| /* ------------------------------------------------------------------ |
| * 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 */ |
| ) |
| { |
| Word16 i; |
| Word16 j; |
| 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; |
| } |
