _packet, _nal) do
+    {:error, "unsupported nal type #{unsupported_type}"}
+
+    Logger.debug("""
+      Received packet with unsupported NAL type. Supported types are: NAL unit types, STAP-A, FU-A. Dropping packet.
+    """)
+  end
+
   defp prefix_annexb(nal) do
     @annexb_prefix <> nal
   end

lib/ex_webrtc/rtp/h264/nal_formats/fu.ex

@@ -4,7 +4,7 @@ defmodule ExWebRTC.RTP.H264.FU do
   """
   use Bunch
   alias __MODULE__
-  alias Membrane.RTP.H264.NAL
+  alias ExWebRTC.RTP.H264.NAL
 
   defstruct data: []
 

lib/ex_webrtc/rtp/h264/nal_formats/fu/header.ex

@@ -12,7 +12,7 @@ defmodule ExWebRTC.RTP.H264.FU.Header do
   ```
   """
 
-  alias Membrane.RTP.H264.NAL
+  alias ExWebRTC.RTP.H264.NAL
 
   @typedoc """
   MUST be set to true only in the first packet in a sequence.

lib/ex_webrtc/rtp/h264/nal_header.ex

@@ -1,4 +1,4 @@
-defmodule ExWebRTC.RTP.H264.NALHeader do
+defmodule ExWebRTC.RTP.H264.NAL.Header do
   @moduledoc """
   Defines a structure representing Network Abstraction Layer Unit Header