Visualizza wikitesto di Estrarre i dati audio di una traccia di un CD audio e crearne un file WAV con le risorse del API di libcdio paranoia

Usando alcune risorse esterne della libreria "''libcdio_paranoia''" è possibile anche estrarre i dati audio grezzi di una traccia di un CD audio e crearne un file WAV.

E' necessario avere installate nel proprio sistema le librerie condivise "''libcdio.so.18.0.0''", "''libcdio_cdda.so.2.0.0''" e "''libcdio_paranoia.so.2.0.0''".

Nel codice che segue sarà richiamata la sola libreria condivisa: ''libcdio_paranoia.so.2.0.0''
 Private Const <FONT Color=#B22222>TRACCIA</font> As Integer = '''4'''   <FONT Color=#B22222>''''''' Imposta il numero della traccia audio di cui estrarre i dati audio'''''</font>
 Private Const SEEK_SET As Integer = 0
 
 Library "libcdio_paranoia:2.0.0"
 
 Private Const CDIO_CD_FRAMESIZE_RAW As Integer = 2352
 Private Enum CDIO_FS_AUDIO = 1, CDIO_FS_HIGH_SIERRA, CDIO_FS_ISO_9660, CDIO_FS_INTERACTIVE, CDIO_FS_HFS, CDIO_FS_UFS
 Private Enum CDDA_MESSAGE_FORGETIT = 0, CDDA_MESSAGE_PRINTIT, CDDA_MESSAGE_LOGIT, CD_FRAMESAMPLES = 588, MAXTRK = 100
 Private Enum PARANOIA_MODE_DISABLE = 0, PARANOIA_MODE_VERIFY = 1, PARANOIA_MODE_FRAGMENT = 2, PARANOIA_MODE_OVERLAP = 4,
              PARANOIA_MODE_SCRATCH = 8, PARANOIA_MODE_REPAIR = 16, PARANOIA_MODE_NEVERSKIP = 32, PARANOIA_MODE_FULL = 255
 
 <FONT Color=gray>' ''char ** cdio_get_devices_with_cap (char *ppsz_search_devices[], cdio_fs_anal_t capabilities, bool b_any)''
 ' ''Get an array of device names in search_devices that have at least the capabilities listed by the capabities parameter.''</font>
 Private Extern cdio_get_devices_with_cap(ppsz_search_devices As Pointer, capabilities As Integer, b_any As Boolean) As Pointer
 
 <FONT Color=gray>' ''cdrom_drive_t *cdio_cddap_identify(const char *psz_device, int messagedest, char **ppsz_message)''
 ' ''Returns a paranoia CD-ROM drive object with a CD-DA.''</font>
 Private Extern cdio_cddap_identify(psz_device As String, messagedest As Integer, ppsz_message As Pointer) As Pointer
 
 <FONT Color=gray>' ''void cdio_free_device_list (char * device_list[])''
 ' ''Free device list returned.''</font>
 Private Extern cdio_free_device_list(device_list As Pointer)
 
 <FONT Color=gray>' ''void cdio_cddap_verbose_set(cdrom_drive_t *d, int err_action, int mes_action)''</font>
 Private Extern cdio_cddap_verbose_set(d As Pointer, err_action As Integer, mes_action As Integer)
 
 <FONT Color=gray>' ''int cdio_cddap_open(cdrom_drive_t *d)''</font>
 Private Extern cdio_cddap_open(d As Pointer) As Integer
 
 <FONT Color=gray>' ''cdrom_paranoia_t *cdio_paranoia_init(cdrom_drive_t *d)''
 ' ''Get and initialize a new cdrom_paranoia object from cdrom_drive.''</font>
 Private Extern cdio_paranoia_init(d As Pointer) As Pointer
 
 <FONT Color=gray>' ''lsn_t cdio_cddap_track_firstsector(cdrom_drive_t *d, track_t i_track)''
 ' ''Return the lsn for the start of track i_track.''</font>
 Private Extern cdio_cddap_track_firstsector(d As Pointer, i_track As Integer) As Integer
 
 <FONT Color=gray>' ''int cdio_cddap_sector_gettrack(cdrom_drive_t *d, lsn_t lsn)''
 ' ''Return the track containing the given LSN.''</font>
 Private Extern cdio_cddap_sector_gettrack(d As Pointer, lsn As Integer) As Integer
 
 <FONT Color=gray>' ''lsn_t cdio_cddap_track_lastsector(cdrom_drive_t *d, track_t i_track)''
 ' ''Get last lsn of the track.''</font>
 Private Extern cdio_cddap_track_lastsector(d As Pointer, i_track As Integer) As Integer
 
 <FONT Color=gray>' ''void cdio_paranoia_modeset(cdrom_paranoia_t *p, int mode_flags)''
 ' ''Set the kind of repair you want to on for reading.''</font>
 Private Extern cdio_paranoia_modeset(p As Pointer, mode_flags As Integer)
 
 <FONT Color=gray>' ''lsn_t cdio_paranoia_seek(cdrom_paranoia_t *p, int32_t seek, int whence)''
 ' ''Reposition reading offset.''</font>
 Private Extern cdio_paranoia_seek(p As Pointer, _seek As Integer, whence As Integer) As Integer
 
 <FONT Color=gray>' ''int16_t *cdio_paranoia_read(cdrom_paranoia_t *p, void(*callback)(long int, paranoia_cb_mode_t))''
 ' ''Reads the next sector of audio data.''</font>
 Private Extern cdio_paranoia_read(p As Pointer, callback As Pointer) As Pointer
 
 <FONT Color=gray>' ''char *cdio_cddap_errors(cdrom_drive_t *d)''
 ' ''Returns the current error buffer.''</font>
 Private Extern cdio_cddap_errors(d As Pointer) As Pointer
 
 <FONT Color=gray>' ''char *cdio_cddap_messages(cdrom_drive_t *d)''
 ' ''Returns the current message buffer.''</font>
 Private Extern cdio_cddap_messages(d As Pointer) As Pointer
 
 <FONT Color=gray>' ''void cdio_paranoia_free(cdrom_paranoia_t *p)''
 ' ''Free any resources associated with p.''</font>
 Private Extern cdio_paranoia_free(p As Pointer)
 
 <FONT Color=gray>' ''int cdio_cddap_close(cdrom_drive_t *d)''
 ' ''Closes d and releases all storage associated with it.''</font>
 Private Extern cdio_cddap_close(d As Pointer) As Integer
 
 
 '''Public''' Sub Main()
  
  Dim cdd, drives, p, buf As Pointer
  Dim err, mes As Pointer
  Dim lsn, cur, tra, llsn As Integer
  Dim fl As File
  
 <FONT Color=gray>' ''Cerca un dispositivo con un CD-DA caricato:''</font>
  drives = cdio_get_devices_with_cap(0, CDIO_FS_AUDIO, False)
  
  If (drives > 0) And (Not IsNull(String@(Pointer@(drives)))) Then
 <FONT Color=gray>' ''Se ha trovato un CD-ROM con un CD-DA caricato, allora utilizza la prima unità nell'elenco:''</font>
    cdd = cdio_cddap_identify(String@(Pointer@(drives)), 1, 0)
    Print "Unità CD-Da trovata e utilizzata: "; String@(Pointer@(drives))
  Else
    Error.Raise("Impossibile cercare o accedere ad un drive CD-ROM contenente un CD audio !")
  Endif
  
 <FONT Color=gray>' ''Non si ha più bisogno della lista dei dispositivi, pertanto si libera la memoria:''</font>
  cdio_free_device_list(drives)
  
  If cdd == 0 Then Error.Raise("Impossibile identificare il disco CD audio !")
  
  cdio_cddap_verbose_set(cdd, CDDA_MESSAGE_PRINTIT, CDDA_MESSAGE_PRINTIT)
  
  If cdio_cddap_open(cdd) <> 0 Then Error.Raise("Impossibile aprire il disco !")
  
 <FONT Color=gray>' ''Ora si leggono i frame del numero della traccia audio, indicato nella Costante "TRACCIA", del CD audio:''</font>
  p = cdio_paranoia_init(cdd)
  
  lsn = cdio_cddap_track_firstsector(cdd, <FONT Color=#B22222>TRACCIA</font>)
  If lsn == -1 Then Error.Raise("Problemi nell'avvio dell'LSN !")
  
  tra = cdio_cddap_sector_gettrack(cdd, lsn)
  llsn = cdio_cddap_track_lastsector(cdd, tra)
  
 <FONT Color=gray>' ''Il file WAV sarà salvato nella cartella "/tmp":''</font>
  fl = Open "/tmp/wave.wav" For Create
  
  cdio_paranoia_modeset(p, PARANOIA_MODE_FULL Xor PARANOIA_MODE_NEVERSKIP)
  cdio_paranoia_seek(p, lsn, SEEK_SET)
  
  Scrive_WAV_header(fl, (llsn - lsn + 1) * CDIO_CD_FRAMESIZE_RAW)
  
  For cur = lsn To llsn - 1
    buf = cdio_paranoia_read(p, 0)
    err = cdio_cddap_errors(cdd)
    mes = cdio_cddap_messages(cdd)
    If mes > 0 Then Print String@(mes)
    If err > 0 Then Print String@(err)
    If buf == 0 Then Error.Raise("Errore lettura di Paranoia !")
    Write #fl, buf, CDIO_CD_FRAMESIZE_RAW
  Next
  
  fl.Close
  cdio_paranoia_free(p)
  cdio_cddap_close(cdd)
  
 '''End'''
  
 
 '''Private''' Procedure Scrive_WAV_header(fl As File, byte As Integer)
  
                                  <FONT Color=gray>' ''Indice:''</font>
  Write #fl, "RIFF"               <FONT Color=gray>' '' 0- 3''</font>
  Numeri(byte + 44 - 8, fl, 4)    <FONT Color=gray>' '' 4- 7''</font>
  Write #fl, "WAVEfmt "           <FONT Color=gray>' '' 8-15''</font>
  Numeri(16, fl, 4)               <FONT Color=gray>' ''16-19''</font>
  Numeri(1, fl, 2)                <FONT Color=gray>' ''20-21''</font>
  Numeri(2, fl, 2)                <FONT Color=gray>' ''22-23''</font>
  Numeri(44100, fl, 4)            <FONT Color=gray>' ''24-27''</font>
  Numeri(44100 * 2 * 2, fl, 4)    <FONT Color=gray>' ''28-31''</font>
  Numeri(4, fl, 2)                <FONT Color=gray>' ''32-33''</font>
  Numeri(16, fl, 2)               <FONT Color=gray>' ''34-35''</font>
  Write #fl, "data"               <FONT Color=gray>' ''36-39''</font>
  Numeri(byte, fl, 4)             <FONT Color=gray>' ''40-43''</font>
  
 '''End'''
   
 '''Private''' Procedure Numeri(num As Long, fi As File, bt As Integer)
  
  Dim i As Integer
  Dim b As Byte
  
  Repeat
    b = Shr(num, Shl(i, 3)) And &FF
    Write #fi, b As Byte
    Inc i
    Dec bt
  Until bt == 0
  
 '''End'''