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>
35 static const uint8_t sei_num_clock_ts_table[9] = {
36 1, 1, 1, 2, 2, 3, 3, 2, 3
39 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;
47 static int decode_picture_timing(H264Context *h)
49 if (h->sps.nal_hrd_parameters_present_flag ||
50 h->sps.vcl_hrd_parameters_present_flag) {
51 h->sei_cpb_removal_delay = get_bits(&h->gb,
52 h->sps.cpb_removal_delay_length);
53 h->sei_dpb_output_delay = get_bits(&h->gb,
54 h->sps.dpb_output_delay_length);
56 if (h->sps.pic_struct_present_flag) {
57 unsigned int i, num_clock_ts;
59 h->sei_pic_struct = get_bits(&h->gb, 4);
62 if (h->sei_pic_struct > SEI_PIC_STRUCT_FRAME_TRIPLING)
63 return AVERROR_INVALIDDATA;
65 num_clock_ts = sei_num_clock_ts_table[h->sei_pic_struct];
67 for (i = 0; i < num_clock_ts; i++) {
68 if (get_bits(&h->gb, 1)) { /* clock_timestamp_flag */
69 unsigned int full_timestamp_flag;
71 h->sei_ct_type |= 1 << get_bits(&h->gb, 2);
72 skip_bits(&h->gb, 1); /* nuit_field_based_flag */
73 skip_bits(&h->gb, 5); /* counting_type */
74 full_timestamp_flag = get_bits(&h->gb, 1);
75 skip_bits(&h->gb, 1); /* discontinuity_flag */
76 skip_bits(&h->gb, 1); /* cnt_dropped_flag */
77 skip_bits(&h->gb, 8); /* n_frames */
78 if (full_timestamp_flag) {
79 skip_bits(&h->gb, 6); /* seconds_value 0..59 */
80 skip_bits(&h->gb, 6); /* minutes_value 0..59 */
81 skip_bits(&h->gb, 5); /* hours_value 0..23 */
83 if (get_bits(&h->gb, 1)) { /* seconds_flag */
84 skip_bits(&h->gb, 6); /* seconds_value range 0..59 */
85 if (get_bits(&h->gb, 1)) { /* minutes_flag */
86 skip_bits(&h->gb, 6); /* minutes_value 0..59 */
87 if (get_bits(&h->gb, 1)) /* hours_flag */
88 skip_bits(&h->gb, 5); /* hours_value 0..23 */
92 if (h->sps.time_offset_length > 0)
94 h->sps.time_offset_length); /* time_offset */
98 if (h->avctx->debug & FF_DEBUG_PICT_INFO)
99 av_log(h->avctx, AV_LOG_DEBUG, "ct_type:%X pic_struct:%d\n",
100 h->sei_ct_type, h->sei_pic_struct);
105 static int decode_unregistered_user_data(H264Context *h, int size)
107 uint8_t user_data[16 + 256];
111 return AVERROR_INVALIDDATA;
113 for (i = 0; i < sizeof(user_data) - 1 && i < size; i++)
114 user_data[i] = get_bits(&h->gb, 8);
117 e = sscanf(user_data + 16, "x264 - core %d", &build);
118 if (e == 1 && build > 0)
119 h->x264_build = build;
121 if (h->avctx->debug & FF_DEBUG_BUGS)
122 av_log(h->avctx, AV_LOG_DEBUG, "user data:\"%s\"\n", user_data + 16);
124 for (; i < size; i++)
125 skip_bits(&h->gb, 8);
130 static int decode_recovery_point(H264Context *h)
132 h->sei_recovery_frame_cnt = get_ue_golomb(&h->gb);
134 /* 1b exact_match_flag,
135 * 1b broken_link_flag,
136 * 2b changing_slice_group_idc */
137 skip_bits(&h->gb, 4);
142 static int decode_buffering_period(H264Context *h)
148 sps_id = get_ue_golomb_31(&h->gb);
149 if (sps_id > 31 || !h->sps_buffers[sps_id]) {
150 av_log(h->avctx, AV_LOG_ERROR,
151 "non-existing SPS %d referenced in buffering period\n", sps_id);
152 return AVERROR_INVALIDDATA;
154 sps = h->sps_buffers[sps_id];
156 // NOTE: This is really so duplicated in the standard... See H.264, D.1.1
157 if (sps->nal_hrd_parameters_present_flag) {
158 for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
159 h->initial_cpb_removal_delay[sched_sel_idx] =
160 get_bits(&h->gb, sps->initial_cpb_removal_delay_length);
161 // initial_cpb_removal_delay_offset
162 skip_bits(&h->gb, sps->initial_cpb_removal_delay_length);
165 if (sps->vcl_hrd_parameters_present_flag) {
166 for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
167 h->initial_cpb_removal_delay[sched_sel_idx] =
168 get_bits(&h->gb, sps->initial_cpb_removal_delay_length);
169 // initial_cpb_removal_delay_offset
170 skip_bits(&h->gb, sps->initial_cpb_removal_delay_length);
174 h->sei_buffering_period_present = 1;
178 int ff_h264_decode_sei(H264Context *h)
180 while (get_bits_left(&h->gb) > 16) {
186 type += show_bits(&h->gb, 8);
187 while (get_bits(&h->gb, 8) == 255);
190 size += show_bits(&h->gb, 8);
191 while (get_bits(&h->gb, 8) == 255);
193 if (size > get_bits_left(&h->gb) / 8) {
194 av_log(h->avctx, AV_LOG_ERROR, "SEI type %d truncated at %d\n",
195 type, get_bits_left(&h->gb));
196 return AVERROR_INVALIDDATA;
200 case SEI_TYPE_PIC_TIMING: // Picture timing SEI
201 ret = decode_picture_timing(h);
205 case SEI_TYPE_USER_DATA_UNREGISTERED:
206 ret = decode_unregistered_user_data(h, size);
210 case SEI_TYPE_RECOVERY_POINT:
211 ret = decode_recovery_point(h);
215 case SEI_BUFFERING_PERIOD:
216 ret = decode_buffering_period(h);
221 av_log(h->avctx, AV_LOG_DEBUG, "unknown SEI type %d\n", type);
222 skip_bits(&h->gb, 8 * size);
225 // FIXME check bits here
226 align_get_bits(&h->gb);