FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
dpx_parser.c
Go to the documentation of this file.
1 /*
2  * DPX parser
3  * Copyright (c) 2013 Paul B Mahol
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  * DPX parser
25  */
26 
27 #include "libavutil/bswap.h"
28 #include "parser.h"
29 
30 typedef struct DPXParseContext {
32  uint32_t index;
33  uint32_t fsize;
34  uint32_t remaining_size;
35  int is_be;
37 
39  const uint8_t **poutbuf, int *poutbuf_size,
40  const uint8_t *buf, int buf_size)
41 {
42  DPXParseContext *d = s->priv_data;
43  uint32_t state = d->pc.state;
44  int next = END_NOT_FOUND;
45  int i = 0;
46 
48 
49  *poutbuf_size = 0;
50  if (buf_size == 0)
51  next = 0;
52 
53  if (!d->pc.frame_start_found) {
54  for (; i < buf_size; i++) {
55  state = (state << 8) | buf[i];
56  if (state == MKBETAG('S','D','P','X') ||
57  state == MKTAG('S','D','P','X')) {
58  d->pc.frame_start_found = 1;
59  d->is_be = state == MKBETAG('S','D','P','X');
60  d->index = 0;
61  break;
62  }
63  }
64  d->pc.state = state;
65  } else {
66  if (d->remaining_size) {
67  i = FFMIN(d->remaining_size, buf_size);
68  d->remaining_size -= i;
69  if (d->remaining_size)
70  goto flush;
71  }
72  }
73 
74  for (;d->pc.frame_start_found && i < buf_size; i++) {
75  d->pc.state = (d->pc.state << 8) | buf[i];
76  d->index++;
77  if (d->index == 17) {
78  d->fsize = d->is_be ? d->pc.state : av_bswap32(d->pc.state);
79  if (d->fsize <= 1664) {
80  d->pc.frame_start_found = 0;
81  goto flush;
82  }
83  if (d->fsize > buf_size - i + 19)
84  d->remaining_size = d->fsize - buf_size + i - 19;
85  else
86  i += d->fsize - 19;
87 
88  break;
89  } else if (d->index > 17) {
90  if (d->pc.state == MKBETAG('S','D','P','X') ||
91  d->pc.state == MKTAG('S','D','P','X')) {
92  next = i - 3;
93  break;
94  }
95  }
96  }
97 
98 flush:
99  if (ff_combine_frame(&d->pc, next, &buf, &buf_size) < 0)
100  return buf_size;
101 
102  d->pc.frame_start_found = 0;
103 
104  *poutbuf = buf;
105  *poutbuf_size = buf_size;
106  return next;
107 }
108 
110  .codec_ids = { AV_CODEC_ID_DPX },
111  .priv_data_size = sizeof(DPXParseContext),
112  .parser_parse = dpx_parse,
113  .parser_close = ff_parse_close,
114 };