| /* ------------------------------------------------------------------ |
| * 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 */ |
| ) |
| { |
| 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 (*(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)); |
| } |
| |