/****************************************************************************** * * Copyright (C) 2012 Ittiam Systems Pvt Ltd, Bangalore * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * ******************************************************************************/ /** ******************************************************************************* * @file * ihevcd_parse_residual.c * * @brief * Contains functions for parsing residual data at TU level * * @author * Harish * * @par List of Functions: * * @remarks * None * ******************************************************************************* */ /*****************************************************************************/ /* File Includes */ /*****************************************************************************/ #include #include #include #include #include #include "ihevc_typedefs.h" #include "iv.h" #include "ivd.h" #include "ihevcd_cxa.h" #include "ihevc_defs.h" #include "ihevc_debug.h" #include "ihevc_structs.h" #include "ihevc_macros.h" #include "ihevc_platform_macros.h" #include "ihevc_common_tables.h" #include "ihevc_error.h" #include "ihevc_cabac_tables.h" #include "ihevcd_trace.h" #include "ihevcd_defs.h" #include "ihevcd_function_selector.h" #include "ihevcd_structs.h" #include "ihevcd_error.h" #include "ihevcd_nal.h" #include "ihevcd_bitstream.h" #include "ihevcd_utils.h" #include "ihevcd_parse_residual.h" #include "ihevcd_cabac.h" /** ***************************************************************************** * @brief returns context increment for sig coeff based on csbf neigbour * flags (bottom and right) and current coeff postion in 4x4 block * See section 9.3.3.1.4 for details on this context increment * * input : neigbour csbf flags(bit0:rightcsbf, bit1:bottom csbf) * coeff idx in raster order (0-15) * * output : context increment for sig coeff flag * ***************************************************************************** */ const UWORD8 gau1_ihevcd_sigcoeff_ctxtinc[3][4][16] = { { /* nbr csbf = 0: sigCtx = (xP+yP == 0) ? 2 : (xP+yP < 3) ? 1: 0 */ { 2, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, /* nbr csbf = 1: sigCtx = (yP == 0) ? 2 : (yP == 1) ? 1: 0 */ { 2, 1, 2, 0, 1, 2, 0, 0, 1, 2, 0, 0, 1, 0, 0, 0 }, /* nbr csbf = 2: sigCtx = (xP == 0) ? 2 : (xP == 1) ? 1: 0 */ { 2, 2, 1, 2, 1, 0, 2, 1, 0, 0, 1, 0, 0, 0, 0, 0 }, /* nbr csbf = 3: sigCtx = 2 */ { 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 }, }, { /* nbr csbf = 0: sigCtx = (xP+yP == 0) ? 2 : (xP+yP < 3) ? 1: 0 */ { 2, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0 }, /* nbr csbf = 1: sigCtx = (yP == 0) ? 2 : (yP == 1) ? 1: 0 */ { 2, 2, 2, 2, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0 }, /* nbr csbf = 2: sigCtx = (xP == 0) ? 2 : (xP == 1) ? 1: 0 */ { 2, 1, 0, 0, 2, 1, 0, 0, 2, 1, 0, 0, 2, 1, 0, 0 }, /* nbr csbf = 3: sigCtx = 2 */ { 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 }, }, { /* nbr csbf = 0: sigCtx = (xP+yP == 0) ? 2 : (xP+yP < 3) ? 1: 0 */ { 2, 1, 1, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0 }, /* nbr csbf = 1: sigCtx = (yP == 0) ? 2 : (yP == 1) ? 1: 0 */ { 2, 1, 0, 0, 2, 1, 0, 0, 2, 1, 0, 0, 2, 1, 0, 0 }, /* nbr csbf = 2: sigCtx = (xP == 0) ? 2 : (xP == 1) ? 1: 0 */ { 2, 2, 2, 2, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0 }, /* nbr csbf = 3: sigCtx = 2 */ { 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 }, }, }; /** ***************************************************************************** * @brief returns context increment for sig coeff for 4x4 tranform size as * per Table 9-39 in section 9.3.3.1.4 * * input : coeff idx in raster order (0-15) * * output : context increment for sig coeff flag * ***************************************************************************** */ const UWORD8 gau1_ihevcd_sigcoeff_ctxtinc_tr4[3][16] = { /* Upright diagonal scan */ { 0, 2, 1, 6, 3, 4, 7, 6, 4, 5, 7, 8, 5, 8, 8, 8, }, /* Horizontal scan */ { 0, 1, 4, 5, 2, 3, 4, 5, 6, 6, 8, 8, 7, 7, 8, 8, }, /* Vertical scan */ { 0, 2, 6, 7, 1, 3, 6, 7, 4, 4, 8, 8, 5, 5, 8, 8, }, }; /** ******************************************************************************* * * @brief * Parses Residual coding * * @par Description: * Parses Residual coding as per Section:7.3.13 * * @param[in] ps_codec * Pointer to codec context * * @returns error code from IHEVCD_ERROR_T * * @remarks * * ******************************************************************************* */ WORD32 ihevcd_parse_residual_coding(codec_t *ps_codec, WORD32 x0, WORD32 y0, WORD32 log2_trafo_size, WORD32 c_idx, WORD32 intra_pred_mode) { IHEVCD_ERROR_T ret = (IHEVCD_ERROR_T)IHEVCD_SUCCESS; WORD32 transform_skip_flag; WORD32 value; pps_t *ps_pps; WORD32 last_scan_pos, last_sub_blk; bitstrm_t *ps_bitstrm = &ps_codec->s_parse.s_bitstrm; WORD32 last_significant_coeff_x_prefix, last_significant_coeff_y_prefix; WORD32 last_significant_coeff_x, last_significant_coeff_y; const UWORD8 *pu1_scan_blk = NULL, *pu1_scan_coeff; WORD32 scan_idx; WORD32 i; WORD32 sign_data_hiding_flag; cab_ctxt_t *ps_cabac = &ps_codec->s_parse.s_cabac; WORD32 gt1_ctxt = 1; WORD32 c_max; UWORD16 au2_csbf[9]; tu_sblk_coeff_data_t *ps_tu_sblk_coeff_data; WORD8 *pi1_num_coded_subblks; WORD32 num_subblks; WORD32 sig_coeff_base_ctxt, abs_gt1_base_ctxt; UNUSED(x0); UNUSED(y0); ps_pps = ps_codec->s_parse.ps_pps; sign_data_hiding_flag = ps_pps->i1_sign_data_hiding_flag; transform_skip_flag = 0; if(ps_pps->i1_transform_skip_enabled_flag && !ps_codec->s_parse.s_cu.i4_cu_transquant_bypass && (log2_trafo_size == 2)) { WORD32 ctxt_idx; if(!c_idx) { ctxt_idx = IHEVC_CAB_TFM_SKIP0; } else { ctxt_idx = IHEVC_CAB_TFM_SKIP12; } TRACE_CABAC_CTXT("transform_skip_flag", ps_cabac->u4_range, ctxt_idx); value = ihevcd_cabac_decode_bin(ps_cabac, ps_bitstrm, ctxt_idx); AEV_TRACE("transform_skip_flag", value, ps_cabac->u4_range); transform_skip_flag = value; } /* code the last_coeff_x_prefix as tunary binarized code */ { WORD32 ctxt_idx_x, ctxt_idx_y, ctx_shift; WORD32 ctx_offset; c_max = (log2_trafo_size << 1) - 1; if(!c_idx) { ctx_offset = (3 * (log2_trafo_size - 2)) + ((log2_trafo_size - 1) >> 2); ctxt_idx_x = IHEVC_CAB_COEFFX_PREFIX + ctx_offset; ctxt_idx_y = IHEVC_CAB_COEFFY_PREFIX + ctx_offset; ctx_shift = (log2_trafo_size + 1) >> 2; } else { ctxt_idx_x = IHEVC_CAB_COEFFX_PREFIX + 15; ctxt_idx_y = IHEVC_CAB_COEFFY_PREFIX + 15; ctx_shift = log2_trafo_size - 2; } TRACE_CABAC_CTXT("last_coeff_x_prefix", ps_cabac->u4_range, ctxt_idx_x); last_significant_coeff_x_prefix = ihevcd_cabac_decode_bins_tunary(ps_cabac, ps_bitstrm, c_max, ctxt_idx_x, ctx_shift, c_max); AEV_TRACE("last_coeff_x_prefix", last_significant_coeff_x_prefix, ps_cabac->u4_range); TRACE_CABAC_CTXT("last_coeff_y_prefix", ps_cabac->u4_range, ctxt_idx_y); last_significant_coeff_y_prefix = ihevcd_cabac_decode_bins_tunary(ps_cabac, ps_bitstrm, c_max, ctxt_idx_y, ctx_shift, c_max); AEV_TRACE("last_coeff_y_prefix", last_significant_coeff_y_prefix, ps_cabac->u4_range); last_significant_coeff_x = last_significant_coeff_x_prefix; if(last_significant_coeff_x_prefix > 3) { WORD32 suf_length = ((last_significant_coeff_x_prefix - 2) >> 1); value = ihevcd_cabac_decode_bypass_bins(ps_cabac, ps_bitstrm, suf_length); AEV_TRACE("last_coeff_x_suffix", value, ps_cabac->u4_range); last_significant_coeff_x = (1 << ((last_significant_coeff_x_prefix >> 1) - 1)) * (2 + (last_significant_coeff_x_prefix & 1)) + value; } last_significant_coeff_y = last_significant_coeff_y_prefix; if(last_significant_coeff_y_prefix > 3) { WORD32 suf_length = ((last_significant_coeff_y_prefix - 2) >> 1); value = ihevcd_cabac_decode_bypass_bins(ps_cabac, ps_bitstrm, suf_length); AEV_TRACE("last_coeff_y_suffix", value, ps_cabac->u4_range); last_significant_coeff_y = (1 << ((last_significant_coeff_y_prefix >> 1) - 1)) * (2 + (last_significant_coeff_y_prefix & 1)) + value; } } /* Choose a scan matrix based on intra flag, intra pred mode, transform size and luma/chroma */ scan_idx = SCAN_DIAG_UPRIGHT; if(PRED_MODE_INTRA == ps_codec->s_parse.s_cu.i4_pred_mode) { if((2 == log2_trafo_size) || ((3 == log2_trafo_size) && (0 == c_idx))) { if((6 <= intra_pred_mode) && (14 >= intra_pred_mode)) { scan_idx = SCAN_VERT; } else if((22 <= intra_pred_mode) && (30 >= intra_pred_mode)) { scan_idx = SCAN_HORZ; } } } /* In case the scan is vertical, then swap X and Y positions */ if(SCAN_VERT == scan_idx) { SWAP(last_significant_coeff_x, last_significant_coeff_y); } { WORD8 *pi1_scan_idx; WORD8 *pi1_buf = (WORD8 *)ps_codec->s_parse.pv_tu_coeff_data; /* First WORD8 gives number of coded subblocks */ pi1_num_coded_subblks = pi1_buf++; /* Set number of coded subblocks in the current TU to zero */ /* This will be updated later */ *pi1_num_coded_subblks = 0; /* Second WORD8 gives (scan idx << 1) | trans_skip */ pi1_scan_idx = pi1_buf++; *pi1_scan_idx = (scan_idx << 1) | transform_skip_flag; /* Store the incremented pointer in pv_tu_coeff_data */ ps_codec->s_parse.pv_tu_coeff_data = pi1_buf; } /** * Given last_significant_coeff_y and last_significant_coeff_x find last sub block * This is done by ignoring lower two bits of last_significant_coeff_y and last_significant_coeff_x * and using scan matrix for lookup */ /* If transform is 4x4, last_sub_blk is zero */ last_sub_blk = 0; /* If transform is larger than 4x4, then based on scan_idx and transform size, choose a scan table */ if(log2_trafo_size > 2) { WORD32 scan_pos; WORD32 scan_mat_size; pu1_scan_blk = (UWORD8 *)gapv_ihevc_scan[scan_idx * 3 + (log2_trafo_size - 2 - 1)]; /* Divide the current transform to 4x4 subblocks and count number of 4x4 in the first row */ /* This will be size of scan matrix to be used for subblock scanning */ scan_mat_size = 1 << (log2_trafo_size - 2); scan_pos = ((last_significant_coeff_y >> 2) * scan_mat_size) + (last_significant_coeff_x >> 2); last_sub_blk = pu1_scan_blk[scan_pos]; } pu1_scan_coeff = &gau1_ihevc_scan4x4[scan_idx][0]; { WORD32 scan_pos; scan_pos = ((last_significant_coeff_y & 3) << 2) + (last_significant_coeff_x & 3); last_scan_pos = pu1_scan_coeff[scan_pos]; } if(log2_trafo_size > 2) pu1_scan_blk = (UWORD8 *)gapv_ihevc_invscan[scan_idx * 3 + (log2_trafo_size - 2 - 1)]; pu1_scan_coeff = &gau1_ihevc_invscan4x4[scan_idx][0]; /* Set CSBF array to zero */ { UWORD32 *pu4_csbf; pu4_csbf = (void *)au2_csbf; *pu4_csbf++ = 0; *pu4_csbf++ = 0; *pu4_csbf++ = 0; *pu4_csbf = 0; /* To avoid a check for y pos, 9th WORD16 in the array is set to zero */ au2_csbf[8] = 0; } /*************************************************************************/ /* derive base context index for sig coeff as per section 9.3.3.1.4 */ /* TODO; convert to look up based on luma/chroma, scan type and tfr size */ /*************************************************************************/ if(!c_idx) { sig_coeff_base_ctxt = IHEVC_CAB_COEFF_FLAG; abs_gt1_base_ctxt = IHEVC_CAB_COEFABS_GRTR1_FLAG; if(3 == log2_trafo_size) { /* 8x8 transform size */ sig_coeff_base_ctxt += (scan_idx == SCAN_DIAG_UPRIGHT) ? 9 : 15; } else if(3 < log2_trafo_size) { /* larger transform sizes */ sig_coeff_base_ctxt += 21; } } else { /* chroma context initializations */ sig_coeff_base_ctxt = IHEVC_CAB_COEFF_FLAG + 27; abs_gt1_base_ctxt = IHEVC_CAB_COEFABS_GRTR1_FLAG + 16; if(3 == log2_trafo_size) { /* 8x8 transform size */ sig_coeff_base_ctxt += 9; } else if(3 < log2_trafo_size) { /* larger transform sizes */ sig_coeff_base_ctxt += 12; } } num_subblks = 0; /* Parse each 4x4 subblocks */ for(i = last_sub_blk; i >= 0; i--) { WORD32 sub_blk_pos; WORD32 infer_sig_coeff_flag; WORD32 cur_csbf; WORD32 n; WORD32 num_coeff; /* Sig coeff map for 16 entries in raster scan order. Upper 16 bits are used. * MSB gives sig coeff flag for 0th coeff and so on * UWORD16 would have been enough but kept as UWORD32 for code optimizations * In arm unnecessary masking operations are saved */ UWORD32 u4_sig_coeff_map_raster; WORD32 sign_hidden; /* Sig coeff map in scan order */ UWORD32 u4_sig_coeff_map; WORD32 coeff_abs_level_greater2_flag; UWORD32 u4_coeff_abs_level_greater1_map; UWORD32 u4_coeff_abs_level_greater2_map; UWORD32 u4_coeff_sign_map; WORD32 first_sig_scan_pos, last_sig_scan_pos, num_greater1_flag, first_greater1_scan_pos; WORD32 num_sig_coeff, sum_abs_level; WORD32 nbr_csbf; WORD32 ctxt_set; WORD32 rice_param; WORD32 xs, ys; sub_blk_pos = 0; if(i && (log2_trafo_size > 2)) sub_blk_pos = pu1_scan_blk[i]; /* Get xs and ys from scan position */ /* This is needed for context modelling of significant coeff flag */ xs = sub_blk_pos & ((1 << (log2_trafo_size - 2)) - 1); ys = sub_blk_pos >> (log2_trafo_size - 2); /* Check if neighbor subblocks are coded */ { nbr_csbf = 0; /* Get Bottom sub blocks CSBF */ nbr_csbf |= (au2_csbf[ys + 1] >> xs) & 1; nbr_csbf <<= 1; /* Get Right sub blocks CSBF */ /* Even if xs is equal to (1 << (log2_trafo_size - 2 )) - 1, since au2_csbf is set to zero at the beginning, csbf for neighbor will be read as 0 */ nbr_csbf |= (au2_csbf[ys] >> (xs + 1)) & 1; } cur_csbf = 0; /* DC coeff is inferred, only if coded_sub_block is explicitly parsed as 1 */ /* i.e. it is not inferred for first and last subblock */ infer_sig_coeff_flag = 0; if((i < last_sub_blk) && (i > 0)) { WORD32 ctxt_idx = IHEVC_CAB_CODED_SUBLK_IDX; /* ctxt based on right / bottom avail csbf, section 9.3.3.1.3 */ ctxt_idx += (nbr_csbf) ? 1 : 0; /* Ctxt based on luma or chroma */ ctxt_idx += c_idx ? 2 : 0; TRACE_CABAC_CTXT("coded_sub_block_flag", ps_cabac->u4_range, ctxt_idx); IHEVCD_CABAC_DECODE_BIN(cur_csbf, ps_cabac, ps_bitstrm, ctxt_idx); AEV_TRACE("coded_sub_block_flag", cur_csbf, ps_cabac->u4_range); infer_sig_coeff_flag = 1; } else /* if((i == last_sub_blk) || (sub_blk_pos == 0)) */ { /* CSBF is set to 1 for first and last subblock */ /* Note for these subblocks sig_coeff_map is not inferred but instead parsed */ cur_csbf = 1; } /* Set current sub blocks CSBF */ { UWORD32 u4_mask = 1 << xs; if(cur_csbf) au2_csbf[ys] |= u4_mask; else au2_csbf[ys] &= ~u4_mask; } /* If current subblock is not coded, proceed to the next subblock */ if(0 == cur_csbf) continue; n = 15; u4_sig_coeff_map_raster = 0; u4_sig_coeff_map = 0; num_coeff = 0; if(i == last_sub_blk) { WORD32 pos = ((last_significant_coeff_y & 3) << 2) + (last_significant_coeff_x & 3); n = (last_scan_pos - 1); /* Set Significant coeff map for last significant coeff flag as 1 */ u4_sig_coeff_map_raster = 1 << pos; u4_sig_coeff_map = 1 << last_scan_pos; num_coeff = 1; } for(; n >= 0; n--) { WORD32 significant_coeff_flag; if((n > 0 || !infer_sig_coeff_flag)) { //WORD32 coeff_pos; WORD32 sig_ctxinc; WORD32 ctxt_idx; /* Coefficient position is needed for deriving context index for significant_coeff_flag */ //coeff_pos = pu1_scan_coeff[n]; /* derive the context inc as per section 9.3.3.1.4 */ sig_ctxinc = 0; if(2 == log2_trafo_size) { /* 4x4 transform size increment uses lookup */ sig_ctxinc = gau1_ihevcd_sigcoeff_ctxtinc_tr4[scan_idx][n]; } else if(n || i) { /* ctxt for AC coeff depends on curpos and neigbour csbf */ sig_ctxinc = gau1_ihevcd_sigcoeff_ctxtinc[scan_idx][nbr_csbf][n]; /* based on luma subblock pos */ sig_ctxinc += (i && (!c_idx)) ? 3 : 0; } else { /* DC coeff has fixed context for luma and chroma */ sig_coeff_base_ctxt = (0 == c_idx) ? IHEVC_CAB_COEFF_FLAG : (IHEVC_CAB_COEFF_FLAG + 27); } ctxt_idx = sig_ctxinc + sig_coeff_base_ctxt; TRACE_CABAC_CTXT("significant_coeff_flag", ps_cabac->u4_range, ctxt_idx); IHEVCD_CABAC_DECODE_BIN(significant_coeff_flag, ps_cabac, ps_bitstrm, ctxt_idx); AEV_TRACE("significant_coeff_flag", significant_coeff_flag, ps_cabac->u4_range); /* If at least one non-zero coeff is signalled then do not infer sig coeff map */ /* for (0,0) coeff in the current sub block */ if(significant_coeff_flag) infer_sig_coeff_flag = 0; // u4_sig_coeff_map_raster |= significant_coeff_flag // << coeff_pos; u4_sig_coeff_map |= significant_coeff_flag << n; num_coeff += significant_coeff_flag; } } /*********************************************************************/ /* If infer_sig_coeff_flag is 1 then treat the 0th coeff as non zero */ /* If infer_sig_coeff_flag is zero, then last significant_coeff_flag */ /* is parsed in the above loop */ /*********************************************************************/ if(infer_sig_coeff_flag) { u4_sig_coeff_map_raster |= 1; u4_sig_coeff_map |= 1; num_coeff++; } /*********************************************************************/ /* First subblock does not get an explicit csbf. It is assumed to */ /* be 1. For this subblock there is chance of getting all */ /* sig_coeff_flags to be zero. In such a case proceed to the next */ /* subblock(which is end of parsing for the current transform block) */ /*********************************************************************/ if(0 == num_coeff) continue; /* Increment number of coded subblocks for the current TU */ num_subblks++; /* Set sig coeff map and subblock position */ ps_tu_sblk_coeff_data = (tu_sblk_coeff_data_t *)ps_codec->s_parse.pv_tu_coeff_data; ps_tu_sblk_coeff_data->u2_sig_coeff_map = u4_sig_coeff_map; ps_tu_sblk_coeff_data->u2_subblk_pos = (ys << 8) | xs; first_sig_scan_pos = 16; last_sig_scan_pos = -1; num_greater1_flag = 0; first_greater1_scan_pos = -1; u4_coeff_abs_level_greater1_map = 0; /* context set based on luma subblock pos */ ctxt_set = (i && (!c_idx)) ? 2 : 0; /* See section 9.3.3.1.5 */ ctxt_set += (0 == gt1_ctxt) ? 1 : 0; gt1_ctxt = 1; /* Instead of initializing n to 15, set it to 31-CLZ(sig coeff map) */ { UWORD32 u4_sig_coeff_map_shift; UWORD32 clz; clz = CLZ(u4_sig_coeff_map); n = 31 - clz; u4_sig_coeff_map_shift = u4_sig_coeff_map << clz; /* For loop for n changed to do while to break early if sig_coeff_map_shift becomes zero */ do { //WORD32 coeff_pos; WORD32 ctxt_idx; //TODO: Scan lookup will be removed later and instead u4_sig_coeff_map will be used //coeff_pos = pu1_scan_coeff[n]; if((u4_sig_coeff_map_shift >> 31) & 1) { /* abs_level_greater1_flag is sent for only first 8 non-zero levels in a subblock */ if(num_greater1_flag < 8) { WORD32 coeff_abs_level_greater1_flag; ctxt_idx = (ctxt_set * 4) + abs_gt1_base_ctxt + gt1_ctxt; TRACE_CABAC_CTXT("coeff_abs_level_greater1_flag", ps_cabac->u4_range, ctxt_idx); IHEVCD_CABAC_DECODE_BIN(coeff_abs_level_greater1_flag, ps_cabac, ps_bitstrm, ctxt_idx); AEV_TRACE("coeff_abs_level_greater1_flag", coeff_abs_level_greater1_flag, ps_cabac->u4_range); u4_coeff_abs_level_greater1_map |= coeff_abs_level_greater1_flag << n; num_greater1_flag++; /* first_greater1_scan_pos is obtained using CLZ on u4_coeff_abs_level_greater1_map*/ /* outside the loop instead of the following check inside the loop */ /* if( coeff_abs_level_greater1_flag && first_greater1_scan_pos == -1) */ /* first_greater1_scan_pos = n; */ if(coeff_abs_level_greater1_flag) { gt1_ctxt = 0; } else if(gt1_ctxt && (gt1_ctxt < 3)) { gt1_ctxt++; } } else break; /* instead of computing last and first significan scan position using checks below */ /* They are computed outside the loop using CLZ and CTZ on sig_coeff_map */ /* if(last_sig_scan_pos == -1) */ /* last_sig_scan_pos = n; */ /* first_sig_scan_pos = n; */ } u4_sig_coeff_map_shift <<= 1; n--; /* If there are zero coeffs, then shift by as many zero coeffs and decrement n */ clz = CLZ(u4_sig_coeff_map_shift); u4_sig_coeff_map_shift <<= clz; n -= (WORD32)clz; }while(u4_sig_coeff_map_shift); } /* At this level u4_sig_coeff_map is non-zero i.e. has atleast one non-zero coeff */ last_sig_scan_pos = (31 - CLZ(u4_sig_coeff_map)); first_sig_scan_pos = CTZ(u4_sig_coeff_map); sign_hidden = (((last_sig_scan_pos - first_sig_scan_pos) > 3) && !ps_codec->s_parse.s_cu.i4_cu_transquant_bypass); u4_coeff_abs_level_greater2_map = 0; if(u4_coeff_abs_level_greater1_map) { /* Check if the first level > 1 is greater than 2 */ WORD32 ctxt_idx; first_greater1_scan_pos = (31 - CLZ(u4_coeff_abs_level_greater1_map)); ctxt_idx = IHEVC_CAB_COEFABS_GRTR2_FLAG; ctxt_idx += (!c_idx) ? ctxt_set : (ctxt_set + 4); TRACE_CABAC_CTXT("coeff_abs_level_greater2_flag", ps_cabac->u4_range, ctxt_idx); IHEVCD_CABAC_DECODE_BIN(coeff_abs_level_greater2_flag, ps_cabac, ps_bitstrm, ctxt_idx); AEV_TRACE("coeff_abs_level_greater2_flag", coeff_abs_level_greater2_flag, ps_cabac->u4_range); u4_coeff_abs_level_greater2_map = coeff_abs_level_greater2_flag << first_greater1_scan_pos; } u4_coeff_sign_map = 0; /* Parse sign flags */ if(!sign_data_hiding_flag || !sign_hidden) { IHEVCD_CABAC_DECODE_BYPASS_BINS(value, ps_cabac, ps_bitstrm, num_coeff); AEV_TRACE("sign_flags", value, ps_cabac->u4_range); u4_coeff_sign_map = value << (32 - num_coeff); } else { IHEVCD_CABAC_DECODE_BYPASS_BINS(value, ps_cabac, ps_bitstrm, (num_coeff - 1)); AEV_TRACE("sign_flags", value, ps_cabac->u4_range); u4_coeff_sign_map = value << (32 - (num_coeff - 1)); } num_sig_coeff = 0; sum_abs_level = 0; rice_param = 0; { UWORD32 clz; UWORD32 u4_sig_coeff_map_shift; clz = CLZ(u4_sig_coeff_map); n = 31 - clz; u4_sig_coeff_map_shift = u4_sig_coeff_map << clz; /* For loop for n changed to do while to break early if sig_coeff_map_shift becomes zero */ do { if((u4_sig_coeff_map_shift >> 31) & 1) { WORD32 base_lvl; WORD32 coeff_abs_level_remaining; WORD32 level; base_lvl = 1; /* Update base_lvl if it is greater than 1 */ if((u4_coeff_abs_level_greater1_map >> n) & 1) base_lvl++; /* Update base_lvl if it is greater than 2 */ if((u4_coeff_abs_level_greater2_map >> n) & 1) base_lvl++; /* If level is greater than 3/2/1 based on the greater1 and greater2 maps, * decode remaining level (level - base_lvl) will be signalled as bypass bins */ coeff_abs_level_remaining = 0; if(base_lvl == ((num_sig_coeff < 8) ? ((n == first_greater1_scan_pos) ? 3 : 2) : 1)) { UWORD32 u4_prefix; WORD32 bin; u4_prefix = 0; do { IHEVCD_CABAC_DECODE_BYPASS_BIN(bin, ps_cabac, ps_bitstrm); u4_prefix++; if((WORD32)u4_prefix == 19 - rice_param) { bin = 1; break; } }while(bin); u4_prefix = u4_prefix - 1; if(u4_prefix < 3) { UWORD32 u4_suffix; coeff_abs_level_remaining = (u4_prefix << rice_param); if(rice_param) { IHEVCD_CABAC_DECODE_BYPASS_BINS(u4_suffix, ps_cabac, ps_bitstrm, rice_param); coeff_abs_level_remaining |= u4_suffix; } } else { UWORD32 u4_suffix; UWORD32 u4_numbins; //u4_prefix = CLIP3(u4_prefix, 0, 19 - rice_param); u4_numbins = (u4_prefix - 3 + rice_param); coeff_abs_level_remaining = (((1 << (u4_prefix - 3)) + 3 - 1) << rice_param); if(u4_numbins) { IHEVCD_CABAC_DECODE_BYPASS_BINS(u4_suffix, ps_cabac, ps_bitstrm, u4_numbins); coeff_abs_level_remaining += u4_suffix; } } AEV_TRACE("coeff_abs_level_remaining", coeff_abs_level_remaining, ps_cabac->u4_range); base_lvl += coeff_abs_level_remaining; } /* update the rice param based on coeff level */ if((base_lvl > (3 << rice_param)) && (rice_param < 4)) { rice_param++; } /* Compute absolute level */ level = base_lvl; /* Update level with the sign */ if((u4_coeff_sign_map >> 31) & 1) level = -level; u4_coeff_sign_map <<= 1; /* Update sign in case sign is hidden */ if(sign_data_hiding_flag && sign_hidden) { sum_abs_level += base_lvl; if(n == first_sig_scan_pos && ((sum_abs_level % 2) == 1)) level = -level; } /* Store the resulting level in non-zero level array */ ps_tu_sblk_coeff_data->ai2_level[num_sig_coeff++] = level; //AEV_TRACE("level", level, 0); } u4_sig_coeff_map_shift <<= 1; n--; /* If there are zero coeffs, then shift by as many zero coeffs and decrement n */ clz = CLZ(u4_sig_coeff_map_shift); u4_sig_coeff_map_shift <<= clz; n -= (WORD32)clz; }while(u4_sig_coeff_map_shift); } /* Increment the pv_tu_sblk_coeff_data */ { UWORD8 *pu1_buf = (UWORD8 *)ps_codec->s_parse.pv_tu_coeff_data; pu1_buf += sizeof(tu_sblk_coeff_data_t) - SUBBLK_COEFF_CNT * sizeof(WORD16); pu1_buf += num_coeff * sizeof(WORD16); ps_codec->s_parse.pv_tu_coeff_data = pu1_buf; } } /* Set number of coded sub blocks in the current TU */ *pi1_num_coded_subblks = num_subblks; return ret; }