From c1d32ccfc586d0292ca4ec35a03fb403c3c45a07 Mon Sep 17 00:00:00 2001
From: Carl Hetherington <cth@carlh.net>
Date: Thu, 27 May 2021 11:45:11 +0200
Subject: [PATCH] Read the bits we can from the MXF header even when it is
 encrypted.

---
 src/smpte_subtitle_asset.cc | 17 ++++++++++++++---
 src/smpte_subtitle_asset.h  |  5 +++--
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/src/smpte_subtitle_asset.cc b/src/smpte_subtitle_asset.cc
index 0fa315b9..dc8acf51 100644
--- a/src/smpte_subtitle_asset.cc
+++ b/src/smpte_subtitle_asset.cc
@@ -106,7 +106,10 @@ SMPTESubtitleAsset::SMPTESubtitleAsset (boost::filesystem::path file)
 			reader->ReadTimedTextResource (_raw_xml);
 			xml->read_string (_raw_xml);
 			parse_xml (xml);
-			read_mxf_descriptor (reader, make_shared<DecryptionContext>(optional<Key>(), Standard::SMPTE));
+			read_mxf_descriptor (reader);
+			read_mxf_resources (reader, make_shared<DecryptionContext>(optional<Key>(), Standard::SMPTE));
+		} else {
+			read_mxf_descriptor (reader);
 		}
 	} else {
 		/* Plain XML */
@@ -202,7 +205,7 @@ SMPTESubtitleAsset::parse_xml (shared_ptr<cxml::Document> xml)
 
 
 void
-SMPTESubtitleAsset::read_mxf_descriptor (shared_ptr<ASDCP::TimedText::MXFReader> reader, shared_ptr<DecryptionContext> dec)
+SMPTESubtitleAsset::read_mxf_resources (shared_ptr<ASDCP::TimedText::MXFReader> reader, shared_ptr<DecryptionContext> dec)
 {
 	ASDCP::TimedText::TimedTextDescriptor descriptor;
 	reader->FillTimedTextDescriptor (descriptor);
@@ -253,6 +256,14 @@ SMPTESubtitleAsset::read_mxf_descriptor (shared_ptr<ASDCP::TimedText::MXFReader>
 			break;
 		}
 	}
+}
+
+
+void
+SMPTESubtitleAsset::read_mxf_descriptor (shared_ptr<ASDCP::TimedText::MXFReader> reader)
+{
+	ASDCP::TimedText::TimedTextDescriptor descriptor;
+	reader->FillTimedTextDescriptor (descriptor);
 
 	_intrinsic_duration = descriptor.ContainerDuration;
 	/* The thing which is called AssetID in the descriptor is also known as the
@@ -300,7 +311,7 @@ SMPTESubtitleAsset::set_key (Key key)
 	auto xml = make_shared<cxml::Document>("SubtitleReel");
 	xml->read_string (_raw_xml);
 	parse_xml (xml);
-	read_mxf_descriptor (reader, dec);
+	read_mxf_resources (reader, dec);
 }
 
 
diff --git a/src/smpte_subtitle_asset.h b/src/smpte_subtitle_asset.h
index 1ece2405..f63392c7 100644
--- a/src/smpte_subtitle_asset.h
+++ b/src/smpte_subtitle_asset.h
@@ -180,7 +180,7 @@ public:
 		return _xml_id;
 	}
 
-	/** @return ResourceID read from the MXF, if there was one */
+	/** @return ResourceID read from any MXF that was read */
 	boost::optional<std::string> resource_id () const {
 		return _resource_id;
 	}
@@ -204,7 +204,8 @@ private:
 
 	void read_fonts (std::shared_ptr<ASDCP::TimedText::MXFReader>);
 	void parse_xml (std::shared_ptr<cxml::Document> xml);
-	void read_mxf_descriptor (std::shared_ptr<ASDCP::TimedText::MXFReader> reader, std::shared_ptr<DecryptionContext> dec);
+	void read_mxf_descriptor (std::shared_ptr<ASDCP::TimedText::MXFReader> reader);
+	void read_mxf_resources (std::shared_ptr<ASDCP::TimedText::MXFReader> reader, std::shared_ptr<DecryptionContext> dec);
 
 	/** The total length of this content in video frames.  The amount of
 	 *  content presented may be less than this.
-- 
2.30.2