text: /***************************************************************************
   *             __________               __   ___.
   *   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 <stdlib.h>
  #include <ctype.h>
  #include <inttypes.h>
  #include "platform.h"
  
  #include "metadata.h"
  #include <string-extra.h>
  #include "metadata_common.h"
  #include "metadata_parsers.h"
  #include "rbunicode.h"
  
  #define MODULEHEADERSIZE 0x438
  
  bool get_mod_metadata(int fd, struct mp3entry* id3)
  {    
      /* Use the trackname part of the id3 structure as a temporary buffer */
      unsigned char *buf = id3->id3v2buf;
      unsigned char id[4];
      bool is_mod_file = false;
  
      /* Seek to file begin */
      if (lseek(fd, 0, SEEK_SET) < 0)
          return false;
      /* Use id3v2buf as buffer for the track name */
      if (read(fd, buf, sizeof(id3->id3v2buf)) < (ssize_t)sizeof(id3->id3v2buf))
          return false;
      /* Seek to MOD ID position */
      if (lseek(fd, MODULEHEADERSIZE, SEEK_SET) < 0)
          return false;
      /* Read MOD ID */
      if (read(fd, id, sizeof(id)) < (ssize_t)sizeof(id))
          return false;
  
      /* Mod type checking based on MikMod */
      /* Protracker and variants */
      if ((!memcmp(id, "M.K.", 4)) || (!memcmp(id, "M!K!", 4))) {
          is_mod_file = true;
      }
      
      /* Star Tracker */
      if (((!memcmp(id, "FLT", 3)) || (!memcmp(id, "EXO", 3))) &&
          (isdigit(id[3]))) {
          char numchn = id[3] - '0';
          if (numchn == 4 || numchn == 8)
              is_mod_file = true;
      }
  
      /* Oktalyzer (Amiga) */
      if (!memcmp(id, "OKTA", 4)) {
          is_mod_file = true;
      }
  
      /* Oktalyser (Atari) */
      if (!memcmp(id, "CD81", 4)) {
          is_mod_file = true;
      }
  
      /* Fasttracker */
      if ((!memcmp(id + 1, "CHN", 3)) && (isdigit(id[0]))) {
          is_mod_file = true;
      }
      /* Fasttracker or Taketracker */
      if (((!memcmp(id + 2, "CH", 2)) || (!memcmp(id + 2, "CN", 2)))
          && (isdigit(id[0])) && (isdigit(id[1]))) {
          is_mod_file = true;
      }
  
      /* Don't try to play if we can't find a known mod type
       * (there are mod files which have nothing to do with music) */
      if (!is_mod_file)
          return false;
  
      id3->title = id3->id3v2buf; /* Point title to previous read ID3 buffer. */
      id3->bitrate = filesize(fd)/1024; /* size in kb */
      id3->frequency = 44100;
      id3->length = 120*1000;
      id3->vbr = false;
      id3->filesize = filesize(fd);
          
      return true;
  }
  
  