rockbox/apps/metadata/adx.c

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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2005 Dave Chapman
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <inttypes.h>
#include "system.h"
#include "id3.h"
#include "metadata_common.h"
#include "metadata_parsers.h"
#include "debug.h"
bool get_adx_metadata(int fd, struct mp3entry* id3)
{
/* Use the trackname part of the id3 structure as a temporary buffer */
unsigned char * buf = (unsigned char *)id3->path;
int chanstart, channels, read_bytes;
int looping = 0, start_adr = 0, end_adr = 0;
/* try to get the basic header */
if ((lseek(fd, 0, SEEK_SET) < 0)
|| ((read_bytes = read(fd, buf, 0x38)) < 0x38))
{
DEBUGF("lseek or read failed\n");
return false;
}
/* ADX starts with 0x80 */
if (buf[0] != 0x80) {
DEBUGF("get_adx_metadata: wrong first byte %c\n",buf[0]);
return false;
}
/* check for a reasonable offset */
chanstart = ((buf[2] << 8) | buf[3]) + 4;
if (chanstart > 4096) {
DEBUGF("get_adx_metadata: bad chanstart %i\n", chanstart);
return false;
}
/* check for a workable number of channels */
channels = buf[7];
if (channels != 1 && channels != 2) {
DEBUGF("get_adx_metadata: bad channel count %i\n",channels);
return false;
}
id3->frequency = get_long_be(&buf[8]);
/* 32 samples per 18 bytes */
id3->bitrate = id3->frequency * channels * 18 * 8 / 32 / 1000;
id3->length = get_long_be(&buf[12]) / id3->frequency * 1000;
id3->vbr = false;
id3->filesize = filesize(fd);
/* get loop info */
if (!memcmp(buf+0x10,"\x01\xF4\x03\x00",4)) {
/* Soul Calibur 2 style (type 03) */
DEBUGF("get_adx_metadata: type 03 found\n");
/* check if header is too small for loop data */
if (chanstart-6 < 0x2c) looping=0;
else {
looping = get_long_be(&buf[0x18]);
end_adr = get_long_be(&buf[0x28]);
start_adr = get_long_be(&buf[0x1c])/32*channels*18+chanstart;
}
} else if (!memcmp(buf+0x10,"\x01\xF4\x04\x00",4)) {
/* Standard (type 04) */
DEBUGF("get_adx_metadata: type 04 found\n");
/* check if header is too small for loop data */
if (chanstart-6 < 0x38) looping=0;
else {
looping = get_long_be(&buf[0x24]);
end_adr = get_long_be(&buf[0x34]);
start_adr = get_long_be(&buf[0x28])/32*channels*18+chanstart;
}
} else {
DEBUGF("get_adx_metadata: error, couldn't determine ADX type\n");
return false;
}
if (looping) {
/* 2 loops, 10 second fade */
id3->length = (start_adr-chanstart + 2*(end_adr-start_adr))
*8 / id3->bitrate + 10000;
}
/* try to get the channel header */
if ((lseek(fd, chanstart-6, SEEK_SET) < 0)
|| ((read_bytes = read(fd, buf, 6)) < 6))
{
return false;
}
/* check channel header */
if (memcmp(buf, "(c)CRI", 6) != 0) return false;
return true;
}