Differenze tra le versioni di "Conoscere la durata di un file Midi mediante le funzioni esterne del API di Libsmf"

Da Gambas-it.org - Wikipedia.
Riga 14: Riga 14:
 
  ' ''Length of SMF, in seconds.''</font>
 
  ' ''Length of SMF, in seconds.''</font>
 
  Private Extern smf_get_length_seconds(smf_t As Pointer) As Float
 
  Private Extern smf_get_length_seconds(smf_t As Pointer) As Float
 +
 +
<FONT Color=gray>' ''void smf_delete (smf_t *smf)''
 +
' ''Frees smf and all it's descendant structures.''</font>
 +
Private Extern smf_delete(smf As Smf_struct)
 
   
 
   
 
   
 
   
Riga 25: Riga 29:
 
   durata = smf_get_length_seconds(smf)
 
   durata = smf_get_length_seconds(smf)
 
      
 
      
 +
  smf_delete(smf)
 +
 
 
   Print "Durata del file Midi: "; Date(0, 0, 0, 0, 0, 0, durata * 1000)
 
   Print "Durata del file Midi: "; Date(0, 0, 0, 0, 0, 0, durata * 1000)
 
   
 
   

Versione delle 03:11, 1 giu 2016

La libreria Libsmf, ideata per la gestione degli standard Midi File, consente, fra l'altro, di conoscere la durata in secondi di un file Midi.

E' necessario aver installata e richiamare la libreria condivisa: "libsmf:0.0.0"


Mostriamo un semplice esempio:

Library "libsmf:0.0.0"

' smf_t* smf_load (const char * file_name)
' Loads SMF file.
Private Extern smf_load(file_name As String) As Pointer

' double smf_get_length_seconds (const smf_t * smf)
' Length of SMF, in seconds.
Private Extern smf_get_length_seconds(smf_t As Pointer) As Float

' void smf_delete (smf_t *smf)
' Frees smf and all it's descendant structures.
Private Extern smf_delete(smf As Smf_struct)


Public Sub Main()

 Dim smf As Pointer
 Dim durata As Float
 
  smf = smf_load("/percorso/del/file.mid")
   
  durata = smf_get_length_seconds(smf)
   
  smf_delete(smf)
  
  Print "Durata del file Midi: "; Date(0, 0, 0, 0, 0, 0, durata * 1000)

End



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