| /* ------------------------------------------------------------------ |
| * 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/pstfilt.c |
| Functions: |
| Post_Filter_reset |
| Post_Filter |
| |
| Date: 04/14/2000 |
| |
| ------------------------------------------------------------------------------ |
| REVISION HISTORY |
| |
| Description: Changed template used to PV coding template. First attempt at |
| optimizing C code. |
| |
| Description: Updated file per comments gathered from Phase 2/3 review. |
| |
| 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. Modified FOR loops to count down. |
| 3. Fixed typecasting issue with TI C compiler. |
| 4. Added "break" statement after overflow condition occurs. |
| |
| Description: Removed the functions pstfilt_init and pstfilt_exit. |
| The pst_filt related structure is no longer dynamically allocated. |
| |
| Description: Modified code for EPOC changes where pOverflow is passed in |
| rather than allowing overflow to be a global variable. |
| |
| Description: Replaced OSCL mem type functions and eliminated include |
| files that now are chosen by OSCL definitions |
| |
| Description: Replaced "int" and/or "char" with defined types. |
| Added proper casting (Word32) to some left shifting operations |
| |
| Description: |
| |
| ------------------------------------------------------------------------------ |
| MODULE DESCRIPTION |
| |
| This file contains the function that performs adaptive post-filtering on the |
| synthesized speech. It also contains the functions that initialize, reset, |
| and exit the post-filtering function. |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| /*---------------------------------------------------------------------------- |
| ; INCLUDES |
| ----------------------------------------------------------------------------*/ |
| #include <string.h> |
| |
| #include "pstfilt.h" |
| #include "typedef.h" |
| #include "mode.h" |
| #include "basicop_malloc.h" |
| #include "basic_op.h" |
| #include "weight_a.h" |
| #include "residu.h" |
| #include "copy.h" |
| #include "syn_filt.h" |
| #include "preemph.h" |
| #include "cnst.h" |
| |
| /*---------------------------------------------------------------------------- |
| ; MACROS |
| ; Define module specific macros here |
| ----------------------------------------------------------------------------*/ |
| |
| /*---------------------------------------------------------------------------- |
| ; DEFINES |
| ; Include all pre-processor statements here. Include conditional |
| ; compile variables also. |
| ----------------------------------------------------------------------------*/ |
| #define L_H 22 /* size of truncated impulse response of A(z/g1)/A(z/g2) */ |
| |
| /*---------------------------------------------------------------------------- |
| ; LOCAL FUNCTION DEFINITIONS |
| ; Function Prototype declaration |
| ----------------------------------------------------------------------------*/ |
| |
| /*---------------------------------------------------------------------------- |
| ; LOCAL VARIABLE DEFINITIONS |
| ; Variable declaration - defined here and used outside this module |
| ----------------------------------------------------------------------------*/ |
| |
| /* Spectral expansion factors */ |
| static const Word16 gamma3_MR122[M] = |
| { |
| 22938, 16057, 11240, 7868, 5508, |
| 3856, 2699, 1889, 1322, 925 |
| }; |
| |
| static const Word16 gamma3[M] = |
| { |
| 18022, 9912, 5451, 2998, 1649, 907, 499, 274, 151, 83 |
| }; |
| |
| static const Word16 gamma4_MR122[M] = |
| { |
| 24576, 18432, 13824, 10368, 7776, |
| 5832, 4374, 3281, 2461, 1846 |
| }; |
| |
| static const Word16 gamma4[M] = |
| { |
| 22938, 16057, 11240, 7868, 5508, 3856, 2699, 1889, 1322, 925 |
| }; |
| |
| /*---------------------------------------------------------------------------- |
| ; EXTERNAL FUNCTION REFERENCES |
| ; Declare functions defined elsewhere and referenced in this module |
| ----------------------------------------------------------------------------*/ |
| |
| /*---------------------------------------------------------------------------- |
| ; EXTERNAL VARIABLES REFERENCES |
| ; Declare variables used in this module but defined elsewhere |
| ----------------------------------------------------------------------------*/ |
| |
| /* |
| ------------------------------------------------------------------------------ |
| FUNCTION NAME: Post_Filter_reset |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Inputs: |
| state = pointer to structure of type Post_FilterState |
| |
| Outputs: |
| fields of the structure pointed to by state is 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 the state memory used by the Post_Filter function |
| to zero. |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| None |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| pstfilt.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| int Post_Filter_reset (Post_FilterState *state) |
| { |
| if (state == (Post_FilterState *) NULL){ |
| fprintf(stderr, "Post_Filter_reset: invalid parameter\n"); |
| return -1; |
| } |
| |
| Set_zero (state->mem_syn_pst, M); |
| Set_zero (state->res2, L_SUBFR); |
| Set_zero (state->synth_buf, L_FRAME + M); |
| agc_reset(state->agc_state); |
| preemphasis_reset(state->preemph_state); |
| |
| 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_Filter_reset(Post_FilterState *state) |
| { |
| if (state == (Post_FilterState *) NULL) |
| { |
| /*fprintf(stderr, "Post_Filter_reset: invalid parameter\n"); */ |
| return(-1); |
| } |
| |
| memset(state->mem_syn_pst, 0, sizeof(Word16)*M); |
| memset(state->res2, 0, sizeof(Word16)*L_SUBFR); |
| memset(state->synth_buf, 0, sizeof(Word16)*(L_FRAME + M)); |
| agc_reset(&(state->agc_state)); |
| preemphasis_reset(&(state->preemph_state)); |
| |
| return(0); |
| } |
| |
| /****************************************************************************/ |
| |
| /* |
| ------------------------------------------------------------------------------ |
| FUNCTION NAME: Post_Filter |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Inputs: |
| st = pointer to a structure of type Post_FilterState |
| mode = AMR mode |
| syn = pointer to a buffer containing synthesized speech; upon |
| exiting this function, it will contain the post-filtered |
| synthesized speech |
| Az_4 = pointer to the interpolated LPC parameters for all subframes |
| pOverflow = pointer to overflow indicator of type Flag |
| |
| Outputs: |
| fields of the structure pointed to by st contains the updated field |
| values |
| syn buffer contains the post-filtered synthesized speech |
| pOverflow = 1 if overflow occurrs in the math functions called else |
| it is zero. |
| |
| Returns: |
| return_value = 0 (int) |
| |
| Global Variables Used: |
| None |
| |
| Local Variables Needed: |
| None |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| This function performs the post-filtering on the synthesized speech. The |
| post-filtering process is described as follows: |
| (1) inverse filtering of syn[] through A(z/0.7) to get res2[] |
| (2) tilt compensation filtering; 1 - MU*k*z^-1 |
| (3) synthesis filtering through 1/A(z/0.75) |
| (4) adaptive gain control |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| None |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| pstfilt.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| int Post_Filter ( |
| Post_FilterState *st, // i/o : post filter states |
| enum Mode mode, // i : AMR mode |
| Word16 *syn, // i/o : synthesis speech (postfiltered is output) |
| Word16 *Az_4 // i : interpolated LPC parameters in all subfr. |
| ) |
| { |
| *-------------------------------------------------------------------* |
| * Declaration of parameters * |
| *-------------------------------------------------------------------* |
| |
| Word16 Ap3[MP1], Ap4[MP1]; // bandwidth expanded LP parameters |
| Word16 *Az; // pointer to Az_4: |
| // LPC parameters in each subframe |
| Word16 i_subfr; // index for beginning of subframe |
| Word16 h[L_H]; |
| |
| Word16 i; |
| Word16 temp1, temp2; |
| Word32 L_tmp; |
| Word16 *syn_work = &st->synth_buf[M]; |
| |
| |
| *-----------------------------------------------------* |
| * Post filtering * |
| *-----------------------------------------------------* |
| |
| Copy (syn, syn_work , L_FRAME); |
| |
| Az = Az_4; |
| |
| for (i_subfr = 0; i_subfr < L_FRAME; i_subfr += L_SUBFR) |
| { |
| // Find weighted filter coefficients Ap3[] and ap[4] |
| |
| if (sub(mode, MR122) == 0 || sub(mode, MR102) == 0) |
| { |
| Weight_Ai (Az, gamma3_MR122, Ap3); |
| Weight_Ai (Az, gamma4_MR122, Ap4); |
| } |
| else |
| { |
| Weight_Ai (Az, gamma3, Ap3); |
| Weight_Ai (Az, gamma4, Ap4); |
| } |
| |
| // filtering of synthesis speech by A(z/0.7) to find res2[] |
| |
| Residu (Ap3, &syn_work[i_subfr], st->res2, L_SUBFR); |
| |
| // tilt compensation filter |
| |
| // impulse response of A(z/0.7)/A(z/0.75) |
| |
| Copy (Ap3, h, M + 1); |
| Set_zero (&h[M + 1], L_H - M - 1); |
| Syn_filt (Ap4, h, h, L_H, &h[M + 1], 0); |
| |
| // 1st correlation of h[] |
| |
| L_tmp = L_mult (h[0], h[0]); |
| for (i = 1; i < L_H; i++) |
| { |
| L_tmp = L_mac (L_tmp, h[i], h[i]); |
| } |
| temp1 = extract_h (L_tmp); |
| |
| L_tmp = L_mult (h[0], h[1]); |
| for (i = 1; i < L_H - 1; i++) |
| { |
| L_tmp = L_mac (L_tmp, h[i], h[i + 1]); |
| } |
| temp2 = extract_h (L_tmp); |
| |
| if (temp2 <= 0) |
| { |
| temp2 = 0; |
| } |
| else |
| { |
| temp2 = mult (temp2, MU); |
| temp2 = div_s (temp2, temp1); |
| } |
| |
| preemphasis (st->preemph_state, st->res2, temp2, L_SUBFR); |
| |
| // filtering through 1/A(z/0.75) |
| |
| Syn_filt (Ap4, st->res2, &syn[i_subfr], L_SUBFR, st->mem_syn_pst, 1); |
| |
| // scale output to input |
| |
| agc (st->agc_state, &syn_work[i_subfr], &syn[i_subfr], |
| AGC_FAC, L_SUBFR); |
| |
| Az += MP1; |
| } |
| |
| // update syn_work[] buffer |
| |
| Copy (&syn_work[L_FRAME - M], &syn_work[-M], M); |
| |
| 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_Filter( |
| Post_FilterState *st, /* i/o : post filter states */ |
| enum Mode mode, /* i : AMR mode */ |
| Word16 *syn, /* i/o : synthesis speech (postfiltered is output) */ |
| Word16 *Az_4, /* i : interpolated LPC parameters in all subfr. */ |
| Flag *pOverflow |
| ) |
| { |
| Word16 Ap3[MP1]; |
| Word16 Ap4[MP1]; /* bandwidth expanded LP parameters */ |
| Word16 *Az; /* pointer to Az_4: */ |
| /* LPC parameters in each subframe */ |
| Word16 i_subfr; /* index for beginning of subframe */ |
| Word16 h[L_H]; |
| |
| Word16 i; |
| Word16 temp1; |
| Word16 temp2; |
| Word32 L_tmp; |
| Word32 L_tmp2; |
| Word16 *syn_work = &st->synth_buf[M]; |
| |
| |
| /*-----------------------------------------------------* |
| * Post filtering * |
| *-----------------------------------------------------*/ |
| |
| Copy(syn, syn_work , L_FRAME); |
| |
| Az = Az_4; |
| |
| for (i_subfr = 0; i_subfr < L_FRAME; i_subfr += L_SUBFR) |
| { |
| /* Find weighted filter coefficients Ap3[] and ap[4] */ |
| |
| if (mode == MR122 || mode == MR102) |
| { |
| Weight_Ai(Az, gamma3_MR122, Ap3); |
| Weight_Ai(Az, gamma4_MR122, Ap4); |
| } |
| else |
| { |
| Weight_Ai(Az, gamma3, Ap3); |
| Weight_Ai(Az, gamma4, Ap4); |
| } |
| |
| /* filtering of synthesis speech by A(z/0.7) to find res2[] */ |
| |
| Residu(Ap3, &syn_work[i_subfr], st->res2, L_SUBFR); |
| |
| /* tilt compensation filter */ |
| |
| /* impulse response of A(z/0.7)/A(z/0.75) */ |
| |
| Copy(Ap3, h, M + 1); |
| memset(&h[M + 1], 0, sizeof(Word16)*(L_H - M - 1)); |
| Syn_filt(Ap4, h, h, L_H, &h[M + 1], 0); |
| |
| /* 1st correlation of h[] */ |
| |
| L_tmp = 0; |
| |
| for (i = L_H - 1; i >= 0; i--) |
| { |
| L_tmp2 = ((Word32) h[i]) * h[i]; |
| |
| if (L_tmp2 != (Word32) 0x40000000L) |
| { |
| L_tmp2 = L_tmp2 << 1; |
| } |
| else |
| { |
| *pOverflow = 1; |
| L_tmp2 = MAX_32; |
| break; |
| } |
| |
| L_tmp = L_add(L_tmp, L_tmp2, pOverflow); |
| } |
| temp1 = (Word16)(L_tmp >> 16); |
| |
| L_tmp = 0; |
| |
| for (i = L_H - 2; i >= 0; i--) |
| { |
| L_tmp2 = ((Word32) h[i]) * h[i + 1]; |
| |
| if (L_tmp2 != (Word32) 0x40000000L) |
| { |
| L_tmp2 = L_tmp2 << 1; |
| } |
| else |
| { |
| *pOverflow = 1; |
| L_tmp2 = MAX_32; |
| break; |
| } |
| |
| L_tmp = L_add(L_tmp, L_tmp2, pOverflow); |
| } |
| temp2 = (Word16)(L_tmp >> 16); |
| |
| if (temp2 <= 0) |
| { |
| temp2 = 0; |
| } |
| else |
| { |
| L_tmp = (((Word32) temp2) * MU) >> 15; |
| |
| /* Sign-extend product */ |
| if (L_tmp & (Word32) 0x00010000L) |
| { |
| L_tmp = L_tmp | (Word32) 0xffff0000L; |
| } |
| temp2 = (Word16) L_tmp; |
| |
| temp2 = div_s(temp2, temp1); |
| } |
| |
| preemphasis(&(st->preemph_state), st->res2, temp2, L_SUBFR, pOverflow); |
| |
| /* filtering through 1/A(z/0.75) */ |
| |
| Syn_filt(Ap4, st->res2, &syn[i_subfr], L_SUBFR, st->mem_syn_pst, 1); |
| |
| /* scale output to input */ |
| |
| agc(&(st->agc_state), &syn_work[i_subfr], &syn[i_subfr], |
| AGC_FAC, L_SUBFR, pOverflow); |
| |
| Az += MP1; |
| } |
| |
| /* update syn_work[] buffer */ |
| |
| Copy(&syn_work[L_FRAME - M], &syn_work[-M], M); |
| |
| return; |
| } |
