Registrare e salvare in un file video un flusso di dati da una IPTV con le funzioni esterne del API di VLC

Da Gambas-it.org - Wikipedia.

E' possibile rgistrare e salvare in un file video un flusso di dati da una IPTV (web-TV) con le funzioni esterne del API di VLC.

Sarà necessario avere installata nel sistema e richiamare nell'applicazione Gambas la libreria condivisa: "libvlc.so.5.6.1 ".

Mostriamo di seguito un semplice esempio in ambiente grafico: 

Private bo As Boolean


Library "libvlc:5.6.1"

' libvlc_instance_t * libvlc_new (int argc, const char *const *argv) ' Create And initialize a libvlc instance. Private Extern libvlc_new(argc As Integer, argv As String[]) As Pointer

' libvlc_media_t *libvlc_media_new_location (libvlc_instance_t *p_instance, const char * psz_mrl) ' Create a media with a certain given media resource location, for instance a valid URL. Private Extern libvlc_media_new_location(p_instance As Pointer, path As String) As Pointer

' void libvlc_media_add_option (libvlc_media_t *p_md, const char *psz_options) ' Add an option to the media. Private Extern libvlc_media_add_option(p_mi As Pointer, psz_options As String)

' libvlc_media_player_t * libvlc_media_player_new (libvlc_instance_t *p_libvlc_instance) ' Create an empty Media Player object. Private Extern libvlc_media_player_new(p_libvlc_instance As Pointer) As Pointer

' void libvlc_media_player_set_media (libvlc_media_player_t *p_mi, libvlc_media_t *p_md) ' Set the media that will be used by the media_player. Private Extern libvlc_media_player_set_media(p_md As Pointer, mp As Pointer)

' int libvlc_media_player_play (libvlc_media_player_t * p_mi) ' Play the video file. Private Extern libvlc_media_player_play(p_mi As Pointer) As Integer

' libvlc_time_t libvlc_media_player_get_time (libvlc_media_player_t * p_mi) ' Get the current movie time (in ms). Private Extern libvlc_media_player_get_time(p_mi As Pointer) As Integer

' void libvlc_media_player_release (libvlc_media_player_t * p_mi) ' Release a media_player after use Decrement the reference count of a media player object. Private Extern libvlc_media_player_release(p_mi As Pointer)

' void libvlc_media_release (libvlc_media_t *p_md) ' Decrement the reference count of a media descriptor object. Private Extern libvlc_media_release(p_md As Pointer)

' libvlc_release (libvlc_instance_t * p_instance) ' Decrement the reference count of a libvlc instance, and destroy it if it reaches zero. Private Extern libvlc_release(p_instance As Pointer)


Public Sub ToggleButton1_Click() 

Dim inst, mp, m As Pointer 

 If ToggleButton1.Value Then

' Inizializza e imposta le opzioni relative al video: ' ["vcodec=mp4v,fps=30,vb=512"] ' ["vcodec=flv,fps=30,vb=512"] 

inst = libvlc_new(1, ["vcodec=h264,fps=30,vb=512"])
If inst == 0 Then Error.Raise("Impossibile inizializzare la libreria VLC !")

' Crea il media player: 

mp = libvlc_media_player_new(inst)
If mp == 0 Then Error.Raise("Impossibile creare il media player !")

' Crea un nuovo oggetto multimedia. ' Nel secondo argomento della funzione va specificato il percorso del file-device video: 

m = libvlc_media_new_location(inst, "http://wzstreaming.rai.it/TVlive/liveStream/playlist.m3u8")
If m == 0 Then Error.Raise("Impossibile creare un oggetto multimediale !")

' Viene aggiunta l'opzione per la registrazione dell'audio mediante il sistema ALSA: 

libvlc_media_add_option(m, ":sout=#transcode{acodec=mp3,ab=192,channels=2,samplerate=44100,deinterlace} :duplicate{dst=display,dst=std{access=file,mux=avi,dst=/tmp/zzz.avi}}")

' ":sout=#transcode{acodec=mp3,ab=192,channels=2,samplerate=44100,deinterlace} :duplicate{dst=display,dst=std{access=file,mux=flv,dst=/tmp/zzz.flv}}") 
' ":sout=#transcode{acodec=mp3,ab=192,channels=2,samplerate=44100,deinterlace} :duplicate{dst=display,dst=std{access=file,mux=mp4,dst=/tmp/zzz.mp4}}")
 
libvlc_media_player_set_media(mp, m)

' Avvia la cattura del video-audio da parte del media player: 

libvlc_media_player_play(mp)
 
While bo = False
  Me.Title = Str(Time(0, 0, 0, libvlc_media_player_get_time(mp)))

' Il Wait consente di agire su altri oggetti posti sul Form: 

  Wait 0.01
Wend

' Chiude la libreria VLC ed il programma: 

libvlc_media_player_release(mp)
libvlc_media_release(m)
libvlc_release(inst)
Me.Close

Else ' Causa l'arresto della registrazione, la chiusura della libreria VLC e del programma: 

bo = True
Endif

End

Estratto da "https://www.gambas-it.org/wiki/index.php?title=Registrare_e_salvare_in_un_file_video_un_flusso_di_dati_da_una_IPTV_con_le_funzioni_esterne_del_API_di_VLC&oldid=38986"