GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/webp_parser.c Lines: 41 48 85.4 %
Date: 2020-10-23 17:01:47 Branches: 21 30 70.0 %

Line Branch Exec Source
1
/*
2
 * WebP parser
3
 *
4
 * This file is part of FFmpeg.
5
 *
6
 * FFmpeg is free software; you can redistribute it and/or
7
 * modify it under the terms of the GNU Lesser General Public
8
 * License as published by the Free Software Foundation; either
9
 * version 2.1 of the License, or (at your option) any later version.
10
 *
11
 * FFmpeg is distributed in the hope that it will be useful,
12
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14
 * Lesser General Public License for more details.
15
 *
16
 * You should have received a copy of the GNU Lesser General Public
17
 * License along with FFmpeg; if not, write to the Free Software
18
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19
 */
20
21
/**
22
 * @file
23
 * WebP parser
24
 */
25
26
#include "libavutil/bswap.h"
27
#include "libavutil/common.h"
28
29
#include "parser.h"
30
31
typedef struct WebPParseContext {
32
    ParseContext pc;
33
    uint32_t fsize;
34
    uint32_t remaining_size;
35
} WebPParseContext;
36
37
42
static int webp_parse(AVCodecParserContext *s, AVCodecContext *avctx,
38
                      const uint8_t **poutbuf, int *poutbuf_size,
39
                      const uint8_t *buf, int buf_size)
40
{
41
42
    WebPParseContext *ctx = s->priv_data;
42
42
    uint64_t state = ctx->pc.state64;
43
42
    int next = END_NOT_FOUND;
44
42
    int i = 0;
45
46
42
    *poutbuf      = NULL;
47
42
    *poutbuf_size = 0;
48
49
56
restart:
50
56
    if (ctx->pc.frame_start_found <= 8) {
51
133
        for (; i < buf_size; i++) {
52
112
            state = (state << 8) | buf[i];
53
112
            if (ctx->pc.frame_start_found == 0) {
54
56
                if ((state >> 32) == MKBETAG('R', 'I', 'F', 'F')) {
55
7
                    ctx->fsize = av_bswap32(state);
56

7
                    if (ctx->fsize > 15 && ctx->fsize <= UINT32_MAX - 10) {
57
7
                        ctx->pc.frame_start_found = 1;
58
7
                        ctx->fsize += 8;
59
                    }
60
                }
61
56
            } else if (ctx->pc.frame_start_found == 8) {
62
7
                if ((state >> 32) != MKBETAG('W', 'E', 'B', 'P')) {
63
                    ctx->pc.frame_start_found = 0;
64
                    continue;
65
                }
66
7
                ctx->pc.frame_start_found++;
67
7
                ctx->remaining_size = ctx->fsize + i - 15;
68
7
                if (ctx->pc.index + i > 15) {
69
                    next = i - 15;
70
                    state = 0;
71
                    break;
72
                } else {
73
7
                    ctx->pc.state64 = 0;
74
7
                    goto restart;
75
                }
76
49
            } else if (ctx->pc.frame_start_found)
77
49
                ctx->pc.frame_start_found++;
78
        }
79
21
        ctx->pc.state64 = state;
80
    } else {
81
28
        if (ctx->remaining_size) {
82
28
            i = FFMIN(ctx->remaining_size, buf_size);
83
28
            ctx->remaining_size -= i;
84
28
            if (ctx->remaining_size)
85
21
                goto flush;
86
87
7
            ctx->pc.frame_start_found = 0;
88
7
            goto restart;
89
        }
90
    }
91
92
flush:
93
42
    if (ff_combine_frame(&ctx->pc, next, &buf, &buf_size) < 0)
94
28
        return buf_size;
95
96

14
    if (next != END_NOT_FOUND && next < 0)
97
        ctx->pc.frame_start_found = FFMAX(ctx->pc.frame_start_found - i - 1, 0);
98
    else
99
14
        ctx->pc.frame_start_found = 0;
100
101
14
    *poutbuf      = buf;
102
14
    *poutbuf_size = buf_size;
103
104
14
    return next;
105
}
106
107
AVCodecParser ff_webp_parser = {
108
    .codec_ids      = { AV_CODEC_ID_WEBP },
109
    .priv_data_size = sizeof(WebPParseContext),
110
    .parser_parse   = webp_parse,
111
    .parser_close   = ff_parse_close,
112
};