/* ------------------------------------------------------------------ * 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_envelope_unmapping.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_envelope_unmapping.h" #include "sbr_constants.h" #include "fxp_mul32.h" /*---------------------------------------------------------------------------- ; MACROS ; Define module specific macros here ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- ; DEFINES ; Include all pre-processor statements here. Include conditional ; compile variables also. ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- ; LOCAL FUNCTION DEFINITIONS ; Function Prototype declaration ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- ; LOCAL STORE/BUFFER/POINTER DEFINITIONS ; Variable declaration - defined here and used outside this module ----------------------------------------------------------------------------*/ #define R_SHIFT 30 #define Qfmt(x) (Int32)(x*((Int32)1<=0?0.5F:-0.5F)) /* * 1./(1+2.^-[0:10]) */ const Int32 one_over_one_plus_two_to_n[11] = { Qfmt(0.50000000000000F), Qfmt(0.66666666666667F), Qfmt(0.80000000000000F), Qfmt(0.88888888888889F), Qfmt(0.94117647058824F), Qfmt(0.96969696969697F), Qfmt(0.98461538461538F), Qfmt(0.99224806201550F), Qfmt(0.99610894941634F), Qfmt(0.99805068226121F), Qfmt(0.99902439024390F) }; /* * 1./(1+2.^[0.5:-1:-10.5]) */ const Int32 one_over_one_plus_sq_2_by_two_to_n[12] = { Qfmt(0.41421356237310F), Qfmt(0.58578643762690F), Qfmt(0.73879612503626F), Qfmt(0.84977889517767F), Qfmt(0.91878969685839F), Qfmt(0.95767628767521F), Qfmt(0.97838063800882F), Qfmt(0.98907219289563F), Qfmt(0.99450607818892F), Qfmt(0.99724547251514F), Qfmt(0.99862083678608F), Qfmt(0.99930994254211F) }; /*---------------------------------------------------------------------------- ; 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 ----------------------------------------------------------------------------*/ void sbr_envelope_unmapping(SBR_FRAME_DATA * hFrameData1, SBR_FRAME_DATA * hFrameData2) { Int32 i; Int32 tempLeft; Int32 tempRight; Int32 tmp; Int32 *iEnvelopeLeft_man = hFrameData1->iEnvelope_man; Int32 *iEnvelopeLeft_exp = hFrameData1->iEnvelope_exp; Int32 *noiseFloorLeft_man = hFrameData1->sbrNoiseFloorLevel_man; Int32 *noiseFloorLeft_exp = hFrameData1->sbrNoiseFloorLevel_exp; Int32 *iEnvelopeRight_man = hFrameData2->iEnvelope_man; Int32 *iEnvelopeRight_exp = hFrameData2->iEnvelope_exp; Int32 *noiseFloorRight_man = hFrameData2->sbrNoiseFloorLevel_man; Int32 *noiseFloorRight_exp = hFrameData2->sbrNoiseFloorLevel_exp; if (hFrameData2->ampRes) { for (i = 0; i < hFrameData1->nScaleFactors; i++) { tempRight = iEnvelopeRight_man[i]; tempLeft = iEnvelopeLeft_man[i]; /* iEnvelope[i] always positive 6 bits max */ iEnvelopeLeft_exp[i] = tempLeft + 7; iEnvelopeRight_exp[i] = tempRight - 12; iEnvelopeRight_man[i] = Qfmt(1.000F); /* * iEnvelopeRight[i] = tempLeft / (1 + tempRight); * iEnvelopeLeft[i] = tempRight * iEnvelopeRight[i]; * * * iEnvelopeRight[i] = k*2^n/(1+2^m) = k*2^(n-m)/(1 + 2^-m); * where k = 1 or sqrt(2) */ if (iEnvelopeRight_exp[i] >= 0) { if (iEnvelopeRight_exp[i] < 11) { iEnvelopeRight_man[i] = one_over_one_plus_two_to_n[ iEnvelopeRight_exp[i]]; } else /* 1/(1+2^-m) == 1 - 2^-m ; for m >= 10 */ { iEnvelopeRight_man[i] -= (Qfmt(1.000F) >> iEnvelopeRight_exp[i]); } iEnvelopeRight_exp[i] = iEnvelopeLeft_exp[i] - iEnvelopeRight_exp[i]; } else { if (iEnvelopeRight_exp[i] > -11) { iEnvelopeRight_man[i] -= one_over_one_plus_two_to_n[ -iEnvelopeRight_exp[i]]; iEnvelopeRight_exp[i] = iEnvelopeLeft_exp[i] - iEnvelopeRight_exp[i]; } else /* 1/(1+2^m) == 2^-m ; for m >= 10 */ { iEnvelopeRight_exp[i] = iEnvelopeLeft_exp[i]; iEnvelopeLeft_exp[i] = 0; } } iEnvelopeLeft_man[i] = iEnvelopeRight_man[i]; } } else { for (i = 0; i < hFrameData1->nScaleFactors; i++) { /* iEnvelope[i] always positive 7 bits max */ tempRight = iEnvelopeRight_man[i]; tempLeft = iEnvelopeLeft_man[i]; iEnvelopeLeft_exp[i] = (tempLeft >> 1) + 7; if (tempLeft & 0x1) /* odd */ { iEnvelopeLeft_man[i] = Qfmt(1.41421356237310F); } else { iEnvelopeLeft_man[i] = Qfmt(1.000F); } iEnvelopeRight_exp[i] = (tempRight >> 1) - 12; if (tempRight & 0x1) /* odd */ { if (iEnvelopeRight_exp[i] > 0) { iEnvelopeRight_man[i] = Qfmt(1.41421356237310F); } else { iEnvelopeRight_man[i] = Qfmt(0.7071067811865F); } } else { iEnvelopeRight_man[i] = Qfmt(1.000F); } if (iEnvelopeRight_man[i] == Qfmt(1.000F)) { /* * iEnvelopeRight[i] = tempLeft / (1 + tempRight); * iEnvelopeLeft[i] = tempRight * iEnvelopeRight[i]; * * * iEnvelopeRight[i] = k*2^n/(1+2^m) = k*2^(n-m)/(1 + 2^-m); * where k = 1 or sqrt(2) */ if (iEnvelopeRight_exp[i] >= 0) { if (iEnvelopeRight_exp[i] < 11) { iEnvelopeRight_man[i] = one_over_one_plus_two_to_n[ iEnvelopeRight_exp[i]]; } else /* 1/(1+2^-m) == 1 - 2^-m ; for m >= 10 */ { iEnvelopeRight_man[i] -= (Qfmt(1.000F) >> iEnvelopeRight_exp[i]); } iEnvelopeRight_exp[i] = iEnvelopeLeft_exp[i] - iEnvelopeRight_exp[i]; } else { if (iEnvelopeRight_exp[i] > -11) { iEnvelopeRight_man[i] -= one_over_one_plus_two_to_n[ -iEnvelopeRight_exp[i]]; iEnvelopeRight_exp[i] = iEnvelopeLeft_exp[i] - iEnvelopeRight_exp[i]; } else /* 1/(1+2^m) == 2^-m ; for m >= 10 */ { iEnvelopeRight_exp[i] = iEnvelopeLeft_exp[i]; iEnvelopeLeft_exp[i] = 0; } } /* * apply "k" factor 1 or sqrt(2) * * (2^m)*2*k*2^n/(1+2^m) = k*2^(n+1)/(1 + 2^-m); * */ if (iEnvelopeLeft_man[i] != Qfmt(1.000F)) { iEnvelopeRight_man[i] = fxp_mul32_Q30(iEnvelopeLeft_man[i], iEnvelopeRight_man[i]); } iEnvelopeLeft_man[i] = iEnvelopeRight_man[i]; } else { /* * iEnvelopeRight[i] = tempLeft / (1 + tempRight); * iEnvelopeLeft[i] = tempRight * iEnvelopeRight[i]; * * * iEnvelopeRight[i] = k*2^n/(1+q2^m) = k*2^(n-m)/(1 + q2^-m); * where k = 1 or sqrt(2) * and q = sqrt(2) */ if (iEnvelopeRight_exp[i] >= 0) { if (iEnvelopeRight_exp[i] < 12) { iEnvelopeRight_man[i] = one_over_one_plus_sq_2_by_two_to_n[ iEnvelopeRight_exp[i]]; } else /* 1/(1+2^-m) == 1 - 2^-m ; for m >= 11 */ { iEnvelopeRight_man[i] = Qfmt(1.000F) - (Qfmt(1.000F) >> iEnvelopeRight_exp[i]); } } else { if (iEnvelopeRight_exp[i] > -12) { iEnvelopeRight_man[i] = Qfmt(1.000F) - one_over_one_plus_sq_2_by_two_to_n[ -iEnvelopeRight_exp[i]]; } else /* 1/(1+2^m) == 2^-m ; for m >= 11 */ { iEnvelopeRight_man[i] = Qfmt(1.000F); iEnvelopeRight_exp[i] = 0; } } iEnvelopeRight_exp[i] = iEnvelopeLeft_exp[i] - iEnvelopeRight_exp[i]; /* * apply "k" factor 1 or sqrt(2) * * Right == k*2^(n-m)/(1 + q2^-m) * Left == (q2^m)*k*2^n/(1 + q2^m) = qk*2^n/(1 + q2^-m); */ if (iEnvelopeLeft_man[i] != Qfmt(1.000F)) { /* * k/(1 + q2^-m); */ tmp = iEnvelopeRight_man[i]; iEnvelopeRight_man[i] = fxp_mul32_Q30(iEnvelopeLeft_man[i], iEnvelopeRight_man[i]); iEnvelopeLeft_man[i] = tmp; iEnvelopeLeft_exp[i] += 1; /* extra one due to sqrt(2)^2 */ } else { iEnvelopeLeft_man[i] = fxp_mul32_Q30(iEnvelopeRight_man[i], Qfmt(1.41421356237310F)); } } /* end of if (iEnvelopeRight_man[i] == Qfmt( 1.000F) ) */ } /* end of for loop */ } /* end if (hFrameData2->ampRes) */ for (i = 0; i < hFrameData1->nNoiseFactors; i++) { noiseFloorLeft_exp[i] = NOISE_FLOOR_OFFSET_PLUS_1 - noiseFloorLeft_man[i]; noiseFloorRight_exp[i] = noiseFloorRight_man[i] - SBR_ENERGY_PAN_OFFSET_INT; /* * noiseFloorRight[i] = tempLeft / (1.0f + tempRight); * noiseFloorLeft[i] = tempRight*noiseFloorRight[i]; * * * noiseFloorRight[i] = 2^n/(1+2^m) = 2^(n-m)/(1 + 2^-m); */ if (noiseFloorRight_exp[i] >= 0) { if (noiseFloorRight_exp[i] < 11) { noiseFloorRight_man[i] = one_over_one_plus_two_to_n[ noiseFloorRight_exp[i]]; } else /* 1/(1+2^-m) == 1 - 2^-m ; for m >= 10 */ { noiseFloorRight_man[i] = Qfmt(1.000F) - (Qfmt(1.000F) >> noiseFloorRight_exp[i]); } } else { if (noiseFloorRight_exp[i] > -11) { noiseFloorRight_man[i] = Qfmt(1.000F) - one_over_one_plus_two_to_n[ -noiseFloorRight_exp[i]]; } else /* 1/(1+2^m) == 2^-m ; for m >= 10 */ { noiseFloorRight_man[i] = Qfmt(1.000F); noiseFloorRight_exp[i] = 0; } } noiseFloorRight_exp[i] = noiseFloorLeft_exp[i] - noiseFloorRight_exp[i]; /* * (2^m)*2^n/(1+2^m) = 2^n/(1 + 2^-m); */ noiseFloorLeft_man[i] = noiseFloorRight_man[i]; noiseFloorLeft_exp[i] = noiseFloorLeft_exp[i]; } } #endif