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>
33 static const uint8_t sei_num_clock_ts_table[9] = {
34 1, 1, 1, 2, 2, 3, 3, 2, 3
37 void ff_h264_reset_sei(H264Context *h)
39 h->sei_recovery_frame_cnt = -1;
40 h->sei_dpb_output_delay = 0;
41 h->sei_cpb_removal_delay = -1;
42 h->sei_buffering_period_present = 0;
43 h->sei_frame_packing_present = 0;
46 static int decode_picture_timing(H264Context *h)
48 if (h->sps.nal_hrd_parameters_present_flag ||
49 h->sps.vcl_hrd_parameters_present_flag) {
50 h->sei_cpb_removal_delay = get_bits(&h->gb,
51 h->sps.cpb_removal_delay_length);
52 h->sei_dpb_output_delay = get_bits(&h->gb,
53 h->sps.dpb_output_delay_length);
55 if (h->sps.pic_struct_present_flag) {
56 unsigned int i, num_clock_ts;
58 h->sei_pic_struct = get_bits(&h->gb, 4);
61 if (h->sei_pic_struct > SEI_PIC_STRUCT_FRAME_TRIPLING)
62 return AVERROR_INVALIDDATA;
64 num_clock_ts = sei_num_clock_ts_table[h->sei_pic_struct];
66 for (i = 0; i < num_clock_ts; i++) {
67 if (get_bits(&h->gb, 1)) { /* clock_timestamp_flag */
68 unsigned int full_timestamp_flag;
70 h->sei_ct_type |= 1 << get_bits(&h->gb, 2);
71 skip_bits(&h->gb, 1); /* nuit_field_based_flag */
72 skip_bits(&h->gb, 5); /* counting_type */
73 full_timestamp_flag = get_bits(&h->gb, 1);
74 skip_bits(&h->gb, 1); /* discontinuity_flag */
75 skip_bits(&h->gb, 1); /* cnt_dropped_flag */
76 skip_bits(&h->gb, 8); /* n_frames */
77 if (full_timestamp_flag) {
78 skip_bits(&h->gb, 6); /* seconds_value 0..59 */
79 skip_bits(&h->gb, 6); /* minutes_value 0..59 */
80 skip_bits(&h->gb, 5); /* hours_value 0..23 */
82 if (get_bits(&h->gb, 1)) { /* seconds_flag */
83 skip_bits(&h->gb, 6); /* seconds_value range 0..59 */
84 if (get_bits(&h->gb, 1)) { /* minutes_flag */
85 skip_bits(&h->gb, 6); /* minutes_value 0..59 */
86 if (get_bits(&h->gb, 1)) /* hours_flag */
87 skip_bits(&h->gb, 5); /* hours_value 0..23 */
91 if (h->sps.time_offset_length > 0)
93 h->sps.time_offset_length); /* time_offset */
97 if (h->avctx->debug & FF_DEBUG_PICT_INFO)
98 av_log(h->avctx, AV_LOG_DEBUG, "ct_type:%X pic_struct:%d\n",
99 h->sei_ct_type, h->sei_pic_struct);
104 static int decode_unregistered_user_data(H264Context *h, int size)
106 uint8_t user_data[16 + 256];
110 return AVERROR_INVALIDDATA;
112 for (i = 0; i < sizeof(user_data) - 1 && i < size; i++)
113 user_data[i] = get_bits(&h->gb, 8);
116 e = sscanf(user_data + 16, "x264 - core %d", &build);
117 if (e == 1 && build > 0)
118 h->x264_build = build;
120 if (h->avctx->debug & FF_DEBUG_BUGS)
121 av_log(h->avctx, AV_LOG_DEBUG, "user data:\"%s\"\n", user_data + 16);
123 for (; i < size; i++)
124 skip_bits(&h->gb, 8);
129 static int decode_recovery_point(H264Context *h)
131 h->sei_recovery_frame_cnt = get_ue_golomb(&h->gb);
133 /* 1b exact_match_flag,
134 * 1b broken_link_flag,
135 * 2b changing_slice_group_idc */
136 skip_bits(&h->gb, 4);
141 static int decode_buffering_period(H264Context *h)
147 sps_id = get_ue_golomb_31(&h->gb);
148 if (sps_id > 31 || !h->sps_buffers[sps_id]) {
149 av_log(h->avctx, AV_LOG_ERROR,
150 "non-existing SPS %d referenced in buffering period\n", sps_id);
151 return AVERROR_INVALIDDATA;
153 sps = h->sps_buffers[sps_id];
155 // NOTE: This is really so duplicated in the standard... See H.264, D.1.1
156 if (sps->nal_hrd_parameters_present_flag) {
157 for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
158 h->initial_cpb_removal_delay[sched_sel_idx] =
159 get_bits(&h->gb, sps->initial_cpb_removal_delay_length);
160 // initial_cpb_removal_delay_offset
161 skip_bits(&h->gb, sps->initial_cpb_removal_delay_length);
164 if (sps->vcl_hrd_parameters_present_flag) {
165 for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) {
166 h->initial_cpb_removal_delay[sched_sel_idx] =
167 get_bits(&h->gb, sps->initial_cpb_removal_delay_length);
168 // initial_cpb_removal_delay_offset
169 skip_bits(&h->gb, sps->initial_cpb_removal_delay_length);
173 h->sei_buffering_period_present = 1;
177 static int decode_frame_packing_arrangement(H264Context *h)
179 get_ue_golomb(&h->gb); // frame_packing_arrangement_id
180 h->sei_frame_packing_present = !get_bits1(&h->gb);
182 if (h->sei_frame_packing_present) {
183 h->frame_packing_arrangement_type = get_bits(&h->gb, 7);
184 h->quincunx_subsampling = get_bits1(&h->gb);
185 h->content_interpretation_type = get_bits(&h->gb, 6);
187 // the following skips: spatial_flipping_flag, frame0_flipped_flag,
188 // field_views_flag, current_frame_is_frame0_flag,
189 // frame0_self_contained_flag, frame1_self_contained_flag
190 skip_bits(&h->gb, 6);
192 if (!h->quincunx_subsampling && h->frame_packing_arrangement_type != 5)
193 skip_bits(&h->gb, 16); // frame[01]_grid_position_[xy]
194 skip_bits(&h->gb, 8); // frame_packing_arrangement_reserved_byte
195 get_ue_golomb(&h->gb); // frame_packing_arrangement_repetition_period
197 skip_bits1(&h->gb); // frame_packing_arrangement_extension_flag
202 int ff_h264_decode_sei(H264Context *h)
204 while (get_bits_left(&h->gb) > 16) {
210 type += show_bits(&h->gb, 8);
211 while (get_bits(&h->gb, 8) == 255);
214 size += show_bits(&h->gb, 8);
215 while (get_bits(&h->gb, 8) == 255);
217 if (size > get_bits_left(&h->gb) / 8) {
218 av_log(h->avctx, AV_LOG_ERROR, "SEI type %d truncated at %d\n",
219 type, get_bits_left(&h->gb));
220 return AVERROR_INVALIDDATA;
224 case SEI_TYPE_PIC_TIMING: // Picture timing SEI
225 ret = decode_picture_timing(h);
229 case SEI_TYPE_USER_DATA_UNREGISTERED:
230 ret = decode_unregistered_user_data(h, size);
234 case SEI_TYPE_RECOVERY_POINT:
235 ret = decode_recovery_point(h);
239 case SEI_TYPE_BUFFERING_PERIOD:
240 ret = decode_buffering_period(h);
244 case SEI_TYPE_FRAME_PACKING:
245 ret = decode_frame_packing_arrangement(h);
250 av_log(h->avctx, AV_LOG_DEBUG, "unknown SEI type %d\n", type);
251 skip_bits(&h->gb, 8 * size);
254 // FIXME check bits here
255 align_get_bits(&h->gb);