Conoscere con le funzioni esterne di SDL2 i dispositivi audio presenti nel sistema
Da Gambas-it.org - Wikipedia.
La libreria SDL 2 è un API multi-piattaforma contenente funzioni per la gestione multimediale dell'audio e del video.
Per poter utilizzare le funzioni esterne di SDL2 in Gambas, si richiamerà la seguente libreria condivisa: "libSDL2-2.0.so.0.3000.0 ".
Mostriamo di seguito un esempio di codice per verificare i dispositivi audio presenti nel sistema.
Library "libSDL2-2.0:0.3000.0"
Private Const SDL_INIT_AUDIO As Integer = 16
' int SDL_Init(Uint32 flags)
' Initialize the SDL library.
Private Extern SDL_Init(flags As Integer) As Integer
' int SDL_GetNumAudioDrivers(void)
' Returns the number of built in audio drivers.
Private Extern SDL_GetNumAudioDrivers() As Integer
' const char* SDL_GetAudioDriver(int index)
' Returns the name of the audio driver at the requested index, or NULL if an invalid index was specified.
Private Extern SDL_GetAudioDriver(index As Integer) As String
' const char* SDL_GetCurrentAudioDriver(void)
' Returns the name of the current audio driver or NULL if no driver has been initialized.
Private Extern SDL_GetCurrentAudioDriver() As String
' int SDL_GetNumAudioDevices(int iscapture)
' Returns the number of available devices exposed by the current driver or -1 if an explicit list of devices can't be determined.
Private Extern SDL_GetNumAudioDevices(iscapture As Integer) As Integer
' const char* SDL_GetAudioDeviceName(int index, int iscapture)
' Returns the name of the audio device at the requested index, or NULL on error.
Private Extern SDL_GetAudioDeviceName(index As Integer, iscapture As Integer) As String
' void SDL_Quit(void)
' Clean up all initialized subsystems.
Private Extern SDL_Quit()
Public Sub Main()
Dim n, i As Integer
' Inizializza la libreria SDL2:
If SDL_Init(SDL_INIT_AUDIO) < 0 Then Error.Raise("Impossibile inizializzare la libreria SDL2 !")
' Mostra i dispositivi audio disponibili:
n = SDL_GetNumAudioDrivers()
If n = 0 Then
Print "Nessun driver audio presente nel sistema !\n\n"
Else
Print "Driver audio presenti nel sistema:"
For i = 0 To n - 1
Print " "; SDL_GetAudioDriver(i)
Next
Endif
Print "\nDriver audio usato: \n "; SDL_GetCurrentAudioDriver()
For i = 0 To 1
Dispositivi(i)
Next
SDL_Quit()
End
Private Procedure Dispositivi(cattura As Integer)
Dim ts As String
Dim n, i As Integer
ts = IIf(cattura, "cattura", "uscita")
n = SDL_GetNumAudioDevices(cattura)
Print "\nDispositivi di "; ts; ":"
If n = -1 Then
Print " Il driver non può verificare specifici dispositivi "; ts; "."
Else If n = 0 Then
Print " Nessun dispositivo di "; ts; " trovato."
Else
For i = 0 To n - 1
Print " "; SDL_GetAudioDeviceName(i, cattura)
Next
Endif
End
