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/*
* id3v1.c
* Copyright 2013 John Lindgren
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions, and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions, and the following disclaimer in the documentation
* provided with the distribution.
*
* This software is provided "as is" and without any warranty, express or
* implied. In no event shall the authors be liable for any damages arising from
* the use of this software.
*/
#include <stdlib.h>
#include <string.h>
#include <glib.h> /* for g_strchomp */
#include <libaudcore/audstrings.h>
#include <libaudtag/builtin.h>
#pragma pack(push)
#pragma pack(1)
struct ID3v1Tag {
char header[3];
char title[30];
char artist[30];
char album[30];
char year[4];
char comment[30];
unsigned char genre;
};
struct ID3v1Ext {
char header[4];
char title[60];
char artist[60];
char album[60];
unsigned char speed;
char genre[30];
char start[6];
char end[6];
};
#pragma pack(pop)
namespace audtag {
static bool read_id3v1_tag (VFSFile & file, ID3v1Tag * tag)
{
if (file.fseek (-sizeof (ID3v1Tag), VFS_SEEK_END) < 0)
return false;
if (file.fread (tag, 1, sizeof (ID3v1Tag)) != sizeof (ID3v1Tag))
return false;
return ! strncmp (tag->header, "TAG", 3);
}
static bool read_id3v1_ext (VFSFile & file, ID3v1Ext * ext)
{
if (file.fseek (-(sizeof (ID3v1Ext) + sizeof (ID3v1Tag)), VFS_SEEK_END) < 0)
return false;
if (file.fread (ext, 1, sizeof (ID3v1Ext)) != sizeof (ID3v1Ext))
return false;
return ! strncmp (ext->header, "TAG+", 4);
}
bool ID3v1TagModule::can_handle_file (VFSFile & file)
{
ID3v1Tag tag;
return read_id3v1_tag (file, & tag);
}
static bool combine_string (Tuple & tuple, Tuple::Field field,
const char * str1, int size1, const char * str2, int size2)
{
StringBuf str = str_copy (str1, strlen_bounded (str1, size1));
str.insert (-1, str2, strlen_bounded (str2, size2));
g_strchomp (str);
str.resize (strlen (str));
if (! str.len ())
return false;
tuple.set_str (field, str);
return true;
}
bool ID3v1TagModule::read_tag (VFSFile & file, Tuple * ptuple, Index<char> * image)
{
if (! ptuple)
return true; // nothing to do
Tuple & tuple = * ptuple;
ID3v1Tag tag;
ID3v1Ext ext;
if (! read_id3v1_tag (file, & tag))
return false;
if (! read_id3v1_ext (file, & ext))
memset (& ext, 0, sizeof (ID3v1Ext));
combine_string (tuple, Tuple::Title, tag.title, sizeof tag.title, ext.title, sizeof ext.title);
combine_string (tuple, Tuple::Artist, tag.artist, sizeof tag.artist, ext.artist, sizeof ext.artist);
combine_string (tuple, Tuple::Album, tag.album, sizeof tag.album, ext.album, sizeof ext.album);
combine_string (tuple, Tuple::Comment, tag.comment, sizeof tag.comment, nullptr, 0);
StringBuf year = str_copy (tag.year, strlen_bounded (tag.year, 4));
if (atoi (year))
tuple.set_int (Tuple::Year, atoi (year));
if (! tag.comment[28] && tag.comment[29])
tuple.set_int (Tuple::Track, (unsigned char) tag.comment[29]);
if (! combine_string (tuple, Tuple::Genre, ext.genre, sizeof ext.genre, nullptr, 0))
{
const char * genre = convert_numericgenre_to_text (tag.genre);
if (genre)
tuple.set_str (Tuple::Genre, genre);
}
return true;
}
}
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