h264_sei.c
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1 /*
2  * H.26L/H.264/AVC/JVT/14496-10/... sei decoding
3  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
28 #include "internal.h"
29 #include "avcodec.h"
30 #include "h264.h"
31 #include "golomb.h"
32 
33 //#undef NDEBUG
34 #include <assert.h>
35 
37  1, 1, 1, 2, 2, 3, 3, 2, 3
38 };
39 
41  h->sei_recovery_frame_cnt = -1;
42  h->sei_dpb_output_delay = 0;
43  h->sei_cpb_removal_delay = -1;
45 }
46 
51  }
53  unsigned int i, num_clock_ts;
54  h->sei_pic_struct = get_bits(&h->gb, 4);
55  h->sei_ct_type = 0;
56 
58  return -1;
59 
60  num_clock_ts = sei_num_clock_ts_table[h->sei_pic_struct];
61 
62  for (i = 0 ; i < num_clock_ts ; i++){
63  if(get_bits(&h->gb, 1)){ /* clock_timestamp_flag */
64  unsigned int full_timestamp_flag;
65  h->sei_ct_type |= 1<<get_bits(&h->gb, 2);
66  skip_bits(&h->gb, 1); /* nuit_field_based_flag */
67  skip_bits(&h->gb, 5); /* counting_type */
68  full_timestamp_flag = get_bits(&h->gb, 1);
69  skip_bits(&h->gb, 1); /* discontinuity_flag */
70  skip_bits(&h->gb, 1); /* cnt_dropped_flag */
71  skip_bits(&h->gb, 8); /* n_frames */
72  if(full_timestamp_flag){
73  skip_bits(&h->gb, 6); /* seconds_value 0..59 */
74  skip_bits(&h->gb, 6); /* minutes_value 0..59 */
75  skip_bits(&h->gb, 5); /* hours_value 0..23 */
76  }else{
77  if(get_bits(&h->gb, 1)){ /* seconds_flag */
78  skip_bits(&h->gb, 6); /* seconds_value range 0..59 */
79  if(get_bits(&h->gb, 1)){ /* minutes_flag */
80  skip_bits(&h->gb, 6); /* minutes_value 0..59 */
81  if(get_bits(&h->gb, 1)) /* hours_flag */
82  skip_bits(&h->gb, 5); /* hours_value 0..23 */
83  }
84  }
85  }
86  if(h->sps.time_offset_length > 0)
87  skip_bits(&h->gb, h->sps.time_offset_length); /* time_offset */
88  }
89  }
90 
92  av_log(h->avctx, AV_LOG_DEBUG, "ct_type:%X pic_struct:%d\n", h->sei_ct_type, h->sei_pic_struct);
93  }
94  return 0;
95 }
96 
98  uint8_t user_data[16+256];
99  int e, build, i;
100 
101  if(size<16)
102  return -1;
103 
104  for(i=0; i<sizeof(user_data)-1 && i<size; i++){
105  user_data[i]= get_bits(&h->gb, 8);
106  }
107 
108  user_data[i]= 0;
109  e= sscanf(user_data+16, "x264 - core %d"/*%s - H.264/MPEG-4 AVC codec - Copyleft 2005 - http://www.videolan.org/x264.html*/, &build);
110  if(e==1 && build>0)
111  h->x264_build= build;
112 
113  if(h->avctx->debug & FF_DEBUG_BUGS)
114  av_log(h->avctx, AV_LOG_DEBUG, "user data:\"%s\"\n", user_data+16);
115 
116  for(; i<size; i++)
117  skip_bits(&h->gb, 8);
118 
119  return 0;
120 }
121 
124  skip_bits(&h->gb, 4); /* 1b exact_match_flag, 1b broken_link_flag, 2b changing_slice_group_idc */
125 
126  return 0;
127 }
128 
130  unsigned int sps_id;
131  int sched_sel_idx;
132  SPS *sps;
133 
134  sps_id = get_ue_golomb_31(&h->gb);
135  if(sps_id > 31 || !h->sps_buffers[sps_id]) {
136  av_log(h->avctx, AV_LOG_ERROR, "non-existing SPS %d referenced in buffering period\n", sps_id);
137  return -1;
138  }
139  sps = h->sps_buffers[sps_id];
140 
141  // NOTE: This is really so duplicated in the standard... See H.264, D.1.1
143  for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
145  skip_bits(&h->gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset
146  }
147  }
149  for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
151  skip_bits(&h->gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset
152  }
153  }
154 
156  return 0;
157 }
158 
160  while (get_bits_left(&h->gb) > 16) {
161  int type = 0;
162  int size = 0;
163  int last = 0;
164 
165  while (get_bits_left(&h->gb) >= 8 &&
166  (last = get_bits(&h->gb, 8)) == 255) {
167  type += 255;
168  }
169  type += last;
170 
171  last = 0;
172  while (get_bits_left(&h->gb) >= 8 &&
173  (last = get_bits(&h->gb, 8)) == 255) {
174  size += 255;
175  }
176  size += last;
177 
178  if (size > get_bits_left(&h->gb) / 8) {
179  av_log(h->avctx, AV_LOG_ERROR, "SEI type %d truncated at %d\n",
180  type, get_bits_left(&h->gb));
181  return AVERROR_INVALIDDATA;
182  }
183 
184  switch(type){
185  case SEI_TYPE_PIC_TIMING: // Picture timing SEI
186  if(decode_picture_timing(h) < 0)
187  return -1;
188  break;
190  if(decode_unregistered_user_data(h, size) < 0)
191  return -1;
192  break;
194  if(decode_recovery_point(h) < 0)
195  return -1;
196  break;
198  if(decode_buffering_period(h) < 0)
199  return -1;
200  break;
201  default:
202  skip_bits(&h->gb, 8*size);
203  }
204 
205  //FIXME check bits here
206  align_get_bits(&h->gb);
207  }
208 
209  return 0;
210 }
GetBitContext gb
Definition: h264.h:259
int sei_cpb_removal_delay
cpb_removal_delay in picture timing SEI message, see H.264 C.1.2
Definition: h264.h:600
int size
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:237
unregistered user data
Definition: h264.h:123
static void align_get_bits(GetBitContext *s)
Definition: get_bits.h:412
Sequence parameter set.
Definition: h264.h:145
int initial_cpb_removal_delay[32]
Initial timestamps for CPBs.
Definition: h264.h:616
H264Context.
Definition: h264.h:252
void ff_h264_reset_sei(H264Context *h)
Reset SEI values at the beginning of the frame.
Definition: h264_sei.c:40
uint8_t
static int decode_picture_timing(H264Context *h)
Definition: h264_sei.c:47
H.264 / AVC / MPEG4 part10 codec.
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:547
static int decode_unregistered_user_data(H264Context *h, int size)
Definition: h264_sei.c:97
static int get_ue_golomb(GetBitContext *gb)
read unsigned exp golomb code.
Definition: golomb.h:53
int time_offset_length
Definition: h264.h:190
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:146
int initial_cpb_removal_delay_length
initial_cpb_removal_delay_length_minus1 + 1
Definition: h264.h:192
int x264_build
Definition: h264.h:452
static int decode_recovery_point(H264Context *h)
Definition: h264_sei.c:122
SPS sps
current sps
Definition: h264.h:354
SPS * sps_buffers[MAX_SPS_COUNT]
Definition: h264.h:488
int vcl_hrd_parameters_present_flag
Definition: h264.h:188
AVCodecContext * avctx
Definition: h264.h:253
external API header
static int get_ue_golomb_31(GetBitContext *gb)
read unsigned exp golomb code, constraint to a max of 31.
Definition: golomb.h:96
int debug
debug
Definition: avcodec.h:2568
int dpb_output_delay_length
dpb_output_delay_length_minus1 + 1
Definition: h264.h:194
SEI_PicStructType sei_pic_struct
pic_struct in picture timing SEI message
Definition: h264.h:575
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:260
buffering period (H.264, D.1.1)
Definition: h264.h:121
int sei_buffering_period_present
Buffering period SEI flag.
Definition: h264.h:615
static const uint8_t sei_num_clock_ts_table[9]
Definition: h264_sei.c:36
int pic_struct_present_flag
Definition: h264.h:189
picture timing
Definition: h264.h:122
common internal api header.
int nal_hrd_parameters_present_flag
Definition: h264.h:187
static int decode_buffering_period(H264Context *h)
Definition: h264_sei.c:129
int sei_ct_type
Bit set of clock types for fields/frames in picture timing SEI message.
Definition: h264.h:590
int ff_h264_decode_sei(H264Context *h)
Decode SEI.
Definition: h264_sei.c:159
int cpb_cnt
See H.264 E.1.2.
Definition: h264.h:191
int cpb_removal_delay_length
cpb_removal_delay_length_minus1 + 1
Definition: h264.h:193
8: frame tripling
Definition: h264.h:139
exp golomb vlc stuff
int sei_recovery_frame_cnt
recovery_frame_cnt from SEI message
Definition: h264.h:609
int sei_dpb_output_delay
dpb_output_delay in picture timing SEI message, see H.264 C.2.2
Definition: h264.h:595
recovery point (frame # to decoder sync)
Definition: h264.h:124