/* * H.26L/H.264/AVC/JVT/14496-10/... sei decoding * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at> * * This file is part of Libav. * * Libav is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * Libav is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * H.264 / AVC / MPEG4 part10 sei decoding. * @author Michael Niedermayer <michaelni@gmx.at> */ #include "avcodec.h" #include "golomb.h" #include "h264.h" #include "internal.h" static const uint8_t sei_num_clock_ts_table[9] = { 1, 1, 1, 2, 2, 3, 3, 2, 3 }; void ff_h264_reset_sei(H264Context *h) { h->sei_recovery_frame_cnt = -1; h->sei_dpb_output_delay = 0; h->sei_cpb_removal_delay = -1; h->sei_buffering_period_present = 0; h->sei_frame_packing_present = 0; } static int decode_picture_timing(H264Context *h) { if (h->sps.nal_hrd_parameters_present_flag || h->sps.vcl_hrd_parameters_present_flag) { h->sei_cpb_removal_delay = get_bits(&h->gb, h->sps.cpb_removal_delay_length); h->sei_dpb_output_delay = get_bits(&h->gb, h->sps.dpb_output_delay_length); } if (h->sps.pic_struct_present_flag) { unsigned int i, num_clock_ts; h->sei_pic_struct = get_bits(&h->gb, 4); h->sei_ct_type = 0; if (h->sei_pic_struct > SEI_PIC_STRUCT_FRAME_TRIPLING) return AVERROR_INVALIDDATA; num_clock_ts = sei_num_clock_ts_table[h->sei_pic_struct]; for (i = 0; i < num_clock_ts; i++) { if (get_bits(&h->gb, 1)) { /* clock_timestamp_flag */ unsigned int full_timestamp_flag; h->sei_ct_type |= 1 << get_bits(&h->gb, 2); skip_bits(&h->gb, 1); /* nuit_field_based_flag */ skip_bits(&h->gb, 5); /* counting_type */ full_timestamp_flag = get_bits(&h->gb, 1); skip_bits(&h->gb, 1); /* discontinuity_flag */ skip_bits(&h->gb, 1); /* cnt_dropped_flag */ skip_bits(&h->gb, 8); /* n_frames */ if (full_timestamp_flag) { skip_bits(&h->gb, 6); /* seconds_value 0..59 */ skip_bits(&h->gb, 6); /* minutes_value 0..59 */ skip_bits(&h->gb, 5); /* hours_value 0..23 */ } else { if (get_bits(&h->gb, 1)) { /* seconds_flag */ skip_bits(&h->gb, 6); /* seconds_value range 0..59 */ if (get_bits(&h->gb, 1)) { /* minutes_flag */ skip_bits(&h->gb, 6); /* minutes_value 0..59 */ if (get_bits(&h->gb, 1)) /* hours_flag */ skip_bits(&h->gb, 5); /* hours_value 0..23 */ } } } if (h->sps.time_offset_length > 0) skip_bits(&h->gb, h->sps.time_offset_length); /* time_offset */ } } if (h->avctx->debug & FF_DEBUG_PICT_INFO) av_log(h->avctx, AV_LOG_DEBUG, "ct_type:%X pic_struct:%d\n", h->sei_ct_type, h->sei_pic_struct); } return 0; } static int decode_unregistered_user_data(H264Context *h, int size) { uint8_t user_data[16 + 256]; int e, build, i; if (size < 16) return AVERROR_INVALIDDATA; for (i = 0; i < sizeof(user_data) - 1 && i < size; i++) user_data[i] = get_bits(&h->gb, 8); user_data[i] = 0; e = sscanf(user_data + 16, "x264 - core %d", &build); if (e == 1 && build > 0) h->x264_build = build; if (h->avctx->debug & FF_DEBUG_BUGS) av_log(h->avctx, AV_LOG_DEBUG, "user data:\"%s\"\n", user_data + 16); for (; i < size; i++) skip_bits(&h->gb, 8); return 0; } static int decode_recovery_point(H264Context *h) { h->sei_recovery_frame_cnt = get_ue_golomb(&h->gb); /* 1b exact_match_flag, * 1b broken_link_flag, * 2b changing_slice_group_idc */ skip_bits(&h->gb, 4); return 0; } static int decode_buffering_period(H264Context *h) { unsigned int sps_id; int sched_sel_idx; SPS *sps; sps_id = get_ue_golomb_31(&h->gb); if (sps_id > 31 || !h->sps_buffers[sps_id]) { av_log(h->avctx, AV_LOG_ERROR, "non-existing SPS %d referenced in buffering period\n", sps_id); return AVERROR_INVALIDDATA; } sps = h->sps_buffers[sps_id]; // NOTE: This is really so duplicated in the standard... See H.264, D.1.1 if (sps->nal_hrd_parameters_present_flag) { for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) { h->initial_cpb_removal_delay[sched_sel_idx] = get_bits(&h->gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset skip_bits(&h->gb, sps->initial_cpb_removal_delay_length); } } if (sps->vcl_hrd_parameters_present_flag) { for (sched_sel_idx = 0; sched_sel_idx < sps->cpb_cnt; sched_sel_idx++) { h->initial_cpb_removal_delay[sched_sel_idx] = get_bits(&h->gb, sps->initial_cpb_removal_delay_length); // initial_cpb_removal_delay_offset skip_bits(&h->gb, sps->initial_cpb_removal_delay_length); } } h->sei_buffering_period_present = 1; return 0; } static int decode_frame_packing_arrangement(H264Context *h) { get_ue_golomb(&h->gb); // frame_packing_arrangement_id h->sei_frame_packing_present = !get_bits1(&h->gb); if (h->sei_frame_packing_present) { h->frame_packing_arrangement_type = get_bits(&h->gb, 7); h->quincunx_subsampling = get_bits1(&h->gb); h->content_interpretation_type = get_bits(&h->gb, 6); // the following skips: spatial_flipping_flag, frame0_flipped_flag, // field_views_flag, current_frame_is_frame0_flag, // frame0_self_contained_flag, frame1_self_contained_flag skip_bits(&h->gb, 6); if (!h->quincunx_subsampling && h->frame_packing_arrangement_type != 5) skip_bits(&h->gb, 16); // frame[01]_grid_position_[xy] skip_bits(&h->gb, 8); // frame_packing_arrangement_reserved_byte get_ue_golomb(&h->gb); // frame_packing_arrangement_repetition_period } skip_bits1(&h->gb); // frame_packing_arrangement_extension_flag return 0; } int ff_h264_decode_sei(H264Context *h) { while (get_bits_left(&h->gb) > 16) { int size = 0; int type = 0; int ret = 0; do type += show_bits(&h->gb, 8); while (get_bits(&h->gb, 8) == 255); do size += show_bits(&h->gb, 8); while (get_bits(&h->gb, 8) == 255); if (size > get_bits_left(&h->gb) / 8) { av_log(h->avctx, AV_LOG_ERROR, "SEI type %d truncated at %d\n", type, get_bits_left(&h->gb)); return AVERROR_INVALIDDATA; } switch (type) { case SEI_TYPE_PIC_TIMING: // Picture timing SEI ret = decode_picture_timing(h); if (ret < 0) return ret; break; case SEI_TYPE_USER_DATA_UNREGISTERED: ret = decode_unregistered_user_data(h, size); if (ret < 0) return ret; break; case SEI_TYPE_RECOVERY_POINT: ret = decode_recovery_point(h); if (ret < 0) return ret; break; case SEI_TYPE_BUFFERING_PERIOD: ret = decode_buffering_period(h); if (ret < 0) return ret; break; case SEI_TYPE_FRAME_PACKING: ret = decode_frame_packing_arrangement(h); if (ret < 0) return ret; break; default: av_log(h->avctx, AV_LOG_DEBUG, "unknown SEI type %d\n", type); skip_bits(&h->gb, 8 * size); } // FIXME check bits here align_get_bits(&h->gb); } return 0; }