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 
36 static const uint8_t sei_num_clock_ts_table[9]={
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 
48  MpegEncContext * const s = &h->s;
52  }
54  unsigned int i, num_clock_ts;
55  h->sei_pic_struct = get_bits(&s->gb, 4);
56  h->sei_ct_type = 0;
57 
59  return -1;
60 
61  num_clock_ts = sei_num_clock_ts_table[h->sei_pic_struct];
62 
63  for (i = 0 ; i < num_clock_ts ; i++){
64  if(get_bits(&s->gb, 1)){ /* clock_timestamp_flag */
65  unsigned int full_timestamp_flag;
66  h->sei_ct_type |= 1<<get_bits(&s->gb, 2);
67  skip_bits(&s->gb, 1); /* nuit_field_based_flag */
68  skip_bits(&s->gb, 5); /* counting_type */
69  full_timestamp_flag = get_bits(&s->gb, 1);
70  skip_bits(&s->gb, 1); /* discontinuity_flag */
71  skip_bits(&s->gb, 1); /* cnt_dropped_flag */
72  skip_bits(&s->gb, 8); /* n_frames */
73  if(full_timestamp_flag){
74  skip_bits(&s->gb, 6); /* seconds_value 0..59 */
75  skip_bits(&s->gb, 6); /* minutes_value 0..59 */
76  skip_bits(&s->gb, 5); /* hours_value 0..23 */
77  }else{
78  if(get_bits(&s->gb, 1)){ /* seconds_flag */
79  skip_bits(&s->gb, 6); /* seconds_value range 0..59 */
80  if(get_bits(&s->gb, 1)){ /* minutes_flag */
81  skip_bits(&s->gb, 6); /* minutes_value 0..59 */
82  if(get_bits(&s->gb, 1)) /* hours_flag */
83  skip_bits(&s->gb, 5); /* hours_value 0..23 */
84  }
85  }
86  }
87  if(h->sps.time_offset_length > 0)
88  skip_bits(&s->gb, h->sps.time_offset_length); /* time_offset */
89  }
90  }
91 
93  av_log(s->avctx, AV_LOG_DEBUG, "ct_type:%X pic_struct:%d\n", h->sei_ct_type, h->sei_pic_struct);
94  }
95  return 0;
96 }
97 
99  MpegEncContext * const s = &h->s;
100  uint8_t user_data[16+256];
101  int e, build, i;
102 
103  if(size<16)
104  return -1;
105 
106  for(i=0; i<sizeof(user_data)-1 && i<size; i++){
107  user_data[i]= get_bits(&s->gb, 8);
108  }
109 
110  user_data[i]= 0;
111  e= sscanf(user_data+16, "x264 - core %d"/*%s - H.264/MPEG-4 AVC codec - Copyleft 2005 - http://www.videolan.org/x264.html*/, &build);
112  if(e==1 && build>0)
113  h->x264_build= build;
114 
115  if(s->avctx->debug & FF_DEBUG_BUGS)
116  av_log(s->avctx, AV_LOG_DEBUG, "user data:\"%s\"\n", user_data+16);
117 
118  for(; i<size; i++)
119  skip_bits(&s->gb, 8);
120 
121  return 0;
122 }
123 
125  MpegEncContext * const s = &h->s;
126 
128  skip_bits(&s->gb, 4); /* 1b exact_match_flag, 1b broken_link_flag, 2b changing_slice_group_idc */
129 
130  return 0;
131 }
132 
134  MpegEncContext * const s = &h->s;
135  unsigned int sps_id;
136  int sched_sel_idx;
137  SPS *sps;
138 
139  sps_id = get_ue_golomb_31(&s->gb);
140  if(sps_id > 31 || !h->sps_buffers[sps_id]) {
141  av_log(h->s.avctx, AV_LOG_ERROR, "non-existing SPS %d referenced in buffering period\n", sps_id);
142  return -1;
143  }
144  sps = h->sps_buffers[sps_id];
145 
146  // NOTE: This is really so duplicated in the standard... See H.264, D.1.1
148  for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
150  skip_bits(&s->gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset
151  }
152  }
154  for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
156  skip_bits(&s->gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset
157  }
158  }
159 
161  return 0;
162 }
163 
165  MpegEncContext * const s = &h->s;
166 
167  while (get_bits_left(&s->gb) > 16) {
168  int type = 0;
169  int size = 0;
170  int last = 0;
171 
172  while (get_bits_left(&s->gb) >= 8 &&
173  (last = get_bits(&s->gb, 8)) == 255) {
174  type += 255;
175  }
176  type += last;
177 
178  last = 0;
179  while (get_bits_left(&s->gb) >= 8 &&
180  (last = get_bits(&s->gb, 8)) == 255) {
181  size += 255;
182  }
183  size += last;
184 
185  if (size > get_bits_left(&s->gb) / 8) {
186  av_log(s->avctx, AV_LOG_ERROR, "SEI type %d truncated at %d\n",
187  type, get_bits_left(&s->gb));
188  return AVERROR_INVALIDDATA;
189  }
190 
191  switch(type){
192  case SEI_TYPE_PIC_TIMING: // Picture timing SEI
193  if(decode_picture_timing(h) < 0)
194  return -1;
195  break;
197  if(decode_unregistered_user_data(h, size) < 0)
198  return -1;
199  break;
201  if(decode_recovery_point(h) < 0)
202  return -1;
203  break;
205  if(decode_buffering_period(h) < 0)
206  return -1;
207  break;
208  default:
209  skip_bits(&s->gb, 8*size);
210  }
211 
212  //FIXME check bits here
213  align_get_bits(&s->gb);
214  }
215 
216  return 0;
217 }