h264_sei: Remove pointless old comment
[libav.git] / libavcodec / h264_sei.c
CommitLineData
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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 *
2912e87a 5 * This file is part of Libav.
9c095463 6 *
2912e87a 7 * Libav is free software; you can redistribute it and/or
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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 *
2912e87a 12 * Libav is distributed in the hope that it will be useful,
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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
2912e87a 18 * License along with Libav; if not, write to the Free Software
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19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
ba87f080 23 * @file
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24 * H.264 / AVC / MPEG4 part10 sei decoding.
25 * @author Michael Niedermayer <michaelni@gmx.at>
26 */
27
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
36static const uint8_t sei_num_clock_ts_table[9]={
37 1, 1, 1, 2, 2, 3, 3, 2, 3
38};
39
40void ff_h264_reset_sei(H264Context *h) {
41 h->sei_recovery_frame_cnt = -1;
42 h->sei_dpb_output_delay = 0;
43 h->sei_cpb_removal_delay = -1;
44 h->sei_buffering_period_present = 0;
45}
46
47static int decode_picture_timing(H264Context *h){
9c095463 48 if(h->sps.nal_hrd_parameters_present_flag || h->sps.vcl_hrd_parameters_present_flag){
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49 h->sei_cpb_removal_delay = get_bits(&h->gb, h->sps.cpb_removal_delay_length);
50 h->sei_dpb_output_delay = get_bits(&h->gb, h->sps.dpb_output_delay_length);
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51 }
52 if(h->sps.pic_struct_present_flag){
53 unsigned int i, num_clock_ts;
2c541554 54 h->sei_pic_struct = get_bits(&h->gb, 4);
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55 h->sei_ct_type = 0;
56
57 if (h->sei_pic_struct > SEI_PIC_STRUCT_FRAME_TRIPLING)
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++){
2c541554 63 if(get_bits(&h->gb, 1)){ /* clock_timestamp_flag */
9c095463 64 unsigned int full_timestamp_flag;
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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 */
9c095463 72 if(full_timestamp_flag){
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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 */
9c095463 76 }else{
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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 */
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83 }
84 }
85 }
86 if(h->sps.time_offset_length > 0)
2c541554 87 skip_bits(&h->gb, h->sps.time_offset_length); /* time_offset */
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88 }
89 }
90
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91 if(h->avctx->debug & FF_DEBUG_PICT_INFO)
92 av_log(h->avctx, AV_LOG_DEBUG, "ct_type:%X pic_struct:%d\n", h->sei_ct_type, h->sei_pic_struct);
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93 }
94 return 0;
95}
96
97static int decode_unregistered_user_data(H264Context *h, int size){
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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++){
2c541554 105 user_data[i]= get_bits(&h->gb, 8);
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106 }
107
108 user_data[i]= 0;
4c7fd58f 109 e = sscanf(user_data + 16, "x264 - core %d", &build);
e1c9d266 110 if(e==1 && build>0)
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111 h->x264_build= build;
112
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113 if(h->avctx->debug & FF_DEBUG_BUGS)
114 av_log(h->avctx, AV_LOG_DEBUG, "user data:\"%s\"\n", user_data+16);
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115
116 for(; i<size; i++)
2c541554 117 skip_bits(&h->gb, 8);
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118
119 return 0;
120}
121
122static int decode_recovery_point(H264Context *h){
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123 h->sei_recovery_frame_cnt = get_ue_golomb(&h->gb);
124 skip_bits(&h->gb, 4); /* 1b exact_match_flag, 1b broken_link_flag, 2b changing_slice_group_idc */
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125
126 return 0;
127}
128
129static int decode_buffering_period(H264Context *h){
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130 unsigned int sps_id;
131 int sched_sel_idx;
132 SPS *sps;
133
2c541554 134 sps_id = get_ue_golomb_31(&h->gb);
9c095463 135 if(sps_id > 31 || !h->sps_buffers[sps_id]) {
2c541554 136 av_log(h->avctx, AV_LOG_ERROR, "non-existing SPS %d referenced in buffering period\n", sps_id);
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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
142 if (sps->nal_hrd_parameters_present_flag) {
143 for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
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144 h->initial_cpb_removal_delay[sched_sel_idx] = get_bits(&h->gb, sps->initial_cpb_removal_delay_length);
145 skip_bits(&h->gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset
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146 }
147 }
148 if (sps->vcl_hrd_parameters_present_flag) {
149 for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
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150 h->initial_cpb_removal_delay[sched_sel_idx] = get_bits(&h->gb, sps->initial_cpb_removal_delay_length);
151 skip_bits(&h->gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset
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152 }
153 }
154
155 h->sei_buffering_period_present = 1;
156 return 0;
157}
158
159int ff_h264_decode_sei(H264Context *h){
2c541554 160 while (get_bits_left(&h->gb) > 16) {
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161 int size, type;
162
163 type=0;
164 do{
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165 type+= show_bits(&h->gb, 8);
166 }while(get_bits(&h->gb, 8) == 255);
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167
168 size=0;
169 do{
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170 size+= show_bits(&h->gb, 8);
171 }while(get_bits(&h->gb, 8) == 255);
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172
173 switch(type){
174 case SEI_TYPE_PIC_TIMING: // Picture timing SEI
175 if(decode_picture_timing(h) < 0)
176 return -1;
177 break;
178 case SEI_TYPE_USER_DATA_UNREGISTERED:
179 if(decode_unregistered_user_data(h, size) < 0)
180 return -1;
181 break;
182 case SEI_TYPE_RECOVERY_POINT:
183 if(decode_recovery_point(h) < 0)
184 return -1;
185 break;
186 case SEI_BUFFERING_PERIOD:
187 if(decode_buffering_period(h) < 0)
188 return -1;
189 break;
190 default:
2c541554 191 skip_bits(&h->gb, 8*size);
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192 }
193
194 //FIXME check bits here
2c541554 195 align_get_bits(&h->gb);
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196 }
197
198 return 0;
199}