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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 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
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
36 static const uint8_t sei_num_clock_ts_table[9]={
37     1,  1,  1,  2,  2,  3,  3,  2,  3
38 };
39
40 void 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
47 static 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
98 static 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
124 static 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
133 static 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
164 int 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         if(s->avctx->debug&FF_DEBUG_STARTCODE)
181             av_log(h->s.avctx, AV_LOG_DEBUG, "SEI %d len:%d\n", type, size);
182
183         switch(type){
184         case SEI_TYPE_PIC_TIMING: // Picture timing SEI
185             if(decode_picture_timing(h) < 0)
186                 return -1;
187             break;
188         case SEI_TYPE_USER_DATA_UNREGISTERED:
189             if(decode_unregistered_user_data(h, size) < 0)
190                 return -1;
191             break;
192         case SEI_TYPE_RECOVERY_POINT:
193             if(decode_recovery_point(h) < 0)
194                 return -1;
195             break;
196         case SEI_BUFFERING_PERIOD:
197             if(decode_buffering_period(h) < 0)
198                 return -1;
199             break;
200         default:
201             skip_bits(&s->gb, 8*size);
202         }
203
204         //FIXME check bits here
205         align_get_bits(&s->gb);
206     }
207
208     return 0;
209 }