1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
|
/*
* H.26L/H.264/AVC/JVT/14496-10/... sei decoding
* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* H.264 / AVC / MPEG4 part10 sei decoding.
* @author Michael Niedermayer <michaelni@gmx.at>
*/
#include "internal.h"
#include "avcodec.h"
#include "h264.h"
#include "golomb.h"
//#undef NDEBUG
#include <assert.h>
static const uint8_t sei_num_clock_ts_table[9]={
1, 1, 1, 2, 2, 3, 3, 2, 3
};
void ff_h264_reset_sei(H264Context *h) {
h->sei_recovery_frame_cnt = -1;
h->sei_dpb_output_delay = 0;
h->sei_cpb_removal_delay = -1;
h->sei_buffering_period_present = 0;
}
static int decode_picture_timing(H264Context *h){
if(h->sps.nal_hrd_parameters_present_flag || h->sps.vcl_hrd_parameters_present_flag){
h->sei_cpb_removal_delay = get_bits_long(&h->gb, h->sps.cpb_removal_delay_length);
h->sei_dpb_output_delay = get_bits_long(&h->gb, h->sps.dpb_output_delay_length);
}
if(h->sps.pic_struct_present_flag){
unsigned int i, num_clock_ts;
h->sei_pic_struct = get_bits(&h->gb, 4);
h->sei_ct_type = 0;
if (h->sei_pic_struct > SEI_PIC_STRUCT_FRAME_TRIPLING)
return -1;
num_clock_ts = sei_num_clock_ts_table[h->sei_pic_struct];
for (i = 0 ; i < num_clock_ts ; i++){
if(get_bits(&h->gb, 1)){ /* clock_timestamp_flag */
unsigned int full_timestamp_flag;
h->sei_ct_type |= 1<<get_bits(&h->gb, 2);
skip_bits(&h->gb, 1); /* nuit_field_based_flag */
skip_bits(&h->gb, 5); /* counting_type */
full_timestamp_flag = get_bits(&h->gb, 1);
skip_bits(&h->gb, 1); /* discontinuity_flag */
skip_bits(&h->gb, 1); /* cnt_dropped_flag */
skip_bits(&h->gb, 8); /* n_frames */
if(full_timestamp_flag){
skip_bits(&h->gb, 6); /* seconds_value 0..59 */
skip_bits(&h->gb, 6); /* minutes_value 0..59 */
skip_bits(&h->gb, 5); /* hours_value 0..23 */
}else{
if(get_bits(&h->gb, 1)){ /* seconds_flag */
skip_bits(&h->gb, 6); /* seconds_value range 0..59 */
if(get_bits(&h->gb, 1)){ /* minutes_flag */
skip_bits(&h->gb, 6); /* minutes_value 0..59 */
if(get_bits(&h->gb, 1)) /* hours_flag */
skip_bits(&h->gb, 5); /* hours_value 0..23 */
}
}
}
if(h->sps.time_offset_length > 0)
skip_bits(&h->gb, h->sps.time_offset_length); /* time_offset */
}
}
if(h->avctx->debug & FF_DEBUG_PICT_INFO)
av_log(h->avctx, AV_LOG_DEBUG, "ct_type:%X pic_struct:%d\n", h->sei_ct_type, h->sei_pic_struct);
}
return 0;
}
static int decode_user_data_itu_t_t35(H264Context *h, int size) {
uint32_t user_identifier;
int dtg_active_format;
if (size < 7)
return -1;
size -= 7;
skip_bits(&h->gb, 8); // country_code
skip_bits(&h->gb, 16); // provider_code
user_identifier = get_bits_long(&h->gb, 32);
switch (user_identifier) {
case 0x44544731: // "DTG1" - AFD_data
if (size < 1)
return -1;
skip_bits(&h->gb, 1);
if (get_bits(&h->gb, 1)) {
skip_bits(&h->gb, 6);
if (size < 2)
return -1;
skip_bits(&h->gb, 4);
dtg_active_format = get_bits(&h->gb, 4);
h->avctx->dtg_active_format = dtg_active_format;
} else {
skip_bits(&h->gb, 6);
}
break;
default:
skip_bits(&h->gb, size * 8);
break;
}
return 0;
}
static int decode_unregistered_user_data(H264Context *h, int size){
uint8_t user_data[16+256];
int e, build, i;
if(size<16)
return -1;
for(i=0; i<sizeof(user_data)-1 && i<size; i++){
user_data[i]= get_bits(&h->gb, 8);
}
user_data[i]= 0;
e= sscanf(user_data+16, "x264 - core %d"/*%s - H.264/MPEG-4 AVC codec - Copyleft 2005 - http://www.videolan.org/x264.html*/, &build);
if(e==1 && build>0)
h->x264_build= build;
if(e==1 && build==1 && !strncmp(user_data+16, "x264 - core 0000", 16))
h->x264_build = 67;
if(h->avctx->debug & FF_DEBUG_BUGS)
av_log(h->avctx, AV_LOG_DEBUG, "user data:\"%s\"\n", user_data+16);
for(; i<size; i++)
skip_bits(&h->gb, 8);
return 0;
}
static int decode_recovery_point(H264Context *h){
h->sei_recovery_frame_cnt = get_ue_golomb(&h->gb);
skip_bits(&h->gb, 4); /* 1b exact_match_flag, 1b broken_link_flag, 2b changing_slice_group_idc */
if(h->avctx->debug & FF_DEBUG_PICT_INFO)
av_log(h->avctx, AV_LOG_DEBUG, "sei_recovery_frame_cnt: %d\n", h->sei_recovery_frame_cnt);
return 0;
}
static int decode_buffering_period(H264Context *h){
unsigned int sps_id;
int sched_sel_idx;
SPS *sps;
sps_id = get_ue_golomb_31(&h->gb);
if(sps_id > 31 || !h->sps_buffers[sps_id]) {
av_log(h->avctx, AV_LOG_ERROR, "non-existing SPS %d referenced in buffering period\n", sps_id);
return -1;
}
sps = h->sps_buffers[sps_id];
// NOTE: This is really so duplicated in the standard... See H.264, D.1.1
if (sps->nal_hrd_parameters_present_flag) {
for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
h->initial_cpb_removal_delay[sched_sel_idx] = get_bits_long(&h->gb, sps->initial_cpb_removal_delay_length);
skip_bits(&h->gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset
}
}
if (sps->vcl_hrd_parameters_present_flag) {
for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
h->initial_cpb_removal_delay[sched_sel_idx] = get_bits_long(&h->gb, sps->initial_cpb_removal_delay_length);
skip_bits(&h->gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset
}
}
h->sei_buffering_period_present = 1;
return 0;
}
int ff_h264_decode_sei(H264Context *h){
while (get_bits_left(&h->gb) > 16) {
int size, type;
type=0;
do{
if (get_bits_left(&h->gb) < 8)
return -1;
type+= show_bits(&h->gb, 8);
}while(get_bits(&h->gb, 8) == 255);
size=0;
do{
if (get_bits_left(&h->gb) < 8)
return -1;
size+= show_bits(&h->gb, 8);
}while(get_bits(&h->gb, 8) == 255);
if(h->avctx->debug&FF_DEBUG_STARTCODE)
av_log(h->avctx, AV_LOG_DEBUG, "SEI %d len:%d\n", type, size);
switch(type){
case SEI_TYPE_PIC_TIMING: // Picture timing SEI
if(decode_picture_timing(h) < 0)
return -1;
break;
case SEI_TYPE_USER_DATA_ITU_T_T35:
if(decode_user_data_itu_t_t35(h, size) < 0)
return -1;
break;
case SEI_TYPE_USER_DATA_UNREGISTERED:
if(decode_unregistered_user_data(h, size) < 0)
return -1;
break;
case SEI_TYPE_RECOVERY_POINT:
if(decode_recovery_point(h) < 0)
return -1;
break;
case SEI_BUFFERING_PERIOD:
if(decode_buffering_period(h) < 0)
return -1;
break;
default:
skip_bits(&h->gb, 8*size);
}
//FIXME check bits here
align_get_bits(&h->gb);
}
return 0;
}
|
