FFmpeg
xwd_parser.c
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1 /*
2  * XWD parser
3  * Copyright (c) 2022 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  * XWD parser
25  **/
26 
27 #include "libavutil/intreadwrite.h"
28 #include "parser.h"
29 #include "xwd.h"
30 
31 typedef struct XWDParseContext {
33  int left;
34  int idx;
35  uint8_t hdr[XWD_HEADER_SIZE];
37 
39  const uint8_t **poutbuf, int *poutbuf_size,
40  const uint8_t *buf, int buf_size)
41 {
42  XWDParseContext *t = s->priv_data;
43  ParseContext *pc = &t->pc;
44  int next = END_NOT_FOUND;
45 
46  s->pict_type = AV_PICTURE_TYPE_NONE;
47 
48  *poutbuf = NULL;
49  *poutbuf_size = 0;
50 
51  if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
52  next = buf_size;
53  } else {
54  for (int i = 0; i < buf_size; i++) {
55  if (t->left > 0) {
56  t->left--;
57  if (t->left == 0) {
58  next = i;
59  break;
60  }
61  continue;
62  }
63 
64  if (t->idx >= 100) {
65  t->idx = 99;
66  memmove(&t->hdr[0], &t->hdr[1], XWD_HEADER_SIZE-1);
67  }
68 
69  t->hdr[t->idx++] = buf[i];
70 
71  if (t->idx >= 100 && AV_RB32(t->hdr + 4) == XWD_VERSION) {
72  uint32_t header_size = AV_RB32(t->hdr + 0);
73  uint32_t height = AV_RB32(t->hdr + 20);
74  uint32_t lsize = AV_RB32(t->hdr + 48);
75  uint32_t ncolors = AV_RB32(t->hdr + 76);
76  uint32_t size = header_size + ncolors * XWD_CMAP_SIZE + height * lsize;
77  pc->frame_start_found = 1;
78  t->left = size - XWD_HEADER_SIZE + 1;
79  t->idx = 0;
80  memset(t->hdr, 0, sizeof(t->hdr));
81  }
82  }
83 
84  if (ff_combine_frame(pc, next, &buf, &buf_size) < 0)
85  return buf_size;
86  }
87 
88  *poutbuf = buf;
89  *poutbuf_size = buf_size;
90 
91  s->pict_type = AV_PICTURE_TYPE_I;
92  s->key_frame = 1;
93  s->duration = 1;
94 
95  return next;
96 }
97 
100  .priv_data_size = sizeof(XWDParseContext),
101  .parser_parse = xwd_parse,
102  .parser_close = ff_parse_close,
103 };
ff_parse_close
void ff_parse_close(AVCodecParserContext *s)
Definition: parser.c:284
ParseContext
Definition: parser.h:28
XWDParseContext::idx
int idx
Definition: xwd_parser.c:34
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:256
xwd.h
XWDParseContext::left
int left
Definition: xwd_parser.c:33
NULL
#define NULL
Definition: coverity.c:32
AV_CODEC_ID_XWD
@ AV_CODEC_ID_XWD
Definition: codec_id.h:210
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:274
ParseContext::frame_start_found
int frame_start_found
Definition: parser.h:34
xwd_parse
static int xwd_parse(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size)
Definition: xwd_parser.c:38
XWDParseContext::pc
ParseContext pc
Definition: xwd_parser.c:32
AVCodecParser::codec_ids
int codec_ids[7]
Definition: avcodec.h:2960
XWD_HEADER_SIZE
#define XWD_HEADER_SIZE
Definition: xwd.h:27
size
int size
Definition: twinvq_data.h:10344
AV_RB32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_RB32
Definition: bytestream.h:96
AV_PICTURE_TYPE_NONE
@ AV_PICTURE_TYPE_NONE
Undefined.
Definition: avutil.h:273
height
#define height
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:199
PARSER_FLAG_COMPLETE_FRAMES
#define PARSER_FLAG_COMPLETE_FRAMES
Definition: avcodec.h:2834
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
XWDParseContext::hdr
uint8_t hdr[XWD_HEADER_SIZE]
Definition: xwd_parser.c:35
parser.h
AVCodecParserContext
Definition: avcodec.h:2800
AVCodecContext
main external API structure.
Definition: avcodec.h:398
ff_xwd_parser
const AVCodecParser ff_xwd_parser
Definition: xwd_parser.c:98
END_NOT_FOUND
#define END_NOT_FOUND
Definition: parser.h:40
AVCodecParser
Definition: avcodec.h:2959
XWD_VERSION
#define XWD_VERSION
Definition: xwd.h:26
XWD_CMAP_SIZE
#define XWD_CMAP_SIZE
Definition: xwd.h:28
XWDParseContext
Definition: xwd_parser.c:31