Normalize VobSub .sub to .idx for embedding, add EncodingHelper tests

Move the .sub to .idx path normalization outside the burn-in check so
it applies to subtitle embedding as well. ffmpeg requires the .idx file
to read VobSub subtitles.

Add unit tests for GetMapArgs and GetInputArgument covering internal
subs, external SRT, multi-file SRT, multi-stream MKS containers, and
VobSub .sub/.idx path normalization.

1 files changed, 6 insertions, 10 deletions

diff --git a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs
index 40bb3913e9..6ff2873cc5 100644
--- a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs
+++ b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs
@@ -1272,18 +1272,14 @@ namespace MediaBrowser.Controller.MediaEncoding
                 var subtitlePath = state.SubtitleStream.Path;
                 var isGraphicalBurnIn = ShouldEncodeSubtitle(state) && !state.SubtitleStream.IsTextSubtitleStream;
 
-                if (isGraphicalBurnIn)
+                // dvdsub/vobsub graphical subtitles use .sub+.idx pairs
+                var subtitleExtension = Path.GetExtension(subtitlePath.AsSpan());
+                if (subtitleExtension.Equals(".sub", StringComparison.OrdinalIgnoreCase))
                 {
-                    var subtitleExtension = Path.GetExtension(subtitlePath.AsSpan());
-
-                    // dvdsub/vobsub graphical subtitles use .sub+.idx pairs
-                    if (subtitleExtension.Equals(".sub", StringComparison.OrdinalIgnoreCase))
+                    var idxFile = Path.ChangeExtension(subtitlePath, ".idx");
+                    if (File.Exists(idxFile))
                     {
-                        var idxFile = Path.ChangeExtension(subtitlePath, ".idx");
-                        if (File.Exists(idxFile))
-                        {
-                            subtitlePath = idxFile;
-                        }
+                        subtitlePath = idxFile;
                     }
                 }