Add a special exception for the case when opj_start_compress fails.

3 files changed, 25 insertions, 3 deletions

diff --git a/src/exceptions.cc b/src/exceptions.cc
index a49c7004..7f389f31 100644
--- a/src/exceptions.cc
+++ b/src/exceptions.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2014-2019 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2014-2020 Carl Hetherington <cth@carlh.net>
 
     This file is part of libdcp.
 
@@ -40,6 +40,7 @@
 
 using std::string;
 using std::runtime_error;
+using boost::optional;
 using namespace dcp;
 
 FileError::FileError (string message, boost::filesystem::path filename, int number)
@@ -123,3 +124,10 @@ BadKDMDateError::BadKDMDateError (bool starts_too_early)
 {
 
 }
+
+
+StartCompressionError::StartCompressionError (optional<int> code)
+	: runtime_error (String::compose("Could not start JPEG2000 encoding%1", code ? String::compose(" (%1", *code) : ""))
+	, _code (code)
+{}
+
diff --git a/src/exceptions.h b/src/exceptions.h
index ccf7a081..770bd916 100644
--- a/src/exceptions.h
+++ b/src/exceptions.h
@@ -211,6 +211,20 @@ private:
 	bool _starts_too_early;
 };
 
+
+class StartCompressionError : public std::runtime_error
+{
+public:
+	explicit StartCompressionError (boost::optional<int> code = boost::optional<int>());
+
+	boost::optional<int> code () const {
+		return _code;
+	}
+
+private:
+	boost::optional<int> _code;
+};
+
 }
 
 #endif
diff --git a/src/j2k.cc b/src/j2k.cc
index f1e4c3f5..a81da68c 100644
--- a/src/j2k.cc
+++ b/src/j2k.cc
@@ -310,9 +310,9 @@ dcp::compress_j2k (shared_ptr<const OpenJPEGImage> xyz, int bandwidth, int frame
 	if (!opj_start_compress (encoder, xyz->opj_image(), stream)) {
 		if ((errno & 0x61500) == 0x61500) {
 			/* We've had one of the magic error codes from our patched openjpeg */
-			throw MiscError (String::compose ("could not start JPEG2000 encoding (%1)", errno & 0xff));
+			boost::throw_exception (StartCompressionError (errno & 0xff));
 		} else {
-			throw MiscError ("could not start JPEG2000 encoding");
+			boost::throw_exception (StartCompressionError ());
 		}
 	}