Check that all image data is present after loading a SMPTE subtitle asset.

If we load SMPTE subtitles from a XML file try to load PNG data
from the same directory; this feels like a hack.

3 files changed, 41 insertions, 1 deletions

diff --git a/src/exceptions.cc b/src/exceptions.cc
index e9cdcef1..7516d085 100644
--- a/src/exceptions.cc
+++ b/src/exceptions.cc
@@ -110,7 +110,7 @@ KDMFormatError::KDMFormatError (std::string message)
 
 }
 
-CertificateChainError::CertificateChainError (std::string message)
+CertificateChainError::CertificateChainError (string message)
 	: runtime_error (message)
 {
 
@@ -123,3 +123,9 @@ DCPReadError::DCPReadError (string message, string detail)
 {
 
 }
+
+MissingSubtitleImageError::MissingSubtitleImageError (string id)
+	: runtime_error (String::compose("Could not load image for subtitle %1", id))
+{
+
+}
diff --git a/src/exceptions.h b/src/exceptions.h
index 4c54ac78..65271c16 100644
--- a/src/exceptions.h
+++ b/src/exceptions.h
@@ -222,6 +222,12 @@ public:
 	CertificateChainError (std::string message);
 };
 
+class MissingSubtitleImageError : public std::runtime_error
+{
+public:
+	MissingSubtitleImageError (std::string id);
+};
+
 }
 
 #endif
diff --git a/src/smpte_subtitle_asset.cc b/src/smpte_subtitle_asset.cc
index f9406793..ae473071 100644
--- a/src/smpte_subtitle_asset.cc
+++ b/src/smpte_subtitle_asset.cc
@@ -62,6 +62,7 @@ using boost::is_any_of;
 using boost::shared_array;
 using boost::dynamic_pointer_cast;
 using boost::optional;
+using boost::starts_with;
 using namespace dcp;
 
 static string const subtitle_smpte_ns = "http://www.smpte-ra.org/schemas/428-7/2010/DCST";
@@ -116,6 +117,33 @@ SMPTESubtitleAsset::SMPTESubtitleAsset (boost::filesystem::path file)
 					)
 				);
 		}
+
+		/* Try to read PNG files from the same folder that the XML is in; the wisdom of this is
+		   debatable, at best...
+		*/
+		BOOST_FOREACH (shared_ptr<Subtitle> i, _subtitles) {
+			shared_ptr<SubtitleImage> im = dynamic_pointer_cast<SubtitleImage>(i);
+			if (im && im->png_image().size() == 0) {
+				/* Even more dubious; allow <id>.png or urn:uuid:<id>.png */
+				boost::filesystem::path p = file.parent_path() / String::compose("%1.png", im->id());
+				if (boost::filesystem::is_regular_file(p)) {
+					im->read_png_file (p);
+				} else if (starts_with (im->id(), "urn:uuid:")) {
+					p = file.parent_path() / String::compose("%1.png", remove_urn_uuid(im->id()));
+					if (boost::filesystem::is_regular_file(p)) {
+						im->read_png_file (p);
+					}
+				}
+			}
+		}
+	}
+
+	/* Check that all required image data have been found */
+	BOOST_FOREACH (shared_ptr<Subtitle> i, _subtitles) {
+		shared_ptr<SubtitleImage> im = dynamic_pointer_cast<SubtitleImage>(i);
+		if (im && im->png_image().size() == 0) {
+			throw MissingSubtitleImageError (im->id());
+		}
 	}
 }