Statistics
| Branch: | Revision:

ffmpeg / libavformat / apetag.c @ 12ad6671

History | View | Annotate | Download (3.15 KB)

1
/*
2
 * APE tag handling
3
 * Copyright (c) 2007 Benjamin Zores <ben@geexbox.org>
4
 *  based upon libdemac from Dave Chapman.
5
 *
6
 * This file is part of FFmpeg.
7
 *
8
 * FFmpeg is free software; you can redistribute it and/or
9
 * modify it under the terms of the GNU Lesser General Public
10
 * License as published by the Free Software Foundation; either
11
 * version 2.1 of the License, or (at your option) any later version.
12
 *
13
 * FFmpeg is distributed in the hope that it will be useful,
14
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16
 * Lesser General Public License for more details.
17
 *
18
 * You should have received a copy of the GNU Lesser General Public
19
 * License along with FFmpeg; if not, write to the Free Software
20
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21
 */
22

    
23
#include "libavutil/intreadwrite.h"
24
#include "avformat.h"
25

    
26
#define ENABLE_DEBUG 0
27

    
28
#define APE_TAG_VERSION               2000
29
#define APE_TAG_FOOTER_BYTES          32
30
#define APE_TAG_FLAG_CONTAINS_HEADER  (1 << 31)
31
#define APE_TAG_FLAG_IS_HEADER        (1 << 29)
32

    
33
static int ape_tag_read_field(AVFormatContext *s)
34
{
35
    ByteIOContext *pb = s->pb;
36
    uint8_t key[1024], *value;
37
    uint32_t size, flags;
38
    int i, l, c;
39

    
40
    size = get_le32(pb);  /* field size */
41
    flags = get_le32(pb); /* field flags */
42
    for (i = 0; i < sizeof(key) - 1; i++) {
43
        c = get_byte(pb);
44
        if (c < 0x20 || c > 0x7E)
45
            break;
46
        else
47
            key[i] = c;
48
    }
49
    key[i] = 0;
50
    if (c != 0) {
51
        av_log(s, AV_LOG_WARNING, "Invalid APE tag key '%s'.\n", key);
52
        return -1;
53
    }
54
    if (size >= UINT_MAX)
55
        return -1;
56
    value = av_malloc(size+1);
57
    if (!value)
58
        return AVERROR_NOMEM;
59
    get_buffer(pb, value, size);
60
    value[size] = 0;
61
    av_metadata_set2(&s->metadata, key, value, AV_METADATA_DONT_STRDUP_VAL);
62
    return 0;
63
}
64

    
65
void ff_ape_parse_tag(AVFormatContext *s)
66
{
67
    ByteIOContext *pb = s->pb;
68
    int file_size = url_fsize(pb);
69
    uint32_t val, fields, tag_bytes;
70
    uint8_t buf[8];
71
    int i;
72

    
73
    if (file_size < APE_TAG_FOOTER_BYTES)
74
        return;
75

    
76
    url_fseek(pb, file_size - APE_TAG_FOOTER_BYTES, SEEK_SET);
77

    
78
    get_buffer(pb, buf, 8);    /* APETAGEX */
79
    if (strncmp(buf, "APETAGEX", 8)) {
80
        return;
81
    }
82

    
83
    val = get_le32(pb);        /* APE tag version */
84
    if (val > APE_TAG_VERSION) {
85
        av_log(s, AV_LOG_ERROR, "Unsupported tag version. (>=%d)\n", APE_TAG_VERSION);
86
        return;
87
    }
88

    
89
    tag_bytes = get_le32(pb);  /* tag size */
90
    if (tag_bytes - APE_TAG_FOOTER_BYTES > (1024 * 1024 * 16)) {
91
        av_log(s, AV_LOG_ERROR, "Tag size is way too big\n");
92
        return;
93
    }
94

    
95
    fields = get_le32(pb);     /* number of fields */
96
    if (fields > 65536) {
97
        av_log(s, AV_LOG_ERROR, "Too many tag fields (%d)\n", fields);
98
        return;
99
    }
100

    
101
    val = get_le32(pb);        /* flags */
102
    if (val & APE_TAG_FLAG_IS_HEADER) {
103
        av_log(s, AV_LOG_ERROR, "APE Tag is a header\n");
104
        return;
105
    }
106

    
107
    url_fseek(pb, file_size - tag_bytes, SEEK_SET);
108

    
109
    for (i=0; i<fields; i++)
110
        if (ape_tag_read_field(s) < 0) break;
111
}