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, 6 insertions, 0 deletions

diff --git a/src/jpeg-utils.h b/src/jpeg-utils.h
index 9e4c729..bddb096 100644
--- a/src/jpeg-utils.h
+++ b/src/jpeg-utils.h
@@ -63,6 +63,12 @@ typedef struct {
 
 
 /*
+ *   Thread-safe ImageMagick and exiv2 libraries initialization and cleanup
+ */
+void init_jpeg_utils (void);
+void destroy_jpeg_utils (void);
+
+/*
  *   EXIF and IPTC info retrieval, keeps the source file open until freed
  */
 ExifData * read_exif (const gchar *filename);