Visualizza wikitesto di Sapere con le funzioni esterne del API di Rhythmbox se un file contiene dati audio e/o video

Con alcune funzioni esterne del API di ''Rhythmbox'' è possibile sapere se un file contiene dati audio e/o video.

E' necessario avere installata nel sistema e richiamare in Gambas la libreria condivisa: "''librhythmbox-core.so.10.0.0'' ".


Mostriamo di seguito un esempio pratico:
 Library "librhythmbox-core:10.0.0"
 
 <FONT Color=gray>' ''RBMetaData *rb_metadata_new (void)''
 ' ''Creates a new metadata backend instance.''</font>
 Private Extern rb_metadata_new() As Pointer
 
 <FONT Color=gray>' ''void rb_metadata_load (RBMetaData *md, const char *uri, GError **error)''
 ' ''Reads metadata information from the specified URI.''</font>
 Private Extern rb_metadata_load(md As Pointer, uri As String, gerror As Pointer)
 
 <FONT Color=gray>' ''gboolean rb_metadata_has_audio (RBMetaData *md)''
 ' ''Retrieves the value of a metadata field extracted from the target URI.''</font>
 Private Extern rb_metadata_has_audio(md As Pointer) As Boolean
 
 <FONT Color=gray>' ''gboolean rb_metadata_has_video (RBMetaData *md)''
 ' ''Retrieves the value of a metadata field extracted from the target URI.''</font>
 Private Extern rb_metadata_has_video(md As Pointer) As Boolean
 
 <FONT Color=gray>' ''void gst_object_unref(gpointer object)''
 ' ''Decrements the reference count on object.''</font>
 Private Extern gst_object_unref(gobject As Pointer)
 
 
 '''Public''' Sub Main()
  
  Dim uri as String
  Dim met As Pointer
  Dim bo as Boolean
  
  uri = "file://"
  met = rb_metadata_new()
  If met == 0 Then Error.Raise("Errore !")
  
  rb_metadata_load(met, uri & "<FONT Color=gray>''/percorso/del/file''</font>", 0)
  
  bo = rb_metadata_has_audio(met)
  Print bo
  bo = rb_metadata_has_video(met)
  Print bo
  
  gst_object_unref(met)
  
 '''End'''



=Riferimenti=
* https://developer.gnome.org/rhythmbox/stable/RBMetaData.html