2024-09-24 14:54:57 +02:00

117 lines
3.6 KiB
C

/* --------------------------------------------------------------------------
MusicBrainz -- The Internet music metadatabase
Copyright (C) 2006 Lukas Lalinsky
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
--------------------------------------------------------------------------- */
#ifdef _MSC_VER
#define _CRT_SECURE_NO_WARNINGS
#if (_MSC_VER < 1900)
#define snprintf _snprintf
#endif
#endif
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include "discid/discid_private.h"
#define XA_INTERVAL ((60 + 90 + 2) * 75)
#define DATA_TRACK 0x04
int mb_disc_load_toc(mb_disc_private *disc, mb_disc_toc *toc) {
int first_audio_track, last_audio_track, i;
mb_disc_toc_track *track;
if (toc->first_track_num < 1) {
snprintf(disc->error_msg, MB_ERROR_MSG_LENGTH,
"invalid CD TOC - first track number must be 1 or higher");
return 0;
}
if (toc->last_track_num < 1) {
snprintf(disc->error_msg, MB_ERROR_MSG_LENGTH,
"invalid CD TOC - last track number must be 99 or lower");
return 0;
}
/* we can't just skip data tracks at the front
* releases are always expected to start with track 1 by MusicBrainz
*/
first_audio_track = toc->first_track_num;
last_audio_track = -1;
/* scan the TOC for audio tracks */
for (i = toc->first_track_num; i <= toc->last_track_num; i++) {
track = &toc->tracks[i];
if ( !(track->control & DATA_TRACK) ) {
last_audio_track = i;
}
}
if (last_audio_track < 0) {
snprintf(disc->error_msg, MB_ERROR_MSG_LENGTH,
"no actual audio tracks on disc: CDROM or DVD?");
return 0;
}
disc->first_track_num = first_audio_track;
disc->last_track_num = last_audio_track;
/* get offsets for all found data tracks */
for (i = first_audio_track; i <= last_audio_track; i++) {
track = &toc->tracks[i];
if (track->address > 0) {
disc->track_offsets[i] = track->address + 150;
} else {
/* this seems to happen on "copy-protected" discs */
disc->track_offsets[i] = 150;
}
}
/* if the last audio track is not the last track on the CD,
* use the offset of the next data track as the "lead-out" offset */
if (last_audio_track < toc->last_track_num) {
track = &toc->tracks[last_audio_track + 1];
disc->track_offsets[0] = track->address - XA_INTERVAL + 150;
} else {
/* use the regular lead-out track */
track = &toc->tracks[0];
disc->track_offsets[0] = track->address + 150;
}
/* as long as the lead-out isn't actually bigger than
* the position of the last track, the last track is invalid.
* This happens on "copy-protected"/invalid discs.
* The track is then neither a valid audio track, nor data track.
*/
while (disc->track_offsets[0] < disc->track_offsets[last_audio_track]) {
disc->last_track_num = --last_audio_track;
disc->track_offsets[last_audio_track + 1] = 0;
track = &toc->tracks[last_audio_track + 1];
disc->track_offsets[0] = track->address - XA_INTERVAL + 150;
}
return 1;
}
/* EOF */