| /* ------------------------------------------------------------------ |
| * 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/cor_h_x2.c |
| |
| Date: 11/07/2001 |
| |
| ------------------------------------------------------------------------------ |
| REVISION HISTORY |
| |
| Description: Created a separate file for cor_h_x2 function. |
| |
| Description: Fixed typecasting issue with TI C compiler and defined one |
| local variable per line. Updated copyright year. |
| |
| Description: Added #define for log2(32) = 5. |
| |
| Description: Added call to round() and L_shl() functions in the last FOR |
| loop to make code bit-exact. |
| |
| Description: Added pOverflow as a variable that's passed in for the EPOC |
| modifications. |
| |
| Description: Changed round function name to pv_round to avoid conflict with |
| round function in C standard library. |
| |
| Description: Using intrinsics from fxp_arithmetic.h . |
| |
| Description: Replacing fxp_arithmetic.h with basic_op.h. |
| |
| Description: |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| /*---------------------------------------------------------------------------- |
| ; INCLUDES |
| ----------------------------------------------------------------------------*/ |
| #include "typedef.h" |
| #include "cnst.h" |
| #include "cor_h_x.h" |
| #include "cor_h_x2.h" // BX |
| #include "basic_op.h" |
| |
| /*---------------------------------------------------------------------------- |
| ; MACROS |
| ; Define module specific macros here |
| ----------------------------------------------------------------------------*/ |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; DEFINES |
| ; Include all pre-processor statements here. Include conditional |
| ; compile variables also. |
| ----------------------------------------------------------------------------*/ |
| #define LOG2_OF_32 5 |
| |
| /*---------------------------------------------------------------------------- |
| ; LOCAL FUNCTION DEFINITIONS |
| ; Function Prototype declaration |
| ----------------------------------------------------------------------------*/ |
| |
| /*---------------------------------------------------------------------------- |
| ; LOCAL STORE/BUFFER/POINTER DEFINITIONS |
| ; Variable declaration - defined here and used outside this module |
| ----------------------------------------------------------------------------*/ |
| |
| |
| /* |
| ------------------------------------------------------------------------------ |
| FUNCTION NAME: cor_h_x2 |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Inputs: |
| h = vector containing the impulse response of the weighted synthesis |
| filter; vector contents are of type Word16; vector length is |
| 2 * L_SUBFR |
| x = target signal vector; vector contents are of type Word16; vector |
| length is L_SUBFR |
| dn = vector containing the correlation between the target and the |
| impulse response; vector contents are of type Word16; vector |
| length is L_CODE |
| sf = scaling factor of type Word16 ; 2 when mode is MR122, 1 for all |
| other modes |
| nb_track = number of ACB tracks (Word16) |
| step = step size between pulses in one track (Word16) |
| pOverflow = pointer to overflow (Flag) |
| |
| Outputs: |
| dn contents are the newly calculated correlation values |
| pOverflow = 1 if the math functions called by cor_h_x2 result in overflow |
| else zero. |
| |
| Returns: |
| None |
| |
| Global Variables Used: |
| None |
| |
| Local Variables Needed: |
| None |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| This function computes the correlation between the target signal (x) and the |
| impulse response (h). |
| |
| The correlation is given by: d[n] = sum_{i=n}^{L-1} x[i] h[i-n], |
| where: n=0,...,L-1 |
| |
| d[n] is normalized such that the sum of 5 maxima of d[n] corresponding to |
| each position track does not saturate. |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| None |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| cor_h.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| The original etsi reference code uses a global flag Overflow. However, in the |
| actual implementation a pointer to a the overflow flag is passed in. |
| |
| void cor_h_x2 ( |
| Word16 h[], // (i): impulse response of weighted synthesis filter |
| Word16 x[], // (i): target |
| Word16 dn[], // (o): correlation between target and h[] |
| Word16 sf, // (i): scaling factor: 2 for 12.2, 1 for others |
| Word16 nb_track,// (i): the number of ACB tracks |
| Word16 step // (i): step size from one pulse position to the next |
| in one track |
| ) |
| { |
| Word16 i, j, k; |
| Word32 s, y32[L_CODE], max, tot; |
| |
| // first keep the result on 32 bits and find absolute maximum |
| |
| tot = 5; |
| |
| for (k = 0; k < nb_track; k++) |
| { |
| max = 0; |
| for (i = k; i < L_CODE; i += step) |
| { |
| s = 0; |
| for (j = i; j < L_CODE; j++) |
| s = L_mac (s, x[j], h[j - i]); |
| |
| y32[i] = s; |
| |
| s = L_abs (s); |
| if (L_sub (s, max) > (Word32) 0L) |
| max = s; |
| } |
| tot = L_add (tot, L_shr (max, 1)); |
| } |
| |
| j = sub (norm_l (tot), sf); |
| |
| for (i = 0; i < L_CODE; i++) |
| { |
| dn[i] = pv_round (L_shl (y32[i], j)); |
| } |
| } |
| |
| ------------------------------------------------------------------------------ |
| 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 cor_h_x2( |
| Word16 h[], /* (i): impulse response of weighted synthesis filter */ |
| Word16 x[], /* (i): target */ |
| Word16 dn[], /* (o): correlation between target and h[] */ |
| Word16 sf, /* (i): scaling factor: 2 for 12.2, 1 for others */ |
| Word16 nb_track,/* (i): the number of ACB tracks */ |
| Word16 step, /* (i): step size from one pulse position to the next |
| in one track */ |
| Flag *pOverflow |
| ) |
| { |
| Word16 i; |
| Word16 j; |
| Word16 k; |
| Word32 s; |
| Word32 y32[L_CODE]; |
| Word32 max; |
| Word32 tot; |
| |
| |
| /* first keep the result on 32 bits and find absolute maximum */ |
| tot = LOG2_OF_32; |
| for (k = 0; k < nb_track; k++) |
| { |
| max = 0; |
| for (i = k; i < L_CODE; i += step) |
| { |
| s = 0; |
| |
| for (j = i; j < L_CODE; j++) |
| { |
| s = amrnb_fxp_mac_16_by_16bb((Word32)x[j], (Word32)h[j-i], s); |
| } |
| |
| s = s << 1; |
| y32[i] = s; |
| s = L_abs(s); |
| |
| if (s > max) |
| { |
| max = s; |
| } |
| } |
| tot = (tot + (max >> 1)); |
| } |
| |
| j = sub(norm_l(tot), sf, pOverflow); |
| |
| for (i = 0; i < L_CODE; i++) |
| { |
| dn[i] = pv_round(L_shl(y32[i], j, pOverflow), pOverflow); |
| } |
| |
| return; |
| } |
