levinson.cpp

实现3GPP的GSM中AMR语音的CODECS。

/* ------------------------------------------------------------------
 * Copyright (C) 2008 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/levinson.c
 Funtions: Levinson_init
           Levinson_reset
           Levinson_exit
           Levinson

     Date: 06/02/2000

------------------------------------------------------------------------------
 REVISION HISTORY

 Description: Updated template used to PV coding template. First attempt at
          optimizing C code.

 Description: Updated file per comments gathered from Phase 2/3 review.

 Description: Synchronized file with UMTS version 3.2.0. Updated coding
              template. Removed unnecessary include files.

 Description: Replaced basic_op.h and oper_32b.h with the header files of
              the math functions used in the file.

 Description: Defined one local variable per line.

 Description: Added pOverflow as a variable passed into levinson as per
              changed needed for EPOC.

 Description: Removed nested function calls by adding temp variables.

 Description: Fixed a bug where the returned value (32bit) was being stored in
              a 16 bit temp variable. This was changed, and the value is now
              stored in temp32_3.

 Description:  For levinson()
              1. Eliminated unused include files.
              2. Replaced array addressing by pointers
              3. Eliminated math operations that unnecessary checked for
                 saturation, by evaluating the operands
              4. Combined shift operations to eliminate calls to mult() and
                 shr(), extrac_h(), extract_l()
              5. Eliminated if-else statements for sign extension when
                 right-shifting

 Description:  1. Replaced OSCL mem type functions and eliminated include
                  files that now are chosen by OSCL definitions
               2. Modified "int" definition by Word16

 Description:  Replaced "int" and/or "char" with OSCL defined types.


 Description: Changed round function name to pv_round to avoid conflict with
              round function in C standard library.

 Description:

------------------------------------------------------------------------------
 MODULE DESCRIPTION

 This file contains the function the implements the Levinson-Durbin algorithm
 using double-precision arithmetic. This file also includes functions to
 initialize, allocate, and deallocate memory used by the Levinson function.

------------------------------------------------------------------------------
*/

/*----------------------------------------------------------------------------
; INCLUDES
----------------------------------------------------------------------------*/
#include "levinson.h"
#include "basicop_malloc.h"
#include "basic_op.h"
#include "div_32.h"
#include "cnst.h"
#include "oscl_mem.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: Levinson_init
------------------------------------------------------------------------------
 INPUT AND OUTPUT DEFINITIONS

 Inputs:
    state = pointer to an array of pointers to structures of type
            LevinsonState

 Outputs:
    pointer pointed to by state points to the newly allocated memory to
      be used by Levinson function

 Returns:
    return_value = 0, if initialization was successful; -1, otherwise (int)

 Global Variables Used:
    None

 Local Variables Needed:
    None

------------------------------------------------------------------------------
 FUNCTION DESCRIPTION

 This function allocates and initializes the state memory used by the
 Levinson function.

------------------------------------------------------------------------------
 REQUIREMENTS

 None

------------------------------------------------------------------------------
 REFERENCES

 levinson.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001

------------------------------------------------------------------------------
 PSEUDO-CODE

int Levinson_init (LevinsonState **state)
{
  LevinsonState* s;

  if (state == (LevinsonState **) NULL){
      //fprint(stderr, "Levinson_init: invalid parameter\n");
      return -1;
  }
  *state = NULL;

  // allocate memory
  if ((s= (LevinsonState *) malloc(sizeof(LevinsonState))) == NULL){
      //fprint(stderr, "Levinson_init: can not malloc state structure\n");
      return -1;
  }

  Levinson_reset(s);
  *state = s;

  return 0;
}

------------------------------------------------------------------------------
 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 Levinson_init(LevinsonState **state)
{
    LevinsonState* s;

    if (state == (LevinsonState **) NULL)
    {
        /*  fprint(stderr, "Levinson_init: invalid parameter\n");  */
        return(-1);
    }
    *state = NULL;

    /* allocate memory */
    if ((s = (LevinsonState *) oscl_malloc(sizeof(LevinsonState))) == NULL)
    {
        /*  fprint(stderr, "Levinson_init:
                            can not malloc state structure\n");  */
        return(-1);
    }

    Levinson_reset(s);
    *state = s;

    return(0);
}

/****************************************************************************/


/*
------------------------------------------------------------------------------
 FUNCTION NAME: Levinson_reset
------------------------------------------------------------------------------
 INPUT AND OUTPUT DEFINITIONS

 Inputs:
    state = pointer to structures of type LevinsonState

 Outputs:
    old_A field of structure pointed to by state is initialized to 4096
      (first location) and the rest to zeros

 Returns:
    return_value = 0, if reset was successful; -1, otherwise (int)

 Global Variables Used:
    None

 Local Variables Needed:
    None

------------------------------------------------------------------------------
 FUNCTION DESCRIPTION

 This function initializes the state memory used by the Levinson function to
 zero.

------------------------------------------------------------------------------
 REQUIREMENTS

 None

------------------------------------------------------------------------------
 REFERENCES

 levinson.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001

------------------------------------------------------------------------------
 PSEUDO-CODE

int Levinson_reset (LevinsonState *state)
{
  Word16 i;

  if (state == (LevinsonState *) NULL){
      fprint(stderr, "Levinson_reset: invalid parameter\n");
      return -1;
  }

  state->old_A[0] = 4096;
  for(i = 1; i < M + 1; i++)
      state->old_A[i] = 0;

  return 0;
}

------------------------------------------------------------------------------
 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 Levinson_reset(LevinsonState *state)
{
    Word16 i;

    if (state == (LevinsonState *) NULL)
    {
        /*  fprint(stderr, "Levinson_reset: invalid parameter\n");  */
        return(-1);
    }

    state->old_A[0] = 4096;
    for (i = 1; i < M + 1; i++)
    {
        state->old_A[i] = 0;
    }

    return(0);
}

/****************************************************************************/

/*
------------------------------------------------------------------------------
 FUNCTION NAME: Levinson_exit
------------------------------------------------------------------------------
 INPUT AND OUTPUT DEFINITIONS

 Inputs:
    state = pointer to an array of pointers to structures of type
            LevinsonState

 Outputs:
    pointer pointed to by state is set to the NULL address

 Returns:
    None

 Global Variables Used:
    None

 Local Variables Needed:
    None

------------------------------------------------------------------------------
 FUNCTION DESCRIPTION

 This function deallocates the state memory used by the Levinson function.

------------------------------------------------------------------------------
 REQUIREMENTS

 None

------------------------------------------------------------------------------
 REFERENCES

 levinson.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001

------------------------------------------------------------------------------
 PSEUDO-CODE

void Levinson_exit (LevinsonState **state)
{
  if (state == NULL || *state == NULL)
      return;

  // deallocate memory
  free(*state);
  *state = NULL;

  return;
}

------------------------------------------------------------------------------
 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 Levinson_exit(LevinsonState **state)
{
    if (state == NULL || *state == NULL)
    {
        return;
    }

    /* deallocate memory */
    oscl_free(*state);
    *state = NULL;

    return;
}

/****************************************************************************/