feat: write/read uuid box

lib/ex_mp4/box/moov.ex

@@ -5,20 +5,21 @@ defmodule ExMP4.Box.Moov do
 
   import ExMP4.Box.Utils, only: [parse_header: 1]
 
-  alias ExMP4.Box.{Mvex, Mvhd, Trak}
+  alias ExMP4.Box.{Mvex, Mvhd, Trak, UUID}
 
   @type t :: %__MODULE__{
           mvhd: Mvhd.t(),
           trak: [Trak.t()],
-          mvex: Mvex.t() | nil
+          mvex: Mvex.t() | nil,
+          uuid: [UUID.t()]
         }
 
-  defstruct mvhd: %Mvhd{}, trak: [], mvex: nil
+  defstruct mvhd: %Mvhd{}, trak: [], mvex: nil, uuid: []
 
   defimpl ExMP4.Box do
     def size(box) do
       ExMP4.header_size() + ExMP4.Box.size(box.mvhd) + ExMP4.Box.size(box.trak) +
-        ExMP4.Box.size(box.mvex)
+        ExMP4.Box.size(box.mvex) + ExMP4.Box.size(box.uuid)
     end
 
     def parse(box, data), do: do_parse(box, data)
@@ -28,7 +29,8 @@ defmodule ExMP4.Box.Moov do
         <<size(box)::32, "moov">>,
         ExMP4.Box.serialize(box.mvhd),
         ExMP4.Box.serialize(box.trak),
-        ExMP4.Box.serialize(box.mvex)
+        ExMP4.Box.serialize(box.mvex),
+        ExMP4.Box.serialize(box.uuid)
       ]
     end
 
@@ -49,6 +51,10 @@ defmodule ExMP4.Box.Moov do
             box = %{box | mvex: ExMP4.Box.parse(%Mvex{}, box_data)}
             {box, rest}
 
+          {"uuid", box_data, rest} ->
+            box = %{box | uuid: box.uuid ++ [ExMP4.Box.parse(%UUID{}, box_data)]}
+            {box, rest}
+
           {_box_name, _box_data, rest} ->
             # box = %{box | mdia: ExMP4.Box.parse(%Mdia{}, box_data)}
             {box, rest}

lib/ex_mp4/box/trun.ex

@@ -46,7 +46,7 @@ defmodule ExMP4.Box.Trun do
       {first_sample_flags, rest} = parse_entry(flags &&& 0x4, rest)
 
       {entries, <<>>} =
-        Enum.reduce(1..sample_count, {[], rest}, fn _idx, {entries, data} ->
+        Enum.reduce(1..sample_count//1, {[], rest}, fn _idx, {entries, data} ->
           {sample_duration, rest} = parse_entry(flags &&& 0x100, data)
           {sample_size, rest} = parse_entry(flags &&& 0x200, rest)
           {sample_flags, rest} = parse_entry(flags &&& 0x400, rest)

lib/ex_mp4/box/uuid.ex

@@ -1,14 +1,34 @@
 defmodule ExMP4.Box.UUID do
   @moduledoc """
   Module describing a UUID box.
+
+  A `uuid` box is a user extension box, the following fields are available:
+    * `type` - The 16 bytes extended type (`usertype`) identifying the box.
+    * `data` - The raw payload of the box.
   """
 
   @type t :: %__MODULE__{
-          type: binary(),
+          type: <<_::128>>,
           data: binary()
         }
 
-  defstruct [:type, :data]
+  defstruct type: nil, data: <<>>
+
+  @doc """
+  Create a new UUID box.
+
+  `type` must be a 16 bytes binary.
+  """
+  @spec new(<<_::128>>, binary()) :: t()
+  def new(type, data \\ <<>>)
+
+  def new(<<_::binary-size(16)>> = type, data) when is_binary(data) do
+    %__MODULE__{type: type, data: data}
+  end
+
+  def new(type, _data) do
+    raise ArgumentError, "uuid type must be a 16 bytes binary, got: #{inspect(type)}"
+  end
 
   defimpl ExMP4.Box do
     def size(box) do

lib/ex_mp4/fwriter.ex

@@ -30,7 +30,8 @@ defmodule ExMP4.FWriter do
           creation_time: DateTime.t(),
           modification_time: DateTime.t(),
           duration: integer() | boolean(),
-          moof_base_offset: boolean()
+          moof_base_offset: boolean(),
+          uuid: [Box.UUID.t()]
         ]
 
   @type writer_options :: any()
@@ -67,6 +68,7 @@ defmodule ExMP4.FWriter do
       If an integer, it's the total duration in the `movie` timescale and it'll be set in the `mehd` box.
     * `moof_base_offset` - if `true`, it indicates that the `base‐data‐offset` for the track fragments
       is the position of the first byte of the enclosing Movie Fragment Box. Defaults to: `false`.
+    * `uuid` - A list of `ExMP4.Box.UUID` boxes to include in the `moov` box. Defaults to: `[]`.
 
   The last argument is an optional module implementing `ExMP4.FragDataWriter`.
   """
@@ -260,7 +262,8 @@ defmodule ExMP4.FWriter do
       modification_time: utc_date,
       duration: false,
       moof_base_offset: false,
-      sidx: false
+      sidx: false,
+      uuid: []
     )
   end
 
@@ -289,7 +292,8 @@ defmodule ExMP4.FWriter do
       mvex: %Box.Mvex{
         mehd: mehd_box,
         trex: Enum.map(tracks, & &1.trex)
-      }
+      },
+      uuid: opts[:uuid]
     }
 
     writer_state = writer.writer_mod.write_init_header(writer.writer_state, [ftyp_box, movie_box])

lib/ex_mp4/reader.ex

@@ -13,6 +13,7 @@ defmodule ExMP4.Reader do
     * `major_brand`
     * `minor_version`
     * `compatible_brands`
+    * `uuid` - List of `uuid` boxes (`ExMP4.Box.UUID`) found in the `moov` box.
 
 
   ## Examples
@@ -73,6 +74,7 @@ defmodule ExMP4.Reader do
           progressive?: boolean(),
           creation_time: DateTime.t(),
           modification_time: DateTime.t(),
+          uuid: [Box.UUID.t()],
 
           # private fields
           reader_mod: module(),
@@ -94,6 +96,7 @@ defmodule ExMP4.Reader do
     :reader_mod,
     :reader_state,
     :tracks,
+    uuid: [],
     location: 0
   ]
 
@@ -280,7 +283,8 @@ defmodule ExMP4.Reader do
         modification_time: moov.mvhd.modification_time,
         fragmented?: not is_nil(moov.mvex),
         progressive?: is_nil(reader.progressive?),
-        tracks: tracks
+        tracks: tracks,
+        uuid: moov.uuid
     }
   end
 

lib/ex_mp4/writer.ex

@@ -186,16 +186,23 @@ defmodule ExMP4.Writer do
 
   @doc """
   Write the trailer and close the stream.
+
+  The following options can be provided:
+    * `creation_time` - Set the creation time. Defaults to: now.
+    * `modification_time` - Set the modification time. Defaults to: now.
+    * `uuid` - A list of `ExMP4.Box.UUID` boxes to include in the `moov` box. Defaults to: `[]`.
   """
   @spec write_trailer(t()) :: :ok
   def write_trailer(%{fast_start: fast_start} = writer, opts \\ []) do
     [
       creation_time: creation_time,
-      modification_time: modification_time
+      modification_time: modification_time,
+      uuid: uuid
     ] =
       Keyword.validate!(opts,
         creation_time: DateTime.utc_now(:second),
-        modification_time: DateTime.utc_now(:second)
+        modification_time: DateTime.utc_now(:second),
+        uuid: []
       )
       |> Enum.sort()
 
@@ -218,7 +225,8 @@ defmodule ExMP4.Writer do
         creation_time: creation_time,
         modification_time: modification_time
       },
-      trak: trak
+      trak: trak,
+      uuid: uuid
     }
 
     after_ftyp = {:bof, writer.ftyp_size}

mix.lock

@@ -1,19 +1,19 @@
 %{
-  "benchee": {:hex, :benchee, "1.5.0", "4d812c31d54b0ec0167e91278e7de3f596324a78a096fd3d0bea68bb0c513b10", [:mix], [{:deep_merge, "~> 1.0", [hex: :deep_merge, repo: "hexpm", optional: false]}, {:statistex, "~> 1.1", [hex: :statistex, repo: "hexpm", optional: false]}, {:table, "~> 0.1.0", [hex: :table, repo: "hexpm", optional: true]}], "hexpm", "5b075393aea81b8ae74eadd1c28b1d87e8a63696c649d8293db7c4df3eb67535"},
+  "benchee": {:hex, :benchee, "1.5.1", "b95cbc36c4b98969a5c592a246e171041eb683c56bad1cb4f49a3b081ba66087", [:mix], [{:deep_merge, "~> 1.0", [hex: :deep_merge, repo: "hexpm", optional: false]}, {:statistex, "~> 1.1", [hex: :statistex, repo: "hexpm", optional: false]}, {:table, "~> 0.1.0", [hex: :table, repo: "hexpm", optional: true]}], "hexpm", "a539301f8dfd4efc5c5123bfb9d47ebde20092a863a5b5b16c2a60d2243dfce7"},
   "bunt": {:hex, :bunt, "1.0.0", "081c2c665f086849e6d57900292b3a161727ab40431219529f13c4ddcf3e7a44", [:mix], [], "hexpm", "dc5f86aa08a5f6fa6b8096f0735c4e76d54ae5c9fa2c143e5a1fc7c1cd9bb6b5"},
-  "credo": {:hex, :credo, "1.7.13", "126a0697df6b7b71cd18c81bc92335297839a806b6f62b61d417500d1070ff4e", [:mix], [{:bunt, "~> 0.2.1 or ~> 1.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:file_system, "~> 0.2 or ~> 1.0", [hex: :file_system, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "47641e6d2bbff1e241e87695b29f617f1a8f912adea34296fb10ecc3d7e9e84f"},
-  "deep_merge": {:hex, :deep_merge, "1.0.0", "b4aa1a0d1acac393bdf38b2291af38cb1d4a52806cf7a4906f718e1feb5ee961", [:mix], [], "hexpm", "ce708e5f094b9cd4e8f2be4f00d2f4250c4095be93f8cd6d018c753894885430"},
-  "dialyxir": {:hex, :dialyxir, "1.4.6", "7cca478334bf8307e968664343cbdb432ee95b4b68a9cba95bdabb0ad5bdfd9a", [:mix], [{:erlex, ">= 0.2.7", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "8cf5615c5cd4c2da6c501faae642839c8405b49f8aa057ad4ae401cb808ef64d"},
-  "earmark_parser": {:hex, :earmark_parser, "1.4.44", "f20830dd6b5c77afe2b063777ddbbff09f9759396500cdbe7523efd58d7a339c", [:mix], [], "hexpm", "4778ac752b4701a5599215f7030989c989ffdc4f6df457c5f36938cc2d2a2750"},
-  "erlex": {:hex, :erlex, "0.2.7", "810e8725f96ab74d17aac676e748627a07bc87eb950d2b83acd29dc047a30595", [:mix], [], "hexpm", "3ed95f79d1a844c3f6bf0cea61e0d5612a42ce56da9c03f01df538685365efb0"},
-  "ex_doc": {:hex, :ex_doc, "0.39.1", "e19d356a1ba1e8f8cfc79ce1c3f83884b6abfcb79329d435d4bbb3e97ccc286e", [:mix], [{:earmark_parser, "~> 1.4.44", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_c, ">= 0.1.0", [hex: :makeup_c, repo: "hexpm", optional: true]}, {:makeup_elixir, "~> 0.14 or ~> 1.0", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1 or ~> 1.0", [hex: :makeup_erlang, repo: "hexpm", optional: false]}, {:makeup_html, ">= 0.1.0", [hex: :makeup_html, repo: "hexpm", optional: true]}], "hexpm", "8abf0ed3e3ca87c0847dfc4168ceab5bedfe881692f1b7c45f4a11b232806865"},
+  "credo": {:hex, :credo, "1.7.19", "cc52129665fc7c15143d47838fda0f9cd6dac9ceced7bf4da6f85fcbfe64b12a", [:mix], [{:bunt, "~> 0.2.1 or ~> 1.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:file_system, "~> 0.2 or ~> 1.0", [hex: :file_system, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "2d8bc95d5a7bb99dd2613621d4f08c6a3575c3fd4b62e6a2b48a100352a557b8"},
+  "deep_merge": {:hex, :deep_merge, "1.0.2", "476aa7ea61c54de96220051b998d893869069094da65b96101aebf79416f8a1e", [:mix], [], "hexpm", "737a53cdc9758fedbb608bdc213969e65729466c4ef3cd8e8726d0335dff116c"},
+  "dialyxir": {:hex, :dialyxir, "1.4.8", "7ef671a8aff9948b091d8c30f09467fbb16e77305cda451bce48109a0f5e021c", [:mix], [{:erlex, ">= 0.2.8", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "cbd5a851571e5dfeb32aaf2e840bfa98b7864cb3071bf2ef5d95d1276b12e072"},
+  "earmark_parser": {:hex, :earmark_parser, "1.4.46", "67607a0532e810c6f630a515c548d0b24949643f168cc556303bee4cf96105c7", [:mix], [], "hexpm", "9c44636e8a1c68c62f526b2dcd85d941dbbcee7ab82cf64ba06ce28bef8e89f5"},
+  "erlex": {:hex, :erlex, "0.2.9", "7debbbaa9f4f368b8cd648983e0f1d7963028508e9c59e9d4ed504e94ef52a55", [:mix], [], "hexpm", "8cfffc0ec7159e6d73de2ab28a588064de80f88b2798d5cbe4482cbbc200178b"},
+  "ex_doc": {:hex, :ex_doc, "0.40.4", "66f2e42bf588594d5a8aab31cad87f2ddad09d0da1b1a2f379340ec2c2e497cb", [:mix], [{:earmark_parser, "~> 1.4.46", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_c, ">= 0.1.0", [hex: :makeup_c, repo: "hexpm", optional: true]}, {:makeup_elixir, "~> 0.14 or ~> 1.0", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1 or ~> 1.0", [hex: :makeup_erlang, repo: "hexpm", optional: false]}, {:makeup_html, ">= 0.1.0", [hex: :makeup_html, repo: "hexpm", optional: true]}], "hexpm", "6222b9e423d76584ee34df2c82a5ed72c2d53dc153f7f483ad28b378694186cc"},
   "file_system": {:hex, :file_system, "1.1.1", "31864f4685b0148f25bd3fbef2b1228457c0c89024ad67f7a81a3ffbc0bbad3a", [:mix], [], "hexpm", "7a15ff97dfe526aeefb090a7a9d3d03aa907e100e262a0f8f7746b78f8f87a5d"},
-  "jason": {:hex, :jason, "1.4.4", "b9226785a9aa77b6857ca22832cffa5d5011a667207eb2a0ad56adb5db443b8a", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "c5eb0cab91f094599f94d55bc63409236a8ec69a21a67814529e8d5f6cc90b3b"},
-  "makeup": {:hex, :makeup, "1.2.1", "e90ac1c65589ef354378def3ba19d401e739ee7ee06fb47f94c687016e3713d1", [:mix], [{:nimble_parsec, "~> 1.4", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "d36484867b0bae0fea568d10131197a4c2e47056a6fbe84922bf6ba71c8d17ce"},
+  "jason": {:hex, :jason, "1.4.5", "2e3a008590b0b8d7388c20293e9dcc9cf3e5d642fd2a114e4cbbb52e595d940a", [:mix], [{:decimal, "~> 1.0 or ~> 2.0 or ~> 3.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "b0c823996102bcd0239b3c2444eb00409b72f6a140c1950bc8b457d836b30684"},
+  "makeup": {:hex, :makeup, "1.2.3", "c3ef0ff83acf305384acba0f70bff87d8732502baa1eb3eb081d8c154fbe18f5", [:mix], [{:nimble_parsec, "~> 1.4", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "15970751b7021c2bcd7ed56a54b3def23affd3969fb7c214dffdf28e97ce6f76"},
   "makeup_elixir": {:hex, :makeup_elixir, "1.0.1", "e928a4f984e795e41e3abd27bfc09f51db16ab8ba1aebdba2b3a575437efafc2", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.2.3 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "7284900d412a3e5cfd97fdaed4f5ed389b8f2b4cb49efc0eb3bd10e2febf9507"},
-  "makeup_erlang": {:hex, :makeup_erlang, "1.0.2", "03e1804074b3aa64d5fad7aa64601ed0fb395337b982d9bcf04029d68d51b6a7", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "af33ff7ef368d5893e4a267933e7744e46ce3cf1f61e2dccf53a111ed3aa3727"},
+  "makeup_erlang": {:hex, :makeup_erlang, "1.1.0", "835f7e60792e08824cda445639555d7bf1bbbddb1b60b306e33cb6f6db24dc74", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "1cd6780fb1dd1a03979abaed0fe82712b0625118fd5257d3ebbf73f960c73c3c"},
   "media_codecs": {:hex, :media_codecs, "0.10.0", "dcc64779c3b287202fd8083fe49bf11b37f7b6bbd8edf3a9bd756370ee4417c5", [:mix], [], "hexpm", "8ea233ae378acfae3ab95a90f6f5c99711d55f15d0c5fac244d46b42f6a9ca04"},
   "nimble_parsec": {:hex, :nimble_parsec, "1.4.2", "8efba0122db06df95bfaa78f791344a89352ba04baedd3849593bfce4d0dc1c6", [:mix], [], "hexpm", "4b21398942dda052b403bbe1da991ccd03a053668d147d53fb8c4e0efe09c973"},
-  "statistex": {:hex, :statistex, "1.1.0", "7fec1eb2f580a0d2c1a05ed27396a084ab064a40cfc84246dbfb0c72a5c761e5", [:mix], [], "hexpm", "f5950ea26ad43246ba2cce54324ac394a4e7408fdcf98b8e230f503a0cba9cf5"},
+  "statistex": {:hex, :statistex, "1.1.1", "73612aa7f79e53c30569be065fd121e380f1cf57bc4c2da5b41be9246da18df9", [:mix], [], "hexpm", "310c4b49b34adf683de3103639006bed233ab54c08a4add65a531448e653857c"},
   "table_rex": {:hex, :table_rex, "4.1.0", "fbaa8b1ce154c9772012bf445bfb86b587430fb96f3b12022d3f35ee4a68c918", [:mix], [], "hexpm", "95932701df195d43bc2d1c6531178fc8338aa8f38c80f098504d529c43bc2601"},
 }

test/ex_mp4/box_test.exs

@@ -148,4 +148,32 @@ defmodule ExMP4.BoxTest do
     assert Box.serialize(styp) |> IO.iodata_to_binary() == expected
     assert Box.parse(%Box.Styp{}, :binary.part(expected, 8, 16)) == styp
   end
+
+  test "serialize and parse uuid" do
+    type = <<0::128>>
+    uuid = Box.UUID.new(type, "some data")
+
+    expected = <<33::32, "uuid", type::binary, "some data">>
+
+    assert Box.size(uuid) == 33
+    assert Box.serialize(uuid) |> IO.iodata_to_binary() == expected
+    assert Box.parse(%Box.UUID{}, :binary.part(expected, 8, 25)) == uuid
+  end
+
+  test "uuid type must be 16 bytes" do
+    assert_raise ArgumentError, fn -> Box.UUID.new("short", "data") end
+  end
+
+  test "parse and serialize moov with uuid boxes" do
+    assert {:ok, <<_size::32, "moov", rest::binary>>} = File.read("test/fixtures/moov.bin")
+
+    moov = Box.parse(%Box.Moov{}, rest)
+    uuids = [Box.UUID.new(<<1::128>>, "first"), Box.UUID.new(<<2::128>>, "second")]
+    moov = %{moov | uuid: uuids}
+
+    data = Box.serialize(moov) |> IO.iodata_to_binary()
+    assert <<size::32, "moov", rest::binary>> = data
+    assert size == Box.size(moov)
+    assert Box.parse(%Box.Moov{}, rest) == moov
+  end
 end

test/ex_mp4/fwriter_test.exs

@@ -5,7 +5,7 @@ defmodule ExMP4.FWriterTest do
 
   import ExMP4.Support.Utils
 
-  alias ExMP4.{FWriter, Sample}
+  alias ExMP4.{Box, FWriter, Sample}
 
   @moduletag :tmp_dir
 
@@ -72,6 +72,33 @@ defmodule ExMP4.FWriterTest do
     assert :ok = ExMP4.Reader.close(reader)
   end
 
+  test "write fragmented mp4 with uuid boxes", %{tmp_dir: tmp_dir} do
+    filepath = Path.join(tmp_dir, "out.mp4")
+    uuids = [Box.UUID.new(<<1::128>>, "data")]
+
+    assert {:ok, writer} =
+             FWriter.new(filepath, [video_track(), audio_track()], uuid: uuids, duration: true)
+
+    video_samples = for idx <- 0..4, do: video_sample(idx)
+
+    assert :ok =
+             writer
+             |> FWriter.create_fragment()
+             |> then(&Enum.reduce(video_samples, &1, fn s, w -> FWriter.write_sample(w, s) end))
+             |> FWriter.flush_fragment()
+             |> FWriter.close()
+
+    assert {:ok, reader} = ExMP4.Reader.new(filepath)
+    assert reader.uuid == uuids
+    assert reader.duration == 3500
+
+    for idx <- 0..4 do
+      assert Enum.at(video_samples, idx) == ExMP4.Reader.read_sample(reader, 1, idx)
+    end
+
+    assert :ok = ExMP4.Reader.close(reader)
+  end
+
   test "write fragmented mp4 (base is moof)", %{tmp_dir: tmp_dir} do
     filepath = Path.join(tmp_dir, "out.mp4")
 

test/ex_mp4/writer_test.exs

@@ -5,7 +5,7 @@ defmodule ExMP4.WriterTest do
 
   import ExMP4.Support.Utils
 
-  alias ExMP4.{Sample, Writer}
+  alias ExMP4.{Box, Sample, Writer}
 
   @moduletag :tmp_dir
 
@@ -97,6 +97,34 @@ defmodule ExMP4.WriterTest do
     assert <<_ftyp::binary-size(32), _moov_size::binary-size(4), "moov", _rest::binary>> = data
   end
 
+  for fast_start <- [false, true] do
+    test "write mp4 with uuid boxes (fast_start: #{fast_start})", %{tmp_dir: tmp_dir} do
+      filepath = Path.join(tmp_dir, "out.mp4")
+      uuids = [Box.UUID.new(<<1::128>>, "data"), Box.UUID.new(<<2::128>>)]
+
+      assert :ok =
+               filepath
+               |> Writer.new!(fast_start: unquote(fast_start))
+               |> Writer.write_header()
+               |> Writer.add_tracks([video_track(), audio_track()])
+               |> then(&Enum.into(Enum.concat(video_samples(), audio_samples()), &1))
+               |> Writer.write_trailer(uuid: uuids)
+
+      assert {:ok, reader} = ExMP4.Reader.new(filepath)
+      assert reader.uuid == uuids
+
+      for {sample, idx} <- Enum.with_index(video_samples()) do
+        assert sample == ExMP4.Reader.read_sample(reader, 1, idx)
+      end
+
+      for {sample, idx} <- Enum.with_index(audio_samples()) do
+        assert sample == ExMP4.Reader.read_sample(reader, 2, idx)
+      end
+
+      assert :ok = ExMP4.Reader.close(reader)
+    end
+  end
+
   defp video_samples do
     [
       {0, 2000, 1000, true},