| /* ------------------------------------------------------------------ |
| * 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: dec_acelp_2p_in_64.cpp |
| |
| Date: 05/08/2007 |
| |
| ------------------------------------------------------------------------------ |
| REVISION HISTORY |
| |
| |
| Description: |
| |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| int16 index, (i): 12 bits index |
| int16 code[] (o): Q9 algebraic (fixed) codebook excitation |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| 12 bits algebraic codebook decoder. |
| 2 tracks x 32 positions per track = 64 samples. |
| |
| 12 bits --> 2 pulses in a frame of 64 samples. |
| |
| All pulses can have two (2) possible amplitudes: +1 or -1. |
| Each pulse can have 32 possible positions. |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; INCLUDES |
| ----------------------------------------------------------------------------*/ |
| |
| #include "pv_amr_wb_type_defs.h" |
| #include "pvamrwbdecoder_basic_op.h" |
| #include "pvamrwbdecoder_cnst.h" |
| #include "pvamrwbdecoder_acelp.h" |
| |
| /*---------------------------------------------------------------------------- |
| ; MACROS |
| ; Define module specific macros here |
| ----------------------------------------------------------------------------*/ |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; DEFINES |
| ; Include all pre-processor statements here. Include conditional |
| ; compile variables also. |
| ----------------------------------------------------------------------------*/ |
| #define L_CODE 64 /* codevector length */ |
| #define NB_TRACK 2 /* number of track */ |
| #define NB_POS 32 /* number of position */ |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; 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 dec_acelp_2p_in_64( |
| int16 index, /* (i): 12 bits index */ |
| int16 code[] /* (o): Q9 algebraic (fixed) codebook excitation */ |
| ) |
| { |
| int16 i; |
| |
| pv_memset(code, 0, L_CODE*sizeof(*code)); |
| |
| /* decode the positions and signs of pulses and build the codeword */ |
| |
| i = (index >> 5) & 0x003E; |
| |
| if (((index >> 6) & NB_POS) == 0) |
| { |
| code[i] = 512; |
| } |
| else |
| { |
| code[i] = -512; |
| } |
| |
| i = ((index & 0x001F) << 1) + 1; |
| |
| if ((index & NB_POS) == 0) |
| { |
| code[i] = 512; |
| } |
| else |
| { |
| code[i] = -512; |
| } |
| |
| } |