| /* ------------------------------------------------------------------ |
| * 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/post_pro.c |
| Functions: |
| Post_Process_reset |
| Post_Process |
| |
| Date: 04/03/2000 |
| |
| ------------------------------------------------------------------------------ |
| 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. Optimized the "else" portion of the first "if" |
| statement in Post_Process function. |
| |
| Description: Made grouping more explicit in the calculation of |
| signal[i] << 1 in the Post_Process function. |
| |
| Description: Added setting of Overflow flag in inlined code. |
| |
| Description: Synchronized file with UMTS version 3.2.0. Updated coding |
| template. Removed unnecessary include files. |
| |
| Description: Replaced basic_op.h with the header file of the math functions |
| used in the file. |
| |
| Description: Made the following changes per comments from Phase 2/3 review: |
| 1. Updated copyright year. |
| 2. Fixed typecasting issue with TI C compiler. |
| 3. Used short-hand notation for math operations, e.g., "+=", |
| in the code. |
| |
| Description: Removed the functions post_pro_init and post_pro_exit. |
| The post_pro related structure is no longer dynamically allocated. |
| |
| Description: Added pOverflow as a passed in variable as per changes needed |
| for the EPOC release. |
| |
| Description: Optimized file to reduce clock cycle usage. Updated copyright |
| year and removed unused files in Include section. |
| |
| Description: Replaced OSCL mem type functions and eliminated include |
| files that now are chosen by OSCL definitions |
| |
| 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: |
| |
| ------------------------------------------------------------------------------ |
| MODULE DESCRIPTION |
| |
| This file contains the function that performs post-processing on the output |
| speech. Post-processing include filtering the output speech through a second |
| order high pass filter with cutoff frequency of 60 Hz, and up-scaling the |
| output speech by a factor of 2. In addition to the post-processing function |
| itself, a post-processing initialization function, post-processing reset |
| function, and post-processing exit function are also included in this file. |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; INCLUDES |
| ----------------------------------------------------------------------------*/ |
| #include "post_pro.h" |
| #include "typedef.h" |
| #include "basic_op.h" |
| |
| /*---------------------------------------------------------------------------- |
| ; MACROS |
| ; Define module specific macros here |
| ----------------------------------------------------------------------------*/ |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; DEFINES |
| ; Include all pre-processor statements here. Include conditional |
| ; compile variables also. |
| ----------------------------------------------------------------------------*/ |
| |
| /*---------------------------------------------------------------------------- |
| ; LOCAL FUNCTION DEFINITIONS |
| ; Function Prototype declaration |
| ----------------------------------------------------------------------------*/ |
| |
| /*---------------------------------------------------------------------------- |
| ; LOCAL VARIABLE DEFINITIONS |
| ; Variable declaration - defined here and used outside this module |
| ----------------------------------------------------------------------------*/ |
| |
| /* filter coefficients (fc = 60 Hz) */ |
| static const Word16 b[3] = {7699, -15398, 7699}; |
| static const Word16 a[3] = {8192, 15836, -7667}; |
| |
| /* |
| ------------------------------------------------------------------------------ |
| FUNCTION NAME: Post_Process_reset |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Inputs: |
| state = pointer to a structure of type Post_ProcessState |
| |
| Outputs: |
| structure pointed to by state will have all its fields initialized |
| to zero |
| |
| Returns: |
| return_value = 0, if reset was successful; -1, otherwise (int) |
| |
| Global Variables Used: |
| None |
| |
| Local Variables Needed: |
| None |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| This function initializes state memory to zero. |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| None |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| post_pro.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| int Post_Process_reset (Post_ProcessState *state) |
| { |
| if (state == (Post_ProcessState *) NULL){ |
| fprint(stderr, "Post_Process_reset: invalid parameter\n"); |
| return -1; |
| } |
| |
| state->y2_hi = 0; |
| state->y2_lo = 0; |
| state->y1_hi = 0; |
| state->y1_lo = 0; |
| state->x0 = 0; |
| state->x1 = 0; |
| |
| return 0; |
| } |
| ------------------------------------------------------------------------------ |
| 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 Post_Process_reset(Post_ProcessState *state) |
| { |
| if (state == (Post_ProcessState *) NULL) |
| { |
| /* fprint(stderr, "Post_Process_reset: invalid parameter\n"); */ |
| return(-1); |
| } |
| |
| state->y2_hi = 0; |
| state->y2_lo = 0; |
| state->y1_hi = 0; |
| state->y1_lo = 0; |
| state->x0 = 0; |
| state->x1 = 0; |
| |
| return(0); |
| } |
| |
| /****************************************************************************/ |
| |
| /* |
| ------------------------------------------------------------------------------ |
| FUNCTION NAME: Post_Process |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Inputs: |
| st = pointer to a structure of type Post_ProcessState |
| signal = buffer containing the input signal (Word16) |
| lg = length of the input signal (Word16) |
| pOverflow = pointer to overflow indicator of type Flag |
| |
| Outputs: |
| structure pointed to by st contains new filter input and output values |
| signal buffer contains the HP filtered and up-scaled input signal |
| pOverflow points to 1 if overflow occurs in the math functions called |
| else it points to 0. |
| |
| Returns: |
| return_value = 0 (int) |
| |
| Global Variables Used: |
| a = buffer containing filter coefficients |
| b = buffer containing filter coefficients |
| |
| Local Variables Needed: |
| None |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| This function performs post-processing on the output speech signal. First, |
| the output speech goes through a second order high pass filter with a |
| cutoff frequency of 60 Hz. Then, the filtered output speech is multiplied |
| by a factor of 2. The algorithm implemented follows the following difference |
| equation: |
| |
| y[i] = b[0]*x[i]*2 + b[1]*x[i-1]*2 + b[2]*x[i-2]*2 + a[1]*y[i-1] + a[2]*y[i-2]; |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| None |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| post_pro.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| int Post_Process ( |
| Post_ProcessState *st, //i/o : post process state |
| Word16 signal[], //i/o : signal |
| Word16 lg //i : length of signal |
| ) |
| { |
| Word16 i, x2; |
| Word32 L_tmp; |
| |
| for (i = 0; i < lg; i++) |
| { |
| x2 = st->x1; |
| st->x1 = st->x0; |
| st->x0 = signal[i]; |
| |
| // y[i] = b[0]*x[i]*2 + b[1]*x[i-1]*2 + b140[2]*x[i-2]/2 |
| // + a[1]*y[i-1] + a[2] * y[i-2]; |
| |
| L_tmp = Mpy_32_16 (st->y1_hi, st->y1_lo, a[1]); |
| L_tmp = L_add (L_tmp, Mpy_32_16 (st->y2_hi, st->y2_lo, a[2])); |
| L_tmp = L_mac (L_tmp, st->x0, b[0]); |
| L_tmp = L_mac (L_tmp, st->x1, b[1]); |
| L_tmp = L_mac (L_tmp, x2, b[2]); |
| L_tmp = L_shl (L_tmp, 2); |
| |
| //Multiplication by two of output speech with saturation. |
| signal[i] = pv_round(L_shl(L_tmp, 1)); |
| |
| st->y2_hi = st->y1_hi; |
| st->y2_lo = st->y1_lo; |
| L_Extract (L_tmp, &st->y1_hi, &st->y1_lo); |
| } |
| |
| return 0; |
| } |
| |
| ------------------------------------------------------------------------------ |
| 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 Post_Process( |
| Post_ProcessState *st, /* i/o : post process state */ |
| Word16 signal[], /* i/o : signal */ |
| Word16 lg, /* i : length of signal */ |
| Flag *pOverflow |
| ) |
| { |
| Word16 i, x2; |
| Word32 L_tmp; |
| |
| Word16 *p_signal; |
| Word16 c_a1 = a[1]; |
| Word16 c_a2 = a[2]; |
| Word16 c_b0 = b[0]; |
| Word16 c_b1 = b[1]; |
| Word16 c_b2 = b[2]; |
| |
| p_signal = &signal[0]; |
| |
| for (i = 0; i < lg; i++) |
| { |
| x2 = st->x1; |
| st->x1 = st->x0; |
| st->x0 = *(p_signal); |
| |
| /* y[i] = b[0]*x[i]*2 + b[1]*x[i-1]*2 + b140[2]*x[i-2]/2 */ |
| /* + a[1]*y[i-1] + a[2] * y[i-2]; */ |
| |
| L_tmp = ((Word32) st->y1_hi) * c_a1; |
| L_tmp += (((Word32) st->y1_lo) * c_a1) >> 15; |
| L_tmp += ((Word32) st->y2_hi) * c_a2; |
| L_tmp += (((Word32) st->y2_lo) * c_a2) >> 15; |
| L_tmp += ((Word32) st->x0) * c_b0; |
| L_tmp += ((Word32) st->x1) * c_b1; |
| L_tmp += ((Word32) x2) * c_b2; |
| L_tmp = L_shl(L_tmp, 3, pOverflow); |
| |
| |
| /* Multiplication by two of output speech with saturation. */ |
| |
| *(p_signal++) = pv_round(L_shl(L_tmp, 1, pOverflow), pOverflow); |
| |
| st->y2_hi = st->y1_hi; |
| st->y2_lo = st->y1_lo; |
| |
| st->y1_hi = (Word16)(L_tmp >> 16); |
| st->y1_lo = (Word16)((L_tmp >> 1) - ((Word32) st->y1_hi << 15)); |
| |
| } |
| |
| return; |
| } |
