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Diffstat (limited to 'media/libstagefright/codecs/amrnb/common/src/pred_lt.cpp')
| -rw-r--r-- | media/libstagefright/codecs/amrnb/common/src/pred_lt.cpp | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/amrnb/common/src/pred_lt.cpp b/media/libstagefright/codecs/amrnb/common/src/pred_lt.cpp new file mode 100644 index 0000000..9163623 --- /dev/null +++ b/media/libstagefright/codecs/amrnb/common/src/pred_lt.cpp @@ -0,0 +1,349 @@ +/* ------------------------------------------------------------------ + * 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/pred_lt.c + +------------------------------------------------------------------------------ + REVISION HISTORY + + Description: Updated template used to PV coding template. First attempt at + optimizing C code. + + Description: Deleted variables listed in the Local Stores Needed/Modified + sections. + + Description: Updated file per comments from Phase 2/3 review. + + Description: Synchronized file with UMTS version 3.2.0. Updated coding + template. Removed unnecessary include files. + + Description: Fixed typecasting issue with TI C compiler. Updated copyright + year. + + Description: + (1) Removed instance of static in the const table "inter_6" + (2) Changed Overflow from a global to a parameter passed via a pointer. + (3) Made numerous small changes to bring code more in line with PV standards. + + Description: For pred_ltp() + 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, + loaded into memory filter coefficient in linear order for + faster execution in main loop. + 5. Eliminated call to round by proper initialization + + Description: Replaced "int" and/or "char" with defined types. + Added proper casting (Word32) to some left shifting operations + + + Description: Changed round function name to pv_round to avoid conflict with + round function in C standard library. + + Who: Date: + Description: + +------------------------------------------------------------------------------ +*/ + +/*---------------------------------------------------------------------------- +; INCLUDES +----------------------------------------------------------------------------*/ +#include "pred_lt.h" +#include "cnst.h" + +/*---------------------------------------------------------------------------- +; MACROS +; Define module specific macros here +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; DEFINES +; Include all pre-processor statements here. Include conditional +; compile variables also. +----------------------------------------------------------------------------*/ +#define UP_SAMP_MAX 6 +#define L_INTER10 (L_INTERPOL-1) +#define FIR_SIZE (UP_SAMP_MAX*L_INTER10+1) + +/*---------------------------------------------------------------------------- +; LOCAL FUNCTION DEFINITIONS +; Function Prototype declaration +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; LOCAL STORE/BUFFER/POINTER DEFINITIONS +; Variable declaration - defined here and used outside this module +----------------------------------------------------------------------------*/ + +/* 1/6 resolution interpolation filter (-3 dB at 3600 Hz) */ +/* Note: the 1/3 resolution filter is simply a subsampled + * version of the 1/6 resolution filter, i.e. it uses + * every second coefficient: + * + * inter_3l[k] = inter_6[2*k], 0 <= k <= 3*L_INTER10 + */ + +const Word16 inter_6_pred_lt[FIR_SIZE] = +{ + 29443, + 28346, 25207, 20449, 14701, 8693, 3143, + -1352, -4402, -5865, -5850, -4673, -2783, + -672, 1211, 2536, 3130, 2991, 2259, + 1170, 0, -1001, -1652, -1868, -1666, + -1147, -464, 218, 756, 1060, 1099, + 904, 550, 135, -245, -514, -634, + -602, -451, -231, 0, 191, 308, + 340, 296, 198, 78, -36, -120, + -163, -165, -132, -79, -19, 34, + 73, 91, 89, 70, 38, 0 +}; + + +/* +------------------------------------------------------------------------------ + FUNCTION NAME: Pred_lt_3or6 +------------------------------------------------------------------------------ + INPUT AND OUTPUT DEFINITIONS + + Inputs: + exc = buffer containing the excitation (Word16) + T0 = integer pitch lag (Word16) + frac = fraction of lag (Word16) + L_subfr = number of samples per subframe (Word16) + flag3 = flag to indicate the upsampling rate; if set, upsampling + rate is 3, otherwise, upsampling rate is 6 (Word16) + + pOverflow = pointer to overflow (Flag) + + Returns: + None + + Outputs: + exc buffer contains the newly formed adaptive codebook excitation + pOverflow -> 1 if the add operation resulted in overflow + + Global Variables Used: + inter_6_pred_lt = (1/6) resolution interpolation filter table (Word16) + + Local Variables Needed: + None + +------------------------------------------------------------------------------ + FUNCTION DESCRIPTION + + This function computes the result of long term prediction with fractional + interpolation of resolution 1/3 or 1/6. (Interpolated past excitation). + + The past excitation signal at the given delay is interpolated at + the given fraction to build the adaptive codebook excitation. + On return exc[0..L_subfr-1] contains the interpolated signal + (adaptive codebook excitation). + +------------------------------------------------------------------------------ + REQUIREMENTS + + None + +------------------------------------------------------------------------------ + REFERENCES + + pred_lt.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 + +------------------------------------------------------------------------------ + PSEUDO-CODE + +void Pred_lt_3or6 ( + Word16 exc[], // in/out: excitation buffer + Word16 T0, // input : integer pitch lag + Word16 frac, // input : fraction of lag + Word16 L_subfr, // input : subframe size + Word16 flag3 // input : if set, upsampling rate = 3 (6 otherwise) +) +{ + Word16 i, j, k; + Word16 *pX0, *pX1, *pX2; + const Word16 *pC1, *pC2; + Word32 s; + + pX0 = &exc[-T0]; + + frac = negate (frac); + if (flag3 != 0) + { + frac = shl (frac, 1); // inter_3l[k] = inter_6[2*k] -> k' = 2*k + } + + if (frac < 0) + { + frac = add (frac, UP_SAMP_MAX); + pX0--; + } + + for (j = 0; j < L_subfr; j++) + { + pX1 = pX0++; + pX2 = pX0; + pC1 = &inter_6[frac]; + pC2 = &inter_6[sub (UP_SAMP_MAX, frac)]; + + s = 0; + for (i = 0, k = 0; i < L_INTER10; i++, k += UP_SAMP_MAX) + { + s = L_mac (s, pX1[-i], pC1[k]); + s = L_mac (s, pX2[i], pC2[k]); + } + + exc[j] = pv_round (s); + } + + 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 Pred_lt_3or6( + Word16 exc[], /* in/out: excitation buffer */ + Word16 T0, /* input : integer pitch lag */ + Word16 frac, /* input : fraction of lag */ + Word16 L_subfr, /* input : subframe size */ + Word16 flag3, /* input : if set, upsampling rate = 3 (6 otherwise) */ + Flag *pOverflow /* output: if set, overflow occurred in this function */ +) +{ + register Word16 i; + register Word16 j; + register Word16 k; + + Word16 *pX0; + Word16 *pX2; + Word16 *pX3; + Word16 *p_exc; + Word16 *pC1; + const Word16 *pC1_ref; + const Word16 *pC2_ref; + + Word16 Coeff_1[(L_INTER10<<1)]; + + Word32 s1; + Word32 s2; + OSCL_UNUSED_ARG(pOverflow); + + pX0 = &(exc[-T0]); + + /* frac goes between -3 and 3 */ + + frac = -frac; + + if (flag3 != 0) + { + frac <<= 1; /* inter_3l[k] = inter_6[2*k] -> k' = 2*k */ + } + + if (frac < 0) + { + frac += UP_SAMP_MAX; + pX0--; + } + + pC1_ref = &inter_6_pred_lt[frac]; + pC2_ref = &inter_6_pred_lt[UP_SAMP_MAX-frac]; + + + pC1 = Coeff_1; + + k = 0; + + for (i = L_INTER10 >> 1; i > 0; i--) + { + *(pC1++) = pC1_ref[k]; + *(pC1++) = pC2_ref[k]; + k += UP_SAMP_MAX; + *(pC1++) = pC1_ref[k]; + *(pC1++) = pC2_ref[k]; + k += UP_SAMP_MAX; + + } + + p_exc = exc; + + for (j = (L_subfr >> 1); j != 0 ; j--) + { + pX0++; + pX2 = pX0; + pX3 = pX0++; + + pC1 = Coeff_1; + + s1 = 0x00004000L; + s2 = 0x00004000L; + + for (i = L_INTER10 >> 1; i > 0; i--) + { + s2 += ((Word32) * (pX3--)) * *(pC1); + s1 += ((Word32) * (pX3)) * *(pC1++); + s1 += ((Word32) * (pX2++)) * *(pC1); + s2 += ((Word32) * (pX2)) * *(pC1++); + s2 += ((Word32) * (pX3--)) * *(pC1); + s1 += ((Word32) * (pX3)) * *(pC1++); + s1 += ((Word32) * (pX2++)) * *(pC1); + s2 += ((Word32) * (pX2)) * *(pC1++); + + } /* for (i = L_INTER10>>1; i > 0; i--) */ + + *(p_exc++) = (Word16)(s1 >> 15); + *(p_exc++) = (Word16)(s2 >> 15); + + } /* for (j = (L_subfr>>1); j != 0 ; j--) */ + + return; +} |