jpeg-utils: Unify media libraries initialization

Both MagickWand and exiv2 needs some initialization and cleanup, move
it to jpeg-utils for clean includes in cgg.c.

Also add explicit exiv2 XMP initialization as stated on
http://dev.exiv2.org/projects/exiv2/wiki/Thread_safety:

"The XMP SDK initialization function is not mutex protected, thus
Exiv2::XmpParser::initialize is not thread-safe. Therefore, multi-threaded
applications need to ensure that this XMP function is serialized, e.g.,
by calling them from an initialization section which is run before any
threads are started."

See also https://bugs.kde.org/show_bug.cgi?id=166424

1 files changed, 20 insertions, 0 deletions

diff --git a/src/jpeg-utils.cpp b/src/jpeg-utils.cpp
index 965d751..2d85d3b 100644
--- a/src/jpeg-utils.cpp
+++ b/src/jpeg-utils.cpp
@@ -35,6 +35,26 @@ struct ExifDataPrivate {
 };
 
 
+/*
+ *   Thread-safe ImageMagick and exiv2 libraries initialization and cleanup
+ */
+void
+init_jpeg_utils (void)
+{
+  MagickWandGenesis();
+  /*  http://dev.exiv2.org/projects/exiv2/wiki/Thread_safety  */
+  /*  https://bugs.kde.org/show_bug.cgi?id=166424  */
+  Exiv2::XmpParser::initialize();
+}
+
+void
+destroy_jpeg_utils (void)
+{
+  Exiv2::XmpParser::terminate();
+  MagickWandTerminus();
+}
+
+
 static void
 shift_time (struct tm *tm, int offset_min)
 {