blob: 61e59d50fc4c9fbb728bcde98f485928523c91eb [file] [log] [blame]
/* Copyright (C) 2007 Brian Koropoff <bkoropoff at gmail com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#include <tag.h>
#include <string.h>
#include <stdlib.h>
#define EXTENDED_OFFSET 0x10200
#define EXTENDED_MAGIC ((guint32) ('x' << 0 | 'i' << 8 | 'd' << 16 | '6' << 24))
#define TYPE_LENGTH 0x0
#define TYPE_STRING 0x1
#define TYPE_INTEGER 0x4
#define TAG_TITLE 0x01
#define TAG_GAME 0x02
#define TAG_ARTIST 0x03
#define TAG_DUMPER 0x04
#define TAG_DUMP_DATE 0x05
#define TAG_EMULATOR 0x06
#define TAG_COMMENT 0x07
#define TAG_ALBUM 0x10
#define TAG_DISC 0x11
#define TAG_TRACK 0x12
#define TAG_PUBLISHER 0x13
#define TAG_YEAR 0x14
#define TAG_INTRO 0x30
#define TAG_LOOP 0x31
#define TAG_END 0x32
#define TAG_FADE 0x33
#define TAG_MUTED 0x34
#define TAG_COUNT 0x35
#define TAG_AMP 0x36
#define READ_INT8(data, offset) (data[offset])
#define READ_INT16(data, offset) ((data[offset] << 0) + (data[offset+1] << 8))
#define READ_INT24(data, offset) ((data[offset] << 0) + (data[offset+1] << 8) + (data[offset+2] << 16))
#define READ_INT32(data, offset) ((data[offset] << 0) + (data[offset+1] << 8) + (data[offset+2] << 16) + (data[offset+3] << 24))
static inline gboolean
spc_tag_is_extended (guchar * data, guint length)
{
// Extended tags come at the end of the file (at a known offset)
// and start with "xid6"
return (length > EXTENDED_OFFSET + 4
&& READ_INT32 (data, EXTENDED_OFFSET) == EXTENDED_MAGIC);
}
static inline gboolean
spc_tag_is_text_format (guchar * data, guint length)
{
// Because the id666 format is brain dead, there's
// no definite way to decide if it is in text
// format. This function implements a set of
// heuristics to make a best-effort guess.
// If the date field contains separators, it is probably text
if (data[0xA0] == '/' || data[0xA0] == '.')
return TRUE;
// If the first byte of the date field is small (but not 0,
// which could indicate an empty string), it's probably binary
if (data[0x9E] >= 1 && data[0x9E] <= 31)
return FALSE;
// If all previous tests turned up nothing, assume it's text
return TRUE;
}
static inline gboolean
spc_tag_is_present (guchar * data, guint length)
{
return data[0x23] == 26;
}
static inline GDate *
spc_tag_unpack_date (guint32 packed)
{
guint dump_year = packed / 10000;
guint dump_month = (packed % 10000) / 100;
guint dump_day = packed % 100;
if (dump_month == 0)
dump_month = 1;
if (dump_day == 0)
dump_day = 1;
if (dump_year != 0)
return g_date_new_dmy (dump_day, dump_month, dump_year);
else
return NULL;
}
void
spc_tag_clear (spc_tag_info * info)
{
info->title = info->game = info->publisher = info->artist = info->album =
info->comment = info->dumper = NULL;
info->dump_date = NULL;
info->time_seconds = 0;
info->time_fade_milliseconds = 0;
info->time_intro = 0;
info->time_end = 0;
info->time_loop = 0;
info->time_fade = 0;
info->loop_count = 0;
info->muted = 0;
info->disc = 0;
info->amplification = 0;
}
void
spc_tag_get_info (guchar * data, guint length, spc_tag_info * info)
{
spc_tag_clear (info);
if (spc_tag_is_present (data, length)) {
gboolean text_format = spc_tag_is_text_format (data, length);
info->title = g_new0 (gchar, 0x21);
info->game = g_new0 (gchar, 0x21);
info->artist = g_new0 (gchar, 0x21);
info->dumper = g_new0 (gchar, 0x10);
info->comment = g_new0 (gchar, 0x32);
strncpy (info->title, (gchar *) & data[0x2E], 32);
strncpy (info->artist, (gchar *) & data[(text_format ? 0xB1 : 0xB0)], 32);
strncpy (info->game, (gchar *) & data[0x4E], 32);
strncpy (info->dumper, (gchar *) & data[0x6E], 16);
strncpy (info->comment, (gchar *) & data[0x7E], 32);
if (text_format) {
gchar time[4];
gchar fade[6];
guint dump_year, dump_month, dump_day;
strncpy (time, (gchar *) data + 0xA9, 3);
strncpy (fade, (gchar *) data + 0xAC, 5);
time[3] = fade[5] = 0;
info->time_seconds = atoi (time);
info->time_fade_milliseconds = atoi (fade);
dump_year = (guint) atoi ((gchar *) data + 0x9E);
dump_month = (guint) atoi ((gchar *) data + 0x9E + 3);
dump_day = (guint) atoi ((gchar *) data + 0x9E + 3 + 3);
if (dump_month == 0)
dump_month = 1;
if (dump_day == 0)
dump_day = 1;
if (dump_year != 0)
info->dump_date = g_date_new_dmy (dump_day, dump_month, dump_year);
info->muted = READ_INT8 (data, 0xD1);
info->emulator = READ_INT8 (data, 0xD2);
} else {
info->time_seconds = READ_INT24 (data, 0xA9);
info->time_fade_milliseconds = READ_INT32 (data, 0xAC);
info->dump_date = spc_tag_unpack_date (READ_INT32 (data, 0x9E));
info->muted = READ_INT8 (data, 0xD0);
info->emulator = READ_INT8 (data, 0xD1);
}
}
if (spc_tag_is_extended (data, length)) {
guchar *chunk = data + EXTENDED_OFFSET + 8;
guint32 chunk_size = *((guint32 *) (data + EXTENDED_OFFSET + 4));
guchar *subchunk, *subchunk_next;
for (subchunk = chunk; subchunk < chunk + chunk_size;
subchunk = subchunk_next) {
guint8 tag = READ_INT8 (subchunk, 0);
guint8 type = READ_INT8 (subchunk, 1);
guint16 length = READ_INT16 (subchunk, 2);
guchar *value = subchunk + 4;
switch (type) {
case TYPE_LENGTH:
{
switch (tag) {
case TAG_TRACK:
info->track = READ_INT8 (subchunk, 2 + 1);
break;
case TAG_YEAR:
info->year = READ_INT16 (subchunk, 2);
break;
case TAG_COUNT:
info->loop_count = READ_INT8 (subchunk, 2);
break;
case TAG_EMULATOR:
info->emulator = READ_INT8 (subchunk, 2);
break;
case TAG_DISC:
info->disc = READ_INT8 (subchunk, 2);
break;
case TAG_MUTED:
info->muted = READ_INT8 (subchunk, 2);
break;
default:
break;
}
subchunk_next = subchunk + 4;
break;
}
case TYPE_STRING:
{
gchar *dest;
if (length <= 1)
dest = NULL;
else
switch (tag) {
case TAG_TITLE:
dest = info->title = g_renew (gchar, info->title, length);
break;
case TAG_GAME:
dest = info->game = g_renew (gchar, info->game, length);
break;
case TAG_ARTIST:
dest = info->artist = g_renew (gchar, info->artist, length);
break;
case TAG_ALBUM:
dest = info->album = g_renew (gchar, info->album, length);
break;
case TAG_DUMPER:
dest = info->dumper = g_renew (gchar, info->dumper, length);
break;
case TAG_COMMENT:
dest = info->comment = g_renew (gchar, info->comment, length);
break;
case TAG_PUBLISHER:
dest = info->publisher =
g_renew (gchar, info->publisher, length);
break;
default:
dest = NULL;
break;
}
if (dest)
strncpy (dest, (gchar *) value, length);
subchunk_next = value + length;
break;
}
case TYPE_INTEGER:
{
switch (tag) {
case TAG_INTRO:
info->time_intro = READ_INT32 (value, 0);
break;
case TAG_END:
info->time_end = READ_INT32 (value, 0);
break;
case TAG_FADE:
info->time_fade = READ_INT32 (value, 0);
break;
case TAG_LOOP:
info->time_loop = READ_INT32 (value, 0);
break;
case TAG_DUMP_DATE:
info->dump_date = spc_tag_unpack_date (READ_INT32 (value, 0));
break;
case TAG_AMP:
info->amplification = READ_INT32 (value, 0);
break;
default:
break;
}
subchunk_next = value + length;
break;
}
default:
subchunk_next = value + length;
break;
}
}
}
if (info->title && !*info->title) {
g_free (info->title);
info->title = NULL;
}
if (info->game && !*info->game) {
g_free (info->game);
info->game = NULL;
}
if (info->artist && !*info->artist) {
g_free (info->artist);
info->artist = NULL;
}
if (info->album && !*info->album) {
g_free (info->album);
info->album = NULL;
}
if (info->publisher && !*info->publisher) {
g_free (info->publisher);
info->publisher = NULL;
}
if (info->comment && !*info->comment) {
g_free (info->comment);
info->comment = NULL;
}
if (info->dumper && !*info->dumper) {
g_free (info->dumper);
info->dumper = NULL;
}
}
void
spc_tag_free (spc_tag_info * info)
{
if (info->title)
g_free (info->title);
if (info->game)
g_free (info->game);
if (info->artist)
g_free (info->artist);
if (info->album)
g_free (info->album);
if (info->publisher)
g_free (info->publisher);
if (info->comment)
g_free (info->comment);
if (info->dumper)
g_free (info->dumper);
if (info->dump_date)
g_date_free (info->dump_date);
}