FFmpeg: libavcodec/dnxhd_parser.c Source File

FFmpeg
dnxhd_parser.c
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1 /*
2  * DNxHD/VC-3 parser
3  * Copyright (c) 2008 Baptiste Coudurier <baptiste.coudurier@free.fr>
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  * DNxHD/VC-3 parser
25  */
26 
27 #include "parser.h"
28 #include "dnxhddata.h"
29 
30  typedef struct {
31   ParseContext pc;
32   int cur_byte;
33   int remaining;
34   int w, h;
35 } DNXHDParserContext;
36 
37  static int dnxhd_find_frame_end(DNXHDParserContext *dctx,
38  const uint8_t *buf, int buf_size)
39 {
40  ParseContext *pc = &dctx->pc;
41  uint64_t state = pc->state64;
42  int pic_found = pc->frame_start_found;
43  int i = 0;
44 
45  if (!pic_found) {
46  for (i = 0; i < buf_size; i++) {
47  state = (state << 8) | buf[i];
48  if (ff_dnxhd_check_header_prefix(state & 0xffffffffff00LL) != 0) {
49  i++;
50  pic_found = 1;
51  dctx->cur_byte = 0;
52  dctx->remaining = 0;
53  break;
54  }
55  }
56  }
57 
58  if (pic_found && !dctx->remaining) {
59  if (!buf_size) /* EOF considered as end of frame */
60  return 0;
61  for (; i < buf_size; i++) {
62  dctx->cur_byte++;
63  state = (state << 8) | buf[i];
64 
65  if (dctx->cur_byte == 24) {
66  dctx->h = (state >> 32) & 0xFFFF;
67  } else if (dctx->cur_byte == 26) {
68  dctx->w = (state >> 32) & 0xFFFF;
69  } else if (dctx->cur_byte == 42) {
70  int cid = (state >> 32) & 0xFFFFFFFF;
71  int remaining;
72 
73  if (cid <= 0)
74  continue;
75 
76  remaining = avpriv_dnxhd_get_frame_size(cid);
77  if (remaining <= 0) {
78  remaining = ff_dnxhd_get_hr_frame_size(cid, dctx->w, dctx->h);
79  if (remaining <= 0)
80  continue;
81  }
82  dctx->remaining = remaining;
83  if (buf_size - i + 47 >= dctx->remaining) {
84  int remaining = dctx->remaining;
85 
86  pc->frame_start_found = 0;
87  pc->state64 = -1;
88  dctx->cur_byte = 0;
89  dctx->remaining = 0;
90  return remaining;
91  } else {
92  dctx->remaining -= buf_size;
93  }
94  }
95  }
96  } else if (pic_found) {
97  if (dctx->remaining > buf_size) {
98  dctx->remaining -= buf_size;
99  } else {
100  int remaining = dctx->remaining;
101 
102  pc->frame_start_found = 0;
103  pc->state64 = -1;
104  dctx->cur_byte = 0;
105  dctx->remaining = 0;
106  return remaining;
107  }
108  }
109  pc->frame_start_found = pic_found;
110  pc->state64 = state;
111  return END_NOT_FOUND;
112 }
113 
114  static int dnxhd_parse(AVCodecParserContext *s,
115  AVCodecContext *avctx,
116  const uint8_t **poutbuf, int *poutbuf_size,
117  const uint8_t *buf, int buf_size)
118 {
119  DNXHDParserContext *dctx = s->priv_data;
120  ParseContext *pc = &dctx->pc;
121  int next;
122 
123  if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
124  next = buf_size;
125  } else {
126  next = dnxhd_find_frame_end(dctx, buf, buf_size);
127  if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
128  *poutbuf = NULL;
129  *poutbuf_size = 0;
130  return buf_size;
131  }
132  }
133  *poutbuf = buf;
134  *poutbuf_size = buf_size;
135  return next;
136 }
137 
138  AVCodecParser ff_dnxhd_parser = {
139  .codec_ids = { AV_CODEC_ID_DNXHD },
140  .priv_data_size = sizeof(DNXHDParserContext),
141  .parser_parse = dnxhd_parse,
142  .parser_close = ff_parse_close,
143 };
NULL
#define NULL
Definition: coverity.c:32
ff_dnxhd_check_header_prefix
static av_always_inline uint64_t ff_dnxhd_check_header_prefix(uint64_t prefix)
Definition: dnxhddata.h:77
s
const char * s
Definition: avisynth_c.h:768
AV_CODEC_ID_DNXHD
Definition: avcodec.h:317
h
h
Definition: vp9dsp_template.c:2038
AVCodecParser::codec_ids
int codec_ids[5]
Definition: avcodec.h:5200
ParseContext::frame_start_found
int frame_start_found
Definition: parser.h:34
uint8_t
uint8_t
Definition: audio_convert.c:194
dnxhd_parse
static int dnxhd_parse(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size)
Definition: dnxhd_parser.c:114
avpriv_dnxhd_get_frame_size
int avpriv_dnxhd_get_frame_size(int cid)
Definition: dnxhddata.c:1087
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:319
ff_dnxhd_parser
AVCodecParser ff_dnxhd_parser
Definition: dnxhd_parser.c:138
AVCodecParserContext::priv_data
void * priv_data
Definition: avcodec.h:5033
ff_parse_close
void ff_parse_close(AVCodecParserContext *s)
Definition: parser.c:397
dnxhd_find_frame_end
static int dnxhd_find_frame_end(DNXHDParserContext *dctx, const uint8_t *buf, int buf_size)
Definition: dnxhd_parser.c:37
ff_dnxhd_get_hr_frame_size
static av_always_inline int ff_dnxhd_get_hr_frame_size(int cid, int w, int h)
Definition: dnxhddata.h:93
DNXHDParserContext::pc
ParseContext pc
Definition: dnxhd_parser.c:31
state
static struct @271 state
AVCodecContext
main external API structure.
Definition: avcodec.h:1518
buf
void * buf
Definition: avisynth_c.h:690
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
PARSER_FLAG_COMPLETE_FRAMES
#define PARSER_FLAG_COMPLETE_FRAMES
Definition: avcodec.h:5066
Generated on Sun May 13 2018 02:03:45 for FFmpeg by   doxygen 1.8.6

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