From 2891aa5cdd114ce556c401310c161e19591e9bf5 Mon Sep 17 00:00:00 2001
From: Prakash Duggaraju <duggaraju@gmail.com>
Date: Mon, 21 Aug 2023 17:36:16 -0700
Subject: [PATCH] Fix failures when text track has both VTT and CMFT. Use VTT
 over CMFT since shaka supports CMFT.

---
 transform/BasePackager.cs  | 34 ++++++++++++++++------------------
 transform/ShakaPackager.cs |  3 ++-
 2 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/transform/BasePackager.cs b/transform/BasePackager.cs
index 40601f5..5867e37 100644
--- a/transform/BasePackager.cs
+++ b/transform/BasePackager.cs
@@ -54,6 +54,21 @@ abstract class BasePackager : IPackager
 
         public IDictionary<string, IList<Track>> FileToTrackMap => _fileToTrackMap;
 
+        public static bool IsTextTrackSupported(Track track, Manifest manifest)
+        {
+            return !track.IsMultiFile && (track.Source.EndsWith(VTT_FILE) || track.Parameters.Any(t => t.Name == TRANSCRIPT_SOURCE));
+        }
+
+        public static bool IsLiveTextTrackSupported(Track track, ClientManifest clientManifest)
+        {
+            return track.IsMultiFile && 
+                // Choose the text track with a list of fragblobs for close captions.
+                clientManifest!.Streams.Any(
+                    stream => (stream.Type == StreamType.Text &&
+                    stream.SubType == "SUBT") &&
+                    stream.Name == track.TrackName);
+        }
+
         public BasePackager(AssetDetails assetDetails, TransMuxer transMuxer, ILogger logger)
         {
             _assetDetails = assetDetails;
@@ -65,24 +80,7 @@ public BasePackager(AssetDetails assetDetails, TransMuxer transMuxer, ILogger lo
             SelectedTracks = manifest.Tracks.Where(t =>
             {
                 if (t is TextTrack)
-                {
-                    bool pickThisTextTrack = !t.IsMultiFile && (t.Source.EndsWith(VTT_FILE) || t.Parameters.Any(t => t.Name == TRANSCRIPT_SOURCE));
-
-                    if (manifest.IsLiveArchive)
-                    {
-                        pickThisTextTrack = false;
-
-                        if (t.IsMultiFile)
-                        {
-                            // Choose the text track with a list of fragblobs for close captions.
-                            pickThisTextTrack = assetDetails.ClientManifest!.Streams.Any(
-                                                              stream => (stream.Type == StreamType.Text &&
-                                                                         stream.SubType == "SUBT") &&
-                                                                         stream.Name == t.TrackName);
-                        }
-                    }
-                    return pickThisTextTrack;
-                }
+                    return manifest.IsLiveArchive && IsLiveTextTrackSupported(t, assetDetails.ClientManifest!) || IsTextTrackSupported(t, manifest);
                 return true;
             }).ToList();
 
diff --git a/transform/ShakaPackager.cs b/transform/ShakaPackager.cs
index 7c40a5b..8c952c7 100644
--- a/transform/ShakaPackager.cs
+++ b/transform/ShakaPackager.cs
@@ -112,8 +112,9 @@ private IEnumerable<string> GetArguments(IList<string> inputs, IList<string> out
 
             List<string> arguments = new(SelectedTracks.Select((t, i) =>
             {
+                var source = t.Parameters.SingleOrDefault(p => p.Name == TRANSCRIPT_SOURCE)?.Value ?? t.Source;
                 var ext = t.IsMultiFile ? (t is TextTrack ? VTT_FILE : MEDIA_FILE) : string.Empty;
-                var file = $"{t.Source}{ext}";
+                var file = $"{source}{ext}";
                 var index = Inputs.IndexOf(file);
                 var multiTrack = TransmuxedSmooth && FileToTrackMap[file].Count > 1;
                 var inputFile = multiTrack ?