aboutsummaryrefslogtreecommitdiffstats
path: root/libavformat/flac_picture.c
blob: 53e24b28b741bfe50da87c2e7b86b490c1e49032 (plain) (blame)
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
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
/*
 * Raw FLAC picture parser
 * Copyright (c) 2001 Fabrice Bellard
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg 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.
 *
 * FFmpeg 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 FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "libavutil/intreadwrite.h"
#include "libavcodec/bytestream.h"
#include "libavcodec/png.h"
#include "avformat.h"
#include "flac_picture.h"
#include "id3v2.h"
#include "internal.h"

#define MAX_TRUNC_PICTURE_SIZE (500 * 1024 * 1024)

int ff_flac_parse_picture(AVFormatContext *s, uint8_t *buf, int buf_size, int truncate_workaround)
{
    const CodecMime *mime = ff_id3v2_mime_tags;
    enum AVCodecID id = AV_CODEC_ID_NONE;
    AVBufferRef *data = NULL;
    uint8_t mimetype[64], *desc = NULL;
    GetByteContext g;
    AVStream *st;
    int width, height, ret = 0;
    unsigned int type;
    uint32_t len, left, trunclen = 0;

    if (buf_size < 34) {
        av_log(s, AV_LOG_ERROR, "Attached picture metadata block too short\n");
        if (s->error_recognition & AV_EF_EXPLODE)
            return AVERROR_INVALIDDATA;
        return 0;
    }

    bytestream2_init(&g, buf, buf_size);

    /* read the picture type */
    type = bytestream2_get_be32u(&g);
    if (type >= FF_ARRAY_ELEMS(ff_id3v2_picture_types)) {
        av_log(s, AV_LOG_ERROR, "Invalid picture type: %d.\n", type);
        if (s->error_recognition & AV_EF_EXPLODE) {
            return AVERROR_INVALIDDATA;
        }
        type = 0;
    }

    /* picture mimetype */
    len = bytestream2_get_be32u(&g);
    if (len <= 0 || len >= sizeof(mimetype)) {
        av_log(s, AV_LOG_ERROR, "Could not read mimetype from an attached "
               "picture.\n");
        if (s->error_recognition & AV_EF_EXPLODE)
            return AVERROR_INVALIDDATA;
        return 0;
    }
    if (len + 24 > bytestream2_get_bytes_left(&g)) {
        av_log(s, AV_LOG_ERROR, "Attached picture metadata block too short\n");
        if (s->error_recognition & AV_EF_EXPLODE)
            return AVERROR_INVALIDDATA;
        return 0;
    }
    bytestream2_get_bufferu(&g, mimetype, len);
    mimetype[len] = 0;

    while (mime->id != AV_CODEC_ID_NONE) {
        if (!strncmp(mime->str, mimetype, sizeof(mimetype))) {
            id = mime->id;
            break;
        }
        mime++;
    }
    if (id == AV_CODEC_ID_NONE) {
        av_log(s, AV_LOG_ERROR, "Unknown attached picture mimetype: %s.\n",
               mimetype);
        if (s->error_recognition & AV_EF_EXPLODE)
            return AVERROR_INVALIDDATA;
        return 0;
    }

    /* picture description */
    len = bytestream2_get_be32u(&g);
    if (len > bytestream2_get_bytes_left(&g) - 20) {
        av_log(s, AV_LOG_ERROR, "Attached picture metadata block too short\n");
        if (s->error_recognition & AV_EF_EXPLODE)
            return AVERROR_INVALIDDATA;
        return 0;
    }
    if (len > 0) {
        if (!(desc = av_malloc(len + 1))) {
            return AVERROR(ENOMEM);
        }

        bytestream2_get_bufferu(&g, desc, len);
        desc[len] = 0;
    }

    /* picture metadata */
    width  = bytestream2_get_be32u(&g);
    height = bytestream2_get_be32u(&g);
    bytestream2_skipu(&g, 8);

    /* picture data */
    len = bytestream2_get_be32u(&g);

    left = bytestream2_get_bytes_left(&g);
    if (len <= 0 || len > left) {
        if (len > MAX_TRUNC_PICTURE_SIZE || len >= INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE) {
            av_log(s, AV_LOG_ERROR, "Attached picture metadata block too big %u\n", len);
            if (s->error_recognition & AV_EF_EXPLODE)
                ret = AVERROR_INVALIDDATA;
            goto fail;
        }

        // Workaround bug for flac muxers that writs truncated metadata picture block size if
        // the picture size do not fit in 24 bits. lavf flacenc used to have the issue and based
        // on existing broken files other unknown flac muxers seems to truncate also.
        if (truncate_workaround &&
            s->strict_std_compliance <= FF_COMPLIANCE_NORMAL &&
            len > left && (len & 0xffffff) == left) {
            av_log(s, AV_LOG_INFO, "Correcting truncated metadata picture size from %u to %u\n", left, len);
            trunclen = len - left;
        } else {
            av_log(s, AV_LOG_ERROR, "Attached picture metadata block too short\n");
            if (s->error_recognition & AV_EF_EXPLODE)
                ret = AVERROR_INVALIDDATA;
            goto fail;
        }
    }
    if (!(data = av_buffer_alloc(len + AV_INPUT_BUFFER_PADDING_SIZE))) {
        RETURN_ERROR(AVERROR(ENOMEM));
    }

    if (trunclen == 0) {
        bytestream2_get_bufferu(&g, data->data, len);
    } else {
        // If truncation was detected copy all data from block and read missing bytes
        // not included in the block size
        bytestream2_get_bufferu(&g, data->data, left);
        if (avio_read(s->pb, data->data + len - trunclen, trunclen) < trunclen)
            RETURN_ERROR(AVERROR_INVALIDDATA);
    }
    memset(data->data + len, 0, AV_INPUT_BUFFER_PADDING_SIZE);

    if (AV_RB64(data->data) == PNGSIG)
        id = AV_CODEC_ID_PNG;

    st = avformat_new_stream(s, NULL);
    if (!st) {
        RETURN_ERROR(AVERROR(ENOMEM));
    }

    av_init_packet(&st->attached_pic);
    st->attached_pic.buf          = data;
    st->attached_pic.data         = data->data;
    st->attached_pic.size         = len;
    st->attached_pic.stream_index = st->index;
    st->attached_pic.flags       |= AV_PKT_FLAG_KEY;

    st->disposition      |= AV_DISPOSITION_ATTACHED_PIC;
    st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
    st->codecpar->codec_id   = id;
    st->codecpar->width      = width;
    st->codecpar->height     = height;
    av_dict_set(&st->metadata, "comment", ff_id3v2_picture_types[type], 0);
    if (desc)
        av_dict_set(&st->metadata, "title", desc, AV_DICT_DONT_STRDUP_VAL);

    return 0;

fail:
    av_buffer_unref(&data);
    av_freep(&desc);

    return ret;
}