/* ------------------------------------------------------------------ * Copyright (C) 1998-2009 PacketVideo * * 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. * ------------------------------------------------------------------- */ /* Filename: sbr_aliasing_reduction.c ------------------------------------------------------------------------------ REVISION HISTORY Who: Date: MM/DD/YYYY Description: ------------------------------------------------------------------------------ INPUT AND OUTPUT DEFINITIONS ------------------------------------------------------------------------------ FUNCTION DESCRIPTION ------------------------------------------------------------------------------ REQUIREMENTS ------------------------------------------------------------------------------ REFERENCES SC 29 Software Copyright Licencing Disclaimer: This software module was originally developed by Coding Technologies and edited by - in the course of development of the ISO/IEC 13818-7 and ISO/IEC 14496-3 standards for reference purposes and its performance may not have been optimized. This software module is an implementation of one or more tools as specified by the ISO/IEC 13818-7 and ISO/IEC 14496-3 standards. ISO/IEC gives users free license to this software module or modifications thereof for use in products claiming conformance to audiovisual and image-coding related ITU Recommendations and/or ISO/IEC International Standards. ISO/IEC gives users the same free license to this software module or modifications thereof for research purposes and further ISO/IEC standardisation. Those intending to use this software module in products are advised that its use may infringe existing patents. ISO/IEC have no liability for use of this software module or modifications thereof. Copyright is not released for products that do not conform to audiovisual and image-coding related ITU Recommendations and/or ISO/IEC International Standards. The original developer retains full right to modify and use the code for its own purpose, assign or donate the code to a third party and to inhibit third parties from using the code for products that do not conform to audiovisual and image-coding related ITU Recommendations and/or ISO/IEC International Standards. This copyright notice must be included in all copies or derivative works. Copyright (c) ISO/IEC 2002. ------------------------------------------------------------------------------ PSEUDO-CODE ------------------------------------------------------------------------------ */ /*---------------------------------------------------------------------------- ; INCLUDES ----------------------------------------------------------------------------*/ #ifdef AAC_PLUS #include "sbr_aliasing_reduction.h" #include "pv_sqrt.h" #include "aac_mem_funcs.h" #include "pv_div.h" #include "fxp_mul32.h" /*---------------------------------------------------------------------------- ; MACROS ; Define module specific macros here ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- ; DEFINES ; Include all pre-processor statements here. Include conditional ; compile variables also. ----------------------------------------------------------------------------*/ #define Q30fmt(x) (Int32)(x*((Int32)1<<30) + (x>=0?0.5F:-0.5F)) /*---------------------------------------------------------------------------- ; LOCAL FUNCTION DEFINITIONS ; Function Prototype declaration ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- ; LOCAL STORE/BUFFER/POINTER DEFINITIONS ; Variable declaration - defined here and used outside this module ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- ; EXTERNAL FUNCTION REFERENCES ; Declare functions defined elsewhere and referenced in this module ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES ; Declare variables used in this module but defined elsewhere ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- ; FUNCTION CODE ----------------------------------------------------------------------------*/ #include "pv_normalize.h" #include "sbr_constants.h" /******************************************************************************* Functionname: sbr_aliasing_reduction ******************************************************************************* Description: Arguments: Return: none *******************************************************************************/ void sbr_aliasing_reduction(Int32 *degreeAlias, Int32 * nrg_gain_man, Int32 * nrg_gain_exp, Int32 * nrg_est_man, Int32 * nrg_est_exp, Int32 * dontUseTheseGainValues, Int32 noSubbands, Int32 lowSubband, Int32 sqrt_cache[][4], Int32 * groupVector) { Int32 temp1; Int32 est_total; Int32 ref_total_man; Int32 ref_total_exp; Int32 tmp_q1; Int32 tmp_q2; Int32 tmp_q3; Int32 tmp_q4; Int32 bst_man; Int32 bst_exp; struct intg_div quotient; struct intg_sqrt root_sq; Int32 group; Int32 grouping = 0; Int32 index = 0; Int32 noGroups; Int32 k; /* Calculate grouping*/ for (k = 0; k < noSubbands - 1; k++) { if (degreeAlias[k + lowSubband + 1] && dontUseTheseGainValues[k] == 0) { if (grouping == 0) { groupVector[index] = k + lowSubband; grouping = 1; index++; } } else { if (grouping) { groupVector[index] = k + lowSubband; if (! dontUseTheseGainValues[k]) { (groupVector[index])++; } grouping = 0; index++; } } } if (grouping) { groupVector[index] = noSubbands + lowSubband; index++; } noGroups = (index >> 1); /*Calculate new gain*/ for (group = 0; group < noGroups; group ++) { int startGroup = groupVector[(group<<1)] - lowSubband; int stopGroup = groupVector[(group<<1)+1] - lowSubband; est_total = 0; ref_total_man = 0; tmp_q1 = -100; tmp_q2 = -100; for (k = startGroup; k < stopGroup; k++) { if (tmp_q1 < nrg_est_exp[k]) { tmp_q1 = nrg_est_exp[k]; /* max */ } if (tmp_q2 < (nrg_est_exp[k] + (nrg_gain_exp[k] << 1))) { tmp_q2 = (nrg_est_exp[k] + (nrg_gain_exp[k] << 1)); /* max */ } } k -= startGroup; /* number of element used in the addition */ /* adjust Q format */ tmp_q2 += 59 - pv_normalize(k); for (k = startGroup; k < stopGroup; k++) { /* * est_total += nrg_est[k] * ref_total += nrg_est[k]*nrg_gain[k]*nrg_gain[k */ est_total += nrg_est_man[k] >> (tmp_q1 - nrg_est_exp[k]); if (tmp_q2 - (nrg_est_exp[k] + (nrg_gain_exp[k] << 1)) < 60) { nrg_gain_man[k] = fxp_mul32_Q28(nrg_gain_man[k], nrg_gain_man[k]); nrg_gain_exp[k] = (nrg_gain_exp[k] << 1) + 28; tmp_q3 = fxp_mul32_Q28(nrg_gain_man[k], nrg_est_man[k]); ref_total_man += tmp_q3 >> (tmp_q2 - (nrg_est_exp[k] + nrg_gain_exp[k])); } } ref_total_exp = tmp_q2 + 28; pv_div(ref_total_man, est_total, "ient); tmp_q2 += - tmp_q1 - quotient.shift_factor - 2; for (k = startGroup; k < stopGroup; k++) { Int32 alpha; temp1 = k + lowSubband; if (k < noSubbands - 1) { alpha = degreeAlias[temp1 + 1] > degreeAlias[temp1 ] ? degreeAlias[temp1 + 1] : degreeAlias[temp1 ]; } else { alpha = degreeAlias[temp1]; } /* * nrg_gain[k] = alpha*newGain + (1.0f-alpha)*nrg_gain[k]*nrg_gain[k]; */ tmp_q1 = tmp_q2 > nrg_gain_exp[k] ? tmp_q2 : nrg_gain_exp[k]; tmp_q1++; tmp_q3 = fxp_mul32_Q30(alpha, quotient.quotient); tmp_q4 = fxp_mul32_Q30(Q30fmt(1.0f) - alpha, nrg_gain_man[k]); nrg_gain_man[k] = (tmp_q3 >> (tmp_q1 - tmp_q2)) + (tmp_q4 >> (tmp_q1 - nrg_gain_exp[k])); nrg_gain_exp[k] = tmp_q1; } bst_exp = -100; for (k = startGroup; k < stopGroup; k++) { if (bst_exp < nrg_gain_exp[k] + nrg_est_exp[k]) { bst_exp = nrg_gain_exp[k] + nrg_est_exp[k]; /* max */ } } k -= startGroup; /* number of element used in the addition */ while (k != 0) /* bit guard protection depends on log2(k) */ { k >>= 1; bst_exp++; /* add extra bit-overflow-guard */ } bst_man = 0; for (k = startGroup; k < stopGroup; k++) { tmp_q2 = fxp_mul32_Q28(nrg_gain_man[k], nrg_est_man[k]); bst_man += tmp_q2 >> (bst_exp - nrg_gain_exp[k] - nrg_est_exp[k]); } bst_exp += 28; /* compensate for shift down */ if (bst_man) { /* * bst = ref_total / bst */ pv_div(ref_total_man, bst_man, "ient); bst_exp = ref_total_exp - bst_exp - quotient.shift_factor - 30; bst_man = quotient.quotient; /* Q30 */ for (k = startGroup; k < stopGroup; k++) { tmp_q1 = fxp_mul32_Q30(bst_man, nrg_gain_man[k]); pv_sqrt(tmp_q1, (bst_exp + nrg_gain_exp[k] + 60), &root_sq, sqrt_cache[0]); nrg_gain_man[k] = root_sq.root; nrg_gain_exp[k] = root_sq.shift_factor; } } else { pv_memset((void *)&nrg_gain_man[startGroup], 0, (stopGroup - startGroup)*sizeof(nrg_gain_man[0])); pv_memset((void *)&nrg_gain_exp[startGroup], 0, (stopGroup - startGroup)*sizeof(nrg_gain_exp[0])); } } } #endif