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