2 * H.26L/H.264/AVC/JVT/14496-10/... sei decoding
3 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
5 * This file is part of Libav.
7 * Libav 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.
12 * Libav 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.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * H.264 / AVC / MPEG4 part10 sei decoding.
25 * @author Michael Niedermayer <michaelni@gmx.at>
36 static const uint8_t sei_num_clock_ts_table[9] = {
37 1, 1, 1, 2, 2, 3, 3, 2, 3
40 void ff_h264_reset_sei(H264Context *h)
42 h->sei_recovery_frame_cnt = -1;
43 h->sei_dpb_output_delay = 0;
44 h->sei_cpb_removal_delay = -1;
45 h->sei_buffering_period_present = 0;
48 static int decode_picture_timing(H264Context *h)
50 if (h->sps.nal_hrd_parameters_present_flag ||
51 h->sps.vcl_hrd_parameters_present_flag) {
52 h->sei_cpb_removal_delay = get_bits(&h->gb,
53 h->sps.cpb_removal_delay_length);
54 h->sei_dpb_output_delay = get_bits(&h->gb,
55 h->sps.dpb_output_delay_length);
57 if (h->sps.pic_struct_present_flag) {
58 unsigned int i, num_clock_ts;
60 h->sei_pic_struct = get_bits(&h->gb, 4);
63 if (h->sei_pic_struct > SEI_PIC_STRUCT_FRAME_TRIPLING)
64 return AVERROR_INVALIDDATA;
66 num_clock_ts = sei_num_clock_ts_table[h->sei_pic_struct];
68 for (i = 0; i < num_clock_ts; i++) {
69 if (get_bits(&h->gb, 1)) { /* clock_timestamp_flag */
70 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 */
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 */
93 if (h->sps.time_offset_length > 0)
95 h->sps.time_offset_length); /* time_offset */
99 if (h->avctx->debug & FF_DEBUG_PICT_INFO)
100 av_log(h->avctx, AV_LOG_DEBUG, "ct_type:%X pic_struct:%d\n",
101 h->sei_ct_type, h->sei_pic_struct);
106 static int decode_unregistered_user_data(H264Context *h, int size)
108 uint8_t user_data[16 + 256];
112 return AVERROR_INVALIDDATA;
114 for (i = 0; i < sizeof(user_data) - 1 && i < size; i++)
115 user_data[i] = get_bits(&h->gb, 8);
118 e = sscanf(user_data + 16, "x264 - core %d", &build);
119 if (e == 1 && build > 0)
120 h->x264_build = build;
122 if (h->avctx->debug & FF_DEBUG_BUGS)
123 av_log(h->avctx, AV_LOG_DEBUG, "user data:\"%s\"\n", user_data + 16);
125 for (; i < size; i++)
126 skip_bits(&h->gb, 8);
131 static int decode_recovery_point(H264Context *h)
133 h->sei_recovery_frame_cnt = get_ue_golomb(&h->gb);
135 /* 1b exact_match_flag,
136 * 1b broken_link_flag,
137 * 2b changing_slice_group_idc */
138 skip_bits(&h->gb, 4);
143 static int decode_buffering_period(H264Context *h)
149 sps_id = get_ue_golomb_31(&h->gb);
150 if (sps_id > 31 || !h->sps_buffers[sps_id]) {
151 av_log(h->avctx, AV_LOG_ERROR,
152 "non-existing SPS %d referenced in buffering period\n", sps_id);
153 return AVERROR_INVALIDDATA;
155 sps = h->sps_buffers[sps_id];
157 // NOTE: This is really so duplicated in the standard... See H.264, D.1.1
158 if (sps->nal_hrd_parameters_present_flag) {
159 for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
160 h->initial_cpb_removal_delay[sched_sel_idx] =
161 get_bits(&h->gb, sps->initial_cpb_removal_delay_length);
162 // initial_cpb_removal_delay_offset
163 skip_bits(&h->gb, sps->initial_cpb_removal_delay_length);
166 if (sps->vcl_hrd_parameters_present_flag) {
167 for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
168 h->initial_cpb_removal_delay[sched_sel_idx] =
169 get_bits(&h->gb, sps->initial_cpb_removal_delay_length);
170 // initial_cpb_removal_delay_offset
171 skip_bits(&h->gb, sps->initial_cpb_removal_delay_length);
175 h->sei_buffering_period_present = 1;
179 int ff_h264_decode_sei(H264Context *h)
181 while (get_bits_left(&h->gb) > 16) {
187 type += show_bits(&h->gb, 8);
188 while (get_bits(&h->gb, 8) == 255);
191 size += show_bits(&h->gb, 8);
192 while (get_bits(&h->gb, 8) == 255);
195 case SEI_TYPE_PIC_TIMING: // Picture timing SEI
196 ret = decode_picture_timing(h);
200 case SEI_TYPE_USER_DATA_UNREGISTERED:
201 ret = decode_unregistered_user_data(h, size);
205 case SEI_TYPE_RECOVERY_POINT:
206 ret = decode_recovery_point(h);
210 case SEI_BUFFERING_PERIOD:
211 ret = decode_buffering_period(h);
216 skip_bits(&h->gb, 8 * size);
219 // FIXME check bits here
220 align_get_bits(&h->gb);