Libav
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 "avcodec.h"
29 #include "golomb.h"
30 #include "h264.h"
31 #include "internal.h"
32 
33 static const uint8_t sei_num_clock_ts_table[9] = {
34  1, 1, 1, 2, 2, 3, 3, 2, 3
35 };
36 
38 {
39  h->sei_recovery_frame_cnt = -1;
40  h->sei_dpb_output_delay = 0;
41  h->sei_cpb_removal_delay = -1;
44 }
45 
47 {
54  }
56  unsigned int i, num_clock_ts;
57 
58  h->sei_pic_struct = get_bits(&h->gb, 4);
59  h->sei_ct_type = 0;
60 
62  return AVERROR_INVALIDDATA;
63 
64  num_clock_ts = sei_num_clock_ts_table[h->sei_pic_struct];
65 
66  for (i = 0; i < num_clock_ts; i++) {
67  if (get_bits(&h->gb, 1)) { /* clock_timestamp_flag */
68  unsigned int full_timestamp_flag;
69 
70  h->sei_ct_type |= 1 << get_bits(&h->gb, 2);
71  skip_bits(&h->gb, 1); /* nuit_field_based_flag */
72  skip_bits(&h->gb, 5); /* counting_type */
73  full_timestamp_flag = get_bits(&h->gb, 1);
74  skip_bits(&h->gb, 1); /* discontinuity_flag */
75  skip_bits(&h->gb, 1); /* cnt_dropped_flag */
76  skip_bits(&h->gb, 8); /* n_frames */
77  if (full_timestamp_flag) {
78  skip_bits(&h->gb, 6); /* seconds_value 0..59 */
79  skip_bits(&h->gb, 6); /* minutes_value 0..59 */
80  skip_bits(&h->gb, 5); /* hours_value 0..23 */
81  } else {
82  if (get_bits(&h->gb, 1)) { /* seconds_flag */
83  skip_bits(&h->gb, 6); /* seconds_value range 0..59 */
84  if (get_bits(&h->gb, 1)) { /* minutes_flag */
85  skip_bits(&h->gb, 6); /* minutes_value 0..59 */
86  if (get_bits(&h->gb, 1)) /* hours_flag */
87  skip_bits(&h->gb, 5); /* hours_value 0..23 */
88  }
89  }
90  }
91  if (h->sps.time_offset_length > 0)
92  skip_bits(&h->gb,
93  h->sps.time_offset_length); /* time_offset */
94  }
95  }
96 
97  if (h->avctx->debug & FF_DEBUG_PICT_INFO)
98  av_log(h->avctx, AV_LOG_DEBUG, "ct_type:%X pic_struct:%d\n",
100  }
101  return 0;
102 }
103 
105 {
106  uint8_t user_data[16 + 256];
107  int e, build, i;
108 
109  if (size < 16)
110  return AVERROR_INVALIDDATA;
111 
112  for (i = 0; i < sizeof(user_data) - 1 && i < size; i++)
113  user_data[i] = get_bits(&h->gb, 8);
114 
115  user_data[i] = 0;
116  e = sscanf(user_data + 16, "x264 - core %d", &build);
117  if (e == 1 && build > 0)
118  h->x264_build = build;
119 
120  if (h->avctx->debug & FF_DEBUG_BUGS)
121  av_log(h->avctx, AV_LOG_DEBUG, "user data:\"%s\"\n", user_data + 16);
122 
123  for (; i < size; i++)
124  skip_bits(&h->gb, 8);
125 
126  return 0;
127 }
128 
130 {
132 
133  /* 1b exact_match_flag,
134  * 1b broken_link_flag,
135  * 2b changing_slice_group_idc */
136  skip_bits(&h->gb, 4);
137 
138  return 0;
139 }
140 
142 {
143  unsigned int sps_id;
144  int sched_sel_idx;
145  SPS *sps;
146 
147  sps_id = get_ue_golomb_31(&h->gb);
148  if (sps_id > 31 || !h->sps_buffers[sps_id]) {
150  "non-existing SPS %d referenced in buffering period\n", sps_id);
151  return AVERROR_INVALIDDATA;
152  }
153  sps = h->sps_buffers[sps_id];
154 
155  // NOTE: This is really so duplicated in the standard... See H.264, D.1.1
157  for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
158  h->initial_cpb_removal_delay[sched_sel_idx] =
160  // initial_cpb_removal_delay_offset
162  }
163  }
165  for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
166  h->initial_cpb_removal_delay[sched_sel_idx] =
168  // initial_cpb_removal_delay_offset
170  }
171  }
172 
174  return 0;
175 }
176 
178 {
179  get_ue_golomb(&h->gb); // frame_packing_arrangement_id
181 
182  if (h->sei_frame_packing_present) {
186 
187  // the following skips: spatial_flipping_flag, frame0_flipped_flag,
188  // field_views_flag, current_frame_is_frame0_flag,
189  // frame0_self_contained_flag, frame1_self_contained_flag
190  skip_bits(&h->gb, 6);
191 
193  skip_bits(&h->gb, 16); // frame[01]_grid_position_[xy]
194  skip_bits(&h->gb, 8); // frame_packing_arrangement_reserved_byte
195  get_ue_golomb(&h->gb); // frame_packing_arrangement_repetition_period
196  }
197  skip_bits1(&h->gb); // frame_packing_arrangement_extension_flag
198 
199  return 0;
200 }
201 
203 {
204  while (get_bits_left(&h->gb) > 16) {
205  int size = 0;
206  int type = 0;
207  int ret = 0;
208 
209  do
210  type += show_bits(&h->gb, 8);
211  while (get_bits(&h->gb, 8) == 255);
212 
213  do
214  size += show_bits(&h->gb, 8);
215  while (get_bits(&h->gb, 8) == 255);
216 
217  if (size > get_bits_left(&h->gb) / 8) {
218  av_log(h->avctx, AV_LOG_ERROR, "SEI type %d truncated at %d\n",
219  type, get_bits_left(&h->gb));
220  return AVERROR_INVALIDDATA;
221  }
222 
223  switch (type) {
224  case SEI_TYPE_PIC_TIMING: // Picture timing SEI
225  ret = decode_picture_timing(h);
226  if (ret < 0)
227  return ret;
228  break;
230  ret = decode_unregistered_user_data(h, size);
231  if (ret < 0)
232  return ret;
233  break;
235  ret = decode_recovery_point(h);
236  if (ret < 0)
237  return ret;
238  break;
240  ret = decode_buffering_period(h);
241  if (ret < 0)
242  return ret;
243  break;
246  if (ret < 0)
247  return ret;
248  break;
249  default:
250  av_log(h->avctx, AV_LOG_DEBUG, "unknown SEI type %d\n", type);
251  skip_bits(&h->gb, 8 * size);
252  }
253 
254  // FIXME check bits here
255  align_get_bits(&h->gb);
256  }
257 
258  return 0;
259 }
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:54
GetBitContext gb
Definition: h264.h:267
int sei_cpb_removal_delay
cpb_removal_delay in picture timing SEI message, see H.264 C.1.2
Definition: h264.h:608
int size
int quincunx_subsampling
Definition: h264.h:591
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:240
unregistered user data
Definition: h264.h:125
Sequence parameter set.
Definition: h264.h:148
int initial_cpb_removal_delay[32]
Initial timestamps for CPBs.
Definition: h264.h:645
H264Context.
Definition: h264.h:258
void ff_h264_reset_sei(H264Context *h)
Reset SEI values at the beginning of the frame.
Definition: h264_sei.c:37
uint8_t
static int decode_picture_timing(H264Context *h)
Definition: h264_sei.c:46
#define FF_DEBUG_PICT_INFO
Definition: avcodec.h:2349
H.264 / AVC / MPEG4 part10 codec.
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:555
static int decode_unregistered_user_data(H264Context *h, int size)
Definition: h264_sei.c:104
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
static int get_ue_golomb(GetBitContext *gb)
read unsigned exp golomb code.
Definition: golomb.h:53
int time_offset_length
Definition: h264.h:196
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:144
#define FF_DEBUG_BUGS
Definition: avcodec.h:2366
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:148
int initial_cpb_removal_delay_length
initial_cpb_removal_delay_length_minus1 + 1
Definition: h264.h:198
int x264_build
Definition: h264.h:452
int sei_frame_packing_present
frame_packing_arrangment SEI message
Definition: h264.h:588
static int decode_recovery_point(H264Context *h)
Definition: h264_sei.c:129
SPS sps
current sps
Definition: h264.h:357
static unsigned int show_bits(GetBitContext *s, int n)
Show 1-25 bits.
Definition: get_bits.h:254
frame packing arrangement
Definition: h264.h:127
SPS * sps_buffers[MAX_SPS_COUNT]
Definition: h264.h:488
int vcl_hrd_parameters_present_flag
Definition: h264.h:194
AVCodecContext * avctx
Definition: h264.h:259
Libavcodec 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:2348
int dpb_output_delay_length
dpb_output_delay_length_minus1 + 1
Definition: h264.h:200
int frame_packing_arrangement_type
Definition: h264.h:589
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:271
SEI_PicStructType sei_pic_struct
pic_struct in picture timing SEI message
Definition: h264.h:575
static void skip_bits1(GetBitContext *s)
Definition: get_bits.h:296
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:263
int sei_buffering_period_present
Buffering period SEI flag.
Definition: h264.h:644
static const uint8_t sei_num_clock_ts_table[9]
Definition: h264_sei.c:33
int pic_struct_present_flag
Definition: h264.h:195
picture timing
Definition: h264.h:124
common internal api header.
int nal_hrd_parameters_present_flag
Definition: h264.h:193
static int decode_buffering_period(H264Context *h)
Definition: h264_sei.c:141
int sei_ct_type
Bit set of clock types for fields/frames in picture timing SEI message.
Definition: h264.h:598
int ff_h264_decode_sei(H264Context *h)
Decode SEI.
Definition: h264_sei.c:202
int content_interpretation_type
Definition: h264.h:590
static const uint8_t * align_get_bits(GetBitContext *s)
Definition: get_bits.h:416
buffering period (H.264, D.1.1)
Definition: h264.h:123
int cpb_cnt
See H.264 E.1.2.
Definition: h264.h:197
int cpb_removal_delay_length
cpb_removal_delay_length_minus1 + 1
Definition: h264.h:199
8: frame tripling
Definition: h264.h:142
exp golomb vlc stuff
int sei_recovery_frame_cnt
recovery_frame_cnt from SEI message
Definition: h264.h:617
int sei_dpb_output_delay
dpb_output_delay in picture timing SEI message, see H.264 C.2.2
Definition: h264.h:603
recovery point (frame # to decoder sync)
Definition: h264.h:126
static int decode_frame_packing_arrangement(H264Context *h)
Definition: h264_sei.c:177