| /* ------------------------------------------------------------------ |
| * 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/convolve.c |
| |
| Date: 06/19/2000 |
| |
| ------------------------------------------------------------------------------ |
| REVISION HISTORY |
| |
| Description: Optimize for speed. Update to code template. |
| |
| Description: Added author name and date, fixed tabs, and added missing |
| sections. Updated Input/Output section. |
| |
| Description: Optimized code by calculating two convolution sums per iteration |
| of the outer loop, thereby, decreasing outer loop count by 2. |
| Updated input/output definitions to be the same as the assembly |
| file (convolve.asm). Left Pseudo-code section blank. |
| |
| Description: Deleted semi-colon in the Pointers modified section. |
| |
| Description: Synchronized file with UMTS version 3.2.0. Updated coding |
| template. Removed unnecessary include files. |
| |
| Description: Made the following changes per comments from Phase 2/3 review: |
| 1. Fixed typecasting issue with TI C compiler. |
| 2. Modified FOR loop to count down, wherever applicable. |
| |
| Description: Made the following changes |
| 1. Unrolled the correlation loop. |
| 2. Performed 2 correlation per pass per sample to avoid recalling |
| the same data twice. |
| 3. Eliminated math operations that check for saturation. |
| |
| Description: |
| 1. Modified loop counter, extra unrolling did speed up code |
| |
| Description: Replaced "int" and/or "char" with OSCL defined types. |
| |
| Description: Using inlines from fxp_arithmetic.h . |
| |
| Description: Replacing fxp_arithmetic.h with basic_op.h. |
| |
| Description: |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| /*---------------------------------------------------------------------------- |
| ; INCLUDES |
| ----------------------------------------------------------------------------*/ |
| #include "typedef.h" |
| #include "convolve.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: Convolve |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Inputs: |
| x = pointer to input vector of L elements of type Word16 |
| h = pointer to the filter's impulse response vector of L elements |
| of type Word16 |
| y = pointer to the output vector of L elements of type Word16 used for |
| storing the convolution of x and h; |
| L = Length of the convolution; type definition is Word16 |
| |
| Outputs: |
| y buffer contains the new convolution output |
| |
| Returns: |
| None |
| |
| Global Variables Used: |
| None |
| |
| Local Variables Needed: |
| None |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| Perform the convolution between two vectors x[] and h[] and write the result |
| in the vector y[]. All vectors are of length L and only the first L samples |
| of the convolution are computed. |
| |
| The convolution is given by: |
| |
| y[n] = sum_{i=0}^{n} x[i] h[n-i], n=0,...,L-1 |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| None |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| convolve.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| void Convolve ( |
| Word16 x[], // (i) : input vector |
| Word16 h[], // (i) : impulse response |
| Word16 y[], // (o) : output vector |
| Word16 L // (i) : vector size |
| ) |
| { |
| Word16 i, n; |
| Word32 s; |
| |
| for (n = 0; n < L; n++) |
| { |
| s = 0; move32 (); |
| for (i = 0; i <= n; i++) |
| { |
| s = L_mac (s, x[i], h[n - i]); |
| } |
| s = L_shl (s, 3); |
| y[n] = extract_h (s); move16 (); |
| } |
| |
| 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 Convolve( |
| Word16 x[], /* (i) : input vector */ |
| Word16 h[], /* (i) : impulse response */ |
| Word16 y[], /* (o) : output vector */ |
| Word16 L /* (i) : vector size */ |
| ) |
| { |
| Word16 i, n; |
| Word32 s1, s2; |
| |
| |
| for (n = 1; n < L; n = n + 2) |
| { |
| |
| h = h + n; |
| |
| s2 = ((Word32) * (x)) * *(h--); |
| s1 = ((Word32) * (x++)) * *(h); |
| |
| for (i = (n - 1) >> 1; i != 0; i--) |
| { |
| s2 = amrnb_fxp_mac_16_by_16bb((Word32) * (x), (Word32) * (h--), s2); |
| s1 = amrnb_fxp_mac_16_by_16bb((Word32) * (x++), (Word32) * (h), s1); |
| s2 = amrnb_fxp_mac_16_by_16bb((Word32) * (x), (Word32) * (h--), s2); |
| s1 = amrnb_fxp_mac_16_by_16bb((Word32) * (x++), (Word32) * (h), s1); |
| } |
| |
| s2 = amrnb_fxp_mac_16_by_16bb((Word32) * (x), (Word32) * (h), s2); |
| |
| *(y++) = (Word16)(s1 >> 12); |
| *(y++) = (Word16)(s2 >> 12); |
| |
| x = x - n; |
| |
| } |
| |
| return; |
| } |
