On 08.10.2010 13:02, cristiurban wrote: > An example of how I can do this ? It would be very helpfull. > Look at the use of: GstTagList * gst_tag_list_from_xmp_buffer (const GstBuffer *buffer); GstBuffer * gst_tag_list_to_xmp_buffer (const GstTagList *list, gboolean read_only); in qtdemux (gst-plugins-good) and qtmux (gst-plugins-bad). Stefan