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Diffstat (limited to 'media/libstagefright/codecs/aacdec/sbr_downsample_lo_res.cpp')
-rw-r--r-- | media/libstagefright/codecs/aacdec/sbr_downsample_lo_res.cpp | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/aacdec/sbr_downsample_lo_res.cpp b/media/libstagefright/codecs/aacdec/sbr_downsample_lo_res.cpp new file mode 100644 index 0000000..c2b007a --- /dev/null +++ b/media/libstagefright/codecs/aacdec/sbr_downsample_lo_res.cpp @@ -0,0 +1,162 @@ +/* ------------------------------------------------------------------ + * 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 + + |