| /* |
| * 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 { |
| unsigned num_remaining_tiles_in_slice_minus1 = get_ue_golomb_long(gb); |
| if (num_remaining_tiles_in_slice_minus1 > EVC_MAX_TILE_ROWS * EVC_MAX_TILE_COLUMNS - 2) |
| return AVERROR_INVALIDDATA; |
| |
| num_tiles_in_slice = num_remaining_tiles_in_slice_minus1 + 2; |
| sh->num_remaining_tiles_in_slice_minus1 = num_remaining_tiles_in_slice_minus1; |
| 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 = 1 << sps->log2_sub_gop_length; |
| |
| if (tid > (SubGopLength > 1 ? 1 + av_log2(SubGopLength - 1) : 0)) |
| return AVERROR_INVALIDDATA; |
| |
| 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 + av_log2(poc->DocOffset); |
| |
| while (tid != ExpectedTemporalId) { |
| poc->DocOffset = (poc->DocOffset + 1) % SubGopLength; |
| if (poc->DocOffset == 0) |
| ExpectedTemporalId = 0; |
| else |
| ExpectedTemporalId = 1 + av_log2(poc->DocOffset); |
| } |
| PocOffset = (int)(SubGopLength * ((2.0 * poc->DocOffset + 1) / (1 << tid) - 2)); |
| poc->PicOrderCntVal = poc->prevPicOrderCntVal + PocOffset; |
| } |
| } |
| } |
| |
| return 0; |
| } |
