libextractor

GNU libextractor
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it_extractor.c (3166B)

      1 /*
      2  * This file is part of libextractor.
      3  * Copyright (C) 2008 Toni Ruottu
      4  *
      5  * libextractor is free software; you can redistribute it and/or modify
      6  * it under the terms of the GNU General Public License as published
      7  * by the Free Software Foundation; either version 3, or (at your
      8  * option) any later version.
      9  *
     10  * libextractor is distributed in the hope that it will be useful, but
     11  * WITHOUT ANY WARRANTY; without even the implied warranty of
     12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     13  * General Public License for more details.
     14  *
     15  * You should have received a copy of the GNU General Public License
     16  * along with libextractor; see the file COPYING.  If not, write to the
     17  * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     18  * Boston, MA 02110-1301, USA.
     19  *
     20  */
     21 /**
     22  * @file plugins/xm_extractor.c
     23  * @brief plugin to support Impulse Tracker (IT) files
     24  * @author Toni Ruottu
     25  * @author Christian Grothoff
     26  */
     27 #include "platform.h"
     28 #include "extractor.h"
     29 
     30 
     31 /**
     32  * Number of bytes in the full IT header and thus
     33  * the minimum size we're going to accept for an IT file.
     34  */
     35 #define HEADER_SIZE  0xD0
     36 
     37 
     38 /**
     39  * Header of an IT file.
     40  */
     41 struct Header
     42 {
     43   char magicid[4];
     44   char title[26];
     45   char hilight[2];
     46   char orders[2];
     47   char instruments[2];
     48   char samples[2];
     49   char patterns[2];
     50   char version[2];
     51   char compatible[2];
     52   char flags[2];
     53   char special[2];
     54 };
     55 
     56 
     57 /**
     58  * extract meta data from an Impulse Tracker module
     59  *
     60  * ITTECH.TXT as taken from IT 2.14p5 was used, while this piece of
     61  * software was originally written.
     62  *
     63  * @param ec extraction context
     64  */
     65 void
     66 EXTRACTOR_it_extract_method (struct EXTRACTOR_ExtractContext *ec)
     67 {
     68   void *data;
     69   char title[27];
     70   char itversion[8];
     71   const struct Header *head;
     72 
     73   if ((ssize_t) HEADER_SIZE >
     74       ec->read (ec->cls,
     75                 &data,
     76                 HEADER_SIZE))
     77     return;
     78   head = (struct Header *) data;
     79   /* Check "magic" id bytes */
     80   if (memcmp (head->magicid, "IMPM", 4))
     81     return;
     82   /* Mime-type */
     83   if (0 != ec->proc (ec->cls,
     84                      "it",
     85                      EXTRACTOR_METATYPE_MIMETYPE,
     86                      EXTRACTOR_METAFORMAT_UTF8,
     87                      "text/plain",
     88                      "audio/x-mod",
     89                      strlen ("audio/x-mod") + 1))
     90     return;
     91 
     92   /* Version of Tracker */
     93   snprintf (itversion,
     94             sizeof (itversion),
     95             "%d.%d",
     96             (head->version[0] & 0x01),
     97             head->version[1]);
     98   if (0 != ec->proc (ec->cls,
     99                      "it",
    100                      EXTRACTOR_METATYPE_FORMAT_VERSION,
    101                      EXTRACTOR_METAFORMAT_C_STRING,
    102                      "text/plain",
    103                      itversion,
    104                      strlen (itversion) + 1))
    105     return;
    106 
    107   /* Song title */
    108   memcpy (&title, head->title, 26);
    109   title[26] = '\0';
    110   if (0 != ec->proc (ec->cls,
    111                      "it",
    112                      EXTRACTOR_METATYPE_TITLE,
    113                      EXTRACTOR_METAFORMAT_C_STRING,
    114                      "text/plain",
    115                      title,
    116                      strlen (title) + 1))
    117     return;
    118 }
    119 
    120 
    121 /* end of it_extractor.c */