54   bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");

   115     {GST_TAG_IMAGE_TYPE_NONE, "GST_TAG_IMAGE_TYPE_NONE", "none"},

   154 

   155   /* work around thread-safety issue with class creation in GLib */

   156   g_type_class_ref (*id);

   167 

   172 }

   173 

   174 static inline gboolean

   175 gst_tag_image_type_is_valid (GstTagImageType type)

   176 {

   177   GEnumClass *klass;

   178 

   179   gboolean res;

   180 

   181   klass = g_type_class_ref (gst_tag_image_type_get_type ());

   182   res = (g_enum_get_value (klass, type) != NULL);

   183   g_type_class_unref (klass);

   184 

   185   return res;

   284 

   286 

   368 

   369 /**

   370  * gst_tag_image_data_to_image_buffer:

   371  * @image_data: the (encoded) image

   372  * @image_data_len: the length of the encoded image data at @image_data

   373  * @image_type: type of the image, or #GST_TAG_IMAGE_TYPE_UNDEFINED. Pass

   374  *     #GST_TAG_IMAGE_TYPE_NONE if no image type should be set at all (e.g.

   375  *     for preview images)

   376  *

   377  * Helper function for tag-reading plugins to create a #GstBuffer suitable to

   378  * add to a #GstTagList as an image tag (such as #GST_TAG_IMAGE or

   379  * #GST_TAG_PREVIEW_IMAGE) from the encoded image data and an (optional) image

   380  * type.

   381  *

   382  * Background: cover art and other images in tags are usually stored as a

   383  * blob of binary image data, often accompanied by a MIME type or some other

   384  * content type string (e.g. 'png', 'jpeg', 'jpg'). Sometimes there is also an

   385  * 'image type' to indicate what kind of image this is (e.g. front cover,

   386  * back cover, artist, etc.). The image data may also be an URI to the image

   387  * rather than the image itself.

   388  *

   389  * In GStreamer, image tags are #GstBuffer<!-- -->s containing the raw image

   390  * data, with the buffer caps describing the content type of the image

   391  * (e.g. image/jpeg, image/png, text/uri-list). The buffer caps may contain

   392  * an additional 'image-type' field of #GST_TYPE_TAG_IMAGE_TYPE to describe

   393  * the type of image (front cover, back cover etc.). #GST_TAG_PREVIEW_IMAGE

   394  * tags should not carry an image type, their type is already indicated via

   395  * the special tag name.

   396  *

   397  * This function will do various checks and typefind the encoded image

   398  * data (we can't trust the declared mime type).

   399  *

   400  * Returns: a newly-allocated image buffer for use in tag lists, or NULL

   401  *

   402  * Since: 0.10.20

   403  */

   404 #ifdef __SYMBIAN32__

   405 EXPORT_C

   406 #endif

   407 

   408 GstBuffer *

   409 gst_tag_image_data_to_image_buffer (const guint8 * image_data,

   410     guint image_data_len, GstTagImageType image_type)

   411 {

   412   const gchar *name;

   413 

   414   GstBuffer *image;

   415 

   416   GstCaps *caps;

   417 

   418   g_return_val_if_fail (image_data != NULL, NULL);

   419   g_return_val_if_fail (image_data_len > 0, NULL);

   420   g_return_val_if_fail (gst_tag_image_type_is_valid (image_type), NULL);

   421 

   422   GST_DEBUG ("image data len: %u bytes", image_data_len);

   423 

   424   /* allocate space for a NUL terminator for an uri too */

   425   image = gst_buffer_try_new_and_alloc (image_data_len + 1);

   426   if (image == NULL) {

   427     GST_WARNING ("failed to allocate buffer of %d for image", image_data_len);

   428     return NULL;

   429   }

   430 

   431   memcpy (GST_BUFFER_DATA (image), image_data, image_data_len);

   432   GST_BUFFER_DATA (image)[image_data_len] = '\0';

   433 

   434   /* Find GStreamer media type, can't trust declared type */

   435   caps = gst_type_find_helper_for_buffer (NULL, image, NULL);

   436 

   437   if (caps == NULL)

   438     goto no_type;

   439 

   440   GST_DEBUG ("Found GStreamer media type: %" GST_PTR_FORMAT, caps);

   441 

   442   /* sanity check: make sure typefound/declared caps are either URI or image */

   443   name = gst_structure_get_name (gst_caps_get_structure (caps, 0));

   444 

   445   if (!g_str_has_prefix (name, "image/") &&

   446       !g_str_has_prefix (name, "video/") &&

   447       !g_str_equal (name, "text/uri-list")) {

   448     GST_DEBUG ("Unexpected image type '%s', ignoring image frame", name);

   449     goto error;

   450   }

   451 

   452   /* Decrease size by 1 if we don't have an URI list

   453    * to keep the original size of the image

   454    */

   455   if (!g_str_equal (name, "text/uri-list"))

   456     GST_BUFFER_SIZE (image) = image_data_len;

   457 

   458   if (image_type != GST_TAG_IMAGE_TYPE_NONE) {

   459     GST_LOG ("Setting image type: %d", image_type);

   460     caps = gst_caps_make_writable (caps);

   461     gst_caps_set_simple (caps, "image-type", GST_TYPE_TAG_IMAGE_TYPE,

   462         image_type, NULL);

   463   }

   464 

   465   gst_buffer_set_caps (image, caps);

   466   gst_caps_unref (caps);

   467   return image;

   468 

   469 /* ERRORS */

   470 no_type:

   471   {

   472     GST_DEBUG ("Could not determine GStreamer media type, ignoring image");

   473     /* fall through */

   474   }

   475 error:

   476   {

   477     if (image)

   478       gst_buffer_unref (image);

   479     if (caps)

   480       gst_caps_unref (caps);

   481     return NULL;

   482   }

   483 }