| /* ------------------------------------------------------------------ |
| * 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/dec_gain.c |
| Funtions: dec_gain |
| |
| Date: 01/31/2002 |
| |
| ------------------------------------------------------------------------------ |
| REVISION HISTORY |
| |
| Description: Updating include file lists, and other things as per review |
| comments. |
| |
| Description: Added fixes to the code as per review comments. Removed nested |
| function calls and declared temp2 as a variable. |
| |
| Description: A Word32 was being stored improperly in a Word16. |
| |
| Description: Removed qua_gain.tab and qgain475.tab from Include section and |
| added qua_gain_tbl.h and qgain475_tab.h to Include section. |
| |
| Description: Changed round function name to pv_round to avoid conflict with |
| round function in C standard library. |
| |
| Description: Added casting to eliminate warnings |
| |
| Description: Replaced "int" and/or "char" with OSCL defined types. |
| |
| Description: |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; INCLUDES |
| ----------------------------------------------------------------------------*/ |
| |
| #include "dec_gain.h" |
| #include "typedef.h" |
| #include "mode.h" |
| #include "cnst.h" |
| #include "pow2.h" |
| #include "log2.h" |
| #include "gc_pred.h" |
| #include "basic_op.h" |
| #include "qua_gain_tbl.h" |
| #include "qgain475_tab.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 |
| ----------------------------------------------------------------------------*/ |
| |
| /* |
| ------------------------------------------------------------------------------ |
| FUNCTION NAME: dec_gain |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Inputs: |
| pred_state = pointer to MA predictor state of type gc_predState |
| index = AMR mode of type enum Mode |
| code[] = pointer to innovative vector of type Word16 |
| evenSubfr = Flag for even subframes of type Word16 |
| pOverflow = pointer to overflow flag |
| |
| |
| Outputs: |
| pred_state = pointer to MA predictor state of type gc_predState |
| gain_pit = pointer to pitch gain of type Word16 |
| gain_cod = pointer to code gain of type Word16 |
| |
| Returns: |
| None. |
| |
| Global Variables Used: |
| None. |
| |
| Local Variables Needed: |
| None. |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| File : dec_gain.c |
| Purpose : Decode the pitch and codebook gains |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| None. |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| agc.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| |
| |
| |
| |
| |
| |
| |
| ------------------------------------------------------------------------------ |
| 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 Dec_gain( |
| gc_predState *pred_state, /* i/o: MA predictor state */ |
| enum Mode mode, /* i : AMR mode */ |
| Word16 index, /* i : index of quantization. */ |
| Word16 code[], /* i : Innovative vector. */ |
| Word16 evenSubfr, /* i : Flag for even subframes */ |
| Word16 * gain_pit, /* o : Pitch gain. */ |
| Word16 * gain_cod, /* o : Code gain. */ |
| Flag * pOverflow |
| ) |
| { |
| const Word16 *p; |
| Word16 frac; |
| Word16 gcode0; |
| Word16 exp; |
| Word16 qua_ener; |
| Word16 qua_ener_MR122; |
| Word16 g_code; |
| Word32 L_tmp; |
| Word16 temp1; |
| Word16 temp2; |
| |
| /* Read the quantized gains (table depends on mode) */ |
| index = shl(index, 2, pOverflow); |
| |
| if (mode == MR102 || mode == MR74 || mode == MR67) |
| { |
| p = &table_gain_highrates[index]; |
| |
| *gain_pit = *p++; |
| g_code = *p++; |
| qua_ener_MR122 = *p++; |
| qua_ener = *p; |
| } |
| else |
| { |
| if (mode == MR475) |
| { |
| index += (1 ^ evenSubfr) << 1; /* evenSubfr is 0 or 1 */ |
| |
| if (index > (MR475_VQ_SIZE*4 - 2)) |
| { |
| index = (MR475_VQ_SIZE * 4 - 2); /* avoid possible buffer overflow */ |
| } |
| |
| p = &table_gain_MR475[index]; |
| |
| *gain_pit = *p++; |
| g_code = *p++; |
| |
| /*---------------------------------------------------------* |
| * calculate predictor update values (not stored in 4.75 * |
| * quantizer table to save space): * |
| * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * |
| * * |
| * qua_ener = log2(g) * |
| * qua_ener_MR122 = 20*log10(g) * |
| *---------------------------------------------------------*/ |
| |
| /* Log2(x Q12) = log2(x) + 12 */ |
| temp1 = (Word16) L_deposit_l(g_code); |
| Log2(temp1, &exp, &frac, pOverflow); |
| exp = sub(exp, 12, pOverflow); |
| |
| temp1 = shr_r(frac, 5, pOverflow); |
| temp2 = shl(exp, 10, pOverflow); |
| qua_ener_MR122 = add(temp1, temp2, pOverflow); |
| |
| /* 24660 Q12 ~= 6.0206 = 20*log10(2) */ |
| L_tmp = Mpy_32_16(exp, frac, 24660, pOverflow); |
| L_tmp = L_shl(L_tmp, 13, pOverflow); |
| qua_ener = pv_round(L_tmp, pOverflow); |
| /* Q12 * Q0 = Q13 -> Q10 */ |
| } |
| else |
| { |
| p = &table_gain_lowrates[index]; |
| |
| *gain_pit = *p++; |
| g_code = *p++; |
| qua_ener_MR122 = *p++; |
| qua_ener = *p; |
| } |
| } |
| |
| /*-------------------------------------------------------------------* |
| * predict codebook gain * |
| * ~~~~~~~~~~~~~~~~~~~~~ * |
| * gc0 = Pow2(int(d)+frac(d)) * |
| * = 2^exp + 2^frac * |
| * * |
| * gcode0 (Q14) = 2^14*2^frac = gc0 * 2^(14-exp) * |
| *-------------------------------------------------------------------*/ |
| |
| gc_pred(pred_state, mode, code, &exp, &frac, NULL, NULL, pOverflow); |
| |
| gcode0 = (Word16) Pow2(14, frac, pOverflow); |
| |
| /*------------------------------------------------------------------* |
| * read quantized gains, update table of past quantized energies * |
| * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * |
| * st->past_qua_en(Q10) = 20 * Log10(g_fac) / constant * |
| * = Log2(g_fac) * |
| * = qua_ener * |
| * constant = 20*Log10(2) * |
| *------------------------------------------------------------------*/ |
| |
| L_tmp = L_mult(g_code, gcode0, pOverflow); |
| temp1 = sub(10, exp, pOverflow); |
| L_tmp = L_shr(L_tmp, temp1, pOverflow); |
| *gain_cod = extract_h(L_tmp); |
| |
| /* update table of past quantized energies */ |
| |
| gc_pred_update(pred_state, qua_ener_MR122, qua_ener); |
| |
| return; |
| } |
| |
| |
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| |
