[Enhancement] Add audio track language selection to Media Profile (#487)

* Moved quality options to their own module

* Added language and format selection to quality option builder

* [WIP] migrating tests

* Added audio_lang to media_profile table

* Renamed column; added format options and tests

* Adds UI for audio_track to the media profile form

* Adds a version string to in-app streams to help with cache busting

lib/pinchflat/downloading/download_option_builder.ex

@@ -4,10 +4,10 @@ defmodule Pinchflat.Downloading.DownloadOptionBuilder do
   """
 
   alias Pinchflat.Sources
-  alias Pinchflat.Settings
   alias Pinchflat.Sources.Source
   alias Pinchflat.Media.MediaItem
   alias Pinchflat.Downloading.OutputPathBuilder
+  alias Pinchflat.Downloading.QualityOptionBuilder
 
   alias Pinchflat.Utils.FilesystemUtils, as: FSUtils
 
@@ -142,27 +142,7 @@ defmodule Pinchflat.Downloading.DownloadOptionBuilder do
   end
 
   defp quality_options(media_profile) do
-    vcodec = Settings.get!(:video_codec_preference)
-    acodec = Settings.get!(:audio_codec_preference)
-    container = media_profile.media_container
-
-    case media_profile.preferred_resolution do
-      # Also be aware that :audio disabled all embedding options for subtitles
-      :audio ->
-        [:extract_audio, format_sort: "+acodec:#{acodec}", audio_format: container || "best"]
-
-      resolution_atom ->
-        {resolution_string, _} =
-          resolution_atom
-          |> Atom.to_string()
-          |> Integer.parse()
-
-        [
-          # Since Plex doesn't support reading metadata from MKV
-          remux_video: container || "mp4",
-          format_sort: "res:#{resolution_string},+codec:#{vcodec}:#{acodec}"
-        ]
-    end
+    QualityOptionBuilder.build(media_profile)
   end
 
   defp sponsorblock_options(media_profile) do

lib/pinchflat/downloading/quality_option_builder.ex

@@ -0,0 +1,66 @@
+defmodule Pinchflat.Downloading.QualityOptionBuilder do
+  @moduledoc """
+  A standalone builder module for building quality-related options for yt-dlp to download media.
+
+  Currently exclusively used in DownloadOptionBuilder since this logic is too complex to just
+  place in the main module.
+  """
+
+  alias Pinchflat.Settings
+  alias Pinchflat.Profiles.MediaProfile
+
+  @doc """
+  Builds the quality-related options for yt-dlp to download media based on the given media profile
+
+  Includes things like container, preferred format/codec, and audio track options.
+  """
+  def build(%MediaProfile{preferred_resolution: :audio, media_container: container} = media_profile) do
+    acodec = Settings.get!(:audio_codec_preference)
+
+    [
+      :extract_audio,
+      format_sort: "+acodec:#{acodec}",
+      audio_format: container || "best",
+      format: build_format_string(media_profile)
+    ]
+  end
+
+  def build(%MediaProfile{preferred_resolution: resolution_atom, media_container: container} = media_profile) do
+    vcodec = Settings.get!(:video_codec_preference)
+    acodec = Settings.get!(:audio_codec_preference)
+    {resolution_string, _} = resolution_atom |> Atom.to_string() |> Integer.parse()
+
+    [
+      # Since Plex doesn't support reading metadata from MKV
+      remux_video: container || "mp4",
+      format_sort: "res:#{resolution_string},+codec:#{vcodec}:#{acodec}",
+      format: build_format_string(media_profile)
+    ]
+  end
+
+  defp build_format_string(%MediaProfile{preferred_resolution: :audio, audio_track: audio_track}) do
+    if audio_track do
+      "bestaudio[#{build_format_modifier(audio_track)}]/bestaudio/best"
+    else
+      "bestaudio/best"
+    end
+  end
+
+  defp build_format_string(%MediaProfile{audio_track: audio_track}) do
+    if audio_track do
+      "bestvideo+bestaudio[#{build_format_modifier(audio_track)}]/bestvideo*+bestaudio/best"
+    else
+      "bestvideo*+bestaudio/best"
+    end
+  end
+
+  # Reminder to self: this conflicts with `--extractor-args "youtube:lang=<LANG>"`
+  # since that will translate the format_notes as well, which means they may not match.
+  # At least that's what happens now - worth a re-check if I have to come back to this
+  defp build_format_modifier("original"), do: "format_note*=original"
+  defp build_format_modifier("default"), do: "format_note*='(default)'"
+  # This uses the carat to anchor the language to the beginning of the string
+  # since that's what's needed to match `en` to `en-US` and `en-GB`, etc. The user
+  # can always specify the full language code if they want.
+  defp build_format_modifier(language_code), do: "language^=#{language_code}"
+end

lib/pinchflat/profiles/media_profile.ex

@@ -26,6 +26,7 @@ defmodule Pinchflat.Profiles.MediaProfile do
     sponsorblock_categories
     shorts_behaviour
     livestream_behaviour
+    audio_track
     preferred_resolution
     media_container
     redownload_delay_days
@@ -65,6 +66,7 @@ defmodule Pinchflat.Profiles.MediaProfile do
     # See `build_format_clauses` in the Media context for more.
     field :shorts_behaviour, Ecto.Enum, values: ~w(include exclude only)a, default: :include
     field :livestream_behaviour, Ecto.Enum, values: ~w(include exclude only)a, default: :include
+    field :audio_track, :string
     field :preferred_resolution, Ecto.Enum, values: ~w(4320p 2160p 1080p 720p 480p 360p audio)a, default: :"1080p"
     field :media_container, :string, default: nil