FFmpeg
jpeg2000_parser.c
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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,
34 };
35 
36 typedef struct JPEG2000ParserContext {
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
45  uint8_t read_tp;
46  uint8_t in_codestream;
48 
49 static inline void reset_context(JPEG2000ParserContext *m)
50 {
51  ParseContext *pc = &m->pc;
52 
53  pc->frame_start_found= 0;
54  pc->state = 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  if (marker == 0xFF92 || marker == 0xFF4F ||
69  marker == 0xFF90 || marker == 0xFF93 ||
70  marker == 0xFFD9)
71  return 0;
72  else
73  if (marker > 0xFF00) return 1;
74  return 0;
75 }
76 
77 /**
78  * Find the end of the current frame in the bitstream.
79  * @return the position of the first byte of the next frame, or -1
80  */
81 static int find_frame_end(JPEG2000ParserContext *m, const uint8_t *buf, int buf_size)
82 {
83  ParseContext *pc= &m->pc;
84  int i;
85  uint32_t state, next_state;
86  uint64_t state64;
87  state= pc->state;
88  state64 = pc->state64;
89  if (buf_size == 0) {
90  return 0;
91  }
92 
93  for (i = 0; i < buf_size; i++) {
94  state = state << 8 | buf[i];
95  state64 = state64 << 8 | buf[i];
96  m->bytes_read++;
97  if (m->skip_bytes) {
98  m->skip_bytes--;
99  continue;
100  }
101  if (m->read_tp) { // Find out how many bytes inside Tile part codestream to skip.
102  if (m->read_tp == 1) {
103  m->skip_bytes = (state64 & 0xFFFFFFFF) - 9 > 0?
104  (state64 & 0xFFFFFFFF) - 9 : 0;
105  }
106  m->read_tp--;
107  continue;
108  }
109  if (m->fheader_read) {
110  if (m->fheader_read == 1) {
111  if (state64 == 0x6A5020200D0A870A) { // JP2 signature box value.
112  if (pc->frame_start_found) {
113  pc->frame_start_found = 0;
114  reset_context(m);
115  return i - 11;
116  } else {
117  pc->frame_start_found = 1;
118  m->ft = jp2_file;
119  }
120  }
121  }
122  m->fheader_read--;
123  }
124  if (state == 0x0000000C && m->bytes_read >= 3) { // Indicates start of JP2 file. Check signature next.
125  m->fheader_read = 8;
126  } else if ((state & 0xFFFF) == 0xFF4F) {
127  m->in_codestream = 1;
128  if (!pc->frame_start_found) {
129  pc->frame_start_found = 1;
130  m->ft = j2k_cstream;
131  } else if (pc->frame_start_found && m->ft == jp2_file && m->skipped_codestream) {
132  reset_context(m);
133  return i - 1;
134  }
135  } else if ((state & 0xFFFF) == 0xFFD9) {
136  if (pc->frame_start_found && m->ft == jp2_file) {
137  m->skipped_codestream = 1;
138  } else if (pc->frame_start_found && m->ft == j2k_cstream) {
139  reset_context(m);
140  return i + 1; // End of frame detected, return frame size.
141  }
142  m->in_codestream = 0;
143  } else if (m->in_codestream && (state & 0xFFFF) == 0xFF90) { // Are we in tile part header?
144  m->read_tp = 8;
145  } else if (pc->frame_start_found && info_marker((state & 0xFFFF0000)>>16) && m->in_codestream && (state & 0xFFFF)) {
146  // Calculate number of bytes to skip to get to end of the next marker.
147  m->skip_bytes = (state & 0xFFFF)-1;
148 
149  // If the next marker is an info marker, skip to the end of of the marker length.
150  if (i + m->skip_bytes + 1 < buf_size) {
151  next_state = (buf[i + m->skip_bytes] << 8) | buf[i + m->skip_bytes + 1];
152  if (info_marker(next_state)) {
153  // Skip an additional 2 bytes to get to the end of the marker length.
154  m->skip_bytes += 2;
155  }
156  }
157  }
158  }
159 
160  pc->state = state;
161  pc->state64 = state64;
162  return END_NOT_FOUND;
163 }
164 
166  AVCodecContext *avctx,
167  const uint8_t **poutbuf, int *poutbuf_size,
168  const uint8_t *buf, int buf_size)
169 {
170  JPEG2000ParserContext *m = s->priv_data;
171  ParseContext *pc = &m->pc;
172  int next;
173 
174  if(s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
175  next= buf_size;
176  } else {
177  next= find_frame_end(m, buf, buf_size);
178 
179  if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
180  *poutbuf = NULL;
181  *poutbuf_size = 0;
182  return buf_size;
183  }
184  }
185 
186  *poutbuf = buf;
187  *poutbuf_size = buf_size;
188  return next;
189 }
190 
193  .priv_data_size = sizeof(JPEG2000ParserContext),
194  .parser_parse = jpeg2000_parse,
195  .parser_close = ff_parse_close,
196 };
j2k_cstream
@ j2k_cstream
Definition: jpeg2000_parser.c:33
ff_parse_close
void ff_parse_close(AVCodecParserContext *s)
Definition: parser.c:286
JPEG2000ParserContext::in_codestream
uint8_t in_codestream
Definition: jpeg2000_parser.c:46
ParseContext::state
uint32_t state
contains the last few bytes in MSB order
Definition: parser.h:33
state
static struct @319 state
ParseContext
Definition: parser.h:28
jpeg2000_parse
static int jpeg2000_parse(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size)
Definition: jpeg2000_parser.c:165
s
#define s(width, name)
Definition: cbs_vp9.c:257
JPEG2000ParserContext::reading_file_header
uint8_t reading_file_header
Definition: jpeg2000_parser.c:43
JPEG2000ParserContext::pc
ParseContext pc
Definition: jpeg2000_parser.c:37
if
if(ret)
Definition: filter_design.txt:179
NULL
#define NULL
Definition: coverity.c:32
JPEG2000ParserContext::read_tp
uint8_t read_tp
Definition: jpeg2000_parser.c:45
ParseContext::frame_start_found
int frame_start_found
Definition: parser.h:34
find_frame_end
static int find_frame_end(JPEG2000ParserContext *m, const uint8_t *buf, int buf_size)
Find the end of the current frame in the bitstream.
Definition: jpeg2000_parser.c:81
JPEG2000ParserContext::fheader_read
uint8_t fheader_read
Definition: jpeg2000_parser.c:42
AVCodecParser::codec_ids
int codec_ids[7]
Definition: avcodec.h:2935
jp2_file
@ jp2_file
Definition: jpeg2000_parser.c:32
ff_combine_frame
int ff_combine_frame(ParseContext *pc, int next, const uint8_t **buf, int *buf_size)
Combine the (truncated) bitstream to a complete frame.
Definition: parser.c:201
reset_context
static void reset_context(JPEG2000ParserContext *m)
Definition: jpeg2000_parser.c:49
ff_jpeg2000_parser
const AVCodecParser ff_jpeg2000_parser
Definition: jpeg2000_parser.c:191
PARSER_FLAG_COMPLETE_FRAMES
#define PARSER_FLAG_COMPLETE_FRAMES
Definition: avcodec.h:2809
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:271
frame_type
frame_type
Definition: jpeg2000_parser.c:31
JPEG2000ParserContext
Definition: jpeg2000_parser.c:36
parser.h
AV_CODEC_ID_JPEG2000
@ AV_CODEC_ID_JPEG2000
Definition: codec_id.h:138
AVCodecParserContext
Definition: avcodec.h:2775
JPEG2000ParserContext::skip_bytes
uint32_t skip_bytes
Definition: jpeg2000_parser.c:40
JPEG2000ParserContext::skipped_codestream
uint8_t skipped_codestream
Definition: jpeg2000_parser.c:44
AVCodecContext
main external API structure.
Definition: avcodec.h:383
info_marker
static uint8_t info_marker(uint16_t marker)
Definition: jpeg2000_parser.c:66
JPEG2000ParserContext::fheader_state
uint64_t fheader_state
Definition: jpeg2000_parser.c:39
ParseContext::state64
uint64_t state64
contains the last 8 bytes in MSB order
Definition: parser.h:37
JPEG2000ParserContext::ft
enum frame_type ft
Definition: jpeg2000_parser.c:41
END_NOT_FOUND
#define END_NOT_FOUND
Definition: parser.h:40
AVCodecParser
Definition: avcodec.h:2934
JPEG2000ParserContext::bytes_read
uint64_t bytes_read
Definition: jpeg2000_parser.c:38