summaryrefslogtreecommitdiffstats
path: root/apps/plugins/lib/mul_id3.c
blob: c40a495ecd2fc47e5a9e6fcc19500860f55a374d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2023 Christian Soffke
 *
 * 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 "plugin.h"
#include "mul_id3.h"

struct multiple_tracks_id3 {
    unsigned long long filesize;
    unsigned long long length;
    unsigned long frequency;
    unsigned int artist_hash;
    unsigned int composer_hash;
    unsigned int albumartist_hash;
    unsigned int grouping_hash;
    unsigned int comment_hash;
    unsigned int album_hash;
    unsigned int genre_hash;
    unsigned int codectype;
    unsigned int bitrate;
    int year;
    bool vbr;
};

static struct multiple_tracks_id3 mul_id3;


/* Calculate modified FNV hash of string
 * has good avalanche behaviour and uniform distribution
 * see http://home.comcast.net/~bretm/hash/ */
static unsigned int mfnv(char *str)
{
    const unsigned int p = 16777619;
    unsigned int hash = 0x811C9DC5; // 2166136261;

    if (!str)
        return 0;

    while(*str)
        hash = (hash ^ *str++) * p;
    hash += hash << 13;
    hash ^= hash >> 7;
    hash += hash << 3;
    hash ^= hash >> 17;
    hash += hash << 5;
    return hash;
}

static void init_mul_id3(void)
{
    mul_id3.artist_hash = 0;
    mul_id3.album_hash = 0;
    mul_id3.genre_hash = 0;
    mul_id3.composer_hash = 0;
    mul_id3.albumartist_hash = 0;
    mul_id3.grouping_hash = 0;
    mul_id3.comment_hash = 0;
    mul_id3.codectype = 0;
    mul_id3.vbr = false;
    mul_id3.bitrate = 0;
    mul_id3.frequency = 0;
    mul_id3.length = 0;
    mul_id3.filesize = 0;
    mul_id3.year = 0;
}

void collect_id3(struct mp3entry *id3, bool is_first_track)
{
    if (is_first_track)
    {
        init_mul_id3();
        mul_id3.artist_hash = mfnv(id3->artist);
        mul_id3.album_hash = mfnv(id3->album);
        mul_id3.genre_hash = mfnv(id3->genre_string);
        mul_id3.composer_hash = mfnv(id3->composer);
        mul_id3.albumartist_hash = mfnv(id3->albumartist);
        mul_id3.grouping_hash = mfnv(id3->grouping);
        mul_id3.comment_hash = mfnv(id3->comment);
        mul_id3.codectype = id3->codectype;
        mul_id3.vbr = id3->vbr;
        mul_id3.bitrate = id3->bitrate;
        mul_id3.frequency = id3->frequency;
        mul_id3.year = id3->year;
    }
    else
    {
        if (mul_id3.artist_hash && (mfnv(id3->artist) != mul_id3.artist_hash))
            mul_id3.artist_hash = 0;
        if (mul_id3.album_hash && (mfnv(id3->album) != mul_id3.album_hash))
            mul_id3.album_hash = 0;
        if (mul_id3.genre_hash && (mfnv(id3->genre_string) != mul_id3.genre_hash))
            mul_id3.genre_hash = 0;
        if (mul_id3.composer_hash && (mfnv(id3->composer) != mul_id3.composer_hash))
            mul_id3.composer_hash = 0;
        if (mul_id3.albumartist_hash && (mfnv(id3->albumartist) !=
                                          mul_id3.albumartist_hash))
            mul_id3.albumartist_hash = 0;
        if (mul_id3.grouping_hash && (mfnv(id3->grouping) != mul_id3.grouping_hash))
            mul_id3.grouping_hash = 0;
        if (mul_id3.comment_hash && (mfnv(id3->comment) != mul_id3.comment_hash))
            mul_id3.comment_hash = 0;

        if (mul_id3.codectype && (id3->codectype != mul_id3.codectype))
            mul_id3.codectype = AFMT_UNKNOWN;
        if (mul_id3.bitrate && (id3->bitrate != mul_id3.bitrate ||
                                 id3->vbr != mul_id3.vbr))
            mul_id3.bitrate = 0;
        if (mul_id3.frequency && (id3->frequency != mul_id3.frequency))
            mul_id3.frequency = 0;
        if (mul_id3.year && (id3->year != mul_id3.year))
            mul_id3.year = 0;
    }
    mul_id3.length += id3->length;
    mul_id3.filesize += id3->filesize;
}

/* (!) Note scale factor applied to returned metadata:
 *     - Unit for filesize will be KiB instead of Bytes
 *     - Unit for length will be s instead of ms
 *
 *     Use result only as input for browse_id3,
 *     and set multiple_tracks parameter to true.
 */
void finalize_id3(struct mp3entry *id3)
{
    id3->path[0] = '\0';
    id3->title = NULL;
    if (!mul_id3.artist_hash)
        id3->artist = NULL;
    if (!mul_id3.album_hash)
        id3->album = NULL;
    if (!mul_id3.genre_hash)
        id3->genre_string = NULL;
    if (!mul_id3.composer_hash)
        id3->composer = NULL;
    if (!mul_id3.albumartist_hash)
        id3->albumartist = NULL;
    if (!mul_id3.grouping_hash)
        id3->grouping = NULL;
    if (!mul_id3.comment_hash)
        id3->comment = NULL;
    id3->disc_string = NULL;
    id3->track_string = NULL;
    id3->year_string = NULL;
    id3->year = mul_id3.year;
    mul_id3.length /= 1000;
    mul_id3.filesize >>= 10;
    id3->length = mul_id3.length > ULONG_MAX ? 0 : mul_id3.length;
    id3->filesize = mul_id3.filesize > INT_MAX ? 0 : mul_id3.filesize;
    id3->frequency = mul_id3.frequency;
    id3->bitrate = mul_id3.bitrate;
    id3->codectype = mul_id3.codectype;
    id3->vbr = mul_id3.vbr;
    id3->discnum = 0;
    id3->tracknum = 0;
    id3->track_level = 0;
    id3->album_level = 0;
}