3 files changed, 44 insertions, 18 deletions
diff --git a/MediaBrowser.Model/Dlna/ConditionProcessor.cs b/MediaBrowser.Model/Dlna/ConditionProcessor.cs
index 09b966367..1b61bfe15 100644
--- a/MediaBrowser.Model/Dlna/ConditionProcessor.cs
+++ b/MediaBrowser.Model/Dlna/ConditionProcessor.cs
@@ -345,6 +345,15 @@ namespace MediaBrowser.Model.Dlna
                 return !condition.IsRequired;
             }
 
+            // Special case: HDR10 also satisfies if the video is HDR10Plus
+            if (currentValue.Value == VideoRangeType.HDR10Plus)
+            {
+                if (IsConditionSatisfied(condition, VideoRangeType.HDR10))
+                {
+                    return true;
+                }
+            }
+
             var conditionType = condition.Condition;
             if (conditionType == ProfileConditionType.EqualsAny)
             {
diff --git a/MediaBrowser.Model/Dlna/StreamBuilder.cs b/MediaBrowser.Model/Dlna/StreamBuilder.cs
index 806900e9a..61e04a813 100644
--- a/MediaBrowser.Model/Dlna/StreamBuilder.cs
+++ b/MediaBrowser.Model/Dlna/StreamBuilder.cs
@@ -665,15 +665,39 @@ namespace MediaBrowser.Model.Dlna
 
             // Collect candidate audio streams
             ICollection<MediaStream> candidateAudioStreams = audioStream is null ? [] : [audioStream];
-            if (!options.AudioStreamIndex.HasValue || options.AudioStreamIndex < 0)
+            // When the index is explicitly required by client or the default is specified by user, don't do any stream reselection.
+            if (!item.DefaultAudioIndexSource.HasFlag(AudioIndexSource.User) && (options.AudioStreamIndex is null or < 0))
             {
-                if (audioStream?.IsDefault == true)
+                // When user has no preferences allow stream selection on all streams.
+                if (item.DefaultAudioIndexSource == AudioIndexSource.None && audioStream is not null)
                 {
-                    candidateAudioStreams = item.MediaStreams.Where(stream => stream.Type == MediaStreamType.Audio && stream.IsDefault).ToArray();
+                    candidateAudioStreams = item.MediaStreams.Where(stream => stream.Type == MediaStreamType.Audio).ToArray();
+                    if (audioStream.IsDefault)
+                    {
+                        // If default is picked, only allow selection within default streams.
+                        candidateAudioStreams = candidateAudioStreams.Where(stream => stream.IsDefault).ToArray();
+                    }
                 }
-                else
+
+                if (item.DefaultAudioIndexSource.HasFlag(AudioIndexSource.Language))
                 {
+                    // If user has language preference, only allow stream selection within the same language.
                     candidateAudioStreams = item.MediaStreams.Where(stream => stream.Type == MediaStreamType.Audio && stream.Language == audioStream?.Language).ToArray();
+                    if (item.DefaultAudioIndexSource.HasFlag(AudioIndexSource.Default))
+                    {
+                        var defaultStreamsInPreferredLanguage = candidateAudioStreams.Where(stream => stream.IsDefault).ToArray();
+
+                        // If the user also prefers default streams, try limit selection within default tracks in the same language.
+                        // If there is no default stream in the preferred language, allow selection on all default streams to match the "Play default audio track regardless of language" setting.
+                        candidateAudioStreams = defaultStreamsInPreferredLanguage.Length > 0
+                            ? defaultStreamsInPreferredLanguage
+                            : item.MediaStreams.Where(stream => stream.Type == MediaStreamType.Audio && stream.IsDefault).ToArray();
+                    }
+                }
+                else if (item.DefaultAudioIndexSource.HasFlag(AudioIndexSource.Default))
+                {
+                    // If user prefers default streams, only allow stream selection on default streams.
+                    candidateAudioStreams = item.MediaStreams.Where(stream => stream.Type == MediaStreamType.Audio && stream.IsDefault).ToArray();
                 }
             }
 
diff --git a/MediaBrowser.Model/Dlna/StreamInfo.cs b/MediaBrowser.Model/Dlna/StreamInfo.cs
index f9aab2d67..13acd15a3 100644
--- a/MediaBrowser.Model/Dlna/StreamInfo.cs
+++ b/MediaBrowser.Model/Dlna/StreamInfo.cs
@@ -2,6 +2,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.ComponentModel;
 using System.Globalization;
 using System.Linq;
 using System.Text;
@@ -956,12 +957,10 @@ public class StreamInfo
             sb.Append(AudioStreamIndex.Value.ToString(CultureInfo.InvariantCulture));
         }
 
-        if (SubtitleStreamIndex.HasValue && SubtitleDeliveryMethod != SubtitleDeliveryMethod.External && SubtitleStreamIndex != -1)
+        if (SubtitleStreamIndex.HasValue && (AlwaysBurnInSubtitleWhenTranscoding || SubtitleDeliveryMethod != SubtitleDeliveryMethod.External) && SubtitleStreamIndex != -1)
         {
             sb.Append("&SubtitleStreamIndex=");
             sb.Append(SubtitleStreamIndex.Value.ToString(CultureInfo.InvariantCulture));
-            sb.Append("&SubtitleMethod=");
-            sb.Append(SubtitleDeliveryMethod.ToString());
         }
 
         if (VideoBitrate.HasValue)
@@ -1095,17 +1094,11 @@ public class StreamInfo
                 sb.Append(CopyTimestamps.ToString(CultureInfo.InvariantCulture));
             }
 
-            if (RequireAvc)
-            {
-                sb.Append("&RequireAvc=");
-                sb.Append(RequireAvc.ToString(CultureInfo.InvariantCulture));
-            }
+            sb.Append("&RequireAvc=");
+            sb.Append(RequireAvc.ToString(CultureInfo.InvariantCulture).ToLowerInvariant());
 
-            if (EnableAudioVbrEncoding)
-            {
-                sb.Append("EnableAudioVbrEncoding=");
-                sb.Append(EnableAudioVbrEncoding.ToString(CultureInfo.InvariantCulture).ToLowerInvariant());
-            }
+            sb.Append("&EnableAudioVbrEncoding=");
+            sb.Append(EnableAudioVbrEncoding.ToString(CultureInfo.InvariantCulture).ToLowerInvariant());
         }
 
         var etag = MediaSource?.ETag;
@@ -1118,7 +1111,7 @@ public class StreamInfo
         if (SubtitleStreamIndex.HasValue && SubtitleDeliveryMethod != SubtitleDeliveryMethod.External)
         {
             sb.Append("&SubtitleMethod=");
-            sb.AppendJoin(',', SubtitleDeliveryMethod);
+            sb.Append(SubtitleDeliveryMethod);
         }
 
         if (SubtitleStreamIndex.HasValue && SubtitleDeliveryMethod == SubtitleDeliveryMethod.Embed && SubtitleCodecs.Count != 0)