FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/jpeg2000_parser.c
Date: 2022-07-06 18:02:43
Exec Total Coverage
Lines: 8 89 9.0%
Branches: 1 68 1.5%

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 static inline void reset_context(JPEG2000ParserContext *m)
50 {
51 ParseContext *pc = &m->pc;
52
53 pc->frame_start_found= 0;
54 pc->state64 = 0;
55 m->bytes_read = 0;
56 m->ft = 0;
57 m->skipped_codestream = 0;
58 m->fheader_read = 0;
59 m->skip_bytes = 0;
60 m->read_tp = 0;
61 m->in_codestream = 0;
62 }
63
64 /* Returns 1 if marker has any data which can be skipped
65 */
66 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 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 static int find_frame_end(JPEG2000ParserContext *m, const uint8_t *buf, int buf_size)
94 {
95 ParseContext *pc= &m->pc;
96 int i;
97 uint64_t state64 = pc->state64;
98 uint64_t bytes_read = m->bytes_read;
99
100 if (buf_size == 0) {
101 return 0;
102 }
103
104 for (i = 0; i < buf_size; i++) {
105 state64 = state64 << 8 | buf[i];
106 bytes_read++;
107 if (m->skip_bytes) {
108 // handle long skips
109 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 int skip = FFMIN(FFMIN((int64_t)m->skip_bytes - 8, buf_size - i - 9), INT_MAX);
113 if (skip > 0) {
114 m->skip_bytes -= skip;
115 i += skip;
116 bytes_read += skip;
117 }
118 }
119 m->skip_bytes--;
120 continue;
121 }
122 if (m->read_tp) { // Find out how many bytes inside Tile part codestream to skip.
123 if (m->read_tp == 1) {
124 m->skip_bytes = (state64 & 0xFFFFFFFF) - 9 > 0?
125 (state64 & 0xFFFFFFFF) - 9 : 0;
126 }
127 m->read_tp--;
128 continue;
129 }
130 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 if ((state64 & 0xFFFFFFFF) == 0x0000000C && bytes_read >= 3) { // Indicates start of JP2 file. Check signature next.
146 m->fheader_read = 8;
147 } else if ((state64 & 0xFFFF) == 0xFF4F) {
148 m->in_codestream = 1;
149 if (!pc->frame_start_found) {
150 pc->frame_start_found = 1;
151 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 } else if ((state64 & 0xFFFF) == 0xFFD9) {
157 if (pc->frame_start_found && m->ft == jp2_file) {
158 m->skipped_codestream = 1;
159 } else if (pc->frame_start_found && m->ft == j2k_cstream) {
160 reset_context(m);
161 return i + 1; // End of frame detected, return frame size.
162 }
163 m->in_codestream = 0;
164 } else if (m->in_codestream) {
165 if ((state64 & 0xFFFF) == 0xFF90) { // Are we in tile part header?
166 m->read_tp = 8;
167 } 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 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 if (i + m->skip_bytes + 1 < buf_size) {
173 uint32_t next_state = (buf[i + m->skip_bytes] << 8) | buf[i + m->skip_bytes + 1];
174 if (info_marker(next_state)) {
175 // Skip an additional 2 bytes to get to the end of the marker length.
176 m->skip_bytes += 2;
177 }
178 }
179 }
180 }
181 }
182
183 pc->state64 = state64;
184 m->bytes_read = bytes_read;
185 return END_NOT_FOUND;
186 }
187
188 411 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 {
193 411 JPEG2000ParserContext *m = s->priv_data;
194 411 ParseContext *pc = &m->pc;
195 int next;
196
197
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411 if(s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
198 411 next= buf_size;
199 } else {
200 next= find_frame_end(m, buf, buf_size);
201
202 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
203 *poutbuf = NULL;
204 *poutbuf_size = 0;
205 return buf_size;
206 }
207 }
208
209 411 *poutbuf = buf;
210 411 *poutbuf_size = buf_size;
211 411 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