summaryrefslogtreecommitdiff
path: root/libavformat/id3v2enc.c
blob: 36c73bfecbcd2975b4a81190fef264ebb76a73d5 (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
/*
 * ID3v2 header writer
 *
 * This file is part of Libav.
 *
 * Libav is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * Libav 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <stdint.h>

#include "libavutil/dict.h"
#include "libavutil/intreadwrite.h"
#include "avformat.h"
#include "avio.h"
#include "id3v2.h"

static void id3v2_put_size(AVFormatContext *s, int size)
{
    avio_w8(s->pb, size >> 21 & 0x7f);
    avio_w8(s->pb, size >> 14 & 0x7f);
    avio_w8(s->pb, size >> 7  & 0x7f);
    avio_w8(s->pb, size       & 0x7f);
}

static int string_is_ascii(const uint8_t *str)
{
    while (*str && *str < 128) str++;
    return !*str;
}

/**
 * Write a text frame with one (normal frames) or two (TXXX frames) strings
 * according to encoding (only UTF-8 or UTF-16+BOM supported).
 * @return number of bytes written or a negative error code.
 */
static int id3v2_put_ttag(AVFormatContext *s, const char *str1, const char *str2,
                          uint32_t tag, enum ID3v2Encoding enc)
{
    int len;
    uint8_t *pb;
    int (*put)(AVIOContext*, const char*);
    AVIOContext *dyn_buf;
    if (avio_open_dyn_buf(&dyn_buf) < 0)
        return AVERROR(ENOMEM);

    /* check if the strings are ASCII-only and use UTF16 only if
     * they're not */
    if (enc == ID3v2_ENCODING_UTF16BOM && string_is_ascii(str1) &&
        (!str2 || string_is_ascii(str2)))
        enc = ID3v2_ENCODING_ISO8859;

    avio_w8(dyn_buf, enc);
    if (enc == ID3v2_ENCODING_UTF16BOM) {
        avio_wl16(dyn_buf, 0xFEFF);      /* BOM */
        put = avio_put_str16le;
    } else
        put = avio_put_str;

    put(dyn_buf, str1);
    if (str2)
        put(dyn_buf, str2);
    len = avio_close_dyn_buf(dyn_buf, &pb);

    avio_wb32(s->pb, tag);
    id3v2_put_size(s, len);
    avio_wb16(s->pb, 0);
    avio_write(s->pb, pb, len);

    av_freep(&pb);
    return len + ID3v2_HEADER_SIZE;
}

static int id3v2_check_write_tag(AVFormatContext *s, AVDictionaryEntry *t, const char table[][4],
                                 enum ID3v2Encoding enc)
{
    uint32_t tag;
    int i;

    if (t->key[0] != 'T' || strlen(t->key) != 4)
        return -1;
    tag = AV_RB32(t->key);
    for (i = 0; *table[i]; i++)
        if (tag == AV_RB32(table[i]))
            return id3v2_put_ttag(s, t->value, NULL, tag, enc);
    return -1;
}

int ff_id3v2_write(struct AVFormatContext *s, int id3v2_version,
                   const char *magic)
{
    int64_t size_pos, cur_pos;
    AVDictionaryEntry *t = NULL;

    int totlen = 0, enc = id3v2_version == 3 ? ID3v2_ENCODING_UTF16BOM :
                                               ID3v2_ENCODING_UTF8;


    avio_wb32(s->pb, MKBETAG(magic[0], magic[1], magic[2], id3v2_version));
    avio_w8(s->pb, 0);
    avio_w8(s->pb, 0); /* flags */

    /* reserve space for size */
    size_pos = avio_tell(s->pb);
    avio_wb32(s->pb, 0);

    ff_metadata_conv(&s->metadata, ff_id3v2_34_metadata_conv, NULL);
    if (id3v2_version == 4)
        ff_metadata_conv(&s->metadata, ff_id3v2_4_metadata_conv, NULL);

    while ((t = av_dict_get(s->metadata, "", t, AV_DICT_IGNORE_SUFFIX))) {
        int ret;

        if ((ret = id3v2_check_write_tag(s, t, ff_id3v2_tags, enc)) > 0) {
            totlen += ret;
            continue;
        }
        if ((ret = id3v2_check_write_tag(s, t, id3v2_version == 3 ?
                                               ff_id3v2_3_tags : ff_id3v2_4_tags, enc)) > 0) {
            totlen += ret;
            continue;
        }

        /* unknown tag, write as TXXX frame */
        if ((ret = id3v2_put_ttag(s, t->key, t->value, MKBETAG('T', 'X', 'X', 'X'), enc)) < 0)
            return ret;
        totlen += ret;
    }

    cur_pos = avio_tell(s->pb);
    avio_seek(s->pb, size_pos, SEEK_SET);
    id3v2_put_size(s, totlen);
    avio_seek(s->pb, cur_pos, SEEK_SET);
    return 0;
}