/* ------------------------------------------------------------------ * 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/inter_36.c Date: 01/31/2002 ------------------------------------------------------------------------------ REVISION HISTORY Description: 1. Eliminated unused include files. 2. Replaced array addressing by pointers 3. Eliminated math operations that unnecessary checked for saturation 4. Unrolled loops to speed up processing, use decrement loops 5. Eliminated call to round by proper initialization Description: Added casting to eliminate warnings 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. Description: Using intrinsics from fxp_arithmetic.h . Description: Replacing fxp_arithmetic.h with basic_op.h. Description: ------------------------------------------------------------------------------ */ /*---------------------------------------------------------------------------- ; INCLUDES ----------------------------------------------------------------------------*/ #include "inter_36.h" #include "cnst.h" #include "inter_36_tab.h" #include "basic_op.h" /*---------------------------------------------------------------------------- ; MACROS ; Define module specific macros here ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- ; DEFINES ; Include all pre-processor statements here. Include conditional ; compile variables also. ----------------------------------------------------------------------------*/ #define UP_SAMP_MAX 6 /*---------------------------------------------------------------------------- ; LOCAL FUNCTION DEFINITIONS ; Function Prototype declaration ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- ; LOCAL STORE/BUFFER/POINTER DEFINITIONS ; Variable declaration - defined here and used outside this module ----------------------------------------------------------------------------*/ /* ------------------------------------------------------------------------------ FUNCTION NAME: inter_36 ------------------------------------------------------------------------------ INPUT AND OUTPUT DEFINITIONS Inputs: pX = pointer to input vector of type Word16 frac = fraction (-2..2 for 3*, -3..3 for 6*) of type Word16 flag3 = if set, upsampling rate = 3 (6 otherwise) of type Word16 pOverflow = pointer to overflow flag Outputs: None Returns: None Global Variables Used: None. Local Variables Needed: None. ------------------------------------------------------------------------------ FUNCTION DESCRIPTION File : inter_36.c Purpose : Interpolating the normalized correlation : with 1/3 or 1/6 resolution. ------------------------------------------------------------------------------ REQUIREMENTS None. ------------------------------------------------------------------------------ REFERENCES inter_36.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 ------------------------------------------------------------------------------ PSEUDO-CODE Word16 i, k; Word16 *x1, *x2; const Word16 *c1, *c2; Word32 s; if (flag3 != 0) { frac = shl (frac, 1); // inter_3[k] = inter_6[2*k] -> k' = 2*k } if (frac < 0) { frac = add (frac, UP_SAMP_MAX); x--; } x1 = &x[0]; x2 = &x[1]; c1 = &inter_6[frac]; c2 = &inter_6[sub (UP_SAMP_MAX, frac)]; s = 0; for (i = 0, k = 0; i < L_INTER_SRCH; i++, k += UP_SAMP_MAX) { s = L_mac (s, x1[-i], c1[k]); s = L_mac (s, x2[i], c2[k]); } return pv_round (s); ------------------------------------------------------------------------------ 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 Interpol_3or6( /* o : interpolated value */ Word16 *pX, /* i : input vector */ Word16 frac, /* i : fraction (-2..2 for 3*, -3..3 for 6*) */ Word16 flag3, /* i : if set, upsampling rate = 3 (6 otherwise) */ Flag *pOverflow ) { Word16 i; Word16 k; Word16 *pX1; Word16 *pX2; const Word16 *pC1; const Word16 *pC2; Word32 s; Word16 temp1; OSCL_UNUSED_ARG(pOverflow); if (flag3 != 0) { frac <<= 1; /* inter_3[k] = inter_6[2*k] -> k' = 2*k */ } if (frac < 0) { frac += UP_SAMP_MAX; pX--; } pX1 = &pX[0]; pX2 = &pX[1]; pC1 = &inter_6[frac]; temp1 = UP_SAMP_MAX - frac; pC2 = &inter_6[temp1]; s = 0x04000; k = 0; for (i = (L_INTER_SRCH >> 1); i != 0; i--) { s = amrnb_fxp_mac_16_by_16bb((Word32) * (pX1--), (Word32) pC1[k], s); s = amrnb_fxp_mac_16_by_16bb((Word32) * (pX2++), (Word32) pC2[k], s); k += UP_SAMP_MAX; s = amrnb_fxp_mac_16_by_16bb((Word32) * (pX1--), (Word32) pC1[k], s); s = amrnb_fxp_mac_16_by_16bb((Word32) * (pX2++), (Word32) pC2[k], s); k <<= 1; } return((Word16)(s >> 15)); }