add new subtitle preferences

2 files changed, 120 insertions, 2 deletions

diff --git a/MediaBrowser.Server.Implementations/Dto/DtoService.cs b/MediaBrowser.Server.Implementations/Dto/DtoService.cs
index 38d6034e4..bf77f1869 100644
--- a/MediaBrowser.Server.Implementations/Dto/DtoService.cs
+++ b/MediaBrowser.Server.Implementations/Dto/DtoService.cs
@@ -113,10 +113,26 @@ namespace MediaBrowser.Server.Implementations.Dto
 
             if (user != null && dto.MediaSources != null && item is Video)
             {
+                var preferredAudio = string.IsNullOrEmpty(user.Configuration.AudioLanguagePreference)
+                    ? new string[] { }
+                    : new[] { user.Configuration.AudioLanguagePreference };
+
+                var preferredSubs = string.IsNullOrEmpty(user.Configuration.SubtitleLanguagePreference)
+                    ? new string[] { }
+                    : new[] { user.Configuration.SubtitleLanguagePreference };
+
                 foreach (var source in dto.MediaSources)
                 {
-                    //source.DefaultAudioStreamIndex = GetDefaultAudioStreamIndex(source, user.Configuration);
-                    //source.DefaultSubtitleStreamIndex = GetDefaultSubtitleStreamIndex(source, user.Configuration);
+                    source.DefaultAudioStreamIndex = MediaStreamSelector.GetDefaultAudioStreamIndex(
+                        source.MediaStreams, preferredAudio, user.Configuration.PlayDefaultAudioTrack);
+
+                    var defaultAudioIndex = source.DefaultAudioStreamIndex;
+                    var audioLangage = defaultAudioIndex == null
+                        ? null
+                        : source.MediaStreams.Where(i => i.Type == MediaStreamType.Audio && i.Index == defaultAudioIndex).Select(i => i.Language).FirstOrDefault();
+
+                    source.DefaultSubtitleStreamIndex = MediaStreamSelector.GetDefaultSubtitleStreamIndex(source.MediaStreams, preferredSubs,
+                            user.Configuration.SubtitleMode, audioLangage);
                 }
             }
 
diff --git a/MediaBrowser.Server.Implementations/Dto/MediaStreamSelector.cs b/MediaBrowser.Server.Implementations/Dto/MediaStreamSelector.cs
new file mode 100644
index 000000000..e5a859cdc
--- /dev/null
+++ b/MediaBrowser.Server.Implementations/Dto/MediaStreamSelector.cs
@@ -0,0 +1,102 @@
+using MediaBrowser.Model.Configuration;
+using MediaBrowser.Model.Entities;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace MediaBrowser.Server.Implementations.Dto
+{
+    public static class MediaStreamSelector
+    {
+        public static int? GetDefaultAudioStreamIndex(List<MediaStream> streams, IEnumerable<string> preferredLanguages, bool preferDefaultTrack)
+        {
+            streams = GetSortedStreams(streams, MediaStreamType.Audio, preferredLanguages.ToList())
+               .ToList();
+
+            if (preferDefaultTrack)
+            {
+                var defaultStream = streams.FirstOrDefault(i => i.IsDefault);
+
+                if (defaultStream != null)
+                {
+                    return defaultStream.Index;
+                }
+            }
+
+            var stream = streams.FirstOrDefault();
+
+            if (stream != null)
+            {
+                return stream.Index;
+            }
+
+            return null;
+        }
+
+        public static int? GetDefaultSubtitleStreamIndex(List<MediaStream> streams,
+            IEnumerable<string> preferredLanguages,
+            SubtitlePlaybackMode mode,
+            string audioTrackLanguage)
+        {
+            var languages = preferredLanguages as List<string> ?? preferredLanguages.ToList();
+            streams = GetSortedStreams(streams, MediaStreamType.Subtitle, languages).ToList();
+
+            var full = streams.Where(s => !s.IsForced);
+            var forced = streams.Where(s => s.IsForced && string.Equals(s.Language, audioTrackLanguage, StringComparison.OrdinalIgnoreCase));
+
+            MediaStream stream = null;
+
+            if (mode == SubtitlePlaybackMode.None)
+            {
+                return null;
+            }
+
+            if (mode == SubtitlePlaybackMode.Default)
+            {
+                // if the audio language is not understood by the user, load their preferred subs, if there are any
+                if (!ContainsOrdinal(languages, audioTrackLanguage))
+                {
+                    stream = full.FirstOrDefault(s => ContainsOrdinal(languages, s.Language));
+                }
+            }
+            else if (mode == SubtitlePlaybackMode.Always)
+            {
+                // always load the most suitable full subtitles
+                stream = full.FirstOrDefault();
+            }
+            
+            // load forced subs if we have found no suitable full subtitles
+            stream = stream ?? forced.FirstOrDefault();
+
+            if (stream != null)
+            {
+                return stream.Index;
+            }
+
+            return null;
+        }
+
+        private static bool ContainsOrdinal(IEnumerable<string> list, string item)
+        {
+            return list.Any(i => string.Equals(i, item, StringComparison.OrdinalIgnoreCase));
+        }
+
+        private static IEnumerable<MediaStream> GetSortedStreams(IEnumerable<MediaStream> streams, MediaStreamType type, List<string> languagePreferences)
+        {
+            var orderStreams = streams
+                .Where(i => i.Type == type);
+
+            if (languagePreferences.Count == 0)
+            {
+                return orderStreams.OrderBy(i => i.IsDefault)
+                    .ThenBy(i => i.Index)
+                    .ToList();
+            }
+
+            return orderStreams.OrderBy(i => languagePreferences.FindIndex(l => string.Equals(i.Language, l, StringComparison.OrdinalIgnoreCase)))
+                .ThenBy(i => i.IsDefault)
+                .ThenBy(i => i.Index)
+                .ToList();
+        }
+    }
+}