Forward timestamps

lib/membrane_ffmpeg_swresample_plugin/converter.ex

@@ -122,7 +122,13 @@ defmodule Membrane.FFmpeg.SWResample.Converter do
   end
 
   @impl true
-  def handle_buffer(:input, %Buffer{payload: payload}, _ctx, state) do
+  def handle_buffer(:input, %Buffer{payload: payload, pts: pts}, _ctx, state) do
+    state =
+      state
+      |> Map.merge(%{
+        current_pts: pts
+      })
+
     conversion_result =
       convert!(state.native, RawAudio.frame_size(state.input_stream_format), payload, state.queue)
 
@@ -131,7 +137,7 @@ defmodule Membrane.FFmpeg.SWResample.Converter do
         {[], %{state | queue: queue}}
 
       {converted, queue} ->
-        {[buffer: {:output, %Buffer{payload: converted}}], %{state | queue: queue}}
+        {[buffer: {:output, %Buffer{payload: converted, pts: pts}}], %{state | queue: queue}}
     end
   end
 
@@ -154,8 +160,10 @@ defmodule Membrane.FFmpeg.SWResample.Converter do
         {[end_of_stream: :output], %{state | queue: <<>>}}
 
       converted ->
-        {[buffer: {:output, %Buffer{payload: converted}}, end_of_stream: :output],
-         %{state | queue: <<>>}}
+        {[
+           buffer: {:output, %Buffer{payload: converted, pts: state.current_pts}},
+           end_of_stream: :output
+         ], %{state | queue: <<>>}}
     end
   end
 

test/membrane_ffmpeg_swresample_plugin/converter_test.exs

@@ -27,7 +27,8 @@ defmodule Membrane.FFmpeg.SWResample.ConverterTest do
         output_stream_format: @u8_format,
         frames_per_buffer: 2048,
         native: nil,
-        queue: <<>>
+        queue: <<>>,
+        current_pts: nil
       }
     }
   end
@@ -178,5 +179,23 @@ defmodule Membrane.FFmpeg.SWResample.ConverterTest do
       assert actions == [buffer: {:output, %Membrane.Buffer{payload: result}}]
       assert new_state == %{state | queue: <<0::2*8>>}
     end
+
+    test "timestamps forward test", %{state: initial_state} do
+      state = %{
+        initial_state
+        | queue: <<250, 250, 0>>,
+          native: :mock_handle,
+          input_stream_format: @s16le_format
+      }
+
+      payload = <<0::7*8>>
+      pts = 1000
+      buffer = %Membrane.Buffer{payload: payload, pts: pts}
+      result = <<250, 0, 0, 0>>
+      mock(@native, [convert: 2], {:ok, result})
+
+      assert {[buffer: {:output, %Membrane.Buffer{pts: ^pts}}], _state} =
+               @module.handle_buffer(:input, buffer, nil, state)
+    end
   end
 end