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vp9_parser.c
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1 /*
2  * VP9 compatible video decoder
3  *
4  * Copyright (C) 2013 Ronald S. Bultje <rsbultje gmail com>
5  * Copyright (C) 2013 Clément Bœsch <u pkh me>
6  *
7  * This file is part of FFmpeg.
8  *
9  * FFmpeg is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2.1 of the License, or (at your option) any later version.
13  *
14  * FFmpeg is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with FFmpeg; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22  */
23 
24 #include "libavutil/intreadwrite.h"
25 #include "libavcodec/get_bits.h"
26 #include "parser.h"
27 
28 typedef struct VP9ParseContext {
29  int n_frames; // 1-8
30  int size[8];
31  int64_t pts;
33 
35 {
36  VP9ParseContext *s = ctx->priv_data;
37  GetBitContext gb;
38  int res, profile, keyframe, invisible;
39 
40  if ((res = init_get_bits8(&gb, buf, size)) < 0)
41  return res;
42  get_bits(&gb, 2); // frame marker
43  profile = get_bits1(&gb);
44  profile |= get_bits1(&gb) << 1;
45  if (profile == 3) profile += get_bits1(&gb);
46 
47  if (get_bits1(&gb)) {
48  keyframe = 0;
49  invisible = 0;
50  } else {
51  keyframe = !get_bits1(&gb);
52  invisible = !get_bits1(&gb);
53  }
54 
55  if (!keyframe) {
57  ctx->key_frame = 0;
58  } else {
60  ctx->key_frame = 1;
61  }
62 
63  if (!invisible) {
64  if (ctx->pts == AV_NOPTS_VALUE)
65  ctx->pts = s->pts;
66  s->pts = AV_NOPTS_VALUE;
67  } else if (ctx->pts != AV_NOPTS_VALUE) {
68  s->pts = ctx->pts;
69  ctx->pts = AV_NOPTS_VALUE;
70  }
71 
72  return 0;
73 }
74 
76  AVCodecContext *avctx,
77  const uint8_t **out_data, int *out_size,
78  const uint8_t *data, int size)
79 {
80  VP9ParseContext *s = ctx->priv_data;
81  int full_size = size;
82  int marker;
83 
84  if (size <= 0) {
85  *out_size = 0;
86  *out_data = data;
87 
88  return 0;
89  }
90 
91  if (s->n_frames > 0) {
92  *out_data = data;
93  *out_size = s->size[--s->n_frames];
94  parse_frame(ctx, *out_data, *out_size);
95 
96  return s->n_frames > 0 ? *out_size : size /* i.e. include idx tail */;
97  }
98 
99  marker = data[size - 1];
100  if ((marker & 0xe0) == 0xc0) {
101  int nbytes = 1 + ((marker >> 3) & 0x3);
102  int n_frames = 1 + (marker & 0x7), idx_sz = 2 + n_frames * nbytes;
103 
104  if (size >= idx_sz && data[size - idx_sz] == marker) {
105  const uint8_t *idx = data + size + 1 - idx_sz;
106  int first = 1;
107 
108  switch (nbytes) {
109 #define case_n(a, rd) \
110  case a: \
111  while (n_frames--) { \
112  unsigned sz = rd; \
113  idx += a; \
114  if (sz == 0 || sz > size) { \
115  s->n_frames = 0; \
116  *out_size = size; \
117  *out_data = data; \
118  av_log(avctx, AV_LOG_ERROR, \
119  "Invalid superframe packet size: %u frame size: %d\n", \
120  sz, size); \
121  return full_size; \
122  } \
123  if (first) { \
124  first = 0; \
125  *out_data = data; \
126  *out_size = sz; \
127  s->n_frames = n_frames; \
128  } else { \
129  s->size[n_frames] = sz; \
130  } \
131  data += sz; \
132  size -= sz; \
133  } \
134  parse_frame(ctx, *out_data, *out_size); \
135  return s->n_frames > 0 ? *out_size : full_size
136 
137  case_n(1, *idx);
138  case_n(2, AV_RL16(idx));
139  case_n(3, AV_RL24(idx));
140  case_n(4, AV_RL32(idx));
141  }
142  }
143  }
144 
145  *out_data = data;
146  *out_size = size;
147  parse_frame(ctx, data, size);
148 
149  return size;
150 }
151 
153  .codec_ids = { AV_CODEC_ID_VP9 },
154  .priv_data_size = sizeof(VP9ParseContext),
155  .parser_parse = parse,
156 };
AVCodecParser ff_vp9_parser
Definition: vp9_parser.c:152
const char * s
Definition: avisynth_c.h:631
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
AVFormatContext * ctx
Definition: movenc-test.c:48
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:260
int codec_ids[5]
Definition: avcodec.h:4589
static int parse(AVCodecParserContext *ctx, AVCodecContext *avctx, const uint8_t **out_data, int *out_size, const uint8_t *data, int size)
Definition: vp9_parser.c:75
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:87
uint8_t
bitstream reader API header.
ptrdiff_t size
Definition: opengl_enc.c:101
int out_size
Definition: movenc-test.c:55
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_RL24
Definition: bytestream.h:87
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:449
main external API structure.
Definition: avcodec.h:1532
#define case_n(a, rd)
void * buf
Definition: avisynth_c.h:553
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:312
mfxU16 profile
Definition: qsvenc.c:42
static int parse_frame(AVCodecParserContext *ctx, const uint8_t *buf, int size)
Definition: vp9_parser.c:34
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:87
int key_frame
Set by parser to 1 for key frames and 0 for non-key frames.
Definition: avcodec.h:4470
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:240
Predicted.
Definition: avutil.h:267