Add support for writing external EXIF metadata back to images

Turned off by default, this will copy all data from supplied external
EXIF metadata file back to all generated image files. All user overrides
are still applied on top of it.

Another reason for turning this off is file size concern, target image
files would carry a lot more information that may not be always needed and
would increase total amount of data transferred.

5 files changed, 26 insertions, 2 deletions

diff --git a/src/generators.c b/src/generators.c
index 133c4c1..0e1985a 100644
--- a/src/generators.c
+++ b/src/generators.c
@@ -149,6 +149,7 @@ get_image_paths (TGallerySetup *setup,
 static void
 metadata_apply_overrides (ExifData *exif_data,
                           TGallerySetup *setup,
+                          TPathInfo *path_info,
                           TAlbum *items,
                           TIndexItem *item)
 {
@@ -156,12 +157,19 @@ metadata_apply_overrides (ExifData *exif_data,
 
   g_free (exif_data->override_copyright);
   exif_data->override_copyright = g_strdup (setup->add_copyright);
+
   exif_data->timezone_shift = item->metadata_tz_shift;
   if (exif_data->timezone_shift == 0)
     exif_data->timezone_shift = items->metadata_tz_shift;
+
   exif_data->fake_datetime = item->metadata_fake_datetime;
   if (exif_data->fake_datetime == (time_t) -1)
     exif_data->fake_datetime = items->metadata_fake_datetime;
+
+  g_free (exif_data->external_exif_data);
+  exif_data->external_exif_data = NULL;
+  if (setup->write_supplied_exif && item->metadata_external_exif)
+    exif_data->external_exif_data = g_build_filename (path_info->src_dir, item->metadata_external_exif, NULL);
 }
 
 
@@ -252,7 +260,7 @@ generate_image (TGallerySetup *setup,
     }
     if (! is_thumbnail) {
       exif_data = exif_data_new_empty ();
-      metadata_apply_overrides (exif_data, setup, items, item);
+      metadata_apply_overrides (exif_data, setup, path_info, items, item);
       modify_exif (img_dst, exif_data, setup->erase_exif_thumbnail);
       exif_data_free (exif_data);
     }
@@ -778,7 +786,7 @@ write_html_image (TGallerySetup *setup,
     if (exif == NULL)
       log_error ("write_html_image: error getting exif data from file \"%s\"\n", img_dst);
   }
-  metadata_apply_overrides (exif, setup, parent_items, item);
+  metadata_apply_overrides (exif, setup, path_info, parent_items, item);
   /*  Test for basic EXIF keys presence  */
   if (exif != NULL && exif_has_key (exif, EXIF_APERTURE) &&
                       exif_has_key (exif, EXIF_FOCAL_LENGTH) &&
diff --git a/src/jpeg-utils.cpp b/src/jpeg-utils.cpp
index 6483563..321a9b6 100644
--- a/src/jpeg-utils.cpp
+++ b/src/jpeg-utils.cpp
@@ -129,6 +129,7 @@ exif_data_free (ExifData *data)
 {
   if (data) {
     g_free (data->override_copyright);
+    g_free (data->external_exif_data);
     /* FIXME: free data->priv->image */
     g_free (data->priv);
     g_free (data);
@@ -663,6 +664,18 @@ modify_exif (const gchar *filename, ExifData *exif, gboolean strip_thumbnail)
     g_assert (image.get() != 0);
 
     image->readMetadata();
+
+    /*  Write down metadata from external file if supplied  */
+    if (exif && exif->external_exif_data) {
+      Exiv2::Image::AutoPtr ext_image = Exiv2::ImageFactory::open (exif->external_exif_data);
+      if (ext_image.get() != 0) {
+        ext_image->clearMetadata();
+        ext_image->readMetadata();
+        image->setMetadata (*ext_image);
+        modified = TRUE;
+      }
+    }
+
     Exiv2::ExifData &exifData = image->exifData();
     Exiv2::IptcData &iptcData = image->iptcData();
 
diff --git a/src/jpeg-utils.h b/src/jpeg-utils.h
index cc6c5c7..d393fbe 100644
--- a/src/jpeg-utils.h
+++ b/src/jpeg-utils.h
@@ -53,6 +53,7 @@ typedef struct {
   gchar *override_copyright;
   int timezone_shift;
   time_t fake_datetime;
+  gchar *external_exif_data;
 } ExifData;
 
 
diff --git a/src/setup.c b/src/setup.c
index e4df0dd..7dde0c8 100644
--- a/src/setup.c
+++ b/src/setup.c
@@ -94,6 +94,7 @@ parse_setup_xml (const gchar *filename)
   setup->preload = xml_file_get_node_attribute_boolean (xml, "/gallery_setup/images/preload", "value", TRUE);
   setup->use_iptc_exif = xml_file_get_node_attribute_boolean (xml, "/gallery_setup/images/use_iptc_exif", "value", FALSE);
   setup->erase_exif_thumbnail = xml_file_get_node_attribute_boolean (xml, "/gallery_setup/images/erase_embed_thumbnail", "value", FALSE);
+  setup->write_supplied_exif = xml_file_get_node_attribute_boolean (xml, "/gallery_setup/images/write_supplied_exif", "value", FALSE);
   setup->nofullsize = xml_file_get_node_present (xml, "/gallery_setup/images/nofullsize");
   setup->autorotate = xml_file_get_node_attribute_boolean (xml, "/gallery_setup/images/autorotate", "value", TRUE);
 
diff --git a/src/setup.h b/src/setup.h
index daf8453..10e9d7b 100644
--- a/src/setup.h
+++ b/src/setup.h
@@ -56,6 +56,7 @@ typedef struct {
   gboolean preload;
   gboolean use_iptc_exif;
   gboolean erase_exif_thumbnail;
+  gboolean write_supplied_exif;
   gboolean nofullsize;
   ThumbnailSquareType squared_thumbnail_type;
   gboolean autorotate;