FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/jpeg2000_parser.c
Date: 2025-07-15 19:03:42
Exec Total Coverage
Lines: 75 90 83.3%
Functions: 4 4 100.0%
Branches: 43 68 63.2%
Line Branch Exec Source
1 /*
2 * JPEG2000 parser
3 * Copyright (c) 2020 Gautam Ramakrishnan
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 * JPEG2000 parser.
25 */
26
27 #include "parser.h"
28
29 /* Whether frame is jp2 file or codestream
30 */
31 enum frame_type {
32 jp2_file = 1,
33 j2k_cstream
34 };
35
36 typedef struct JPEG2000ParserContext {
37 ParseContext pc;
38 uint64_t bytes_read;
39 uint64_t fheader_state;
40 uint32_t skip_bytes; // skip bytes inside codestream data
41 enum frame_type ft; // 1 if file, 2 if codestream
42 uint8_t fheader_read; // are we reading
43 uint8_t reading_file_header;
44 uint8_t skipped_codestream;
45 uint8_t read_tp;
46 uint8_t in_codestream;
47 } JPEG2000ParserContext;
48
49 15 static inline void reset_context(JPEG2000ParserContext *m)
50 {
51 15 ParseContext *pc = &m->pc;
52
53 15 pc->frame_start_found= 0;
54 15 pc->state64 = 0;
55 15 m->bytes_read = 0;
56 15 m->ft = 0;
57 15 m->skipped_codestream = 0;
58 15 m->fheader_read = 0;
59 15 m->skip_bytes = 0;
60 15 m->read_tp = 0;
61 15 m->in_codestream = 0;
62 15 }
63
64 /* Returns 1 if marker has any data which can be skipped
65 */
66 213 static uint8_t info_marker(uint16_t marker)
67 {
68 static const uint8_t lut[256] = {
69 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
70 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
71 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
72 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
73 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, // 0xFF4F
74 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
75 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
76 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
77 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
78 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 0xFF90 0xFF92 0xFF93
79 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
80 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
81 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
82 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, // 0xFFD9
83 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
84 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
85 };
86
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 213 return marker < 0xFF00 ? 0 : lut[marker & 0xFF];
87 }
88
89 /**
90 * Find the end of the current frame in the bitstream.
91 * @return the position of the first byte of the next frame, or -1
92 */
93 3284 static int find_frame_end(JPEG2000ParserContext *m, const uint8_t *buf, int buf_size)
94 {
95 3284 ParseContext *pc= &m->pc;
96 int i;
97 3284 uint64_t state64 = pc->state64;
98 3284 uint64_t bytes_read = m->bytes_read;
99
100
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 3284 if (buf_size == 0) {
101 15 return 0;
102 }
103
104
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 38215 for (i = 0; i < buf_size; i++) {
105 34961 state64 = state64 << 8 | buf[i];
106 34961 bytes_read++;
107
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 34961 if (m->skip_bytes) {
108 // handle long skips
109
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 32222 if (m->skip_bytes > 8) {
110 // need -9 else buf_size - i == 8 ==> i == buf_size after this,
111 // and thus i == buf_size + 1 after the loop
112 29647 int skip = FFMIN(FFMIN((int64_t)m->skip_bytes - 8, buf_size - i - 9), INT_MAX);
113
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 29647 if (skip > 0) {
114 3615 m->skip_bytes -= skip;
115 3615 i += skip;
116 3615 bytes_read += skip;
117 }
118 }
119 32222 m->skip_bytes--;
120 32222 continue;
121 }
122
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 2739 if (m->read_tp) { // Find out how many bytes inside Tile part codestream to skip.
123
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 2280 if (m->read_tp == 1) {
124
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 570 m->skip_bytes = (state64 & 0xFFFFFFFF) - 9 > 0?
125 285 (state64 & 0xFFFFFFFF) - 9 : 0;
126 }
127 2280 m->read_tp--;
128 2280 continue;
129 }
130
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 459 if (m->fheader_read) {
131 ✗ if (m->fheader_read == 1) {
132 ✗ if (state64 == 0x6A5020200D0A870A) { // JP2 signature box value.
133 ✗ if (pc->frame_start_found) {
134 ✗ pc->frame_start_found = 0;
135 ✗ reset_context(m);
136 ✗ return i - 11;
137 } else {
138 ✗ pc->frame_start_found = 1;
139 ✗ m->ft = jp2_file;
140 }
141 }
142 }
143 ✗ m->fheader_read--;
144 }
145
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 459 if ((state64 & 0xFFFFFFFF) == 0x0000000C && bytes_read >= 3) { // Indicates start of JP2 file. Check signature next.
146 ✗ m->fheader_read = 8;
147
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 459 } else if ((state64 & 0xFFFF) == 0xFF4F) {
148 15 m->in_codestream = 1;
149
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 15 if (!pc->frame_start_found) {
150 15 pc->frame_start_found = 1;
151 15 m->ft = j2k_cstream;
152 ✗ } else if (pc->frame_start_found && m->ft == jp2_file && m->skipped_codestream) {
153 ✗ reset_context(m);
154 ✗ return i - 1;
155 }
156
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 444 } else if ((state64 & 0xFFFF) == 0xFFD9) {
157
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 15 if (pc->frame_start_found && m->ft == jp2_file) {
158 ✗ m->skipped_codestream = 1;
159
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 15 } else if (pc->frame_start_found && m->ft == j2k_cstream) {
160 15 reset_context(m);
161 15 return i + 1; // End of frame detected, return frame size.
162 }
163 ✗ m->in_codestream = 0;
164
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 429 } else if (m->in_codestream) {
165
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 414 if ((state64 & 0xFFFF) == 0xFF90) { // Are we in tile part header?
166 285 m->read_tp = 8;
167
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 129 } else if (info_marker((state64 & 0xFFFF0000)>>16) && pc->frame_start_found && (state64 & 0xFFFF)) {
168 // Calculate number of bytes to skip to get to end of the next marker.
169 84 m->skip_bytes = (state64 & 0xFFFF)-1;
170
171 // If the next marker is an info marker, skip to the end of of the marker length.
172
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 84 if (i + m->skip_bytes + 1 < buf_size) {
173 84 uint32_t next_state = (buf[i + m->skip_bytes] << 8) | buf[i + m->skip_bytes + 1];
174
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 84 if (info_marker(next_state)) {
175 // Skip an additional 2 bytes to get to the end of the marker length.
176 70 m->skip_bytes += 2;
177 }
178 }
179 }
180 }
181 }
182
183 3254 pc->state64 = state64;
184 3254 m->bytes_read = bytes_read;
185 3254 return END_NOT_FOUND;
186 }
187
188 4104 static int jpeg2000_parse(AVCodecParserContext *s,
189 AVCodecContext *avctx,
190 const uint8_t **poutbuf, int *poutbuf_size,
191 const uint8_t *buf, int buf_size)
192 {
193 4104 JPEG2000ParserContext *m = s->priv_data;
194 4104 ParseContext *pc = &m->pc;
195 int next;
196
197
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 4104 if(s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
198 820 next= buf_size;
199 } else {
200 3284 next= find_frame_end(m, buf, buf_size);
201
202
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 3284 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
203 3254 *poutbuf = NULL;
204 3254 *poutbuf_size = 0;
205 3254 return buf_size;
206 }
207 }
208
209 850 *poutbuf = buf;
210 850 *poutbuf_size = buf_size;
211 850 return next;
212 }
213
214 const AVCodecParser ff_jpeg2000_parser = {
215 .codec_ids = { AV_CODEC_ID_JPEG2000 },
216 .priv_data_size = sizeof(JPEG2000ParserContext),
217 .parser_parse = jpeg2000_parse,
218 .parser_close = ff_parse_close,
219 };
220