id3v2extractor.c

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/*
     This file is part of libextractor.
     (C) 2002, 2003, 2004, 2006 Vidyut Samanta and Christian Grothoff

     libextractor 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, or (at your
     option) any later version.

     libextractor 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
     General Public License for more details.

     You should have received a copy of the GNU General Public License
     along with libextractor; see the file COPYING.  If not, write to the
     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
     Boston, MA 02111-1307, USA.

 */

#include "platform.h"
#include "extractor.h"
#ifndef MINGW
#include <sys/mman.h>
#endif
#include "convert.h"

#define DEBUG_EXTRACT_ID3v2 0


static struct EXTRACTOR_Keywords *
addKeyword (EXTRACTOR_KeywordList * oldhead,
            char *phrase, EXTRACTOR_KeywordType type)
{
  EXTRACTOR_KeywordList *keyword;

  keyword = (EXTRACTOR_KeywordList *) malloc (sizeof (EXTRACTOR_KeywordList));
  keyword->next = oldhead;
  keyword->keyword = phrase;
  keyword->keywordType = type;
  return keyword;
}

typedef struct
{
  char *text;
  EXTRACTOR_KeywordType type;
} Matches;

static Matches tmap[] = {
  {"TAL", EXTRACTOR_TITLE},
  {"TT1", EXTRACTOR_GROUP},
  {"TT2", EXTRACTOR_TITLE},
  {"TT3", EXTRACTOR_TITLE},
  {"TXT", EXTRACTOR_DESCRIPTION},
  {"TPB", EXTRACTOR_PUBLISHER},
  {"WAF", EXTRACTOR_LOCATION},
  {"WAR", EXTRACTOR_LOCATION},
  {"WAS", EXTRACTOR_LOCATION},
  {"WCP", EXTRACTOR_COPYRIGHT},
  {"WAF", EXTRACTOR_LOCATION},
  {"WCM", EXTRACTOR_DISCLAIMER},
  {"TSS", EXTRACTOR_FORMAT},
  {"TYE", EXTRACTOR_DATE},
  {"TLA", EXTRACTOR_LANGUAGE},
  {"TP1", EXTRACTOR_ARTIST},
  {"TP2", EXTRACTOR_ARTIST},
  {"TP3", EXTRACTOR_CONDUCTOR},
  {"TP4", EXTRACTOR_INTERPRET},
  {"IPL", EXTRACTOR_CONTRIBUTOR},
  {"TOF", EXTRACTOR_FILENAME},
  {"TEN", EXTRACTOR_PRODUCER},
  {"TCO", EXTRACTOR_SUBJECT},
  {"TCR", EXTRACTOR_COPYRIGHT},
  {"SLT", EXTRACTOR_LYRICS},
  {"TOA", EXTRACTOR_ARTIST},
  {"TRC", EXTRACTOR_ISRC},
  {"TRK", EXTRACTOR_TRACK_NUMBER},
  {"TCM", EXTRACTOR_CREATOR},
  {"TOT", EXTRACTOR_ALBUM},
  {"TOL", EXTRACTOR_AUTHOR},
  {"COM", EXTRACTOR_COMMENT},
  {"", EXTRACTOR_KEYWORDS},
  {NULL, 0},
};


/* mimetype = audio/mpeg */
struct EXTRACTOR_Keywords *
libextractor_id3v2_extract (const char *filename,
                            const unsigned char *data,
                            size_t size, struct EXTRACTOR_Keywords *prev)
{
  int unsync;
  unsigned int tsize;
  unsigned int pos;

  if ((size < 16) ||
      (data[0] != 0x49) ||
      (data[1] != 0x44) ||
      (data[2] != 0x33) || (data[3] != 0x02) || (data[4] != 0x00))
    return prev;
  unsync = (data[5] & 0x80) > 0;
  tsize = (((data[6] & 0x7F) << 21) |
           ((data[7] & 0x7F) << 14) |
           ((data[8] & 0x7F) << 07) | ((data[9] & 0x7F) << 00));

  if (tsize + 10 > size)
    return prev;
  pos = 10;
  while (pos < tsize)
    {
      size_t csize;
      int i;

      if (pos + 6 > tsize)
        return prev;
      csize = (data[pos + 3] << 16) + (data[pos + 4] << 8) + data[pos + 5];
      if ((pos + 6 + csize > tsize) || (csize > tsize) || (csize == 0))
        break;
      i = 0;
      while (tmap[i].text != NULL)
        {
          if (0 == strncmp (tmap[i].text, (const char *) &data[pos], 3))
            {
              char *word;
              /* this byte describes the encoding
                 try to convert strings to UTF-8
                 if it fails, then forget it */
              switch (data[pos + 6])
                {
                case 0x00:
                  word = EXTRACTOR_common_convert_to_utf8 ((const char *) &data[pos + 7],
                                        csize, "ISO-8859-1");
                  break;
                case 0x01:
                  word = EXTRACTOR_common_convert_to_utf8 ((const char *) &data[pos + 7],
                                        csize, "UCS-2");
                  break;
                default:
                  /* bad encoding byte,
                     try to convert from iso-8859-1 */
                  word = EXTRACTOR_common_convert_to_utf8 ((const char *) &data[pos + 7],
                                        csize, "ISO-8859-1");
                  break;
                }
              pos++;
              csize--;
              if ((word != NULL) && (strlen (word) > 0))
                {
                  prev = addKeyword (prev, word, tmap[i].type);
                }
              else
                {
                  free (word);
                }
              break;
            }
          i++;
        }
      pos += 6 + csize;
    }
  return prev;
}

/* end of id3v2extractor.c */

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