| /* ------------------------------------------------------------------ |
| * 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/d2_9pf.c |
| Functions: decode_2i40_9bits |
| |
| Date: 01/28/2002 |
| |
| ------------------------------------------------------------------------------ |
| REVISION HISTORY |
| |
| Description: Modified to place file in the correct template format. Eliminated |
| use of special functions to perform simple mathematical operations, where |
| possible. Added the parameter pOverflow for the basic math operations. |
| |
| Description: Per review comments... |
| (1) Removed include of basic_op.h, replaced with shl.h |
| (2) Added pOverflow to the output section of the template |
| |
| Description: Replaced "int" and/or "char" with OSCL defined types. |
| |
| Description: Added #ifdef __cplusplus around extern'ed table. |
| |
| Description: |
| |
| ------------------------------------------------------------------------------ |
| MODULE DESCRIPTION |
| |
| |
| FUNCTION: decode_2i40_9bits (decod_ACELP()) |
| |
| PURPOSE: Algebraic codebook decoder. For details about the encoding see |
| c2_9pf.c |
| */ |
| |
| /*---------------------------------------------------------------------------- |
| ; INCLUDES |
| ----------------------------------------------------------------------------*/ |
| #include "d2_9pf.h" |
| #include "typedef.h" |
| #include "basic_op.h" |
| #include "cnst.h" |
| |
| |
| /*--------------------------------------------------------------------------*/ |
| #ifdef __cplusplus |
| extern "C" |
| { |
| #endif |
| |
| /*---------------------------------------------------------------------------- |
| ; MACROS |
| ; Define module specific macros here |
| ----------------------------------------------------------------------------*/ |
| |
| /*---------------------------------------------------------------------------- |
| ; DEFINES |
| ; Include all pre-processor statements here. Include conditional |
| ; compile variables also. |
| ----------------------------------------------------------------------------*/ |
| #define NB_PULSE 2 |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; LOCAL FUNCTION DEFINITIONS |
| ; Function Prototype declaration |
| ----------------------------------------------------------------------------*/ |
| |
| /*---------------------------------------------------------------------------- |
| ; LOCAL VARIABLE DEFINITIONS |
| ; Variable declaration - defined here and used outside this module |
| ----------------------------------------------------------------------------*/ |
| |
| extern const Word16 startPos[]; |
| |
| /*--------------------------------------------------------------------------*/ |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| /* |
| ------------------------------------------------------------------------------ |
| FUNCTION NAME: decode_2i40_11bits |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Inputs: |
| sign -- Word16 -- signs of 2 pulses. |
| index -- Word16 -- Positions of the 2 pulses. |
| |
| Outputs: |
| cod[] -- array of type Word16 -- algebraic (fixed) codebook excitation |
| pOverflow = pointer to overflow flag |
| |
| Returns: |
| None |
| |
| Global Variables Used: |
| None |
| |
| Local Variables Needed: |
| None |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| None |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| d2_9pf.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 decode_2i40_9bits( |
| Word16 subNr, /* i : subframe number */ |
| Word16 sign, /* i : signs of 2 pulses. */ |
| Word16 index, /* i : Positions of the 2 pulses. */ |
| Word16 cod[], /* o : algebraic (fixed) codebook excitation */ |
| Flag *pOverflow /* o : Flag set when overflow occurs */ |
| ) |
| { |
| Word16 i; |
| Word16 j; |
| Word16 k; |
| |
| Word16 pos[NB_PULSE]; |
| |
| /* Decode the positions */ |
| /* table bit is the MSB */ |
| |
| j = (Word16)(index & 64); |
| |
| j >>= 3; |
| |
| i = index & 7; |
| |
| k = |
| shl( |
| subNr, |
| 1, |
| pOverflow); |
| |
| k += j; |
| |
| /* pos0 =i*5+startPos[j*8+subNr*2] */ |
| pos[0] = i * 5 + startPos[k++]; |
| |
| |
| index >>= 3; |
| |
| i = index & 7; |
| |
| /* pos1 =i*5+startPos[j*8+subNr*2 + 1] */ |
| pos[1] = i * 5 + startPos[k]; |
| |
| |
| /* decode the signs and build the codeword */ |
| |
| for (i = L_SUBFR - 1; i >= 0; i--) |
| { |
| cod[i] = 0; |
| } |
| |
| for (j = 0; j < NB_PULSE; j++) |
| { |
| i = sign & 0x1; |
| |
| /* This line is equivalent to... |
| * |
| * |
| * if (i == 1) |
| * { |
| * cod[pos[j]] = 8191; |
| * } |
| * if (i == 0) |
| * { |
| * cod[pos[j]] = -8192; |
| * } |
| */ |
| |
| cod[pos[j]] = i * 16383 - 8192; |
| |
| sign >>= 1; |
| } |
| |
| return; |
| } |