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Diffstat (limited to 'media/libstagefright/codecs/amrnb/enc/src/cor_h_x2.cpp')
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1 files changed, 282 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/amrnb/enc/src/cor_h_x2.cpp b/media/libstagefright/codecs/amrnb/enc/src/cor_h_x2.cpp new file mode 100644 index 0000000..da60640 --- /dev/null +++ b/media/libstagefright/codecs/amrnb/enc/src/cor_h_x2.cpp @@ -0,0 +1,282 @@ +/* ------------------------------------------------------------------ + * 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 +) +{ + register Word16 i; + register Word16 j; + register 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; +} |