FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/png_parser.c
Date: 2024-11-20 23:03:26
Exec Total Coverage
Lines: 48 53 90.6%
Functions: 1 1 100.0%
Branches: 28 34 82.4%
Line Branch Exec Source
1 /*
2 * PNG parser
3 * Copyright (c) 2009 Peter Holik
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file
24 * PNG parser
25 */
26
27 #include "parser.h"
28 #include "png.h"
29
30 typedef struct PNGParseContext {
31 ParseContext pc;
32 uint32_t chunk_pos; ///< position inside current chunk
33 uint32_t chunk_length; ///< length of the current chunk
34 uint32_t remaining_size; ///< remaining size of the current chunk
35 } PNGParseContext;
36
37 899 static int png_parse(AVCodecParserContext *s, AVCodecContext *avctx,
38 const uint8_t **poutbuf, int *poutbuf_size,
39 const uint8_t *buf, int buf_size)
40 {
41 899 PNGParseContext *ppc = s->priv_data;
42 899 int next = END_NOT_FOUND;
43 899 int i = 0;
44
45 899 s->pict_type = AV_PICTURE_TYPE_NONE;
46
47 899 *poutbuf_size = 0;
48 899 *poutbuf = NULL;
49
50
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 899 if (!ppc->pc.frame_start_found) {
51 311 uint64_t state64 = ppc->pc.state64;
52
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 2159 for (; i < buf_size; i++) {
53 2112 state64 = (state64 << 8) | buf[i];
54
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 2112 if (state64 == PNGSIG || state64 == MNGSIG) {
55 264 i++;
56 264 ppc->pc.frame_start_found = 1;
57 264 break;
58 }
59 }
60 311 ppc->pc.state64 = state64;
61
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 588 } else if (ppc->remaining_size) {
62 588 i = FFMIN(ppc->remaining_size, buf_size);
63 588 ppc->remaining_size -= i;
64
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 588 if (ppc->remaining_size)
65 180 goto flush;
66
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 408 if (ppc->chunk_pos == -1) {
67 ✗ next = i;
68 ✗ goto flush;
69 }
70 }
71
72
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 82775 for (; ppc->pc.frame_start_found && i < buf_size; i++) {
73 82728 ppc->pc.state = (ppc->pc.state << 8) | buf[i];
74
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 82728 if (ppc->chunk_pos == 3) {
75 10341 ppc->chunk_length = ppc->pc.state;
76
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 10341 if (ppc->chunk_length > 0x7fffffff) {
77 ✗ ppc->chunk_pos = ppc->pc.frame_start_found = 0;
78 ✗ goto flush;
79 }
80 10341 ppc->chunk_length += 4;
81
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 72387 } else if (ppc->chunk_pos == 7) {
82
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 10341 if (ppc->chunk_length >= buf_size - i)
83 409 ppc->remaining_size = ppc->chunk_length - buf_size + i + 1;
84
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 10341 if (ppc->pc.state == MKBETAG('I', 'E', 'N', 'D')) {
85
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 263 if (ppc->remaining_size)
86 ✗ ppc->chunk_pos = -1;
87 else
88 263 next = ppc->chunk_length + i + 1;
89 263 break;
90 } else {
91 10078 ppc->chunk_pos = 0;
92
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 10078 if (ppc->remaining_size)
93 409 break;
94 else
95 9669 i += ppc->chunk_length;
96 9669 continue;
97 }
98 }
99 72387 ppc->chunk_pos++;
100 }
101
102 47 flush:
103
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 899 if (ff_combine_frame(&ppc->pc, next, &buf, &buf_size) < 0)
104 588 return buf_size;
105
106 311 ppc->chunk_pos = ppc->pc.frame_start_found = 0;
107
108 311 *poutbuf = buf;
109 311 *poutbuf_size = buf_size;
110 311 return next;
111 }
112
113 const AVCodecParser ff_png_parser = {
114 .codec_ids = { AV_CODEC_ID_PNG },
115 .priv_data_size = sizeof(PNGParseContext),
116 .parser_parse = png_parse,
117 .parser_close = ff_parse_close,
118 };
119