FFmpeg
hdr_parser.c
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1 /*
2  * Radiance HDR 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  * Radiance HDR parser
25  */
26 
27 #include "libavutil/intreadwrite.h"
28 #include "parser.h"
29 
30 typedef struct HDRParseContext {
33 
35  const uint8_t **poutbuf, int *poutbuf_size,
36  const uint8_t *buf, int buf_size)
37 {
38  HDRParseContext *ipc = s->priv_data;
39  uint64_t state = ipc->pc.state64;
40  int next = END_NOT_FOUND, i = 0;
41 
42  *poutbuf_size = 0;
43  *poutbuf = NULL;
44 
45  if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
46  next = buf_size;
47  } else {
48  for (; i < buf_size; i++) {
49  state = (state << 8) | buf[i];
50  if (state == AV_RB64("ADIANCE\n") && (i > 10 || ipc->pc.index > 10)) {
51  next = i - 10;
52  break;
53  }
54  }
55 
56  ipc->pc.state64 = state;
57  if (ff_combine_frame(&ipc->pc, next, &buf, &buf_size) < 0) {
58  *poutbuf = NULL;
59  *poutbuf_size = 0;
60  return buf_size;
61  }
62  }
63 
64  *poutbuf = buf;
65  *poutbuf_size = buf_size;
66 
67  s->pict_type = AV_PICTURE_TYPE_I;
68  s->key_frame = 1;
69  s->duration = 1;
70 
71  return next;
72 }
73 
76  .priv_data_size = sizeof(HDRParseContext),
77  .parser_parse = hdr_parse,
78  .parser_close = ff_parse_close,
79 };
hdr_parse
static int hdr_parse(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size)
Definition: hdr_parser.c:34
ff_hdr_parser
const AVCodecParser ff_hdr_parser
Definition: hdr_parser.c:74
ff_parse_close
void ff_parse_close(AVCodecParserContext *s)
Definition: parser.c:284
ParseContext
Definition: parser.h:28
HDRParseContext
Definition: hdr_parser.c:30
ParseContext::index
int index
Definition: parser.h:30
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:256
NULL
#define NULL
Definition: coverity.c:32
state
static struct @336 state
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:274
AVCodecParser::codec_ids
int codec_ids[7]
Definition: avcodec.h:2960
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
parser.h
AVCodecParserContext
Definition: avcodec.h:2800
HDRParseContext::pc
ParseContext pc
Definition: hdr_parser.c:31
AVCodecContext
main external API structure.
Definition: avcodec.h:398
ParseContext::state64
uint64_t state64
contains the last 8 bytes in MSB order
Definition: parser.h:37
END_NOT_FOUND
#define END_NOT_FOUND
Definition: parser.h:40
AVCodecParser
Definition: avcodec.h:2959
AV_CODEC_ID_RADIANCE_HDR
@ AV_CODEC_ID_RADIANCE_HDR
Definition: codec_id.h:319
AV_RB64
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_RB64
Definition: bytestream.h:95