[Libcdio-devel] cd extra audio data boundaries

[Patrick Guimond]

Hi

It seems that the handling of cd extra discs (multisession) has been
commented for review in the cdda_interface imported from cdparanoia.

The attached patch re-enables this support by using internal cdio
functions and explains offset values.

Patrick Guimond

diff -ur libcdio/lib/cdda_interface/common_interface.c 
libcdio_work/lib/cdda_interface/common_interface.c
--- libcdio/lib/cdda_interface/common_interface.c       2006-08-26 
18:08:23.000000000 -0400
+++ libcdio_work/lib/cdda_interface/common_interface.c  2006-08-26 
18:01:50.000000000 -0400
@@ -186,14 +186,12 @@
 /*! Here we fix up a couple of things that will never happen.  yeah,
    right.  
 
-   rocky OMITTED FOR NOW:
    The multisession stuff is from Hannu's code; it assumes it knows
    the leadout/leadin size.
 
    @return -1 if we can't get multisession info, 0 if there is one
-   session only or the multi-session LBA is less than or 100 (don't
-   ask me why -- I don't know), and 1 if the multi-session lba is
-   greater than 100.
+   session only or the last session LBA is the same as the first audio
+   track and 1 if the multi-session lba is higher than first audio track
 */
 int 
 FixupTOC(cdrom_drive_t *d, track_t i_tracks)
@@ -231,36 +229,38 @@
     }
   }
 
-#if LOOKED_OVER
-  /* For a scsi device, the ioctl must go to the specialized SCSI
-     CDROM device, not the generic device. */
-
-  if (d->ioctl_fd != -1) {
-    struct cdrom_multisession ms_str;
-    int result;
-
-    ms_str.addr_format = CDROM_LBA;
-    result = ioctl(d->ioctl_fd, CDROMMULTISESSION, &ms_str);
-    if (result == -1) return -1;
-
-    if (ms_str.addr.lba > 100) {
-
-      /* This is an odd little piece of code --Monty */
-
-      /* believe the multisession offset :-) */
-      /* adjust end of last audio track to be in the first session */
-      for (j = i_tracks-1; j >= 0; j--) {
-       if (j > 0 && !IS_AUDIO(d,j) && IS_AUDIO(d,j-1)) {
-         if ((d->disc_toc[j].dwStartSector > ms_str.addr.lba - 11400) &&
-             (ms_str.addr.lba - 11400 > d->disc_toc[j-1].dwStartSector))
-           d->disc_toc[j].dwStartSector = ms_str.addr.lba - 11400;
+  d->audio_last_sector = CDIO_INVALID_LSN;
+
+  lsn_t last_ses_lsn;
+  if (cdio_get_last_session (d->p_cdio, &last_ses_lsn) < 0)
+         return -1;
+
+  /* A Red Book Disc must have only one session, otherwise this is a 
+   * CD Extra */
+  if (last_ses_lsn > d->disc_toc[0].dwStartSector) {
+    /* CD Extra discs have two session, the first one ending after 
+     * the last audio track 
+     * Thus the need to fix the length of the the audio data portion to 
+     * not cross the lead-out of this session */
+    for (j = i_tracks-1; j > 1; j--) {
+      if (cdio_get_track_format(d->p_cdio, j+1) != TRACK_FORMAT_AUDIO && 
+         cdio_get_track_format(d->p_cdio, j) == TRACK_FORMAT_AUDIO) {
+
+       /* First session lead-out is 1:30
+        * Lead-ins are 1:00
+        * Every session's first track have a 0:02 pregap
+        *
+        * That makes a control data section of (90+60+2)*75 sectors in the 
+        * last audio track */
+       if ((last_ses_lsn - (90+60+2)*75 >= d->disc_toc[j-1].dwStartSector) &&
+           (last_ses_lsn - (90+60+2)*75 < d->disc_toc[j].dwStartSector)) {
+         d->audio_last_sector = last_ses_lsn - (90+60+2)*75 - 1;
          break;
        }
       }
-      return 1;
     }
+    return 1;
   }
-#endif
 
   return 0;
 }
diff -ur libcdio/lib/cdda_interface/toc.c libcdio_work/lib/cdda_interface/toc.c
--- libcdio/lib/cdda_interface/toc.c    2006-08-26 18:08:23.000000000 -0400
+++ libcdio_work/lib/cdda_interface/toc.c       2006-08-26 18:01:50.000000000 
-0400
@@ -109,6 +109,15 @@
     cderror(d,"401: Invalid track number\n");
     return -1;
   }
+  
+  /* CD Extra have their first session ending at the last audio track */
+  if (d->cd_extra > 0 && i_track+1 <= d->tracks) {
+    if (d->audio_last_sector >= d->disc_toc[i_track-1].dwStartSector &&
+        d->audio_last_sector < d->disc_toc[i_track].dwStartSector) {
+      return d->audio_last_sector;
+    }
+  }
+
   /* Safe, we've always the leadout at disc_toc[tracks] */
   return(d->disc_toc[i_track].dwStartSector-1);
 }

signature.asc
Description: OpenPGP digital signature