dec_amr.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/dec_amr.c
 Funtions: Decoder_amr_init
           Decoder_amr_reset
           Decoder_amr

     Date: 04/11/2000

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

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

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

 Description: Made the following changes per comments from Phase 2/3 review:
              1. Fixed Input/Output descriptions by adding typedefs and
                 clarifying definitions.
              2. Used #define instead of hard-coded loop counts.
              3. Modified FOR loops to count down.
              4. Copied function descriptions from dec_amr.h header file.
              5. Defined one local variable per line.

 Description: Copied function descriptions from header file (forgot to do it
              prior to checking-in -- oops!).

 Description: Removed the function decoder_amr_exit.
 The decoder_amr related structure is no longer dynamically allocated.

 Also, modified function calls throughout to reflect the fact that the members
 of the structure Decoder_amrState are no longer pointers to be set via
 malloc, but full-blown structures.  (Changes of the type D_plsfState *lsfState
 to D_plsfState lsfState)

 Description: Fixed bug in the Decoder_amr() caused non-bit exactness. The
              Overflow flag was inadvertently taken out of the IF statement
              that calls agc2 and Syn_filt. It was restored to the original
              form. Updated copyright year.

 Description: Adding changes for EPOC regarding pOverflow being passed in
              rather than being a global variable.

 Description: Initialize overflow flag in Decoder_amr_init() and
               Decoder_amr_reset(). Initialize pointer to overflow flag in
               Decoder_amr().

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

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

 Description:  Replaced "int" and/or "char" with defined types.
               Added proper casting (Word32) to some left shifting operations

 Description:

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

 This file contains the function used to decode one speech frame using a given
 codec mode. The functions used to initialize, reset, and exit are also
 included in this file.

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

/*----------------------------------------------------------------------------
; INCLUDES
----------------------------------------------------------------------------*/
#include "dec_amr.h"
#include "typedef.h"
#include "cnst.h"
#include "copy.h"
#include "set_zero.h"
#include "syn_filt.h"
#include "d_plsf.h"
#include "agc.h"
#include "int_lpc.h"
#include "dec_gain.h"
#include "dec_lag3.h"
#include "dec_lag6.h"
#include "d2_9pf.h"
#include "d2_11pf.h"
#include "d3_14pf.h"
#include "d4_17pf.h"
#include "d8_31pf.h"
#include "d1035pf.h"
#include "pred_lt.h"
#include "d_gain_p.h"
#include "d_gain_c.h"
#include "dec_gain.h"
#include "ec_gains.h"
#include "ph_disp.h"
#include "c_g_aver.h"
#include "int_lsf.h"
#include "lsp_lsf.h"
#include "lsp_avg.h"
#include "bgnscd.h"
#include "ex_ctrl.h"
#include "sqrt_l.h"
#include "frame.h"
#include "bitno_tab.h"
#include "b_cn_cod.h"
#include "basic_op.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: Decoder_amr_init
------------------------------------------------------------------------------
 INPUT AND OUTPUT DEFINITIONS

 Inputs:
    state = pointer to a pointer to structures of type Decoder_amrState

 Outputs:
    structure pointed to by the pointer which is pointed to by state is
      initialized to each field's initial values

    state pointer points to the address of the memory allocated by
      Decoder_amr_init function

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

 Global Variables Used:
    None

 Local Variables Needed:
    None

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

 This function allocates and initializes state memory used by the Decoder_amr
 function. It stores the pointer to the filter status structure in state. This
 pointer has to be passed to Decoder_amr in each call. The function returns
 0, if initialization was successful and -1, otherwise.

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

 None

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

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

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

int Decoder_amr_init (Decoder_amrState **state)
{
  Decoder_amrState* s;
  Word16 i;

  if (state == (Decoder_amrState **) NULL){
      fprintf(stderr, "Decoder_amr_init: invalid parameter\n");
      return -1;
  }
  *state = NULL;

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

  s->T0_lagBuff = 40;
  s->inBackgroundNoise = 0;
  s->voicedHangover = 0;
  for (i = 0; i < 9; i++)
     s->ltpGainHistory[i] = 0;

  s->lsfState = NULL;
  s->ec_gain_p_st = NULL;
  s->ec_gain_c_st = NULL;
  s->pred_state = NULL;
  s->ph_disp_st = NULL;
  s->dtxDecoderState = NULL;

  if (D_plsf_init(&s->lsfState) ||
      ec_gain_pitch_init(&s->ec_gain_p_st) ||
      ec_gain_code_init(&s->ec_gain_c_st) ||
      gc_pred_init(&s->pred_state) ||
      Cb_gain_average_init(&s->Cb_gain_averState) ||
      lsp_avg_init(&s->lsp_avg_st) ||
      Bgn_scd_init(&s->background_state) ||
      ph_disp_init(&s->ph_disp_st) ||
      dtx_dec_init(&s->dtxDecoderState)) {
      Decoder_amr_exit(&s);
      return -1;
  }

  Decoder_amr_reset(s, (enum Mode)0);
  *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 Decoder_amr_init(Decoder_amrState *s)
{
    Word16 i;

    if (s == (Decoder_amrState *) NULL)
    {
        /* fprint(stderr, "Decoder_amr_init: invalid parameter\n");  */
        return(-1);
    }

    s->T0_lagBuff = 40;
    s->inBackgroundNoise = 0;
    s->voicedHangover = 0;

    /* Initialize overflow Flag */

    s->overflow = 0;

    for (i = 0; i < LTP_GAIN_HISTORY_LEN; i++)
    {
        s->ltpGainHistory[i] = 0;
    }

    D_plsf_reset(&s->lsfState);
    ec_gain_pitch_reset(&s->ec_gain_p_st);
    ec_gain_code_reset(&s->ec_gain_c_st);
    Cb_gain_average_reset(&s->Cb_gain_averState);
    lsp_avg_reset(&s->lsp_avg_st);
    Bgn_scd_reset(&s->background_state);
    ph_disp_reset(&s->ph_disp_st);
    dtx_dec_reset(&s->dtxDecoderState);
    gc_pred_reset(&s->pred_state);

    Decoder_amr_reset(s, MR475);

    return(0);
}

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

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

 Inputs:
    state = pointer to a structure of type Decoder_amrState
    mode = codec mode (enum Mode)

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

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

 Global Variables Used:
    None

 Local Variables Needed:
    None

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

 This function resets the state memory used by the Decoder_amr function. It
 returns a 0, if reset was successful and -1, otherwise.

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

 None

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

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

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

int Decoder_amr_reset (Decoder_amrState *state, enum Mode mode)
{
  Word16 i;

  if (state == (Decoder_amrState *) NULL){
      fprintf(stderr, "Decoder_amr_reset: invalid parameter\n");
      return -1;
  }

  // Initialize static pointer
  state->exc = state->old_exc + PIT_MAX + L_INTERPOL;

  // Static vectors to zero
  Set_zero (state->old_exc, PIT_MAX + L_INTERPOL);

  if (mode != MRDTX)
     Set_zero (state->mem_syn, M);

  // initialize pitch sharpening
  state->sharp = SHARPMIN;
  state->old_T0 = 40;

  // Initialize state->lsp_old []

  if (mode != MRDTX) {
      Copy(lsp_init_data, &state->lsp_old[0], M);
  }

  // Initialize memories of bad frame handling
  state->prev_bf = 0;
  state->prev_pdf = 0;
  state->state = 0;

  state->T0_lagBuff = 40;
  state->inBackgroundNoise = 0;
  state->voicedHangover = 0;
  if (mode != MRDTX) {
      for (i=0;i<9;i++)
          state->excEnergyHist[i] = 0;
  }

  for (i = 0; i < 9; i++)
     state->ltpGainHistory[i] = 0;

  Cb_gain_average_reset(state->Cb_gain_averState);
  if (mode != MRDTX)
     lsp_avg_reset(state->lsp_avg_st);
  D_plsf_reset(state->lsfState);
  ec_gain_pitch_reset(state->ec_gain_p_st);
  ec_gain_code_reset(state->ec_gain_c_st);

  if (mode != MRDTX)
     gc_pred_reset(state->pred_state);

  Bgn_scd_reset(state->background_state);
  state->nodataSeed = 21845;
  ph_disp_reset(state->ph_disp_st);
  if (mode != MRDTX)
     dtx_dec_reset(state->dtxDecoderState);

  return 0;
}

------------------------------------------------------------------------------
 RESOURCES USED [optional]

 When the code is written for a specific target processor the
 the resources used should be documented below.