| /* ------------------------------------------------------------------ |
| * 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/lag_wind.c |
| |
| Date: 01/31/2002 |
| |
| ------------------------------------------------------------------------------ |
| REVISION HISTORY |
| |
| Description: |
| 1. Eliminated unused include files. |
| 2. Replaced array addressing by pointers |
| 3. Eliminated l_extract() function call |
| |
| Description: Added casting to eliminate warnings |
| |
| Description: Replaced "int" and/or "char" with OSCL defined types. |
| |
| Description: |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| /*---------------------------------------------------------------------------- |
| ; INCLUDES |
| ----------------------------------------------------------------------------*/ |
| #include "lag_wind.h" |
| #include "lag_wind_tab.h" |
| #include "basic_op.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: lag_wind |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Inputs: |
| m = LPC order of type Word16 |
| r_h[] = pointer to autocorrelations (msb) of type Word16 |
| r_l[] = pointer to autocorrelations (lsb) of type Word16 |
| pOverflow = pointer to overflow flag |
| |
| Outputs: |
| None |
| |
| Returns: |
| None |
| |
| Global Variables Used: |
| None. |
| |
| Local Variables Needed: |
| None. |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| File : lag_wind.c |
| Purpose : Lag windowing of autocorrelations. |
| |
| FUNCTION: Lag_window() |
| |
| PURPOSE: Lag windowing of autocorrelations. |
| |
| DESCRIPTION: |
| r[i] = r[i]*lag_wind[i], i=1,...,10 |
| |
| r[i] and lag_wind[i] are in special double precision format. |
| See "oper_32b.c" for the format. |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| None. |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| lag_wind.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| Word16 i; |
| Word32 x; |
| |
| for (i = 1; i <= m; i++) |
| { |
| x = Mpy_32 (r_h[i], r_l[i], lag_h[i - 1], lag_l[i - 1], pOverflow); |
| L_Extract (x, &r_h[i], &r_l[i], pOverflow); |
| } |
| 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 Lag_window( |
| Word16 m, /* (i) : LPC order */ |
| Word16 r_h[], /* (i/o) : Autocorrelations (msb) */ |
| Word16 r_l[], /* (i/o) : Autocorrelations (lsb) */ |
| Flag *pOverflow |
| ) |
| { |
| Word16 i; |
| Word32 x; |
| const Word16 *p_lag_h = &lag_h[0]; |
| const Word16 *p_lag_l = &lag_l[0]; |
| Word16 *p_r_h = &r_h[1]; |
| Word16 *p_r_l = &r_l[1]; |
| |
| for (i = m; i != 0 ; i--) |
| { |
| x = Mpy_32(*(p_r_h), *(p_r_l), *(p_lag_h++), *(p_lag_l++), pOverflow); |
| *(p_r_h) = (Word16)(x >> 16); |
| *(p_r_l++) = (x >> 1) - (*(p_r_h++) << 15); |
| } |
| |
| return; |
| } |
| |