Merge branch 'master' into release/v0.2.0

Author: varsill

lib/ex_hls/demuxing_engine/mpeg_ts.ex

@@ -148,6 +148,37 @@ defmodule ExHLS.DemuxingEngine.MPEGTS do
     end
   end
 
+  defp maybe_read_tden_tag(demuxer, packet_pts) do
+    withl no_id3_stream:
+            {id3_track_id, _stream_description} <-
+              demuxer.pmt.streams
+              |> Enum.find(fn {_pid, stream_description} ->
+                stream_description.stream_type == :METADATA_IN_PES
+              end),
+          no_id3_data: {[id3], demuxer} <- Demuxer.take(demuxer, id3_track_id),
+          id3_not_in_timerange: true <- id3.pts <= packet_pts do
+      {parse_tden_tag(id3.data), demuxer}
+    else
+      no_id3_stream: nil -> {nil, demuxer}
+      no_id3_data: {[], updated_demuxer} -> {nil, updated_demuxer}
+      id3_not_in_timerange: false -> {nil, demuxer}
+    end
+  end
+
+  defp parse_tden_tag(payload) do
+    # UTF-8 encoding
+    encoding = 3
+
+    with {pos, _len} <- :binary.match(payload, "TDEN"),
+         <<_skip::binary-size(pos), "TDEN", tden::binary>> <- payload,
+         <<size::integer-size(4)-unit(8), _flags::16, ^encoding::8, text::binary-size(size - 2),
+           0::8, _rest::binary>> <- tden do
+      text
+    else
+      _error -> nil
+    end
+  end
+
   # value returned by Demuxer is represented in nanoseconds
   defp packet_ts_to_millis(ts), do: div(ts, 1_000_000)