j2k: restructure bitstream decoding
[ffmpeg.git] / libavcodec / h264_sei.c
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     SPS *sps = &h->sps;
49     int i;
50
51     for (i = 0; i<MAX_SPS_COUNT; i++)
52         if (!sps->log2_max_frame_num && h->sps_buffers[i])
53             sps = h->sps_buffers[i];
54
55     if(sps->nal_hrd_parameters_present_flag || sps->vcl_hrd_parameters_present_flag){
56         h->sei_cpb_removal_delay = get_bits_long(&h->gb, sps->cpb_removal_delay_length);
57         h->sei_dpb_output_delay = get_bits_long(&h->gb, sps->dpb_output_delay_length);
58     }
59     if(sps->pic_struct_present_flag){
60         unsigned int i, num_clock_ts;
61         h->sei_pic_struct = get_bits(&h->gb, 4);
62         h->sei_ct_type    = 0;
63
64         if (h->sei_pic_struct > SEI_PIC_STRUCT_FRAME_TRIPLING)
65             return -1;
66
67         num_clock_ts = sei_num_clock_ts_table[h->sei_pic_struct];
68
69         for (i = 0 ; i < num_clock_ts ; i++){
70             if(get_bits(&h->gb, 1)){                  /* clock_timestamp_flag */
71                 unsigned int full_timestamp_flag;
72                 h->sei_ct_type |= 1<<get_bits(&h->gb, 2);
73                 skip_bits(&h->gb, 1);                 /* nuit_field_based_flag */
74                 skip_bits(&h->gb, 5);                 /* counting_type */
75                 full_timestamp_flag = get_bits(&h->gb, 1);
76                 skip_bits(&h->gb, 1);                 /* discontinuity_flag */
77                 skip_bits(&h->gb, 1);                 /* cnt_dropped_flag */
78                 skip_bits(&h->gb, 8);                 /* n_frames */
79                 if(full_timestamp_flag){
80                     skip_bits(&h->gb, 6);             /* seconds_value 0..59 */
81                     skip_bits(&h->gb, 6);             /* minutes_value 0..59 */
82                     skip_bits(&h->gb, 5);             /* hours_value 0..23 */
83                 }else{
84                     if(get_bits(&h->gb, 1)){          /* seconds_flag */
85                         skip_bits(&h->gb, 6);         /* seconds_value range 0..59 */
86                         if(get_bits(&h->gb, 1)){      /* minutes_flag */
87                             skip_bits(&h->gb, 6);     /* minutes_value 0..59 */
88                             if(get_bits(&h->gb, 1))   /* hours_flag */
89                                 skip_bits(&h->gb, 5); /* hours_value 0..23 */
90                         }
91                     }
92                 }
93                 if(sps->time_offset_length > 0)
94                     skip_bits(&h->gb, sps->time_offset_length); /* time_offset */
95             }
96         }
97
98         if(h->avctx->debug & FF_DEBUG_PICT_INFO)
99             av_log(h->avctx, AV_LOG_DEBUG, "ct_type:%X pic_struct:%d\n", h->sei_ct_type, h->sei_pic_struct);
100     }
101     return 0;
102 }
103
104 static int decode_user_data_itu_t_t35(H264Context *h, int size) {
105     uint32_t user_identifier;
106     int dtg_active_format;
107
108     if (size < 7)
109         return -1;
110     size -= 7;
111
112     skip_bits(&h->gb, 8);   // country_code
113     skip_bits(&h->gb, 16);  // provider_code
114     user_identifier = get_bits_long(&h->gb, 32);
115
116     switch (user_identifier) {
117         case 0x44544731:    // "DTG1" - AFD_data
118             if (size < 1)
119                 return -1;
120             skip_bits(&h->gb, 1);
121             if (get_bits(&h->gb, 1)) {
122                 skip_bits(&h->gb, 6);
123                 if (size < 2)
124                     return -1;
125                 skip_bits(&h->gb, 4);
126                 dtg_active_format = get_bits(&h->gb, 4);
127                 h->avctx->dtg_active_format = dtg_active_format;
128             } else {
129                 skip_bits(&h->gb, 6);
130             }
131             break;
132         default:
133             skip_bits(&h->gb, size * 8);
134             break;
135     }
136
137     return 0;
138 }
139
140 static int decode_unregistered_user_data(H264Context *h, int size){
141     uint8_t user_data[16+256];
142     int e, build, i;
143
144     if(size<16)
145         return -1;
146
147     for(i=0; i<sizeof(user_data)-1 && i<size; i++){
148         user_data[i]= get_bits(&h->gb, 8);
149     }
150
151     user_data[i]= 0;
152     e= sscanf(user_data+16, "x264 - core %d"/*%s - H.264/MPEG-4 AVC codec - Copyleft 2005 - http://www.videolan.org/x264.html*/, &build);
153     if(e==1 && build>0)
154         h->x264_build= build;
155     if(e==1 && build==1 && !strncmp(user_data+16, "x264 - core 0000", 16))
156         h->x264_build = 67;
157
158     if(h->avctx->debug & FF_DEBUG_BUGS)
159         av_log(h->avctx, AV_LOG_DEBUG, "user data:\"%s\"\n", user_data+16);
160
161     for(; i<size; i++)
162         skip_bits(&h->gb, 8);
163
164     return 0;
165 }
166
167 static int decode_recovery_point(H264Context *h){
168     h->sei_recovery_frame_cnt = get_ue_golomb(&h->gb);
169     skip_bits(&h->gb, 4);       /* 1b exact_match_flag, 1b broken_link_flag, 2b changing_slice_group_idc */
170
171     if(h->avctx->debug & FF_DEBUG_PICT_INFO)
172         av_log(h->avctx, AV_LOG_DEBUG, "sei_recovery_frame_cnt: %d\n", h->sei_recovery_frame_cnt);
173
174     return 0;
175 }
176
177 static int decode_buffering_period(H264Context *h){
178     unsigned int sps_id;
179     int sched_sel_idx;
180     SPS *sps;
181
182     sps_id = get_ue_golomb_31(&h->gb);
183     if(sps_id > 31 || !h->sps_buffers[sps_id]) {
184         av_log(h->avctx, AV_LOG_ERROR, "non-existing SPS %d referenced in buffering period\n", sps_id);
185         return -1;
186     }
187     sps = h->sps_buffers[sps_id];
188
189     // NOTE: This is really so duplicated in the standard... See H.264, D.1.1
190     if (sps->nal_hrd_parameters_present_flag) {
191         for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
192             h->initial_cpb_removal_delay[sched_sel_idx] = get_bits_long(&h->gb, sps->initial_cpb_removal_delay_length);
193             skip_bits(&h->gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset
194         }
195     }
196     if (sps->vcl_hrd_parameters_present_flag) {
197         for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
198             h->initial_cpb_removal_delay[sched_sel_idx] = get_bits_long(&h->gb, sps->initial_cpb_removal_delay_length);
199             skip_bits(&h->gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset
200         }
201     }
202
203     h->sei_buffering_period_present = 1;
204     return 0;
205 }
206
207 int ff_h264_decode_sei(H264Context *h){
208     while (get_bits_left(&h->gb) > 16) {
209         int size, type;
210
211         type=0;
212         do{
213             if (get_bits_left(&h->gb) < 8)
214                 return -1;
215             type+= show_bits(&h->gb, 8);
216         }while(get_bits(&h->gb, 8) == 255);
217
218         size=0;
219         do{
220             if (get_bits_left(&h->gb) < 8)
221                 return -1;
222             size+= show_bits(&h->gb, 8);
223         }while(get_bits(&h->gb, 8) == 255);
224
225         if(h->avctx->debug&FF_DEBUG_STARTCODE)
226             av_log(h->avctx, AV_LOG_DEBUG, "SEI %d len:%d\n", type, size);
227
228         switch(type){
229         case SEI_TYPE_PIC_TIMING: // Picture timing SEI
230             if(decode_picture_timing(h) < 0)
231                 return -1;
232             break;
233         case SEI_TYPE_USER_DATA_ITU_T_T35:
234             if(decode_user_data_itu_t_t35(h, size) < 0)
235                 return -1;
236             break;
237         case SEI_TYPE_USER_DATA_UNREGISTERED:
238             if(decode_unregistered_user_data(h, size) < 0)
239                 return -1;
240             break;
241         case SEI_TYPE_RECOVERY_POINT:
242             if(decode_recovery_point(h) < 0)
243                 return -1;
244             break;
245         case SEI_BUFFERING_PERIOD:
246             if(decode_buffering_period(h) < 0)
247                 return -1;
248             break;
249         default:
250             skip_bits(&h->gb, 8*size);
251         }
252
253         //FIXME check bits here
254         align_get_bits(&h->gb);
255     }
256
257     return 0;
258 }