fix secondary audio

Browsers (Chrome, Firefox) can only play the first track,
even if the second track is the default.

Ignore default flag when testing on secondary audio.

External audio tracks are not secondary.

MediaBrowser.Model/Dlna/StreamBuilder.cs

@@ -1088,9 +1088,6 @@ namespace MediaBrowser.Model.Dlna
             bool? isInterlaced = videoStream?.IsInterlaced;
             string videoCodecTag = videoStream?.CodecTag;
             bool? isAvc = videoStream?.IsAVC;
-            // Audio
-            var defaultLanguage = audioStream?.Language ?? string.Empty;
-            var defaultMarked = audioStream?.IsDefault ?? false;
 
             TransportStreamTimestamp? timestamp = videoStream == null ? TransportStreamTimestamp.None : mediaSource.Timestamp;
             int? packetLength = videoStream?.PacketLength;
@@ -1122,7 +1119,7 @@ namespace MediaBrowser.Model.Dlna
                     .SelectMany(codecProfile => checkVideoConditions(codecProfile.Conditions)));
 
             // Check audiocandidates profile conditions
-            var audioStreamMatches = candidateAudioStreams.ToDictionary(s => s, audioStream => CheckVideoAudioStreamDirectPlay(options, mediaSource, container, audioStream, defaultLanguage, defaultMarked));
+            var audioStreamMatches = candidateAudioStreams.ToDictionary(s => s, audioStream => CheckVideoAudioStreamDirectPlay(options, mediaSource, container, audioStream));
 
             TranscodeReason subtitleProfileReasons = 0;
             if (subtitleStream != null)
@@ -1243,10 +1240,10 @@ namespace MediaBrowser.Model.Dlna
             return (Profile: null, PlayMethod: null, AudioStreamIndex: null, TranscodeReasons: failureReasons);
         }
 
-        private TranscodeReason CheckVideoAudioStreamDirectPlay(VideoOptions options, MediaSourceInfo mediaSource, string container, MediaStream audioStream, string language, bool isDefault)
+        private TranscodeReason CheckVideoAudioStreamDirectPlay(VideoOptions options, MediaSourceInfo mediaSource, string container, MediaStream audioStream)
         {
             var profile = options.Profile;
-            var audioFailureConditions = GetProfileConditionsForVideoAudio(profile.CodecProfiles, container, audioStream.Codec, audioStream.Channels, audioStream.BitRate, audioStream.SampleRate, audioStream.BitDepth, audioStream.Profile, !audioStream.IsDefault);
+            var audioFailureConditions = GetProfileConditionsForVideoAudio(profile.CodecProfiles, container, audioStream.Codec, audioStream.Channels, audioStream.BitRate, audioStream.SampleRate, audioStream.BitDepth, audioStream.Profile, mediaSource.IsSecondaryAudio(audioStream));
 
             var audioStreamFailureReasons = AggregateFailureConditions(mediaSource, profile, "VideoAudioCodecProfile", audioFailureConditions);
             if (audioStream?.IsExternal == true)

MediaBrowser.Model/Dto/MediaSourceInfo.cs

@@ -230,19 +230,15 @@ namespace MediaBrowser.Model.Dto
 
         public bool? IsSecondaryAudio(MediaStream stream)
         {
-            // Look for the first audio track marked as default
-            foreach (var currentStream in MediaStreams)
+            if (stream.IsExternal)
             {
-                if (currentStream.Type == MediaStreamType.Audio && currentStream.IsDefault)
-                {
-                    return currentStream.Index != stream.Index;
-                }
+                return false;
             }
 
             // Look for the first audio track
             foreach (var currentStream in MediaStreams)
             {
-                if (currentStream.Type == MediaStreamType.Audio)
+                if (currentStream.Type == MediaStreamType.Audio && !currentStream.IsExternal)
                 {
                     return currentStream.Index != stream.Index;
                 }