| /* ------------------------------------------------------------------ |
| * 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/weight_a.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 unnecessary include files. |
| |
| Description: Fixed typecasting issue with TI C compiler. |
| |
| Description: Made the following changes per comments from Phase 2/3 review: |
| 1. Modified FOR loop to count down. |
| 2. Used address pre-increment instead of address offsets. |
| |
| Description: Replaced "int" and/or "char" with OSCL defined types. |
| |
| Description: Changed round function name to pv_round to avoid conflict with |
| round function in C standard library. |
| |
| Who: Date: |
| Description: |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| /*---------------------------------------------------------------------------- |
| ; INCLUDES |
| ----------------------------------------------------------------------------*/ |
| #include "weight_a.h" |
| #include "typedef.h" |
| #include "cnst.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 |
| ----------------------------------------------------------------------------*/ |
| |
| |
| /* |
| ------------------------------------------------------------------------------ |
| FUNCTION NAME: Weight_Ai |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Inputs: |
| a = LPC coefficients (Word16) |
| fac = Spectral expansion factors (Word16) |
| a_exp = Spectral expanded LPC coefficients (Word16) |
| |
| Outputs: |
| a_exp points to the updated spectral expanded LPC coefficients |
| |
| Returns: |
| None. |
| |
| Global Variables Used: |
| None. |
| |
| Local Variables Needed: |
| None. |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| This function calculates the spectral expansion for the LP coefficients of |
| order M. |
| a_exp[i] = a[i] * fac[i-1] ; i=1..M |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| None. |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| weight_a.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| void Weight_Ai ( |
| Word16 a[], // (i) : a[M+1] LPC coefficients (M=10) |
| const Word16 fac[], // (i) : Spectral expansion factors. |
| Word16 a_exp[] // (o) : Spectral expanded LPC coefficients |
| ) |
| { |
| Word16 i; |
| a_exp[0] = a[0]; |
| |
| for (i = 1; i <= M; i++) |
| { |
| a_exp[i] = pv_round (L_mult (a[i], fac[i - 1])); |
| } |
| return; |
| } |
| |
| ------------------------------------------------------------------------------ |
| 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] |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| void Weight_Ai( |
| Word16 a[], /* (i) : a[M+1] LPC coefficients (M=10) */ |
| const Word16 fac[], /* (i) : Spectral expansion factors. */ |
| Word16 a_exp[] /* (o) : Spectral expanded LPC coefficients */ |
| ) |
| { |
| Word16 i; |
| |
| *(a_exp) = *(a); |
| |
| for (i = M; i >= 1; i--) |
| { |
| a_exp += 1; |
| a += 1; |
| fac += 1; |
| *(a_exp) = (Word16)((((Word32) * (a)) * *(fac - 1) |
| + 0x00004000L) >> 15); |
| } |
| |
| return; |
| } |
| |