Versione delle 18:31, 11 apr 2016

Usando alcune poche funzioni esterne della libreria "libdvdread4" è possibile conoscere quanti titoli e quanti capitoli sono presenti un un disco DVD video.

Per fruire delle risorse di libdvdread4 bisognerà avere installata nel sistema la libreria attualmente: "libdvdread.so.4.1.2".

Mostriamo di seguito un breve codice esemplificativo:

Library "libdvdread:4.1.2"

Private Enum DVD_READ_INFO_FILE = 0, DVD_READ_INFO_BACKUP_FILE, DVD_READ_MENU_VOBS, DVD_READ_TITLE_VOBS

' dvd_reader_t* DVDOpen (const char *)
' Opens a block device of a DVD-ROM file, or an image file, or a directory name for a mounted DVD or HD copy of a DVD.
Private Extern DVDOpen(fldvd As String) As Pointer

' ifo_handle_t * ifoOpen (dvd_reader_t *dvd, int title)
' Opens an IFO and reads in all the data for the IFO file corresponding to the given title.
Private Extern ifoOpen(dvd_reader_t As Pointer, title As Integer) As Pointer    'Ifo_handle_t

' dvd_file_t * DVDOpenFile (dvd_reader_t *, int, dvd_read_domain_t)
' Opens a file on the DVD given the title number and domain.
Private Extern DVDOpenFile(dvd_reader_t As Pointer, dvdI As Integer, dvd_readI As Integer) As Pointer

' void ifoClose(ifo_handle_t * ifofile)
' Cleans up the IFO information.
Private Extern ifoClose(ifop As Pointer)

' void DVDCloseFile(dvd_file_t * )
' Closes a file and frees the associated structure.
Private Extern DVDCloseFile(dvd_file_t As Pointer)

' void DVDClose (dvd_reader_t *dvd)
' Closes and cleans up the DVD reader object.
Private Extern DVDClose(dvd_reader_t As Pointer)


Public Sub Main()

 Dim dvd, dvdR, p As Pointer
 Dim a, b As Byte
 Dim sh, s1, s2 As Short
 Dim pstm As Stream
  
' Apre il disco:
  dvd = DVDOpen("/dev/dvd")
  If dvd = 0 Then Error.Raise("Impossibile aprire il DVD: nessun dvd trovato !")
    
  dvdR = DVDOpenFile(dvd, 0, DVD_READ_MENU_VOBS)
  If dvdR = 0 Then Error.Raise("Impossibile aprire il file !")
     
' Carica il gestore video per cercare informazioni relative ai titoli sul disco:
  p = ifoOpen(dvd, 0)
  If p = 0 Then Error.Raise("Impossibile aprire il gestore video e leggere il file principale IFO !")
 
' Dereferenziamo il "puntatore" mediante i "Memory-Stream" per estrapolare i dati ricercati:
  pstm = Memory p For Read
   
  Seek #pstm, 1184
  Read #pstm, s1
  Seek #pstm, 1218
  Read #pstm, s2
 
  If s1 + s2 > 0 Then
    Print "\n\nTitoli presenti: "; s1
    Print "\nTitolo          Capitoli"
    For sh = 1218 To ((s1 - 1) * 12) + 1218 Step 12
      Inc a
      Seek #pstm, sh
      Read #pstm, b
      Print a; "               "; b
    Next
  Else
    Seek #pstm, 1200
    Read #pstm, s1
    Print "\n\nTitoli presenti: "; s1
    Print "\nTitolo          Capitoli"
    For sh = 1234 To ((s1 - 1) * 12) + 1234 Step 12
      Inc a
      Seek #pstm, sh
      Read #pstm, b
      Print a; "               "; b
    Next
  Endif
  Print

  
' Va in chiusura:
  ifoClose(p)
  DVDCloseFile(dvdR)
  DVDClose(dvd)
   
End

Riferimenti

• http://code.mythtv.org/doxygen/dvd__reader_8c.html