/* * This file is part of FFmpeg. * * FFmpeg 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. * * FFmpeg 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 FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "golomb.h" #include "evc.h" #include "evc_parse.h" // @see ISO_IEC_23094-1 (7.3.2.6 Slice layer RBSP syntax) int ff_evc_parse_slice_header(GetBitContext *gb, EVCParserSliceHeader *sh, const EVCParamSets *ps, enum EVCNALUnitType nalu_type) { const EVCParserPPS *pps; const EVCParserSPS *sps; int num_tiles_in_slice = 0; unsigned slice_pic_parameter_set_id; slice_pic_parameter_set_id = get_ue_golomb_31(gb); if (slice_pic_parameter_set_id >= EVC_MAX_PPS_COUNT) return AVERROR_INVALIDDATA; pps = ps->pps[slice_pic_parameter_set_id]; if(!pps) return AVERROR_INVALIDDATA; sps = ps->sps[pps->pps_seq_parameter_set_id]; if(!sps) return AVERROR_INVALIDDATA; memset(sh, 0, sizeof(*sh)); sh->slice_pic_parameter_set_id = slice_pic_parameter_set_id; if (!pps->single_tile_in_pic_flag) { sh->single_tile_in_slice_flag = get_bits1(gb); sh->first_tile_id = get_bits(gb, pps->tile_id_len_minus1 + 1); } else sh->single_tile_in_slice_flag = 1; if (!sh->single_tile_in_slice_flag) { if (pps->arbitrary_slice_present_flag) sh->arbitrary_slice_flag = get_bits1(gb); if (!sh->arbitrary_slice_flag) sh->last_tile_id = get_bits(gb, pps->tile_id_len_minus1 + 1); else { sh->num_remaining_tiles_in_slice_minus1 = get_ue_golomb_long(gb); num_tiles_in_slice = sh->num_remaining_tiles_in_slice_minus1 + 2; for (int i = 0; i < num_tiles_in_slice - 1; ++i) sh->delta_tile_id_minus1[i] = get_ue_golomb_long(gb); } } sh->slice_type = get_ue_golomb_31(gb); if (nalu_type == EVC_IDR_NUT) sh->no_output_of_prior_pics_flag = get_bits1(gb); if (sps->sps_mmvd_flag && ((sh->slice_type == EVC_SLICE_TYPE_B) || (sh->slice_type == EVC_SLICE_TYPE_P))) sh->mmvd_group_enable_flag = get_bits1(gb); else sh->mmvd_group_enable_flag = 0; if (sps->sps_alf_flag) { int ChromaArrayType = sps->chroma_format_idc; sh->slice_alf_enabled_flag = get_bits1(gb); if (sh->slice_alf_enabled_flag) { sh->slice_alf_luma_aps_id = get_bits(gb, 5); sh->slice_alf_map_flag = get_bits1(gb); sh->slice_alf_chroma_idc = get_bits(gb, 2); if ((ChromaArrayType == 1 || ChromaArrayType == 2) && sh->slice_alf_chroma_idc > 0) sh->slice_alf_chroma_aps_id = get_bits(gb, 5); } if (ChromaArrayType == 3) { int sliceChromaAlfEnabledFlag = 0; int sliceChroma2AlfEnabledFlag = 0; if (sh->slice_alf_chroma_idc == 1) { // @see ISO_IEC_23094-1 (7.4.5) sliceChromaAlfEnabledFlag = 1; sliceChroma2AlfEnabledFlag = 0; } else if (sh->slice_alf_chroma_idc == 2) { sliceChromaAlfEnabledFlag = 0; sliceChroma2AlfEnabledFlag = 1; } else if (sh->slice_alf_chroma_idc == 3) { sliceChromaAlfEnabledFlag = 1; sliceChroma2AlfEnabledFlag = 1; } else { sliceChromaAlfEnabledFlag = 0; sliceChroma2AlfEnabledFlag = 0; } if (!sh->slice_alf_enabled_flag) sh->slice_alf_chroma_idc = get_bits(gb, 2); if (sliceChromaAlfEnabledFlag) { sh->slice_alf_chroma_aps_id = get_bits(gb, 5); sh->slice_alf_chroma_map_flag = get_bits1(gb); } if (sliceChroma2AlfEnabledFlag) { sh->slice_alf_chroma2_aps_id = get_bits(gb, 5); sh->slice_alf_chroma2_map_flag = get_bits1(gb); } } } if (nalu_type != EVC_IDR_NUT) { if (sps->sps_pocs_flag) sh->slice_pic_order_cnt_lsb = get_bits(gb, sps->log2_max_pic_order_cnt_lsb_minus4 + 4); } // @note // If necessary, add the missing fields to the EVCParserSliceHeader structure // and then extend parser implementation return 0; } int ff_evc_derive_poc(const EVCParamSets *ps, const EVCParserSliceHeader *sh, EVCParserPoc *poc, enum EVCNALUnitType nalu_type, int tid) { const EVCParserPPS *pps = ps->pps[sh->slice_pic_parameter_set_id]; const EVCParserSPS *sps; if (!pps) return AVERROR_INVALIDDATA; sps = ps->sps[pps->pps_seq_parameter_set_id]; if (!sps) return AVERROR_INVALIDDATA; if (sps->sps_pocs_flag) { int PicOrderCntMsb = 0; poc->prevPicOrderCntVal = poc->PicOrderCntVal; if (nalu_type == EVC_IDR_NUT) PicOrderCntMsb = 0; else { int MaxPicOrderCntLsb = 1 << (sps->log2_max_pic_order_cnt_lsb_minus4 + 4); int prevPicOrderCntLsb = poc->PicOrderCntVal & (MaxPicOrderCntLsb - 1); int prevPicOrderCntMsb = poc->PicOrderCntVal - prevPicOrderCntLsb; if ((sh->slice_pic_order_cnt_lsb < prevPicOrderCntLsb) && ((prevPicOrderCntLsb - sh->slice_pic_order_cnt_lsb) >= (MaxPicOrderCntLsb / 2))) PicOrderCntMsb = prevPicOrderCntMsb + MaxPicOrderCntLsb; else if ((sh->slice_pic_order_cnt_lsb > prevPicOrderCntLsb) && ((sh->slice_pic_order_cnt_lsb - prevPicOrderCntLsb) > (MaxPicOrderCntLsb / 2))) PicOrderCntMsb = prevPicOrderCntMsb - MaxPicOrderCntLsb; else PicOrderCntMsb = prevPicOrderCntMsb; } poc->PicOrderCntVal = PicOrderCntMsb + sh->slice_pic_order_cnt_lsb; } else { if (nalu_type == EVC_IDR_NUT) { poc->PicOrderCntVal = 0; poc->DocOffset = -1; } else { int SubGopLength = (int)pow(2.0, sps->log2_sub_gop_length); if (tid == 0) { poc->PicOrderCntVal = poc->prevPicOrderCntVal + SubGopLength; poc->DocOffset = 0; poc->prevPicOrderCntVal = poc->PicOrderCntVal; } else { int ExpectedTemporalId; int PocOffset; int prevDocOffset = poc->DocOffset; poc->DocOffset = (prevDocOffset + 1) % SubGopLength; if (poc->DocOffset == 0) { poc->prevPicOrderCntVal += SubGopLength; ExpectedTemporalId = 0; } else ExpectedTemporalId = 1 + (int)log2(poc->DocOffset); while (tid != ExpectedTemporalId) { poc->DocOffset = (poc->DocOffset + 1) % SubGopLength; if (poc->DocOffset == 0) ExpectedTemporalId = 0; else ExpectedTemporalId = 1 + (int)log2(poc->DocOffset); } PocOffset = (int)(SubGopLength * ((2.0 * poc->DocOffset + 1) / (int)pow(2.0, tid) - 2)); poc->PicOrderCntVal = poc->prevPicOrderCntVal + PocOffset; } } } return 0; }