Initial community commit

Src/external_dependencies/libdiscid-0.6.2/src/toc.c

@@ -0,0 +1,116 @@
+/* --------------------------------------------------------------------------
+
+   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 */