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.
| (2 versioni intermedie di uno stesso utente non sono mostrate) | |||
| Riga 1: | Riga 1: | ||
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. | 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''" | + | E' necessario aver installata e richiamare la libreria condivisa: "''libsmf:0.0.0'' ". |
| − | |||
Mostriamo un semplice esempio: | Mostriamo un semplice esempio: | ||
Library "libsmf:0.0.0" | Library "libsmf:0.0.0" | ||
| + | |||
| + | Public Struct smf_struct | ||
| + | formati As Integer | ||
| + | ppqn As Integer | ||
| + | frames_per_second As Integer | ||
| + | resolution As Integer | ||
| + | number_of_tracks As Integer | ||
| + | streamf As Pointer | ||
| + | file_buffer As Pointer | ||
| + | file_buffer_length As Integer | ||
| + | next_chunk_offset As Integer | ||
| + | expected_number_of_tracks As Integer | ||
| + | tracks_array As Pointer | ||
| + | last_seek_position As Float | ||
| + | tempo_array As Pointer | ||
| + | End Struct | ||
<FONT Color=gray>' ''smf_t* smf_load (const char * file_name)'' | <FONT Color=gray>' ''smf_t* smf_load (const char * file_name)'' | ||
| Riga 13: | Riga 28: | ||
<FONT Color=gray>' ''double smf_get_length_seconds (const smf_t * smf) | <FONT Color=gray>' ''double smf_get_length_seconds (const smf_t * smf) | ||
' ''Length of SMF, in seconds.''</font> | ' ''Length of SMF, in seconds.''</font> | ||
| − | Private Extern smf_get_length_seconds(smf_t As | + | Private Extern smf_get_length_seconds(smf_t As Smf_struct) As Float |
<FONT Color=gray>' ''void smf_delete (smf_t *smf)'' | <FONT Color=gray>' ''void smf_delete (smf_t *smf)'' | ||
| Riga 22: | Riga 37: | ||
'''Public''' Sub Main() | '''Public''' Sub Main() | ||
| − | Dim smf As | + | Dim smf As smf_struct |
Dim durata As Float | Dim durata As Float | ||
| Riga 31: | Riga 46: | ||
smf_delete(smf) | smf_delete(smf) | ||
| − | Print "Durata del file Midi: "; | + | Print "Durata del file Midi: "; Time(0, 0, 0, durata * 1000) |
'''End''' | '''End''' | ||
| − | |||
Versione attuale delle 18:44, 2 dic 2021
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"
Public Struct smf_struct
formati As Integer
ppqn As Integer
frames_per_second As Integer
resolution As Integer
number_of_tracks As Integer
streamf As Pointer
file_buffer As Pointer
file_buffer_length As Integer
next_chunk_offset As Integer
expected_number_of_tracks As Integer
tracks_array As Pointer
last_seek_position As Float
tempo_array As Pointer
End Struct
' 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 Smf_struct) 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 smf_struct
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: "; Time(0, 0, 0, durata * 1000)
End
