Refactor executable checks and add version check for non-forked youtube-dl

config/config.exs

@@ -1,9 +1,7 @@
 import Config
 
 config :nostrum,
-  token: "",
-  ffmpeg: "ffmpeg",
-  youtubedl: "youtube-dl"
+  token: ""
 
 config :logger, :console, metadata: [:shard, :guild, :channel]
 

lib/nostrum/application.ex

@@ -4,6 +4,7 @@ defmodule Nostrum.Application do
   use Application
 
   alias Nostrum.Token
+  alias Nostrum.Voice
 
   require Logger
 
@@ -41,34 +42,46 @@ defmodule Nostrum.Application do
   end
 
   defp check_executables do
-    ff = Application.get_env(:nostrum, :ffmpeg)
-    yt = Application.get_env(:nostrum, :youtubedl)
-    sl = Application.get_env(:nostrum, :streamlink)
-
-    cond do
-      is_binary(ff) and is_nil(System.find_executable(ff)) ->
-        Logger.warning("""
-        #{ff} was not found in your path. By default, Nostrum requires ffmpeg to use voice.
-        If you don't intend to use voice with ffmpeg, configure :nostrum, :ffmpeg to nil to suppress.
-        """)
-
-      is_binary(yt) and is_nil(System.find_executable(yt)) ->
-        Logger.warning("""
-        #{yt} was not found in your path. Nostrum supports youtube-dl for voice.
-        If you don't require youtube-dl support, configure :nostrum, :youtubedl to nil to suppress.
-        """)
-
-      is_binary(sl) and is_nil(System.find_executable(sl)) ->
-        Logger.warning("""
-        #{sl} was not found in your path. Nostrum supports streamlink for voice.
-        If you don't require streamlink support, configure :nostrum, :streamlink to nil to suppress.
-        """)
-
-      true ->
-        :ok
-    end
+    ff = Voice.ffmpeg_executable()
+    yt = Voice.youtubedl_executable()
+    sl = Voice.streamlink_executable()
+
+    ff_path = if ff, do: System.find_executable(ff)
+    yt_path = if yt, do: System.find_executable(yt)
+    sl_path = if sl, do: System.find_executable(sl)
+
+    check_ffmpeg(ff_path, ff)
+    check_ytdl(ff_path, yt, yt_path)
+    check_streamlink(ff_path, sl, sl_path)
+  end
+
+  defp check_ffmpeg(_ff_path = nil, ff) when is_binary(ff) do
+    Logger.warning("""
+    #{ff} was not found in your path. By default, Nostrum requires ffmpeg to use voice.
+    If you don't intend to use voice with ffmpeg, configure :nostrum, :ffmpeg to nil or false to suppress all voice warnings.
+    """)
+  end
+
+  defp check_ffmpeg(_ff_path, _ff), do: :noop
+
+  defp check_ytdl(ff_path, yt, _yt_path = nil) when is_binary(ff_path) and is_binary(yt) do
+    Logger.warning("""
+    #{yt} was not found in your path. Nostrum supports youtube-dl for voice.
+    If you don't require youtube-dl support, configure :nostrum, :youtubedl to nil or false to suppress.
+    """)
+  end
+
+  defp check_ytdl(_ff_path, _yt, _yt_path), do: :noop
+
+  defp check_streamlink(ff_path, sl, _sl_path = nil) when is_binary(ff_path) and is_binary(sl) do
+    Logger.warning("""
+    #{sl} was not found in your path. Nostrum supports streamlink for voice.
+    If you don't require streamlink support, configure :nostrum, :streamlink to nil or false to suppress.
+    """)
   end
 
+  defp check_streamlink(_ff_path, _sl, _sl_path), do: :noop
+
   defp check_otp_version do
     _module_info = :pg.module_info()
 

lib/nostrum/dummy.ex

@@ -12,7 +12,7 @@ defmodule DummySupervisor do
   end
 
   def init(_args) do
-    children = for id <- 0..1, do: Supervisor.child_spec({DummyConsumer, []}, id: id)
+    children = [DummyConsumer]
     Supervisor.init(children, strategy: :one_for_one)
   end
 end

lib/nostrum/voice.ex

@@ -33,7 +33,10 @@ defmodule Nostrum.Voice do
   """
 
   alias Nostrum.Api
-  alias Nostrum.Struct.{Channel, Guild, VoiceState, VoiceWSState}
+  alias Nostrum.Struct.Channel
+  alias Nostrum.Struct.Guild
+  alias Nostrum.Struct.VoiceState
+  alias Nostrum.Struct.VoiceWSState
   alias Nostrum.Voice.Audio
   alias Nostrum.Voice.Opus
   alias Nostrum.Voice.Ports
@@ -121,6 +124,13 @@ defmodule Nostrum.Voice do
     GenServer.cast(Nostrum.VoiceStateMap, {:remove, guild_id, pre_cleanup_args})
   end
 
+  @doc false
+  defdelegate ffmpeg_executable, to: Audio
+  @doc false
+  defdelegate youtubedl_executable, to: Audio
+  @doc false
+  defdelegate streamlink_executable, to: Audio
+
   @doc """
   Joins or moves the bot to a voice channel.
 
@@ -242,6 +252,8 @@ defmodule Nostrum.Voice do
   """
   @spec play(Guild.id(), play_input(), play_type(), keyword()) :: :ok | {:error, String.t()}
   def play(guild_id, input, type \\ :url, options \\ []) do
+    maybe_warn(type)
+
     voice = get_voice(guild_id)
 
     cond do
@@ -834,4 +846,34 @@ defmodule Nostrum.Voice do
   end
 
   defp persistent_args(_voice), do: []
+
+  unless Application.compile_env(:nostrum, :suppress_youtubedl_version, false) do
+    @ytdl_old_version "2021.12.17"
+
+    defp check_youtubedl_version do
+      with ytdl when is_binary(ytdl) <- youtubedl_executable(),
+           ["youtube-dl" | _] <- ytdl |> Path.basename() |> String.split("."),
+           {version, 0} <- System.cmd(ytdl, ["--version"]),
+           version when version <= @ytdl_old_version <- String.trim(version) do
+        Logger.warning("""
+        Configured youtube-dl installation '#{System.find_executable(ytdl)}' is version #{version}.
+
+        This version no longer compatible with recent YouTube updates.
+
+        It is recommended to configure :nostrum, :youtubedl to point to a maintained fork such as 'yt-dlp'.
+
+        If you know what you are doing, configure :nostrum, :suppress_youtubedl_version to `true` to suppress this.
+        """)
+      end
+    end
+
+    defp maybe_warn(:ytdl) do
+      unless :persistent_term.get(:nostrum_has_checked_youtubedl_version, false) do
+        :persistent_term.put(:nostrum_has_checked_youtubedl_version, true)
+        {:ok, _pid} = Task.start(fn -> check_youtubedl_version() end)
+      end
+    end
+  end
+
+  defp maybe_warn(_type), do: :noop
 end

lib/nostrum/voice/audio.ex

@@ -22,6 +22,10 @@ defmodule Nostrum.Voice.Audio do
 
   def encryption_mode, do: @encryption_mode
 
+  def ffmpeg_executable, do: Application.get_env(:nostrum, :ffmpeg, @ffmpeg)
+  def youtubedl_executable, do: Application.get_env(:nostrum, :youtubedl, @ytdl)
+  def streamlink_executable, do: Application.get_env(:nostrum, :streamlink, @streamlink)
+
   # How many consecutive packets to send before resting
   def frames_per_burst,
     do: Application.get_env(:nostrum, :audio_frames_per_burst, @frames_per_burst)
@@ -166,7 +170,7 @@ defmodule Nostrum.Voice.Audio do
   def spawn_youtubedl(url) do
     res =
       Ports.execute(
-        Application.get_env(:nostrum, :youtubedl, @ytdl),
+        youtubedl_executable(),
         [
           ["-f", "bestaudio"],
           ["-o", "-"],
@@ -189,7 +193,7 @@ defmodule Nostrum.Voice.Audio do
   def spawn_streamlink(url) do
     res =
       Ports.execute(
-        Application.get_env(:nostrum, :streamlink, @streamlink),
+        streamlink_executable(),
         [
           ["--stdout"],
           ["--quiet"],
@@ -226,7 +230,7 @@ defmodule Nostrum.Voice.Audio do
 
     res =
       Ports.execute(
-        Application.get_env(:nostrum, :ffmpeg, @ffmpeg),
+        ffmpeg_executable(),
         [
           ffmpeg_options(options, input_url),
           ["-ac", "2"],