Support AVC3 (#113)

* support AVC3

* address CR

* Update lib/membrane_mp4/muxer/isom.ex

Co-authored-by: Łukasz Kita <lukasz.kita0@gmail.com>

* bump version

---------

Co-authored-by: Łukasz Kita <lukasz.kita0@gmail.com>

Author: mat-hek

README.md

@@ -12,7 +12,7 @@ The package can be installed by adding `membrane_mp4_plugin` to your list of dep
 ```elixir
 defp deps do
   [
-    {:membrane_mp4_plugin, "~> 0.35.1"}
+    {:membrane_mp4_plugin, "~> 0.35.2"}
   ]
 end
 ```

lib/membrane_mp4/demuxer/isom.ex

@@ -40,7 +40,7 @@ defmodule Membrane.MP4.Demuxer.ISOM do
       any_of(
         %Membrane.AAC{config: {:esds, _esds}},
         %Membrane.H264{
-          stream_structure: {:avc1, _dcr},
+          stream_structure: {_avc, _dcr},
           alignment: :au
         },
         %Membrane.H265{

lib/membrane_mp4/muxer/isom.ex

@@ -17,7 +17,7 @@ defmodule Membrane.MP4.Muxer.ISOM do
       any_of(
         %Membrane.AAC{config: {:esds, _esds}},
         %Membrane.H264{
-          stream_structure: {:avc1, _dcr},
+          stream_structure: {_avc, _dcr},
           alignment: :au
         },
         %Membrane.H265{
@@ -100,21 +100,34 @@ defmodule Membrane.MP4.Muxer.ISOM do
         ctx,
         state
       ) do
-    cond do
+    case {ctx.pads[pad].stream_format, stream_format} do
       # Handle receiving the first stream format on the given pad
-      is_nil(ctx.pads[pad].stream_format) ->
+      {nil, new_format} ->
         update_in(state, [:pad_to_track, pad_ref], fn track_id ->
-          Track.new(track_id, stream_format, state.chunk_duration)
+          Track.new(track_id, new_format, state.chunk_duration)
         end)
 
-      # Handle receiving all but the first stream format on the given pad,
-      # when stream format is duplicated - ignore
-      ctx.pads[pad].stream_format == stream_format ->
+      # If the stream format is identical or remains H264 AVC3 or H265 HEV1,
+      # we can be reasonably sure that the stream can still be appended
+      # to the same MP4
+      {stream_format, stream_format} ->
         state
 
-      # otherwise we can assume that output will be corrupted
-      true ->
-        raise "ISOM Muxer doesn't support variable parameters"
+      {%Membrane.H264{stream_structure: {:avc3, _dcr1}},
+       %Membrane.H264{stream_structure: {:avc3, _dcr2}}} ->
+        state
+
+      {%Membrane.H265{stream_structure: {:hev1, _dcr1}},
+       %Membrane.H265{stream_structure: {:hev1, _dcr2}}} ->
+        state
+
+      # Otherwise we can assume that output will be corrupted
+      {prev_format, new_format} ->
+        raise """
+        Unsupported stream_format change on pad #{inspect(pad_ref)}, \
+        previous format: #{inspect(prev_format)}
+        new format: #{inspect(new_format)}
+        """
     end
     |> then(&{[], &1})
   end

mix.exs

@@ -1,7 +1,7 @@
 defmodule Membrane.MP4.Plugin.MixProject do
   use Mix.Project
 
-  @version "0.35.1"
+  @version "0.35.2"
   @github_url "https://github.com/membraneframework/membrane_mp4_plugin"
 
   def project do

test/fixtures/isom/ref_video_vp.mp4

@@ -62,6 +62,24 @@ defmodule Membrane.MP4.Muxer.ISOM.IntegrationTest do
       perform_test(pid, "video")
     end
 
+    test "variable parameters H264 track" do
+      prepare_test("video")
+
+      structure = [
+        child(:file, %Membrane.File.Source{location: "test/fixtures/in_video_vp.h264"})
+        |> child(:parser, %Membrane.H264.Parser{
+          generate_best_effort_timestamps: %{framerate: {30, 1}},
+          output_stream_structure: :avc3
+        })
+        |> child(:muxer, %Membrane.MP4.Muxer.ISOM{chunk_duration: Time.seconds(1)})
+        |> child(:sink, %Membrane.File.Sink{location: out_path_for("video_vp")})
+      ]
+
+      pid = Pipeline.start_link_supervised!(spec: structure)
+
+      perform_test(pid, "video_vp")
+    end
+
     test "single H265 track" do
       prepare_test("video_hevc")
 
@@ -211,33 +229,6 @@ defmodule Membrane.MP4.Muxer.ISOM.IntegrationTest do
     end
   end
 
-  describe "When fed a variable parameter h264 stream, Muxer.ISOM should" do
-    test "raise when stream format's inband_parameters are not used" do
-      structure = [
-        child(:file, %Membrane.File.Source{location: "test/fixtures/in_video_vp.h264"})
-        |> child(:parser, %Membrane.H264.Parser{
-          generate_best_effort_timestamps: %{framerate: {30, 1}},
-          output_stream_structure: :avc1
-        })
-        |> child(:muxer, %Membrane.MP4.Muxer.ISOM{
-          chunk_duration: Time.seconds(1),
-          fast_start: true
-        })
-        |> child(:sink, Membrane.Fake.Sink.Buffers)
-      ]
-
-      {:ok, _supervisor_pid, pid} = Pipeline.start(spec: structure)
-      monitor_ref = Process.monitor(pid)
-
-      assert_receive {:DOWN, ^monitor_ref, :process, ^pid,
-                      {:membrane_child_crash, :muxer,
-                       {%RuntimeError{
-                          message: "ISOM Muxer doesn't support variable parameters"
-                        }, _stacktrace}}},
-                     1_000
-    end
-  end
-
   describe "ctts table" do
     test "should not be stored when dts and pts values are equal" do
       prepare_test("video")