apps/metadata/adx.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2005 Dave Chapman
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21 #include <stdio.h>
  22 #include <string.h>
  23 #include <stdlib.h>
  24 #include <ctype.h>
  25 #include <inttypes.h>
  26
  27 #include "system.h"
  28 #include "metadata.h"
  29 #include "metadata_common.h"
  30 #include "metadata_parsers.h"
  31 #include "debug.h"
  32
  33 bool get_adx_metadata(int fd, struct mp3entry* id3)
  34 {
  35     /* Use the trackname part of the id3 structure as a temporary buffer */
  36     unsigned char * buf = (unsigned char *)id3->path;
  37     int chanstart, channels, read_bytes;
  38     int looping = 0, start_adr = 0, end_adr = 0;
  39
  40     /* try to get the basic header */
  41     if ((lseek(fd, 0, SEEK_SET) < 0)
  42         || ((read_bytes = read(fd, buf, 0x38)) < 0x38))
  43     {
  44         DEBUGF("lseek or read failed\n");
  45         return false;
  46     }
  47
  48     /* ADX starts with 0x80 */
  49     if (buf[0] != 0x80) {
  50         DEBUGF("get_adx_metadata: wrong first byte %c\n",buf[0]);
  51         return false;
  52     }
  53
  54     /* check for a reasonable offset */
  55     chanstart = ((buf[2] << 8) | buf[3]) + 4;
  56     if (chanstart > 4096) {
  57         DEBUGF("get_adx_metadata: bad chanstart %i\n", chanstart);
  58         return false;
  59     }
  60
  61     /* check for a workable number of channels */
  62     channels = buf[7];
  63     if (channels != 1 && channels != 2) {
  64         DEBUGF("get_adx_metadata: bad channel count %i\n",channels);
  65         return false;
  66     }
  67
  68     id3->frequency = get_long_be(&buf[8]);
  69     /* 32 samples per 18 bytes */
  70     id3->bitrate = id3->frequency * channels * 18 * 8 / 32 / 1000;
  71     id3->length = get_long_be(&buf[12]) / id3->frequency * 1000;
  72     id3->vbr = false;
  73     id3->filesize = filesize(fd);
  74
  75     /* get loop info */
  76     if (!memcmp(buf+0x10,"\x01\xF4\x03\x00",4)) {
  77         /* Soul Calibur 2 style (type 03) */
  78         DEBUGF("get_adx_metadata: type 03 found\n");
  79         /* check if header is too small for loop data */
  80         if (chanstart-6 < 0x2c) looping=0;
  81         else {
  82             looping = get_long_be(&buf[0x18]);
  83             end_adr = get_long_be(&buf[0x28]);
  84             start_adr = get_long_be(&buf[0x1c])/32*channels*18+chanstart;
  85         }
  86     } else if (!memcmp(buf+0x10,"\x01\xF4\x04\x00",4)) {
  87         /* Standard (type 04) */
  88         DEBUGF("get_adx_metadata: type 04 found\n");
  89         /* check if header is too small for loop data */
  90         if (chanstart-6 < 0x38) looping=0;
  91         else {
  92             looping = get_long_be(&buf[0x24]);
  93             end_adr = get_long_be(&buf[0x34]);
  94             start_adr = get_long_be(&buf[0x28])/32*channels*18+chanstart;
  95         }
  96     } else {
  97         DEBUGF("get_adx_metadata: error, couldn't determine ADX type\n");
  98         return false;
  99     }
 100
 101     if (looping) {
 102         /* 2 loops, 10 second fade */
 103         id3->length = (start_adr-chanstart + 2*(end_adr-start_adr))
 104                       *8 / id3->bitrate + 10000;
 105     }
 106
 107     /* try to get the channel header */
 108     if ((lseek(fd, chanstart-6, SEEK_SET) < 0)
 109         || ((read_bytes = read(fd, buf, 6)) < 6))
 110     {
 111         return false;
 112     }
 113
 114     /* check channel header */
 115     if (memcmp(buf, "(c)CRI", 6) != 0) return false;
 116
 117     return true;
 118 }