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Diffstat (limited to 'media/libstagefright/codecs/amrnb/common/src/gmed_n.cpp')
| -rw-r--r-- | media/libstagefright/codecs/amrnb/common/src/gmed_n.cpp | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/amrnb/common/src/gmed_n.cpp b/media/libstagefright/codecs/amrnb/common/src/gmed_n.cpp new file mode 100644 index 0000000..be76241 --- /dev/null +++ b/media/libstagefright/codecs/amrnb/common/src/gmed_n.cpp @@ -0,0 +1,218 @@ +/* ------------------------------------------------------------------ + * 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. + * ------------------------------------------------------------------- + */ +/**************************************************************************************** +Portions of this file are derived from the following 3GPP standard: + + 3GPP TS 26.073 + ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec + Available from http://www.3gpp.org + +(C) 2004, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC) +Permission to distribute, modify and use this file under the standard license +terms listed above has been obtained from the copyright holder. +****************************************************************************************/ +/* + Pathname: ./audio/gsm-amr/c/src/gmed_n.c + +------------------------------------------------------------------------------ + REVISION HISTORY + + Description: Put file into template and first pass at optimization. + + Description: Made changes based on comments from the review meeting. Used + pointers instead of index addressing in the arrays. + + Description: Synchronized file with UMTS version 3.2.0. Updated coding + template. Removed unncessary include files. + + Description: Replaced "int" and/or "char" with OSCL defined types. + + Who: Date: + Description: + +------------------------------------------------------------------------------ +*/ + +/*---------------------------------------------------------------------------- +; INCLUDES +----------------------------------------------------------------------------*/ +#include "gmed_n.h" +#include "typedef.h" + +/*---------------------------------------------------------------------------- +; MACROS +; Define module specific macros here +----------------------------------------------------------------------------*/ + + +/*---------------------------------------------------------------------------- +; DEFINES +; Include all pre-processor statements here. Include conditional +; compile variables also. +----------------------------------------------------------------------------*/ +#define NMAX 9 /* largest N used in median calculation */ + +/*---------------------------------------------------------------------------- +; LOCAL FUNCTION DEFINITIONS +; Function Prototype declaration +----------------------------------------------------------------------------*/ + + +/*---------------------------------------------------------------------------- +; LOCAL STORE/BUFFER/POINTER DEFINITIONS +; Variable declaration - defined here and used outside this module +----------------------------------------------------------------------------*/ + + +/* +------------------------------------------------------------------------------ + FUNCTION NAME: gmed_n +------------------------------------------------------------------------------ + INPUT AND OUTPUT DEFINITIONS + + Inputs: + ind = input values (Word16) + n = number of inputs to find the median (Word16) + + Returns: + median value. + + Outputs: + None. + + Global Variables Used: + None. + + Local Variables Needed: + None. + +------------------------------------------------------------------------------ + FUNCTION DESCRIPTION + + This function calculates N-point median of a data set. This routine is only + valid for a odd number of gains (n <= NMAX). + +------------------------------------------------------------------------------ + REQUIREMENTS + + None. + +------------------------------------------------------------------------------ + REFERENCES + + gmed_n.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 + +------------------------------------------------------------------------------ + PSEUDO-CODE + +Word16 gmed_n ( // o : The median value (0...N-1) + Word16 ind[], // i : Past gain values + Word16 n // i : The number of gains; this routine + // is only valid for a odd number of gains + // (n <= NMAX) +) +{ + Word16 i, j, ix = 0; + Word16 max; + Word16 medianIndex; + Word16 tmp[NMAX]; + Word16 tmp2[NMAX]; + + for (i = 0; i < n; i++) + { + tmp2[i] = ind[i]; + } + + for (i = 0; i < n; i++) + { + max = -32767; + for (j = 0; j < n; j++) + { + if (sub (tmp2[j], max) >= 0) + { + max = tmp2[j]; + ix = j; + } + } + tmp2[ix] = -32768; + tmp[i] = ix; + } + + medianIndex=tmp[ shr(n,1) ]; // account for complex addressing + return (ind[medianIndex]); +} + +------------------------------------------------------------------------------ + RESOURCES USED [optional] + + When the code is written for a specific target processor the + the resources used should be documented below. + + HEAP MEMORY USED: x bytes + + STACK MEMORY USED: x bytes + + CLOCK CYCLES: (cycle count equation for this function) + (variable + used to represent cycle count for each subroutine + called) + where: (cycle count variable) = cycle count for [subroutine + name] + +------------------------------------------------------------------------------ + CAUTION [optional] + [State any special notes, constraints or cautions for users of this function] + +------------------------------------------------------------------------------ +*/ + +Word16 gmed_n( /* o : the median value */ + Word16 ind[], /* i : input values */ + Word16 n /* i : number of inputs */ +) +{ + register Word16 i, j, ix = 0; + register Word16 max; + register Word16 medianIndex; + Word16 tmp[NMAX]; + Word16 tmp2[NMAX]; + + for (i = 0; i < n; i++) + { + *(tmp2 + i) = *(ind + i); + } + + for (i = 0; i < n; i++) + { + max = -32767; + for (j = 0; j < n; j++) + { + if (*(tmp2 + j) >= max) + { + max = *(tmp2 + j); + ix = j; + } + } + *(tmp2 + ix) = -32768; + *(tmp + i) = ix; + } + + medianIndex = *(tmp + (n >> 1)); /* account for complex addressing */ + + return (*(ind + medianIndex)); +} + |