/* ------------------------------------------------------------------ * 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_downsample_lo_res.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_downsample_lo_res.h" #include "sbr_constants.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 ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- ; 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_downsample_lo_res(Int32 v_result[], Int32 num_result, Int freqBandTableRef[], Int32 num_Ref) { Int32 step; Int32 i, j; Int32 org_length; Int32 result_length; Int32 v_index[MAX_FREQ_COEFFS/2]; /* init */ org_length = num_Ref; result_length = num_result; v_index[0] = 0; /* Always use left border */ i = 0; while (org_length > 0) /* Create downsample vector */ { i++; step = org_length / result_length; /* floor; */ org_length = org_length - step; result_length--; v_index[i] = v_index[i-1] + step; } for (j = 0; j <= i; j++) /* Use downsample vector to index LoResolution vector. */ { v_result[j] = freqBandTableRef[ v_index[j]]; } } /* End downSampleLoRes */ #endif