Split SEI code off h264.c.
[libav.git] / libavcodec / h264_sei.c
CommitLineData
9c095463
MN
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 FFmpeg.
6 *
7 * FFmpeg 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 * FFmpeg 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 FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file libavcodec/h264-sei.c
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){
48 MpegEncContext * const s = &h->s;
49 if(h->sps.nal_hrd_parameters_present_flag || h->sps.vcl_hrd_parameters_present_flag){
50 h->sei_cpb_removal_delay = get_bits(&s->gb, h->sps.cpb_removal_delay_length);
51 h->sei_dpb_output_delay = get_bits(&s->gb, h->sps.dpb_output_delay_length);
52 }
53 if(h->sps.pic_struct_present_flag){
54 unsigned int i, num_clock_ts;
55 h->sei_pic_struct = get_bits(&s->gb, 4);
56 h->sei_ct_type = 0;
57
58 if (h->sei_pic_struct > SEI_PIC_STRUCT_FRAME_TRIPLING)
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
92 if(s->avctx->debug & FF_DEBUG_PICT_INFO)
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
98static int decode_unregistered_user_data(H264Context *h, int size){
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
124static int decode_recovery_point(H264Context *h){
125 MpegEncContext * const s = &h->s;
126
127 h->sei_recovery_frame_cnt = get_ue_golomb(&s->gb);
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
133static int decode_buffering_period(H264Context *h){
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
147 if (sps->nal_hrd_parameters_present_flag) {
148 for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
149 h->initial_cpb_removal_delay[sched_sel_idx] = get_bits(&s->gb, sps->initial_cpb_removal_delay_length);
150 skip_bits(&s->gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset
151 }
152 }
153 if (sps->vcl_hrd_parameters_present_flag) {
154 for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
155 h->initial_cpb_removal_delay[sched_sel_idx] = get_bits(&s->gb, sps->initial_cpb_removal_delay_length);
156 skip_bits(&s->gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset
157 }
158 }
159
160 h->sei_buffering_period_present = 1;
161 return 0;
162}
163
164int ff_h264_decode_sei(H264Context *h){
165 MpegEncContext * const s = &h->s;
166
167 while(get_bits_count(&s->gb) + 16 < s->gb.size_in_bits){
168 int size, type;
169
170 type=0;
171 do{
172 type+= show_bits(&s->gb, 8);
173 }while(get_bits(&s->gb, 8) == 255);
174
175 size=0;
176 do{
177 size+= show_bits(&s->gb, 8);
178 }while(get_bits(&s->gb, 8) == 255);
179
180 switch(type){
181 case SEI_TYPE_PIC_TIMING: // Picture timing SEI
182 if(decode_picture_timing(h) < 0)
183 return -1;
184 break;
185 case SEI_TYPE_USER_DATA_UNREGISTERED:
186 if(decode_unregistered_user_data(h, size) < 0)
187 return -1;
188 break;
189 case SEI_TYPE_RECOVERY_POINT:
190 if(decode_recovery_point(h) < 0)
191 return -1;
192 break;
193 case SEI_BUFFERING_PERIOD:
194 if(decode_buffering_period(h) < 0)
195 return -1;
196 break;
197 default:
198 skip_bits(&s->gb, 8*size);
199 }
200
201 //FIXME check bits here
202 align_get_bits(&s->gb);
203 }
204
205 return 0;
206}