dtx_enc.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/dtx_enc.c
 Funtions: dtx_enc_init
           dtx_enc_reset
           dtx_enc_exit
           dtx_enc
           dtx_buffer
           tx_dtx_handler

     Date: 06/08/2000

------------------------------------------------------------------------------
 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.
          Synched up with new template (Inputs/Outputs section). Deleted
          lines leftover from original code prior to the code section of
          dtx_enc_exit function. Deleted confusing comment in the log_en
          calculation in dtx_enc function. Restructured IF statement in
          the calculation of the sum of squares of speech signals in
          dtx_buffer.

 Description: Added setting of Overflow flag in inlined code.

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

 Description: Made the following changes per comments from Phase 2/3 review:
              1. Modified FOR loops to count down.
              2. Fixed typecasting issue with TI C compiler.
              3. Fixed comment in dtx_enc pseudo-code.
              4. Added dtx_enc code comment pertaining to possible assembly
                 implementation.

 Description: Added calls to add() in tx_dtx_handler. Updated copyright year.

 Description: Pass in pointer to overflow flag to all functions requiring this
              flag. This is to make the library EPOC compatible.

 Description:  For dtx_enc_reset() only
              1. Replaced copy() with memcpy.
              2. Eliminated include file copy.h
              3. Eliminated printf statement
              For dtx_buffer()
              1. Replaced copy() with memcpy.
              2. Eliminated math operations that unnecessary checked for
                 saturation, in some cases this by shifting before adding and
                 in other cases by evaluating the operands
              3. Unrolled loop to speed up execution

 Description:  For dtx_buffer()
              1. Modified scaling and added check for saturation. Previous
                 scaling was correct but altered precision, this cause bit
                 exactness test failure.

 Description:  For dtx_buffer()
              1. Modified scaling and saturation checks. Previous
                 scaling was correct but altered precision, this cause bit
                 exactness test failure for dtx vad2.

 Description:  Replaced OSCL mem type functions and eliminated include
               files that now are chosen by OSCL definitions

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

 Description:

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

 This file contains the various functions that perform the computation of the
 Silence Indicator (SID) parameters when in Discontinuous Transmission (DTX)
 mode.

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


/*----------------------------------------------------------------------------
; INCLUDES
----------------------------------------------------------------------------*/
#include "dtx_enc.h"
#include "q_plsf.h"
#include "typedef.h"
#include "mode.h"
#include "basic_op.h"
#include "log2.h"
#include "lsp_lsf.h"
#include "reorder.h"
#include "oscl_mem.h"

/*----------------------------------------------------------------------------
; MACROS
; Define module specific macros here
----------------------------------------------------------------------------*/
extern Word32 L_add(register Word32 L_var1, register Word32 L_var2, Flag *pOverflow);

/*----------------------------------------------------------------------------
; 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: dtx_enc_init
------------------------------------------------------------------------------
 INPUT AND OUTPUT DEFINITIONS

 Inputs:
    st = pointer to an array of pointers to structures of type
         dtx_encState

 Outputs:
    pointer pointed to by st is set to the address of the allocated
      memory

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

 Global Variables Used:
    None

 Local Variables Needed:
    None

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

 This function allocates the state memory used by the dtx_enc function.

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

 None

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

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

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

int dtx_enc_init (dtx_encState **st)
{
  dtx_encState* s;

  if (st == (dtx_encState **) NULL){
    fprintf(stderr, "dtx_enc_init: invalid parameter\n");
    return -1;
  }

  *st = NULL;

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

  dtx_enc_reset(s);
  *st = 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 dtx_enc_init(dtx_encState **st)
{
    dtx_encState* s;

    if (st == (dtx_encState **) NULL)
    {
        return(-1);
    }

    *st = NULL;

    /* allocate memory */
    if ((s = (dtx_encState *) oscl_malloc(sizeof(dtx_encState))) == NULL)
    {
        return(-1);
    }

    dtx_enc_reset(s);
    *st = s;

    return(0);
}

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

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

 Inputs:
    st = pointer to structures of type dtx_encState

 Outputs:
    structure pointed to by st is initialized to its reset value

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

 Global Variables Used:
    None

 Local Variables Needed:
    lsp_init_data = table containing LSP initialization values;
            table elements are constants of type Word16;
            table length is M

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

 This function initializes the fields of the state memory used by dtx_enc
 to their reset values.

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

 None

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

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

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

int dtx_enc_reset (dtx_encState *st)
{
  Word16 i;

  if (st == (dtx_encState *) NULL){
    fprintf(stderr, "dtx_enc_reset: invalid parameter\n");
    return -1;
  }

  st->hist_ptr = 0;
  st->log_en_index = 0;
  st->init_lsf_vq_index = 0;
  st->lsp_index[0] = 0;
  st->lsp_index[1] = 0;
  st->lsp_index[2] = 0;

  // Init lsp_hist[]
  for(i = 0; i < DTX_HIST_SIZE; i++)
  {
    Copy(lsp_init_data, &st->lsp_hist[i * M], M);
  }

  // Reset energy history
  Set_zero(st->log_en_hist, M);

  st->dtxHangoverCount = DTX_HANG_CONST;
  st->decAnaElapsedCount = 32767;

  return 1;
}

------------------------------------------------------------------------------
 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 dtx_enc_reset(dtx_encState *st)
{
    Word16 i;

    if (st == (dtx_encState *) NULL)
    {
        return(-1);
    }

    st->hist_ptr = 0;
    st->log_en_index = 0;
    st->init_lsf_vq_index = 0;
    st->lsp_index[0] = 0;
    st->lsp_index[1] = 0;
    st->lsp_index[2] = 0;

    /* Init lsp_hist[] */
    for (i = 0; i < DTX_HIST_SIZE; i++)
    {
        oscl_memcpy(&st->lsp_hist[i * M], lsp_init_data, M*sizeof(Word16));
    }

    /* Reset energy history */
    oscl_memset(st->log_en_hist, 0, sizeof(Word16)*M);
    st->dtxHangoverCount = DTX_HANG_CONST;
    st->decAnaElapsedCount = 32767;

    return(1);
}

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