get_track_pregap_lba, get_track_pregap_lsn. Section on "CD-DA pregap" in libcdio manual.

All changes from Robert William Fuller.

THANKS

@@ -52,3 +52,7 @@ xboxmediacenter team (www.xboxmediacenter.de)
 
 Daniel Schwarz
  log-summary option in cd-paranoia.
+
+Robert William Fuller
+  get_track_pregap_lba, get_track_pregap_lsn. Section on "CD-DA pregap"
+  in libcdio manual.

configure.ac

@@ -1,4 +1,5 @@
-dnl Copyright (C) 2003, 2004, 2005, 2006, 2007 Rocky Bernstein <rocky@gnu.org>
+dnl Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008
+dnl Rocky Bernstein <rocky@gnu.org>
 dnl
 dnl This program is free software; you can redistribute it and/or modify
 dnl it under the terms of the GNU General Public License as published by
@@ -15,11 +16,11 @@ dnl along with this program; if not, write to the Free Software
 dnl Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 dnl 02110-1301 USA.
 
-define(RELEASE_NUM, 80)
+define(RELEASE_NUM, 81)
-define(CDIO_VERSION_STR, 0.$1)
+define(CDIO_VERSION_STR, 0.$1cvs)
 
 AC_PREREQ(2.52)
-AC_REVISION([$Id: configure.ac,v 1.221 2008/03/15 17:45:17 rocky Exp $])dnl
+AC_REVISION([$Id: configure.ac,v 1.222 2008/03/16 00:12:42 rocky Exp $])dnl
 AC_INIT(libcdio, CDIO_VERSION_STR(RELEASE_NUM))
 AC_CONFIG_SRCDIR(src/cd-info.c)
 

doc/libcdio.texi

@@ -46,7 +46,7 @@ development.''
 
 @titlepage
 @title GNU libcdio library
-@subtitle $Id: libcdio.texi,v 1.53 2007/12/10 10:08:46 rocky Exp $
+@subtitle $Id: libcdio.texi,v 1.54 2008/03/16 00:12:42 rocky Exp $
 @author Rocky Bernstein et al.
 @page
 
@@ -876,18 +876,20 @@ editor.
 @menu
 * Tracks::   Tracks
 * Sectors::  Block addressing (MSF, LSN, LBA)
+* Pre-gaps::  Track pre-gaps
 @end menu
 
 @node Tracks
 @section tracks --- disc subdivisions
 @cindex track
+@cindex gaps
 
 In this section we describe CD properties and terms that we make use
 of in @value{libcdio}.
 
 A CD is formated into a number of @term{tracks}, and a CD can hold at
 most 99 such tracks. This is defined by @code{CDIO_CD_MAX_TRACKS} in
-@file{cdio/sector.h}. Between the tracks CD specifications require a
+@file{cdio/sector.h}. Between some tracks CD specifications require a
 ``2 second'' in gap (called a @term{lead-in gap}. This is unused space
 with no ``data'' similar to the space between tracks on an old
 phonograph. The word ``second'' here really refers to a measure of
@@ -900,9 +902,9 @@ The beginning (or inner edge) of the CD is supposed to have a ``2
 second'' lead-in gap and there is supposed to be another ``2 second''
 @term{lead-out} gap at the end (or outer edge) of the CD.
 
-People have discovered that they can put useful data in the various
+People have discovered that they can put useful data in the @term{lead-in}
-gaps and their equipment can read this, violating the standards but
+and @term{lead-out} gaps, and their equipment can read this, violating
-allowing a CD to store more data.
+the standards but allowing a CD to store more data.
 
 In order to determine the number of tracks on a CD and where they
 start, commands are used to get this table-of-contents or @term{TOC}
@@ -922,7 +924,7 @@ largest legal track position. In @value{libcdio},
 @cindex frames
 
 A track is broken up into a number of 2352-byte @emph{blocks} which we
-sometimes call @emph{sectors} or @emph{frames}. Whereas tracks have to
+sometimes call @emph{sectors} or @emph{frames}. Whereas tracks may
 have a gap between them, a block or sector does not. (In
 @value{libcdio} the block size constant is defined using
 @code{CDIO_CD_FRAMESIZE_RAW}).
@@ -981,6 +983,138 @@ lead-in is are not counted. So to convert a LBA into an LSN you just
 add 150. Why the distinction between LBA and LSN? I don't know,
 perhaps this has something to do with ``multisession'' CDs.
 
+@node Pre-gaps
+@section track pre-gaps -- @acronym{CD-DA} discs and gaps
+@cindex CD-DA
+@cindex gaps
+@cindex lead in
+@cindex lead out
+@cindex pre-gap
+@cindex Q sub-channel
+
+Gaps are possibly one of the least understood topics in audio discs.
+In the case of @acronym{CD-DA} discs, standards require a silent 2
+second gap before the first audio track and after the last audio track
+(in each session.)  These are respectively referred to as
+@term{lead-in} and @term{lead-out} gaps.  No other gaps are required.
+It is important not to confuse the required @term{lead-in} and
+@term{lead-out} gaps with the optional track @term{pre-gap}s.  Track
+@term{pre-gap}s are the gaps that may occur between audio tracks.
+Typically, track @term{pre-gap}s are filled with silence so that the
+listener knows that one song has ended, and the next will soon begin.
+However, track @term{pre-gap}s do not have to contain silence.  One
+exception is an audio disc of a live performance.  Because the
+performer may seamlessly move from one piece of the performance to the
+next, it would be unnatural for the disc to contain silence between
+the two pieces.  Instead, the track number updates with no
+interruption in the performance.  This allows the listener to either
+hear the entire performance without unnatural interruptions, or to
+conveniently skip to certain pieces of the performance.  Finally, some
+@acronym{CD-DA} discs--whose behavior will be described below--lack
+track @term{pre-gap}s altogether although they must still include the
+@term{lead-in} and @term{lead-out} gaps.
+
+In order to understand the track @term{pre-gap}s that occur between
+audio tracks, it is necessary to understand how CD players display the
+track number and time.  Embedded in each block of audio data is
+non-audio information known as the @term{Q sub-channel}.  The
+@term{Q sub-channel} data tells the CD player what track number and time
+it should display while it is playing the block of audio data in which
+the @term{Q sub-channel} data is embedded.  Near the end of some
+tracks, the @term{Q sub-channel} may instruct the CD player to update
+the track number to the next track, and display a count down to the
+next track, often starting at -2 seconds and proceeding to zero.  This
+is known as an audio track @term{pre-gap}.  It may either contain
+silence, or as previously discussed--in the case of live
+performances--it may contain audio.  Almost as often as not, there is
+no @term{pre-gap} whatsoever.  Regardless, an audio track
+@term{pre-gap} is purely determined by the contents of the
+@term{Q sub-channel}, which is embedded in each audio sector.  This has
+some interesting implications for the track forward button.
+
+When the track forward button is pressed on a CD player, the CD player
+advances to the next track, skipping that track's @term{pre-gap}.
+This is because the CD player uses the starting address of the track
+from the disc's table of contents (TOC) to determine where to start
+playing a track when either the track forward or track backward
+buttons are pressed.  So to hear a @term{pre-gap} for track 4, the
+listener must either listen to track 3 first, or use the track forward
+or backward buttons to go to track 4, then use the seek backward
+button to back up into track 4's @term{pre-gap}, which is really part
+of track 3, at least according to the TOC.  Track 1 @term{pre-gap}s
+are especially interesting because some commercial discs have audio
+hidden before the beginning of the first track!  The only way to hear
+this hidden audio with a standard player is to use the seek backward
+button as soon as track 1 begins playing!
+
+Audio track @term{pre-gap}s may be specified in a couple of different
+ways in the popular cue file format.  The first way of specifying a
+@term{pre-gap} is to use the @command{PREGAP} command.  This will
+place a @term{pre-gap} containing silence before a track.  The second
+way of specifying a @term{pre-gap} is to give a track an
+@command{INDEX 00} as well as the more normal @command{INDEX 01}.
+@command{INDEX 01} will be used to specify the start of the track in
+the disc's TOC, while @command{INDEX 00} will be used to specify the
+start of the track's @term{pre-gap} as recorded in the @term{Q sub-channel}.
+@command{INDEX 00} is ordinarily used for specifying
+track @term{pre-gap}s that contain audio rather than silence.  Thus,
+the cue file format may be used to specify track @term{pre-gap}s with
+silence or audio, depending on whether the @command{PREGAP} or
+@command{INDEX 00} commands are specified.  If neither type of
+@term{pre-gap} is specified for a track, no @term{pre-gap} is created
+for that track, which merely means the absence of @term{pre-gap}
+information in the @term{Q sub-channel}, and the lack of a short count
+down to the next track.
+
+Various @acronym{CD-DA} ripping programs take various approaches to
+track @term{pre-gap}s.  Some ripping programs ignore track
+@term{pre-gap}s altogether, relying solely on the disc's TOC to
+determine where tracks begin and end.  If a disc is ripped with such a
+program, then re-burned later, the resulting disc will lack track
+@term{pre-gap}s, and thereby lack the playback behavior of counting
+down to the next track.  Other ripping programs detect track
+@term{pre-gap}s and record them in the popular cue file format among
+others.  Such ripping programs sometimes allow the user to determine
+whether track @term{pre-gap}s will be appended to the prior track or
+pre-pended to the track to which they "belong".  Note that if a
+ripping program is ignorant of track @term{pre-gap}s, the track
+@term{pre-gap}s will be appended to the prior track, because that is
+where the disc's TOC puts them.  Thus, there are many different ways
+an application may chose to deal with track @term{pre-gap}s.
+Consequently, @kbd{libcdio} does not dictate the policy a ripping
+program should use in dealing with track @term{pre-gap}s.  Hence,
+@kbd{libcdio} provides the @code{cdio_get_track_pregap_[lba|lsn]()}
+interfaces to allow the application to deal with track @term{pre-gap}s
+as it sees fit.
+
+Note that the @code{cdio_get_track_pregap_[lba|lsn]()} interfaces
+currently only provide information for CDRDAO TOC, CDRWIN BIN/CUE, and
+NRG images.  Getting the track @term{pre-gap}s from a CD drive is a
+more complicated problem because not all CD drives support reading the
+@term{Q sub-channel} DIRECTLY at @emph{high} speed, and there is no
+interface to determine whether or not a drive supports this optional
+feature, aside from trying to read the @term{Q sub-channel}, and
+possibly incurring IO errors.  However, all drives DO support reading
+the @term{Q sub-channel} INDIRECTLY while playing an audio disc by
+asking the drive for the current position.  Unfortunately, this occurs
+at normal playback speed, and requires a certain settling time after
+the disc starts playing.  Thus, using this @emph{slow} interface
+requires a more sophisticated algorithm, such as binary search or some
+heuristic, like backing up progressively from the end of the prior
+track to look for the next track's @term{pre-gap}.  Note that CD
+drives seek @emph{slow}ly, so it is better to simply use a drive that
+can read the @term{Q sub-channel} directly at @emph{high} speed, and
+avoid complicated software solutions.  (Not to mention that if the
+user has an older system with an analog audio cable hooked up between
+their soundboard and their drive, and a ripping program uses the
+@emph{slow} interface, the user will hear bits of the audio on the
+disc!)  Consequently, because there is no good universal solution to
+the problem of reading the @term{Q sub-channel} from a drive,
+@kbd{libcdio} currently leaves this problem up to the application, a
+problem which is readily approachable through either @kbd{libcdio}'s
+MMC interface or @kbd{libcdio}'s cdda interface.  For an example of
+one such application, see @url{https://gna.org/projects/cued/}.
+
 @node How to use
 @chapter How to use
 

include/cdio/track.h

@@ -1,5 +1,5 @@
 /* -*- c -*-
-    $Id: track.h,v 1.11 2006/01/23 20:30:28 rocky Exp $
+    $Id: track.h,v 1.12 2008/03/16 00:12:42 rocky Exp $
 
     Copyright (C) 2005, 2006 Rocky Bernstein <rocky@panix.com>
 
@@ -196,6 +196,28 @@ extern "C" {
     @return the starting LSN or CDIO_INVALID_LSN on error.
   */
   lsn_t cdio_get_track_lsn(const CdIo_t *p_cdio, track_t i_track);
+
+  /*!  
+    Return the starting LBA for the pregap for track number
+    i_track in p_cdio.  Track numbers usually start at something 
+    greater than 0, usually 1.
+
+    @param p_cdio object to get information from
+    @param i_track  the track number we want the LBA for
+    @return the starting LBA or CDIO_INVALID_LBA on error.
+  */
+  lba_t cdio_get_track_pregap_lba(const CdIo_t *p_cdio, track_t i_track);
+
+  /*!  
+    Return the starting LSN for the pregap for track number
+    i_track in p_cdio.  Track numbers usually start at something 
+    greater than 0, usually 1.
+
+    @param p_cdio object to get information from
+    @param i_track  the track number we want the LSN for
+    @return the starting LSN or CDIO_INVALID_LSN on error.
+  */
+  lsn_t cdio_get_track_pregap_lsn(const CdIo_t *p_cdio, track_t i_track);
   
   /*!  
     Return the starting MSF (minutes/secs/frames) for track number

lib/driver/Makefile.am

@@ -1,4 +1,4 @@
-#   $Id: Makefile.am,v 1.21 2007/10/15 04:53:59 rocky Exp $
+#   $Id: Makefile.am,v 1.22 2008/03/16 00:12:42 rocky Exp $
 #
 #    Copyright (C) 2003, 2004, 2005, 2006, 2007 Rocky Bernstein <rocky@gnu.org>
 #
@@ -43,9 +43,9 @@
 #     public release, then set AGE to 0. A changed interface means an
 #     incompatibility with previous versions.
 
-libcdio_la_CURRENT = 8
+libcdio_la_CURRENT = 9
-libcdio_la_REVISION = 1
+libcdio_la_REVISION = 0
-libcdio_la_AGE = 1
+libcdio_la_AGE = 2
 
 EXTRA_DIST = image/Makefile FreeBSD/Makefile MSWindows/Makefile \
 	     libcdio.sym

lib/driver/cdio_private.h

@@ -1,5 +1,5 @@
 /*
-    $Id: cdio_private.h,v 1.31 2006/01/23 20:48:11 rocky Exp $
+    $Id: cdio_private.h,v 1.32 2008/03/16 00:12:43 rocky Exp $
 
     Copyright (C) 2003, 2004, 2005 Rocky Bernstein <rocky@panix.com>
 
@@ -260,6 +260,13 @@ extern "C" {
       CDIO_INVALID_LBA is returned on error.
     */
     lba_t (*get_track_lba) ( void *p_env, track_t i_track );
+
+    /*!  
+      Return the starting LBA for the pregap for track number
+      i_track in p_env.  Tracks numbers start at 1.
+      CDIO_INVALID_LBA is returned on error.
+    */
+    lba_t (*get_track_pregap_lba) ( const void *p_env, track_t i_track );
     
     /*!  
       Get format of track. 

lib/driver/image.h

@@ -1,5 +1,5 @@
 /*
-    $Id: image.h,v 1.7 2005/02/17 04:57:21 rocky Exp $
+    $Id: image.h,v 1.8 2008/03/16 00:12:43 rocky Exp $
 
     Copyright (C) 2004, 2005 Rocky Bernstein <rocky@panix.com>
 
@@ -48,7 +48,8 @@ typedef struct {
   msf_t          start_msf;
   lba_t          start_lba;
   int            start_index;
-  lba_t          pregap;	/**< pre-gap with zero audio data */
+  lba_t          pregap;	/**< pre-gap */
+  lba_t          silence;	/**< pre-gap with zero audio data */
   int            sec_count;     /**< Number of sectors in this track. Does not
 				     include pregap */
   int            num_indices;

lib/driver/image/bincue.c

@@ -1,5 +1,5 @@
 /*
-    $Id: bincue.c,v 1.19 2006/02/13 11:00:53 rocky Exp $
+    $Id: bincue.c,v 1.20 2008/03/16 00:12:43 rocky Exp $
 
     Copyright (C) 2002, 2003, 2004, 2005, 2006 
     Rocky Bernstein <rocky@panix.com>
@@ -27,7 +27,7 @@
    (*.cue).
 */
 
-static const char _rcsid[] = "$Id: bincue.c,v 1.19 2006/02/13 11:00:53 rocky Exp $";
+static const char _rcsid[] = "$Id: bincue.c,v 1.20 2008/03/16 00:12:43 rocky Exp $";
 
 #include "image.h"
 #include "cdio_assert.h"
@@ -632,7 +632,7 @@ parse_cuefile (_img_private_t *cd, const char *psz_cue_name)
 	      goto err_exit;
 	    }
 	    if (cd) {
-	      cd->tocent[i].pregap = lba;
+	      cd->tocent[i].silence = lba;
 	    }
 	  } else {
 	    goto format_error;
@@ -672,7 +672,14 @@ parse_cuefile (_img_private_t *cd, const char *psz_cue_name)
 	      track_info_t  *this_track=
 		&(cd->tocent[cd->gen.i_tracks - cd->gen.i_first_track]);
 
-	      if (start_index != 0) {
+	      switch (start_index) {
+
+	      case 0:
+		lba += CDIO_PREGAP_SECTORS;
+		this_track->pregap = lba;
+		break;
+
+	      case 1:
 		if (!b_first_index_for_track) {
 		  lba += CDIO_PREGAP_SECTORS;
 		  cdio_lba_to_msf(lba, &(this_track->start_msf));
@@ -709,6 +716,10 @@ parse_cuefile (_img_private_t *cd, const char *psz_cue_name)
 		  }
 		}
 		this_track->num_indices++;
+		break;
+
+	      default:
+		break;
 	      }
 	    }
 #endif  
@@ -1163,6 +1174,7 @@ cdio_open_cue (const char *psz_cue_name)
   _funcs.get_track_lba         = _get_lba_track_bincue;
   _funcs.get_track_msf         = _get_track_msf_image;
   _funcs.get_track_preemphasis = get_track_preemphasis_image,
+  _funcs.get_track_pregap_lba  = get_track_pregap_lba_image;
   _funcs.lseek                 = _lseek_bincue;
   _funcs.read                  = _read_bincue;
   _funcs.read_audio_sectors    = _read_audio_sectors_bincue;

lib/driver/image/cdrdao.c

@@ -1,5 +1,5 @@
 /*
-    $Id: cdrdao.c,v 1.23 2007/03/05 11:49:24 rocky Exp $
+    $Id: cdrdao.c,v 1.24 2008/03/16 00:12:43 rocky Exp $
 
     Copyright (C) 2004, 2005, 2006, 2007 Rocky Bernstein <rocky@gnu.org>
     toc reading routine adapted from cuetools
@@ -25,7 +25,7 @@
    (*.cue).
 */
 
-static const char _rcsid[] = "$Id: cdrdao.c,v 1.23 2007/03/05 11:49:24 rocky Exp $";
+static const char _rcsid[] = "$Id: cdrdao.c,v 1.24 2008/03/16 00:12:43 rocky Exp $";
 
 #include "image.h"
 #include "cdio_assert.h"
@@ -825,6 +825,7 @@ parse_tocfile (_img_private_t *cd, const char *psz_cue_name)
 	  if (NULL != (psz_field = strtok (NULL, " \t\n\r"))) {
 	    /* todo: line is too long! */
 	    if (NULL != cd) {
+	      cd->tocent[i].pregap = cd->tocent[i].start_lba;
 	      cd->tocent[i].start_lba += cdio_mmssff_to_lba (psz_field);
 	      cdio_lba_to_msf(cd->tocent[i].start_lba, 
 			      &(cd->tocent[i].start_msf));
@@ -843,7 +844,7 @@ parse_tocfile (_img_private_t *cd, const char *psz_cue_name)
 	if (0 <= i) {
 	  if (NULL != (psz_field = strtok (NULL, " \t\n\r"))) {
 	    if (NULL != cd) 
-	      cd->tocent[i].pregap = cdio_mmssff_to_lba (psz_field);
+	      cd->tocent[i].silence = cdio_mmssff_to_lba (psz_field);
 	  } else {
 	    goto format_error;
 	  }
@@ -1295,6 +1296,7 @@ cdio_open_cdrdao (const char *psz_cue_name)
   _funcs.get_track_lba         = _get_lba_track_cdrdao;
   _funcs.get_track_msf         = _get_track_msf_image;
   _funcs.get_track_preemphasis = get_track_preemphasis_image,
+  _funcs.get_track_pregap_lba  = get_track_pregap_lba_image;
   _funcs.lseek                 = _lseek_cdrdao;
   _funcs.read                  = _read_cdrdao;
   _funcs.read_audio_sectors    = _read_audio_sectors_cdrdao;

lib/driver/image/nrg.c

@@ -1,5 +1,5 @@
 /*
-    $Id: nrg.c,v 1.24 2006/02/27 10:23:52 flameeyes Exp $
+    $Id: nrg.c,v 1.25 2008/03/16 00:12:43 rocky Exp $
 
     Copyright (C) 2003, 2004, 2005, 2006 Rocky Bernstein <rocky@panix.com>
     Copyright (C) 2001, 2003 Herbert Valerio Riedel <hvr@gnu.org>
@@ -46,7 +46,7 @@
 #include "_cdio_stdio.h"
 #include "nrg.h"
 
-static const char _rcsid[] = "$Id: nrg.c,v 1.24 2006/02/27 10:23:52 flameeyes Exp $";
+static const char _rcsid[] = "$Id: nrg.c,v 1.25 2008/03/16 00:12:43 rocky Exp $";
 
 nero_id_t    nero_id;
 nero_dtype_t nero_dtype;
@@ -371,24 +371,24 @@ parse_nrg (_img_private_t *p_env, const char *psz_nrg_name,
       case DAOX_ID: /* "DAOX" */ 
       case DAOI_ID: /* "DAOI" */
 	{
+	  _daox_t *_xentries = NULL;
+	  _daoi_t *_ientries = NULL;
+	  _dao_common_t	 *_dao_common = (void *) chunk->data;
+	  int disc_mode = _dao_common->unknown[1];
 	  track_format_t track_format;
-	  int disc_mode;
+	  int i;
 
 	  /* We include an extra 0 byte so these can be used as C strings.*/
-	  p_env->psz_mcn    = calloc(1, CDIO_MCN_SIZE+1);
+	  p_env->psz_mcn = calloc(1, CDIO_MCN_SIZE+1);
+	  memcpy(p_env->psz_mcn, &(_dao_common->psz_mcn), CDIO_MCN_SIZE);
+	  p_env->psz_mcn[CDIO_MCN_SIZE] = '\0';
 
 	  if (DAOX_ID == opcode) {
-	    _daox_array_t *_entries = (void *) chunk->data;
+	    _xentries = (void *) chunk->data;
-	    disc_mode    = _entries->_unknown[1];
+	    p_env->dtyp = _xentries->track_info[0].common.unknown[0];
-	    p_env->dtyp  = _entries->_unknown[19];
-	    memcpy(p_env->psz_mcn, &(_entries->psz_mcn), CDIO_MCN_SIZE);
-	    p_env->psz_mcn[CDIO_MCN_SIZE] = '\0';
 	  } else {
-	    _daoi_array_t *_entries = (void *) chunk->data;
+	    _ientries = (void *) chunk->data;
-	    disc_mode    = _entries->_unknown[1];
+	    p_env->dtyp = _ientries->track_info[0].common.unknown[0];
-	    p_env->dtyp  = _entries->_unknown[19];
-	    memcpy(p_env->psz_mcn, &(_entries->psz_mcn), CDIO_MCN_SIZE);
-	    p_env->psz_mcn[CDIO_MCN_SIZE] = '\0';
 	  }
 
 	  p_env->is_dao = true;
@@ -430,7 +430,6 @@ parse_nrg (_img_private_t *p_env, const char *psz_nrg_name,
 	    track_format = TRACK_FORMAT_AUDIO;
 	  }
 	  if (0 == disc_mode) {
-	    int i;
 	    for (i=0; i<p_env->gen.i_tracks; i++) {
 	      cdtext_init (&(p_env->gen.cdtext_track[i]));
 	      p_env->tocent[i].track_format= track_format;
@@ -446,7 +445,6 @@ parse_nrg (_img_private_t *p_env, const char *psz_nrg_name,
 	      }
 	    }
 	  } else if (2 == disc_mode) {
-	    int i;
 	    for (i=0; i<p_env->gen.i_tracks; i++) {
 	      cdtext_init (&(p_env->gen.cdtext_track[i]));
 	      p_env->tocent[i].track_green = true;
@@ -473,6 +471,20 @@ parse_nrg (_img_private_t *p_env, const char *psz_nrg_name,
 		      "Don't know if mode 1, mode 2 or mixed: %x\n", 
 		      disc_mode);
 	  }
+
+	  for (i=0; i<p_env->gen.i_tracks; i++) {
+	    if (!p_env->tocent[i].datasize) {
+	      continue;
+	    }
+	    if (DAOX_ID == opcode) {
+	       p_env->tocent[i].pregap = (uint64_from_be
+		(_xentries->track_info[i].index0)) / (p_env->tocent[i].datasize);
+	    } else {
+	       p_env->tocent[i].pregap = (uint32_from_be
+		(_ientries->track_info[i].index0)) / (p_env->tocent[i].datasize);
+	    }
+	  }
+
 	  break;
 	}
       case NERO_ID: 
@@ -1243,13 +1255,14 @@ cdio_open_nrg (const char *psz_source)
   _funcs.get_media_changed     = get_media_changed_image;
   _funcs.get_mcn               = _get_mcn_image;
   _funcs.get_num_tracks        = _get_num_tracks_image;
-  _funcs.get_track_channels    = get_track_channels_generic,
+  _funcs.get_track_channels    = get_track_channels_generic;
-  _funcs.get_track_copy_permit = get_track_copy_permit_image,
+  _funcs.get_track_copy_permit = get_track_copy_permit_image;
   _funcs.get_track_format      = get_track_format_nrg;
   _funcs.get_track_green       = _get_track_green_nrg;
   _funcs.get_track_lba         = NULL; /* Will use generic routine via msf */
   _funcs.get_track_msf         = _get_track_msf_image;
-  _funcs.get_track_preemphasis = get_track_preemphasis_generic,
+  _funcs.get_track_preemphasis = get_track_preemphasis_generic;
+  _funcs.get_track_pregap_lba  = get_track_pregap_lba_image;
   _funcs.lseek                 = _lseek_nrg;
   _funcs.read                  = _read_nrg;
   _funcs.read_audio_sectors    = _read_audio_sectors_nrg;

lib/driver/image/nrg.h

@@ -1,5 +1,5 @@
 /*
-    $Id: nrg.h,v 1.3 2006/01/14 09:45:44 rocky Exp $
+    $Id: nrg.h,v 1.4 2008/03/16 00:12:43 rocky Exp $
 
     Copyright (C) 2004, 2006 Rocky Bernstein <rocky@panix.com>
     Copyright (C) 2001, 2003 Herbert Valerio Riedel <hvr@gnu.org>
@@ -71,18 +71,47 @@ typedef struct {
   uint32_t lsn        GNUC_PACKED; 
 } _cuex_array_t;
 
+/* New DAO[XI] Information from http://en.wikipedia.org/wiki/NRG_(file_format)
+*/
+
 typedef struct {
-  uint32_t _unknown1  GNUC_PACKED;
+  uint8_t  zero[10];
-  char      psz_mcn[CDIO_MCN_SIZE];             
+  uint32_t sector_size         GNUC_PACKED;
-  uint8_t  _unknown[64-CDIO_MCN_SIZE-sizeof(uint32_t)];
+  uint8_t  unknown[4];
+} _dao_array_common_t;
+
+typedef struct {
+  _dao_array_common_t common;
+  uint64_t index0              GNUC_PACKED;
+  uint64_t index1              GNUC_PACKED;
+  uint64_t end_of_track        GNUC_PACKED;
 } _daox_array_t;
 
 typedef struct {
-  uint32_t _unknown1  GNUC_PACKED;
+  _dao_array_common_t common;
-  char      psz_mcn[CDIO_MCN_SIZE];
+  uint32_t index0              GNUC_PACKED;
-  uint8_t  _unknown[64-CDIO_MCN_SIZE-sizeof(uint32_t)];
+  uint32_t index1              GNUC_PACKED;
+  uint32_t end_of_track        GNUC_PACKED;
 } _daoi_array_t;
 
+typedef struct {
+  uint32_t chunk_size_le       GNUC_PACKED;
+  char     psz_mcn[CDIO_MCN_SIZE];
+  uint8_t  unknown[3];
+  uint8_t  first_track;
+  uint8_t  last_track;
+} _dao_common_t;
+
+typedef struct {
+  _dao_common_t common;
+  _daox_array_t track_info[EMPTY_ARRAY_SIZE];
+} _daox_t;
+
+typedef struct {
+  _dao_common_t common;
+  _daoi_array_t track_info[EMPTY_ARRAY_SIZE];
+} _daoi_t;
+
 typedef struct {
   uint32_t id                    GNUC_PACKED;
   uint32_t len                   GNUC_PACKED;

lib/driver/image_common.c

@@ -1,5 +1,5 @@
 /*
-    $Id: image_common.c,v 1.12 2005/02/17 07:03:37 rocky Exp $
+    $Id: image_common.c,v 1.13 2008/03/16 00:12:43 rocky Exp $
 
     Copyright (C) 2004, 2005 Rocky Bernstein <rocky@panix.com>
 
@@ -246,6 +246,30 @@ get_track_preemphasis_image(const void *p_user_data, track_t i_track)
 	   & PRE_EMPHASIS ) ? CDIO_TRACK_FLAG_TRUE : CDIO_TRACK_FLAG_FALSE;
 }
 
+/*! Return the starting LBA for the pregap for track number i_track.
+  Track numbers start at 1.
+  CDIO_INVALID_LBA is returned on error.
+*/
+lba_t
+get_track_pregap_lba_image(const void *p_user_data, track_t i_track)
+{
+  const _img_private_t *p_env = p_user_data;
+  lba_t pregap, start_lba;
+
+  pregap    = p_env->tocent[i_track-p_env->gen.i_first_track].pregap;
+  start_lba = p_env->tocent[i_track-p_env->gen.i_first_track].start_lba;
+
+  /* avoid initializing pregap to CDIO_INVALID_LBA by letting calloc
+     do the work.  also, nero files have the pregap set equal
+     to the start of the track when there is no pregap
+  */
+  if (!pregap || pregap == start_lba) {
+    pregap = CDIO_INVALID_LBA;
+  }
+
+  return pregap;
+}
+
 /*!
   Read a data sector
   

lib/driver/image_common.h

@@ -1,5 +1,5 @@
 /*
-    $Id: image_common.h,v 1.10 2005/02/17 07:03:37 rocky Exp $
+    $Id: image_common.h,v 1.11 2008/03/16 00:12:43 rocky Exp $
 
     Copyright (C) 2004, 2005 Rocky Bernstein <rocky@panix.com>
 
@@ -150,6 +150,13 @@ track_flag_t get_track_copy_permit_image(void *p_user_data, track_t i_track);
 */
 track_flag_t get_track_preemphasis_image(const void *p_user_data, 
 					 track_t i_track);
+
+/*! Return the starting LBA for the pregap for track number i_track.
+  Track numbers start at 1.
+  CDIO_INVALID_LBA is returned on error.
+*/
+lba_t get_track_pregap_lba_image(const void *p_user_data, track_t i_track);
+
 /*!
   Read a data sector
   

lib/driver/libcdio.sym

@@ -80,6 +80,8 @@ cdio_get_track_format
 cdio_get_track_green
 cdio_get_track_last_lsn
 cdio_get_track_lba
+cdio_get_track_pregap_lba
+cdio_get_track_pregap_lsn
 cdio_get_track_lsn
 cdio_get_track_msf
 cdio_get_track_preemphasis

lib/driver/track.c

@@ -1,5 +1,5 @@
 /*
-    $Id: track.c,v 1.4 2005/02/06 04:20:25 rocky Exp $
+    $Id: track.c,v 1.5 2008/03/16 00:12:43 rocky Exp $
 
     Copyright (C) 2003, 2004, 2005 Rocky Bernstein <rocky@panix.com>
     Copyright (C) 2001 Herbert Valerio Riedel <hvr@gnu.org>
@@ -229,7 +229,7 @@ cdio_get_track_lba(const CdIo_t *p_cdio, track_t i_track)
   i_track in cdio.  Tracks numbers start at 1.
   The "leadout" track is specified either by
   using i_track LEADOUT_TRACK or the total tracks+1.
-  CDIO_INVALID_LBA is returned on error.
+  CDIO_INVALID_LSN is returned on error.
 */
 lsn_t
 cdio_get_track_lsn(const CdIo_t *p_cdio, track_t i_track)
@@ -246,6 +246,34 @@ cdio_get_track_lsn(const CdIo_t *p_cdio, track_t i_track)
   }
 }
 
+/*!  
+  Return the starting LBA for the pregap for track number
+  i_track in cdio.  Track numbers start at 1.
+  CDIO_INVALID_LBA is returned on error.
+*/
+lba_t
+cdio_get_track_pregap_lba(const CdIo_t *p_cdio, track_t i_track)
+{
+  if (p_cdio == NULL) return CDIO_INVALID_LBA;
+
+  if (p_cdio->op.get_track_pregap_lba) {
+    return p_cdio->op.get_track_pregap_lba (p_cdio->env, i_track);
+  } else {
+    return CDIO_INVALID_LBA;
+  }
+}
+
+/*!  
+  Return the starting LSN for the pregap for track number
+  i_track in cdio.  Track numbers start at 1.
+  CDIO_INVALID_LSN is returned on error.
+*/
+lsn_t
+cdio_get_track_pregap_lsn(const CdIo_t *p_cdio, track_t i_track)
+{
+  return cdio_lba_to_lsn(cdio_get_track_pregap_lba(p_cdio, i_track));
+}
+
 /*!  
   Return the ending LSN for track number
   i_track in cdio.  CDIO_INVALID_LSN is returned on error.