dtx_dec.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_dec.c
 Functions:
           dtx_dec_reset
           dtx_dec
           dtx_dec_activity_update
           rx_dtx_handler

     Date: 04/17/2000

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

 Description: First attempt at optimization.

 Description: Made changes based on comments from the review.

 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. Modified FOR loops to count down.
              2. Made some cosmetic changes.
              3. Replaced call to "abs" with "abs_s".
              4. Added lsp.tab and q_plsf_5.tab to the Include section.
              5. Fixed typecasting issue with TI C compiler.
              6. Replaced basic_op.h and oper_32b.h with the header files
                 of the math functions used by the file.

 Description: Removed the functions dtx_dec_init and dtx_dec_exit.
 The dtx_dec related structure is no longer dynamically allocated.

 Description: Made the following changes to make code bit-exact:
              1. Fixed inlining of shl() function in parts of dtx_dec and
                 dtx_dec_activity_update functions.
              2. Fixed optimazation bugs in dtx_dec function.
              3. Modified some FOR loops in dtx_dec to count up.
              4. Added call to add() function in rx_dtx_handler function.
              5. Updated copyright year.

 Description: Passing in pOverflow rather than accessing it as a global
              variable.

 Description: Synchronized file with UMTS (3GPP) version 3.3.0 == GSM version
              7.6.0 == 3GPP Release 4, version 4.1.0.

 Description: Removed call to test() on line 843.

 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

 These modules decode the comfort noise when in DTX.

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


/*----------------------------------------------------------------------------
; INCLUDES
----------------------------------------------------------------------------*/
#include "dtx_dec.h"
#include "typedef.h"
#include "basic_op.h"
#include "copy.h"
#include "set_zero.h"
#include "mode.h"
#include "log2.h"
#include "lsp_az.h"
#include "pow2.h"
#include "a_refl.h"
#include "b_cn_cod.h"
#include "syn_filt.h"
#include "lsp_lsf.h"
#include "reorder.h"
#include "lsp_tab.h"
#include "oscl_mem.h"

/*----------------------------------------------------------------------------
; MACROS
; Define module specific macros here
----------------------------------------------------------------------------*/


/*----------------------------------------------------------------------------
; DEFINES
; Include all pre-processor statements here. Include conditional
; compile variables also.
----------------------------------------------------------------------------*/
#define PN_INITIAL_SEED 0x70816958L   /* Pseudo noise generator seed value  */

/*----------------------------------------------------------------------------
; LOCAL FUNCTION DEFINITIONS
; Function Prototype declaration
----------------------------------------------------------------------------*/


/*----------------------------------------------------------------------------
; LOCAL VARIABLE DEFINITIONS
; Variable declaration - defined here and used outside this module
----------------------------------------------------------------------------*/

/***************************************************
 * Scaling factors for the lsp variability operation *
 ***************************************************/
static const Word16 lsf_hist_mean_scale[M] =
{
    20000,
    20000,
    20000,
    20000,
    20000,
    18000,
    16384,
    8192,
    0,
    0
};

/*************************************************
 * level adjustment for different modes Q11      *
 *************************************************/
static const Word16 dtx_log_en_adjust[9] =
{
    -1023, /* MR475 */
    -878, /* MR515 */
    -732, /* MR59  */
    -586, /* MR67  */
    -440, /* MR74  */
    -294, /* MR795 */
    -148, /* MR102 */
    0, /* MR122 */
    0, /* MRDTX */
};


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

 Inputs:
    st = pointer to a structure of type dtx_decState

 Outputs:
    Structure pointed to by st is initialized to a set of initial values.

 Returns:
    return_value = 0 if memory was successfully initialized,
        otherwise returns -1 (int)

 Global Variables Used:
    None.

 Local Variables Needed:
    None.

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

 Reset of state memory for dtx_dec.

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

 None.

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

 dtx_dec.c, UMTS GSM AMR speech codec, R99 - Version 3.3.0, December 12, 2001

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

int dtx_dec_reset (dtx_decState *st)
{
   int i;

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

   st->since_last_sid = 0;
   st->true_sid_period_inv = (1 << 13);

   st->log_en = 3500;
   st->old_log_en = 3500;
   // low level noise for better performance in  DTX handover cases

   st->L_pn_seed_rx = PN_INITIAL_SEED;

   // Initialize state->lsp [] and state->lsp_old []
   Copy(lsp_init_data, &st->lsp[0], M);
   Copy(lsp_init_data, &st->lsp_old[0], M);

   st->lsf_hist_ptr = 0;
   st->log_pg_mean = 0;
   st->log_en_hist_ptr = 0;

   // initialize decoder lsf history
   Copy(mean_lsf, &st->lsf_hist[0], M);

   for (i = 1; i < DTX_HIST_SIZE; i++)
   {
      Copy(&st->lsf_hist[0], &st->lsf_hist[M*i], M);
   }
   Set_zero(st->lsf_hist_mean, M*DTX_HIST_SIZE);

   // initialize decoder log frame energy
   for (i = 0; i < DTX_HIST_SIZE; i++)
   {
      st->log_en_hist[i] = st->log_en;
   }

   st->log_en_adjust = 0;

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

   st->sid_frame = 0;
   st->valid_data = 0;
   st->dtxHangoverAdded = 0;

   st->dtxGlobalState = DTX;
   st->data_updated = 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 dtx_dec_reset(dtx_decState *st)
{
    Word16 i;

    if (st == (dtx_decState *) NULL)
    {
        /* fprint(stderr, "dtx_dec_reset: invalid parameter\n");  */
        return(-1);
    }

    st->since_last_sid = 0;
    st->true_sid_period_inv = (1 << 13);

    st->log_en = 3500;
    st->old_log_en = 3500;
    /* low level noise for better performance in  DTX handover cases*/

    st->L_pn_seed_rx = PN_INITIAL_SEED;

    /* Initialize state->lsp [] */
    st->lsp[0] = 30000;
    st->lsp[1] = 26000;
    st->lsp[2] = 21000;
    st->lsp[3] = 15000;
    st->lsp[4] = 8000;
    st->lsp[5] = 0;
    st->lsp[6] = -8000;
    st->lsp[7] = -15000;
    st->lsp[8] = -21000;
    st->lsp[9] = -26000;

    /* Initialize state->lsp_old [] */
    st->lsp_old[0] = 30000;
    st->lsp_old[1] = 26000;
    st->lsp_old[2] = 21000;
    st->lsp_old[3] = 15000;
    st->lsp_old[4] = 8000;
    st->lsp_old[5] = 0;
    st->lsp_old[6] = -8000;
    st->lsp_old[7] = -15000;
    st->lsp_old[8] = -21000;
    st->lsp_old[9] = -26000;

    st->lsf_hist_ptr = 0;
    st->log_pg_mean = 0;
    st->log_en_hist_ptr = 0;

    /* initialize decoder lsf history */
    st->lsf_hist[0] =  1384;
    st->lsf_hist[1] =  2077;
    st->lsf_hist[2] =  3420;
    st->lsf_hist[3] =  5108;
    st->lsf_hist[4] =  6742;
    st->lsf_hist[5] =  8122;
    st->lsf_hist[6] =  9863;
    st->lsf_hist[7] = 11092;
    st->lsf_hist[8] = 12714;
    st->lsf_hist[9] = 13701;

    for (i = 1; i < DTX_HIST_SIZE; i++)
    {
        Copy(&st->lsf_hist[0], &st->lsf_hist[M*i], M);
    }
    oscl_memset(st->lsf_hist_mean, 0, sizeof(Word16)*M*DTX_HIST_SIZE);

    /* initialize decoder log frame energy */
    for (i = 0; i < DTX_HIST_SIZE; i++)
    {
        st->log_en_hist[i] = st->log_en;
    }

    st->log_en_adjust = 0;

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

    st->sid_frame = 0;
    st->valid_data = 0;
    st->dtxHangoverAdded = 0;

    st->dtxGlobalState = DTX;
    st->data_updated = 0;

    return(0);
}

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

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

 Inputs:
    st = pointer to a structure of type dtx_decState
    mem_syn = AMR decoder state
    lsfState = decoder lsf states
    predState = prediction states
    averState = CB gain average states
    new_state = new DTX state
    mode = AMR mode
    parm = Vector of synthesis parameters

 Outputs:
    st points to an updated structure of type dtx_decState
    mem_syn = AMR decoder state
    lsfState = decoder lsf states
    predState = prediction states
    averState = CB gain average states
    synth = synthesised speech
    A_t = decoded LP filter in 4 subframes

 Returns:
    return_value = 0 (int)

 Global Variables Used:
    None.

 Local Variables Needed:
    None.

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

 Decode comfort noise when in DTX.

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

 None

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

 dtx_dec.c, UMTS GSM AMR speech codec, R99 - Version 3.3.0, December 12, 2001

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

int dtx_dec(
   dtx_decState *st,                // i/o : State struct
   Word16 mem_syn[],                // i/o : AMR decoder state
   D_plsfState* lsfState,           // i/o : decoder lsf states
   gc_predState* predState,         // i/o : prediction states
   Cb_gain_averageState* averState, // i/o : CB gain average states
   enum DTXStateType new_state,     // i   : new DTX state
   enum Mode mode,                  // i   : AMR mode
   Word16 parm[],                   // i   : Vector of synthesis parameters
   Word16 synth[],                  // o   : synthesised speech
   Word16 A_t[]                     // o   : decoded LP filter in 4 subframes
   )
{
   Word16 log_en_index;
   Word16 i, j;
   Word16 int_fac;
   Word32 L_log_en_int;
   Word16 lsp_int[M];
   Word16 log_en_int_e;
   Word16 log_en_int_m;
   Word16 level;
   Word16 acoeff[M + 1];
   Word16 refl[M];
   Word16 pred_err;
   Word16 ex[L_SUBFR];
   Word16 ma_pred_init;
   Word16 log_pg_e, log_pg_m;
   Word16 log_pg;
   Flag negative;
   Word16 lsf_mean;
   Word32 L_lsf_mean;
   Word16 lsf_variab_index;
   Word16 lsf_variab_factor;
   Word16 lsf_int[M];
   Word16 lsf_int_variab[M];
   Word16 lsp_int_variab[M];
   Word16 acoeff_variab[M + 1];

   Word16 lsf[M];
   Word32 L_lsf[M];
   Word16 ptr;
   Word16 tmp_int_length;


    // This function is called if synthesis state is not SPEECH
    // the globally passed  inputs to this function are
    // st->sid_frame
    // st->valid_data
    // st->dtxHangoverAdded
    // new_state  (SPEECH, DTX, DTX_MUTE)

   if ((st->dtxHangoverAdded != 0) &&
       (st->sid_frame != 0))
   {
      // sid_first after dtx hangover period
      // or sid_upd after dtxhangover

      // set log_en_adjust to correct value
      st->log_en_adjust = dtx_log_en_adjust[mode];

      ptr = add(st->lsf_hist_ptr, M);
      if (sub(ptr, 80) == 0)
      {
         ptr = 0;
      }
      Copy( &st->lsf_hist[st->lsf_hist_ptr],&st->lsf_hist[ptr],M);

      ptr = add(st->log_en_hist_ptr,1);