+--- gpac/src/isomedia/isom_write.c.orig 2012-03-29 14:36:23.000000000 +0200
++++ gpac/src/isomedia/isom_write.c 2012-10-02 21:55:13.269904532 +0200
+@@ -1140,6 +1140,7 @@
+ return Track_SetStreamDescriptor(trak, StreamDescriptionIndex, entry->dataReferenceIndex, esd, NULL);
+ }
+
++GF_EXPORT
+ GF_Err gf_isom_set_visual_info(GF_ISOFile *movie, u32 trackNumber, u32 StreamDescriptionIndex, u32 Width, u32 Height)
+ {
+ GF_Err e;
+@@ -1187,6 +1188,7 @@
+ }
+ }
+
++GF_EXPORT
+ GF_Err gf_isom_set_pixel_aspect_ratio(GF_ISOFile *movie, u32 trackNumber, u32 StreamDescriptionIndex, u32 hSpacing, u32 vSpacing)
+ {
+ GF_Err e;
+--- gpac/src/isomedia/avc_ext.c.orig 2012-03-27 11:48:05.000000000 +0200
++++ gpac/src/isomedia/avc_ext.c 2012-10-02 21:54:35.469905865 +0200
+@@ -170,6 +170,7 @@
+
+
+ #ifndef GPAC_DISABLE_ISOM_WRITE
++GF_EXPORT
+ GF_Err gf_isom_avc_config_new(GF_ISOFile *the_file, u32 trackNumber, GF_AVCConfig *cfg, char *URLname, char *URNname, u32 *outDescriptionIndex)
+ {
+ GF_TrackBox *trak;