| /* ------------------------------------------------------------------ |
| * 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 26.173 |
| ANSI-C code for the Adaptive Multi-Rate - Wideband (AMR-WB) speech codec |
| Available from http://www.3gpp.org |
| |
| (C) 2007, 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. |
| ****************************************************************************************/ |
| /* |
| ------------------------------------------------------------------------------ |
| |
| |
| |
| Filename: agc2_amr_wb.cpp |
| |
| Date: 05/08/2007 |
| |
| ------------------------------------------------------------------------------ |
| REVISION HISTORY |
| |
| |
| Description: |
| |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| int16 * sig_in, (i) : postfilter input signal |
| int16 * sig_out, (i/o) : postfilter output signal |
| int16 l_trm (i) : subframe size |
| |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| Performs adaptive gain control |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; INCLUDES |
| ----------------------------------------------------------------------------*/ |
| |
| #include "pvamrwbdecoder_cnst.h" |
| #include "pvamrwbdecoder_acelp.h" |
| #include "pv_amr_wb_type_defs.h" |
| #include "pvamrwbdecoder_basic_op.h" |
| #include "pvamrwb_math_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 STORE/BUFFER/POINTER DEFINITIONS |
| ; Variable declaration - defined here and used outside this module |
| ----------------------------------------------------------------------------*/ |
| |
| /*---------------------------------------------------------------------------- |
| ; EXTERNAL FUNCTION REFERENCES |
| ; Declare functions defined elsewhere and referenced in this module |
| ----------------------------------------------------------------------------*/ |
| |
| /*---------------------------------------------------------------------------- |
| ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES |
| ; Declare variables used in this module but defined elsewhere |
| ----------------------------------------------------------------------------*/ |
| |
| /*---------------------------------------------------------------------------- |
| ; FUNCTION CODE |
| ----------------------------------------------------------------------------*/ |
| |
| void agc2_amr_wb( |
| int16 * sig_in, /* (i) : postfilter input signal */ |
| int16 * sig_out, /* (i/o) : postfilter output signal */ |
| int16 l_trm /* (i) : subframe size */ |
| ) |
| { |
| |
| int16 i, exp; |
| int16 gain_in, gain_out, g0; |
| int32 s; |
| |
| int16 temp; |
| |
| /* calculate gain_out with exponent */ |
| |
| temp = sig_out[0] >> 2; |
| s = fxp_mul_16by16(temp, temp) << 1; |
| for (i = 1; i < l_trm; i++) |
| { |
| temp = sig_out[i] >> 2; |
| s = mac_16by16_to_int32(s, temp, temp); |
| } |
| |
| |
| if (s == 0) |
| { |
| return; |
| } |
| exp = normalize_amr_wb(s) - 1; |
| gain_out = amr_wb_round(s << exp); |
| |
| /* calculate gain_in with exponent */ |
| |
| temp = sig_in[0] >> 2; |
| s = mul_16by16_to_int32(temp, temp); |
| for (i = 1; i < l_trm; i++) |
| { |
| temp = sig_in[i] >> 2; |
| s = mac_16by16_to_int32(s, temp, temp); |
| } |
| |
| |
| if (s == 0) |
| { |
| g0 = 0; |
| } |
| else |
| { |
| i = normalize_amr_wb(s); |
| gain_in = amr_wb_round(s << i); |
| exp -= i; |
| |
| /* |
| * g0 = sqrt(gain_in/gain_out) |
| */ |
| |
| s = div_16by16(gain_out, gain_in); |
| s = shl_int32(s, 7); /* s = gain_out / gain_in */ |
| s = shr_int32(s, exp); /* add exponent */ |
| |
| s = one_ov_sqrt(s); |
| g0 = amr_wb_round(shl_int32(s, 9)); |
| } |
| /* sig_out(n) = gain(n) sig_out(n) */ |
| |
| for (i = 0; i < l_trm; i++) |
| { |
| sig_out[i] = extract_h(shl_int32(fxp_mul_16by16(sig_out[i], g0), 3)); |
| |
| } |
| |
| return; |
| } |
| |