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| Riga 1: |
Riga 1: |
| − | La libreria '''LibVLC''' consente di eseguire anche file MIDI, purché si abbiano installati nel sistema anche:
| + | * [[Eseguire un file Midi mediante le funzioni esterne del API di VLC]] |
| − | * ''vlc-plugin-fluidsynth'' - le risorse dei plugin di ''FluidSynth'' per VLC;
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| − | * ''fluid-soundfont-gm'' - Fluid (R3) General MIDI SoundFont (GM);
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| − | * ovviamente lo stesso ''FluidSynth''.
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| | | | |
| − | E' possibile eseguire dati Midi anche direttamente da internet.
| + | * [[Ottenere la durata di un file Midi con le funzioni esterne del API di VLC]] |
| | | | |
| − | Per creare in Gambas un'applicazione con la presente risorsa, si dovrà installare e richiamare la libreria dinamica e condivisa "''libvlc.so.5.6.0''".
| + | * [[Ottenere un file audio da un file Midi con le funzioni esterne del API di VLC]] (<FONT Color=#B22222>Non più funzionante</font>) |
| − | | |
| − | | |
| − | ===Esempio con applicazione grafica===
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| − | Mostriamo di seguito un semplice esempio, nel quale si potrà avviare, arrestare, porre in pausa e riprendere l'esecuzione del file Midi:
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| − | Private inst As Pointer
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| − | Private mp As Pointer
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| − | Private m As Pointer
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| − |
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| − | Library "libvlc:5.6.0"
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| − |
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| − | Private Enum libvlc_NothingSpecial = 0,
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| − | libvlc_Opening,
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| − | libvlc_Buffering,
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| − | libvlc_Playing,
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| − | libvlc_Paused,
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| − | libvlc_Stopped,
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| − | libvlc_Ended,
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| − | libvlc_Error
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| − |
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| − | <FONT color=gray>' ''libvlc_instance_t * libvlc_new (int argc, const char *const *argv)''
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| − | ' ''Create And initialize a libvlc instance.''</font>
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| − | Private Extern libvlc_new(argc As Integer, argv As String[]) As Pointer
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| − |
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| − | <FONT color=gray>' ''libvlc_media_t * libvlc_media_new_path (libvlc_instance_t *p_instance, const char *path)''
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| − | ' ''Create a media for a certain file path.''</font>
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| − | Private Extern libvlc_media_new_path(p_instance As Pointer, path As String) As Pointer
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| − |
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| − | <FONT color=gray>' ''libvlc_media_player_t * libvlc_media_player_new_from_media (libvlc_media_t *p_md)''
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| − | ' ''Create a Media Player object from a Media.''</font>
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| − | Private Extern libvlc_media_player_new_from_media(p_md As Pointer) As Pointer
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| − |
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| − | <FONT color=gray>' ''int libvlc_media_player_play (libvlc_media_player_t * p_mi)''
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| − | ' ''Play the audio file.''</font>
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| − | Private Extern libvlc_media_player_play(p_mi As Pointer) As Integer
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| − |
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| − | <FONT color=gray>' ''void libvlc_media_player_stop (libvlc_media_player_t * p_mi)''
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| − | ' ''Stop the audio file.''</font>
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| − | Private Extern libvlc_media_player_stop(p_mi As Pointer)
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| − |
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| − | <FONT color=gray>' ''libvlc_time_t libvlc_media_player_get_length(libvlc_media_player_t *, libvlc_exception_t *)''
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| − | ' ''Get the current movie length (in ms).''</font>
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| − | Private Extern libvlc_media_player_get_length(p_mi As Pointer, l_ex As Pointer) As Integer
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| − |
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| − | <FONT color=gray>' ''libvlc_time_t libvlc_media_player_get_time(libvlc_media_player_t * p_mi)''
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| − | ' ''Get the current movie time (in ms).''</font>
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| − | Private Extern libvlc_media_player_get_time(p_mi As Pointer) As Integer
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| − |
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| − | <FONT color=gray>' ''libvlc_state_t libvlc_media_player_get_state(libvlc_media_player_t *p_mi)''
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| − | ' ''Get current movie state.''</font>
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| − | Private Extern libvlc_media_player_get_state(p_mi As Pointer) As Integer
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| − |
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| − | <FONT color=gray>' ''void libvlc_media_player_pause (libvlc_media_player_t *p_mi)''
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| − | ' ''Toggle pause.''</font>
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| − | Private Extern libvlc_media_player_pause(p_mi As Pointer)
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| − |
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| − | <FONT color=gray>' ''void libvlc_media_player_release (libvlc_media_player_t * p_mi)''
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| − | ' ''Release a media_player after use Decrement the reference count of a media player object.''</font>
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| − | Private Extern libvlc_media_player_release(p_mi As Pointer)
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| − |
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| − | <FONT color=gray>' ''void libvlc_media_release (libvlc_media_t *p_md)''
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| − | ' ''Decrement the reference count of a media descriptor object.''</font>
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| − | Private Extern libvlc_media_release(p_md As Pointer)
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| − |
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| − | <FONT color=gray>' ''libvlc_release (libvlc_instance_t * p_instance)''
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| − | ' ''Decrement the reference count of a libvlc instance, and destroy it if it reaches zero.''</font>
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| − | Private Extern libvlc_release(p_instance As Pointer)
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| − | '''Public''' Sub Button1_Click()
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| − | <FONT color=gray>' ''Inizializza la libreria VLC:''</font>
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| − | inst = libvlc_new(0, Null)
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| − |
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| − | <FONT color=gray>' ''Crea un nuovo oggetto multimedia:''</font>
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| − | m = libvlc_media_new_path(inst, "<FONT color=gray>''/percorso/del/file.mid''</font>")
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| − |
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| − | <FONT color=gray>' ''Crea un media player:''</font>
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| − | mp = libvlc_media_player_new_from_media(m)
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| − |
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| − | <FONT color=gray>' ''Avvia l'esecuzione del file Midi da parte del media player:''</font>
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| − | libvlc_media_player_play(mp)
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| − |
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| − | Do
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| − | TextLabel1.Text = "Durata: " & Str(Date(0, 0, 0, 0, 0, 0, libvlc_media_player_get_length(mp, 0)))
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| − | TextLabel2.Text = "<FONT Color=red>" & Str(Date(0, 0, 0, 0, 0, 0, libvlc_media_player_get_time(mp)))
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| − | Wait 0.01
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| − | Loop Until libvlc_media_player_get_state(mp) > libvlc_Paused
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| − |
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| − | Chiude()
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| − |
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| − | '''End'''
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| − |
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| − | '''Public''' Sub Button2_Click()
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| − | <FONT color=gray>' ''Arresta l'esecuzione del file Midi:''</font>
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| − | libvlc_media_player_stop(mp)
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| − |
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| − | '''End'''
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| − |
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| − |
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| − | '''Private''' Procedure Chiude()
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| − | <FONT color=gray>' ''Chiude la libreria VLC:''</font>
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| − | libvlc_media_player_release(mp)
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| − | libvlc_media_release(m)
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| − | libvlc_release(inst)
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| − |
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| − | '''End'''
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| − |
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| − |
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| − | '''Public''' Sub ToggleButton1_Click()
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| − | <FONT color=gray>' ''Pone in pausa o riprende (se già in pausa) l'esecuzione del file Midi:''</font>
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| − | libvlc_media_player_pause(mp)
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| − |
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| − | '''End'''
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| − | | |
| − | | |
| − | In quest'altro esempio mostreremo un effetto video (''Spectrum analyzer'') di VLC, che rappresenta un "Analizzatore di spettro", all'interno di una ''DrawingArea''
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| − | Private inst As Pointer
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| − | Private mp As Pointer
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| − |
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| − | Library "libvlc:5.6.0"
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| − |
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| − | Private Enum libvlc_NothingSpecial = 0,
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| − | libvlc_Opening,
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| − | libvlc_Buffering,
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| − | libvlc_Playing,
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| − | libvlc_Paused,
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| − | libvlc_Stopped,
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| − | libvlc_Ended,
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| − | libvlc_Error
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| − |
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| − | <FONT color=gray>' ''libvlc_instance_t * libvlc_new (int argc, const char *const *argv)''
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| − | ' ''Create And initialize a libvlc instance.''</font>
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| − | Private Extern libvlc_new(argc As Integer, argv As String[]) As Pointer
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| − |
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| − | <FONT color=gray>' ''libvlc_media_t * libvlc_media_new_path (libvlc_instance_t *p_instance, const char *path)''
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| − | ' ''Create a media for a certain file path.''</font>
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| − | Private Extern libvlc_media_new_path(p_instance As Pointer, path As String) As Pointer
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| − |
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| − | <FONT color=gray>' ''libvlc_media_player_t * libvlc_media_player_new_from_media (libvlc_media_t *p_md)''
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| − | ' ''Create a Media Player object from a Media.''</font>
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| − | Private Extern libvlc_media_player_new_from_media(p_md As Pointer) As Pointer
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| − |
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| − | <FONT color=gray>' ''void libvlc_media_player_set_xwindow (libvlc_media_player_t *p_mi, uint32_t drawable)''
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| − | ' ''Set an X Window System drawable where the media player should render its video output.''</font>
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| − | Private Extern libvlc_media_player_set_xwindow(p_mi As Pointer, drawable As Integer)
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| − |
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| − | <FONT color=gray>' ''int libvlc_media_player_play (libvlc_media_player_t * p_mi)''
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| − | ' ''Play the audio file.''</font>
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| − | Private Extern libvlc_media_player_play(p_mi As Pointer) As Integer
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| − |
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| − | <FONT color=gray>' ''void libvlc_media_player_stop (libvlc_media_player_t * p_mi)''
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| − | ' ''Stop the audio file.''</font>
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| − | Private Extern libvlc_media_player_stop(p_mi As Pointer)
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| − |
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| − | <FONT color=gray>' ''libvlc_time_t libvlc_media_player_get_length(libvlc_media_player_t *, libvlc_exception_t *)''
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| − | ' ''Get the current movie length (in ms).''</font>
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| − | Private Extern libvlc_media_player_get_length(p_mi As Pointer, l_ex As Pointer) As Integer
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| − |
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| − | <FONT color=gray>' ''libvlc_time_t libvlc_media_player_get_time(libvlc_media_player_t * p_mi)''
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| − | ' ''Get the current movie time (in ms).''</font>
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| − | Private Extern libvlc_media_player_get_time(p_mi As Pointer) As Integer
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| − |
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| − | <FONT color=gray>' ''libvlc_state_t libvlc_media_player_get_state(libvlc_media_player_t *p_mi)''
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| − | ' ''Get current movie state.''</font>
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| − | Private Extern libvlc_media_player_get_state(p_mi As Pointer) As Integer
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| − |
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| − | <FONT color=gray>' ''void libvlc_media_player_pause (libvlc_media_player_t *p_mi)''
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| − | ' ''Toggle pause.''</font>
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| − | Private Extern libvlc_media_player_pause(p_mi As Pointer)
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| − |
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| − | <FONT color=gray>' ''void libvlc_media_player_release (libvlc_media_player_t * p_mi)''
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| − | ' ''Release a media_player after use Decrement the reference count of a media player object.''</font>
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| − | Private Extern libvlc_media_player_release(p_mi As Pointer)
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| − |
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| − | <FONT Color=gray>' ''void libvlc_media_player_release (libvlc_media_player_t * p_mi)''
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| − | ' ''Release a media_player after use Decrement the reference count of a media player object.''</font>
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| − | Private Extern libvlc_media_player_release(p_mi As Pointer)
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| − |
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| − | <FONT color=gray>' ''void libvlc_media_release (libvlc_media_t *p_md)''
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| − | ' ''Decrement the reference count of a media descriptor object.''</font>
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| − | Private Extern libvlc_media_release(p_md As Pointer)
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| − |
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| − | <FONT color=gray>' ''libvlc_release (libvlc_instance_t * p_instance)''
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| − | ' ''Decrement the reference count of a libvlc instance, and destroy it if it reaches zero.''</font>
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| − | Private Extern libvlc_release(p_instance As Pointer)
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| − |
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| − |
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| − | '''Public''' Sub Button1_Click()
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| − |
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| − | Dim ss As String[]
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| − | Dim m As Pointer
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| − | Dim id As Integer
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| − |
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| − | ss = ["--audio-visual=visual", "--effect-list=spectrum"]
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| − |
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| − | <FONT color=gray>' ''Inizializza la libreria VLC:''</font>
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| − | inst = libvlc_new(ss.Count, ss)
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| − |
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| − | <FONT color=gray>' ''Crea un nuovo oggetto multimedia:''</font>
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| − | m = libvlc_media_new_path(inst, "<FONT color=gray>''/percorso/del/file.mid''</font>")
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| − |
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| − | <FONT color=gray>' ''Crea un media player:''</font>
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| − | mp = libvlc_media_player_new_from_media(m)
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| − |
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| − | <FONT color=gray>' ''Per far mostrare l'effetto video "Analizzatore di spettro" nella "DrawingArea", ricaviamo il suo identificativo:''</font>
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| − | id = DrawingArea1.Id
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| − |
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| − | <FONT color=gray>' ''Passiamo l'identificativo della finestra, nella quale dovrà essere mostrato l'effetto "Spectrum analyzer":''</font>
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| − | libvlc_media_player_set_xwindow(mp, id)
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| − |
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| − | <FONT color=gray>' ''Avvia l'esecuzione del file Midi da parte del media player:''</font>
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| − | libvlc_media_player_play(mp)
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| − |
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| − | Do
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| − | TextLabel1.Text = "Durata: " & Str(Date(0, 0, 0, 0, 0, 0, libvlc_media_player_get_length(mp, 0)))
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| − | TextLabel2.Text = "<FONT Color=red>" & Str(Date(0, 0, 0, 0, 0, 0, libvlc_media_player_get_time(mp)))
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| − | Wait 0.01
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| − | Loop Until libvlc_media_player_get_state(mp) > libvlc_Paused
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| − |
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| − | Chiude()
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| − |
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| − | '''End'''
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| − |
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| − |
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| − | '''Public''' Sub Button2_Click()
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| − |
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| − | <FONT color=gray>' ''Arresta l'esecuzione del file Midi:''</font>
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| − | libvlc_media_player_stop(mp)
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| − |
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| − | '''End'''
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| − |
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| − |
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| − | '''Private''' Procedure Chiude()
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| − |
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| − | <FONT color=gray>' ''Chiude la libreria VLC:''</font>
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| − | libvlc_media_player_release(mp)
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| − | libvlc_media_release(m)
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| − | libvlc_release(inst)
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| − |
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| − | '''End'''
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| − |
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| − |
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| − | '''Public''' Sub ToggleButton1_Click()
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| − |
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| − | <FONT color=gray>' ''Pone in pausa o riprende (se già in pausa) l'esecuzione del file Midi:''</font>
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| − | libvlc_media_player_pause(mp)
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| − |
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| − | '''End'''
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| − | | |
| − | | |
| − | | |
| − | ===Esempio con applicazione ''a riga di comando''===
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| − | Library "libvlc:5.6.0"
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| − |
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| − | Enum libvlc_NothingSpecial = 0,
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| − | libvlc_Opening,
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| − | libvlc_Buffering,
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| − | libvlc_Playing,
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| − | libvlc_Paused,
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| − | libvlc_Stopped,
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| − | libvlc_Ended,
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| − | libvlc_Error
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| − |
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| − | <FONT color=gray>' ''libvlc_instance_t * libvlc_new (int argc, const char *const *argv)''
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| − | ' ''Create And initialize a libvlc instance.''</font>
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| − | Private Extern libvlc_new(argc As Integer, argv As String) As Pointer
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| − |
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| − | <FONT color=gray>' ''libvlc_media_t * libvlc_media_new_path (libvlc_instance_t *p_instance, const char *path)''
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| − | ' ''Create a media for a certain Midi file path.''</font>
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| − | Private Extern libvlc_media_new_path(p_instance As Pointer, path As String) As Pointer
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| − |
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| − | <FONT color=gray>' ''libvlc_media_player_t * libvlc_media_player_new_from_media (libvlc_media_t *p_md)''
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| − | ' ''Create a Media Player object from a Media.''</font>
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| − | Private Extern libvlc_media_player_new_from_media(p_md As Pointer) As Pointer
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| − |
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| − | <FONT color=gray>' ''int libvlc_media_player_play (libvlc_media_player_t * p_mi)''
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| − | ' ''Play the Midi file.''</font>
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| − | Private Extern libvlc_media_player_play(p_mi As Pointer) As Integer
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| − |
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| − | <FONT color=gray>' ''libvlc_time_t libvlc_media_player_get_time(libvlc_media_player_t * p_mi)''
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| − | ' ''Get the current movie time (in ms).''</font>
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| − | Private Extern libvlc_media_player_get_time(p_mi As Pointer) As Integer
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| − |
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| − | <FONT color=gray>' ''libvlc_state_t libvlc_media_player_get_state(libvlc_media_player_t *p_mi)''
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| − | ' ''Get current movie state.''</font>
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| − | Private Extern libvlc_media_player_get_state(p_mi As Pointer) As Integer
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| − |
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| − | <FONT color=gray>' ''void libvlc_media_player_release (libvlc_media_player_t * p_mi)''
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| − | ' ''Release a media_player after use Decrement the reference count of a media player object.''</font>
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| − | Private Extern libvlc_media_player_release(p_mi As Pointer)
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| − |
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| − | <FONT color=gray>' ''void libvlc_media_release (libvlc_media_t *p_md)''
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| − | ' ''Decrement the reference count of a media descriptor object.''</font>
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| − | Private Extern libvlc_media_release(p_md As Pointer)
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| − |
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| − | <FONT color=gray>' ''libvlc_release (libvlc_instance_t * p_instance)''
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| − | ' ''Decrement the reference count of a libvlc instance, and destroy it if it reaches zero.''</font>
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| − | Private Extern libvlc_release(p_instance As Pointer)
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| − |
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| − |
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| − | '''Public''' Sub Main()
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| − |
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| − | Dim m, inst, mp As Pointer
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| − |
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| − | <FONT color=gray>' ''Inizializza la libreria VLC:''</font>
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| − | inst = libvlc_new(0, Null)
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| − |
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| − | <FONT color=gray>' ''Crea un nuovo oggetto multimedia:''</font>
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| − | m = libvlc_media_new_path(inst, "<FONT color=gray>''/percorso/del/file.mid''</font>")
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| − |
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| − | <FONT color=gray>' ''Crea un media player:''</font>
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| − | mp = libvlc_media_player_new_from_media(m)
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| − |
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| − | <FONT color=gray>' ''Avvia l'esecuzione del file Midi da parte del media player:''</font>
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| − | libvlc_media_player_play(mp)
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| − |
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| − | While libvlc_media_player_get_state(mp) < libvlc_Stopped
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| − | Write "\r\e[31m" & Str(Date(0, 0, 0, 0, 0, 0, libvlc_media_player_get_time(mp)))
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| − | Wend
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| − |
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| − |
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| − | <FONT color=gray>' ''Chiude la libreria VLC:''</font>
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| − | libvlc_media_player_release(mp)
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| − | libvlc_media_release(m)
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| − | libvlc_release(inst)
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| − |
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| − | '''End'''
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| − | | |
| − | | |
| − | | |
| − | =Riferimenti=
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| − | * http://www.videolan.org/developers/vlc/doc/doxygen/html/index.html
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| − | * https://wiki.videolan.org/Midi Videolan
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