Differenze tra le versioni di "Estrarre in formato testuale i dati di un file Midi con le funzioni esterne del API di Libsmf"
Da Gambas-it.org - Wikipedia.
| (5 versioni intermedie di uno stesso utente non sono mostrate) | |||
| Riga 1: | Riga 1: | ||
La libreria '''Libsmf''' consente di gestire i file Midi. | La libreria '''Libsmf''' consente di gestire i file Midi. | ||
| + | Per poter fruire nei programmi Gambas le sue risorse, è necessario installare e richiamare la libreria condivisa: "''libsmf:0.0.0'' ". | ||
| − | + | Mostriamo di seguito un semplice esempio per ottenere in formato testuale gli eventi Midi presenti in uno ''standard Midi file'': | |
| − | |||
| − | |||
| − | Mostriamo di seguito un semplice esempio per ottenere in formato testuale gli eventi Midi presenti in uno ''standard | ||
Library "libsmf:0.0.0" | Library "libsmf:0.0.0" | ||
| − | <FONT Color=gray>' ''smf_t* smf_load (const char * file_name)'' | + | 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)'' | ||
' ''Loads SMF file.''</font> | ' ''Loads SMF file.''</font> | ||
| − | Private Extern smf_load(file_name As String) As | + | Private Extern smf_load(file_name As String) As Smf_struct |
<FONT Color=gray>' ''smf_event_t * smf_get_next_event (smf_t * smf)'' | <FONT Color=gray>' ''smf_event_t * smf_get_next_event (smf_t * smf)'' | ||
' ''Next event, in time order, or NULL, if there are none left.''</font> | ' ''Next event, in time order, or NULL, if there are none left.''</font> | ||
| − | Private Extern smf_get_next_event(smf_t As | + | Private Extern smf_get_next_event(smf_t As Smf_struct) As Pointer |
| − | <FONT Color=gray>' ''char * smf_event_decode (const smf_event_t * event) | + | <FONT Color=gray>' ''char * smf_event_decode (const smf_event_t * event)'' |
' ''Textual representation of the event given, or NULL, if event is unknown.''</font> | ' ''Textual representation of the event given, or NULL, if event is unknown.''</font> | ||
Private Extern smf_event_decode(smf_event As Pointer) As String | Private Extern smf_event_decode(smf_event As Pointer) As String | ||
| + | |||
| + | <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) | ||
'''Public''' Sub Main() | '''Public''' Sub Main() | ||
| − | Dim smf | + | Dim smf As Smf_struct |
| − | Dim | + | Dim evento As Pointer |
| − | + | ||
| − | + | smf = smf_load("<FONT Color=gray>''/percorso/del/file.mid''</font>") | |
| − | |||
| − | |||
| − | + | evento = smf_get_next_event(smf) | |
| − | + | If evento == 0 Then Error.Raise("Errore !") | |
| − | |||
| − | + | While evento > 0 | |
| + | Print smf_event_decode(evento) | ||
| + | evento = smf_get_next_event(smf) | ||
| + | Wend | ||
| − | + | smf_delete(smf) | |
'''End''' | '''End''' | ||
| − | |||
Versione attuale delle 16:12, 4 gen 2022
La libreria Libsmf consente di gestire i file Midi.
Per poter fruire nei programmi Gambas le sue risorse, è necessario installare e richiamare la libreria condivisa: "libsmf:0.0.0 ".
Mostriamo di seguito un semplice esempio per ottenere in formato testuale gli eventi Midi presenti in uno standard Midi file:
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 Smf_struct
' smf_event_t * smf_get_next_event (smf_t * smf)
' Next event, in time order, or NULL, if there are none left.
Private Extern smf_get_next_event(smf_t As Smf_struct) As Pointer
' char * smf_event_decode (const smf_event_t * event)
' Textual representation of the event given, or NULL, if event is unknown.
Private Extern smf_event_decode(smf_event As Pointer) As String
' 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 evento As Pointer
smf = smf_load("/percorso/del/file.mid")
evento = smf_get_next_event(smf)
If evento == 0 Then Error.Raise("Errore !")
While evento > 0
Print smf_event_decode(evento)
evento = smf_get_next_event(smf)
Wend
smf_delete(smf)
End
