FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/png_parser.c
Date: 2021-09-24 03:35:22
Exec Total Coverage
Lines: 48 53 90.6%
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
37 596 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 {
41 596 PNGParseContext *ppc = s->priv_data;
42 596 int next = END_NOT_FOUND;
43 596 int i = 0;
44
45 596 s->pict_type = AV_PICTURE_TYPE_NONE;
46
47 596 *poutbuf_size = 0;
48 596 *poutbuf = NULL;
49
50
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596 if (!ppc->pc.frame_start_found) {
51 289 uint64_t state64 = ppc->pc.state64;
52
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2060 for (; i < buf_size; i++) {
53 2024 state64 = (state64 << 8) | buf[i];
54
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2024 if (state64 == PNGSIG || state64 == MNGSIG) {
55 253 i++;
56 253 ppc->pc.frame_start_found = 1;
57 253 break;
58 }
59 }
60 289 ppc->pc.state64 = state64;
61
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307 } else if (ppc->remaining_size) {
62 307 i = FFMIN(ppc->remaining_size, buf_size);
63 307 ppc->remaining_size -= i;
64
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307 if (ppc->remaining_size)
65 164 goto flush;
66
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143 if (ppc->chunk_pos == -1) {
67 next = i;
68 goto flush;
69 }
70 }
71
72
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80236 for (; ppc->pc.frame_start_found && i < buf_size; i++) {
73 80200 ppc->pc.state = (ppc->pc.state << 8) | buf[i];
74
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80200 if (ppc->chunk_pos == 3) {
75 10025 ppc->chunk_length = ppc->pc.state;
76
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10025 if (ppc->chunk_length > 0x7fffffff) {
77 ppc->chunk_pos = ppc->pc.frame_start_found = 0;
78 goto flush;
79 }
80 10025 ppc->chunk_length += 4;
81
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70175 } else if (ppc->chunk_pos == 7) {
82
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10025 if (ppc->chunk_length >= buf_size - i)
83 144 ppc->remaining_size = ppc->chunk_length - buf_size + i + 1;
84
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10025 if (ppc->pc.state == MKBETAG('I', 'E', 'N', 'D')) {
85
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252 if (ppc->remaining_size)
86 ppc->chunk_pos = -1;
87 else
88 252 next = ppc->chunk_length + i + 1;
89 252 break;
90 } else {
91 9773 ppc->chunk_pos = 0;
92
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9773 if (ppc->remaining_size)
93 144 break;
94 else
95 9629 i += ppc->chunk_length;
96 9629 continue;
97 }
98 }
99 70175 ppc->chunk_pos++;
100 }
101
102 36 flush:
103
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596 if (ff_combine_frame(&ppc->pc, next, &buf, &buf_size) < 0)
104 307 return buf_size;
105
106 289 ppc->chunk_pos = ppc->pc.frame_start_found = 0;
107
108 289 *poutbuf = buf;
109 289 *poutbuf_size = buf_size;
110 289 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