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/* ------------------------------------------------------------------
* 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/q_gain_p.c
Functions: q_gain_pitch
Date: 02/04/2002
------------------------------------------------------------------------------
REVISION HISTORY
Description: Updated template used to PV coding template.
Changed to accept the pOverflow flag for EPOC compatibility.
Description: Replaced "int" and/or "char" with OSCL defined types.
Description: Added #ifdef __cplusplus around extern'ed table.
Description:
------------------------------------------------------------------------------
MODULE DESCRIPTION
------------------------------------------------------------------------------
*/
/*----------------------------------------------------------------------------
; INCLUDES
----------------------------------------------------------------------------*/
#include "q_gain_p.h"
#include "typedef.h"
#include "oper_32b.h"
#include "cnst.h"
#include "basic_op.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_QUA_PITCH 16
/*----------------------------------------------------------------------------
; LOCAL FUNCTION DEFINITIONS
; Function Prototype declaration
----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------
; LOCAL VARIABLE DEFINITIONS
; Variable declaration - defined here and used outside this module
----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------
; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES
; Declare variables used in this module but defined elsewhere
----------------------------------------------------------------------------*/
extern const Word16 qua_gain_pitch[NB_QUA_PITCH];
/*--------------------------------------------------------------------------*/
#ifdef __cplusplus
}
#endif
/*
------------------------------------------------------------------------------
FUNCTION NAME: q_gain_pitch
------------------------------------------------------------------------------
INPUT AND OUTPUT DEFINITIONS
Inputs:
mode -- enum Mode -- AMR mode
gp_limit -- Word16 -- pitch gain limit
gain -- Pointer to Word16 -- Pitch gain (unquant/quant), Q14
Outputs:
gain -- Pointer to Word16 -- Pitch gain (unquant/quant), Q14
gain_cand -- Array of type Word16 -- pitch gain candidates (3),
MR795 only, Q14
gain_cind -- Array of type Word16 -- pitch gain cand. indices (3),
MR795 only, Q0
pOverflow -- Pointer to Flag -- overflow indicator
Returns:
Word16 -- index of quantization
Global Variables Used:
qua_gain_pitch
Local Variables Needed:
None
------------------------------------------------------------------------------
FUNCTION DESCRIPTION
------------------------------------------------------------------------------
REQUIREMENTS
None
------------------------------------------------------------------------------
REFERENCES
q_gain_p.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]
------------------------------------------------------------------------------
*/
Word16 q_gain_pitch( /* Return index of quantization */
enum Mode mode, /* i : AMR mode */
Word16 gp_limit, /* i : pitch gain limit */
Word16 *gain, /* i/o: Pitch gain (unquant/quant), Q14 */
Word16 gain_cand[], /* o : pitch gain candidates (3), MR795 only, Q14 */
Word16 gain_cind[], /* o : pitch gain cand. indices (3),MR795 only, Q0 */
Flag *pOverflow
)
{
Word16 i;
Word16 index;
Word16 err;
Word16 err_min;
err_min = sub(*gain, qua_gain_pitch[0], pOverflow);
err_min = abs_s(err_min);
index = 0;
for (i = 1; i < NB_QUA_PITCH; i++)
{
if (qua_gain_pitch[i] <= gp_limit)
{
err = sub(*gain, qua_gain_pitch[i], pOverflow);
err = abs_s(err);
if (err < err_min)
{
err_min = err;
index = i;
}
}
}
if (mode == MR795)
{
/* in MR795 mode, compute three gain_pit candidates around the index
* found in the quantization loop: the index found and the two direct
* neighbours, except for the extreme cases (i=0 or i=NB_QUA_PITCH-1),
* where the direct neighbour and the neighbour to that is used.
*/
Word16 ii;
if (index == 0)
{
ii = index;
}
else
{
if (index == (NB_QUA_PITCH - 1) ||
(qua_gain_pitch[index+1] > gp_limit))
{
ii = index - 2;
}
else
{
ii = index - 1;
}
}
/* store candidate indices and values */
for (i = 0; i < 3; i++)
{
gain_cind[i] = ii;
gain_cand[i] = qua_gain_pitch[ii];
ii = add(ii, 1, pOverflow);
}
*gain = qua_gain_pitch[index];
}
else
{
/* in MR122 mode, just return the index and gain pitch found.
* If bitexactness is required, mask away the two LSBs (because
* in the original EFR, gain_pit was scaled Q12)
*/
if (mode == MR122)
{
/* clear 2 LSBits */
*gain = qua_gain_pitch[index] & 0xFFFC;
}
else
{
*gain = qua_gain_pitch[index];
}
}
return index;
}
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