dec_amr.c

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.10平台上编译为嵌入式图形界面操作系统。

    /* If there was no DTX muting, the first speech frame is not     */
    /* muted. The BFH state machine starts from state 5, however, to */
    /* keep the audible noise resulting from a SID frame which is    */
    /* erroneously interpreted as a good speech frame as small as    */
    /* possible (the decoder output in this case is quickly muted)   */

    test(); 
    if (sub(st->dtxDecoderState->dtxGlobalState, DTX) == 0)
    {
       st->state = 5;                                    move16 ();
       st->prev_bf = 0;                                  move16 ();
    }
    else if (test (), sub(st->dtxDecoderState->dtxGlobalState, DTX_MUTE) == 0)
    {
       st->state = 5;                                    move16 ();
       st->prev_bf = 1;                                  move16 ();
    }
    
    /* save old LSFs for CB gain smoothing */
    Copy (st->lsfState->past_lsf_q, prev_lsf, M);
    
    /* decode LSF parameters and generate interpolated lpc coefficients
       for the 4 subframes */
    test ();
    if (sub (mode, MR122) != 0)
    {
       D_plsf_3(st->lsfState, mode, bfi, parm, lsp_new);

       fwc ();                     /* function worst case */

       /* Advance synthesis parameters pointer */
       parm += 3;                  move16 ();
       
       Int_lpc_1to3(st->lsp_old, lsp_new, A_t);
    }
    else
    {
       D_plsf_5 (st->lsfState, bfi, parm, lsp_mid, lsp_new);

       fwc ();                     /* function worst case */

       /* Advance synthesis parameters pointer */
       parm += 5;                  move16 ();
       
       Int_lpc_1and3 (st->lsp_old, lsp_mid, lsp_new, A_t);
    }
       
    /* update the LSPs for the next frame */
    for (i = 0; i < M; i++)
    {
       st->lsp_old[i] = lsp_new[i];        move16 (); 
    }

    fwc ();                     /* function worst case */

   /*------------------------------------------------------------------------*
    *          Loop for every subframe in the analysis frame                 *
    *------------------------------------------------------------------------*
    * The subframe size is L_SUBFR and the loop is repeated L_FRAME/L_SUBFR  *
    *  times                                                                 *
    *     - decode the pitch delay                                           *
    *     - decode algebraic code                                            *
    *     - decode pitch and codebook gains                                  *
    *     - find the excitation and compute synthesis speech                 *
    *------------------------------------------------------------------------*/
    
    /* pointer to interpolated LPC parameters */
    Az = A_t;                                                       move16 (); 
    
    evenSubfr = 0;                                                  move16();
    subfrNr = -1;                                                   move16();
    for (i_subfr = 0; i_subfr < L_FRAME; i_subfr += L_SUBFR)
    {
       subfrNr = add(subfrNr, 1);
       evenSubfr = sub(1, evenSubfr);

       /* flag for first and 3th subframe */
       pit_flag = i_subfr;             move16 ();

       test();
       if (sub (i_subfr, L_FRAME_BY2) == 0)
       {
          test(); test();
          if (sub(mode, MR475) != 0 && sub(mode, MR515) != 0) 
          {
             pit_flag = 0;             move16 ();
          }
       }
       
       /* pitch index */
       index = *parm++;                move16 ();

       /*-------------------------------------------------------*
        * - decode pitch lag and find adaptive codebook vector. *
        *-------------------------------------------------------*/
       
       test ();
       if (sub(mode, MR122) != 0)
       {
          /* flag4 indicates encoding with 4 bit resolution;     */
          /* this is needed for mode MR475, MR515, MR59 and MR67 */
          
          flag4 = 0;                                 move16 ();
          test (); test (); test (); test ();        
          if ((sub (mode, MR475) == 0) ||
              (sub (mode, MR515) == 0) ||
              (sub (mode, MR59) == 0) ||
              (sub (mode, MR67) == 0) ) {
             flag4 = 1;                              move16 ();
          }
          
          /*-------------------------------------------------------*
           * - get ranges for the t0_min and t0_max                *
           * - only needed in delta decoding                       *
           *-------------------------------------------------------*/

          delta_frc_low = 5;                      move16();
          delta_frc_range = 9;                    move16();

          test ();
          if ( sub(mode, MR795) == 0 )
          {
             delta_frc_low = 10;                  move16();
             delta_frc_range = 19;                move16();
          }
             
          t0_min = sub(st->old_T0, delta_frc_low);
          test ();
          if (sub(t0_min, PIT_MIN) < 0)
          {
             t0_min = PIT_MIN;                    move16();
          }
          t0_max = add(t0_min, delta_frc_range);
          test ();
          if (sub(t0_max, PIT_MAX) > 0)
          {
             t0_max = PIT_MAX;                    move16();
             t0_min = sub(t0_max, delta_frc_range);
          }
             
          Dec_lag3 (index, t0_min, t0_max, pit_flag, st->old_T0,
                    &T0, &T0_frac, flag4);

          st->T0_lagBuff = T0;                        move16 ();

          test ();
          if (bfi != 0)
          {
             test ();
             if (sub (st->old_T0, PIT_MAX) < 0)     
             {                                      /* Graceful pitch */
                st->old_T0 = add(st->old_T0, 1);    /* degradation    */
             }
             T0 = st->old_T0;                     move16 (); 
             T0_frac = 0;                         move16 (); 

             test (); test (); test (); test (); test ();
             if ( st->inBackgroundNoise != 0 && 
                  sub(st->voicedHangover, 4) > 0 &&
                  ((sub(mode, MR475) == 0 ) ||
                   (sub(mode, MR515) == 0 ) ||
                   (sub(mode, MR59) == 0) )
                  )
             {
                T0 = st->T0_lagBuff;                  move16 ();
             }
          }

          fwc ();             /* function worst case */

          Pred_lt_3or6 (st->exc, T0, T0_frac, L_SUBFR, 1);
       }
       else
       {
          Dec_lag6 (index, PIT_MIN_MR122,
                    PIT_MAX, pit_flag, &T0, &T0_frac);

          test (); test (); test ();
          if ( bfi == 0 && (pit_flag == 0 || sub (index, 61) < 0))
          {
          }                
          else
          {
             st->T0_lagBuff = T0;                 move16 ();
             T0 = st->old_T0;                     move16 (); 
             T0_frac = 0;                         move16 (); 
          }

          fwc ();             /* function worst case */

          Pred_lt_3or6 (st->exc, T0, T0_frac, L_SUBFR, 0);
       }
       
       fwc ();             /* function worst case */
       
       /*-------------------------------------------------------*
        * - (MR122 only: Decode pitch gain.)                    *
        * - Decode innovative codebook.                         *
        * - set pitch sharpening factor                         *
        *-------------------------------------------------------*/

        test (); test (); 
        if (sub (mode, MR475) == 0 || sub (mode, MR515) == 0)
        {   /* MR475, MR515 */
           index = *parm++;        /* index of position */ move16 ();
           i = *parm++;            /* signs             */ move16 ();
           
           fwc ();                 /* function worst case */

           decode_2i40_9bits (subfrNr, i, index, code);
           
           fwc ();                 /* function worst case */

           pit_sharp = shl (st->sharp, 1);
        }
        else if (sub (mode, MR59) == 0)
        {   /* MR59 */
           test (); 
           index = *parm++;        /* index of position */ move16 ();
           i = *parm++;            /* signs             */ move16 ();
           
           fwc ();                 /* function worst case */

           decode_2i40_11bits (i, index, code);
           
           fwc ();                 /* function worst case */

           pit_sharp = shl (st->sharp, 1);
        }
        else if (sub (mode, MR67) == 0)
        {   /* MR67 */
           test (); test ();
           index = *parm++;        /* index of position */ move16 ();
           i = *parm++;            /* signs             */ move16 ();
           
           fwc ();                 /* function worst case */

           decode_3i40_14bits (i, index, code);
            
           fwc ();                 /* function worst case */

           pit_sharp = shl (st->sharp, 1);
        }
        else if (sub (mode, MR795) <= 0)
        {   /* MR74, MR795 */
           test (); test (); test ();
           index = *parm++;        /* index of position */ move16 ();
           i = *parm++;            /* signs             */ move16 ();
           
           fwc ();                 /* function worst case */

           decode_4i40_17bits (i, index, code);
           
           fwc ();                 /* function worst case */

           pit_sharp = shl (st->sharp, 1);
        }
        else if (sub (mode, MR102) == 0)
        {  /* MR102 */
           test (); test (); test ();

           fwc ();                 /* function worst case */

           dec_8i40_31bits (parm, code);
           parm += 7;                                       move16 (); 

           fwc ();                 /* function worst case */

           pit_sharp = shl (st->sharp, 1);
        }
        else
        {  /* MR122 */
           test (); test (); test ();
           index = *parm++;                                move16 ();
           test();
           if (bfi != 0)
           {
              ec_gain_pitch (st->ec_gain_p_st, st->state, &gain_pit);
           }
           else
           {
              gain_pit = d_gain_pitch (mode, index);        move16 ();
           }
           ec_gain_pitch_update (st->ec_gain_p_st, bfi, st->prev_bf,
                                 &gain_pit);
           

           fwc ();                 /* function worst case */


           dec_10i40_35bits (parm, code);
           parm += 10;                                     move16 (); 

           fwc ();                 /* function worst case */

           /* pit_sharp = gain_pit;                   */
           /* if (pit_sharp > 1.0) pit_sharp = 1.0;   */
           
           pit_sharp = shl (gain_pit, 1);
        }
        
        /*-------------------------------------------------------*
         * - Add the pitch contribution to code[].               *
         *-------------------------------------------------------*/
        for (i = T0; i < L_SUBFR; i++)
        {
           temp = mult (code[i - T0], pit_sharp);
           code[i] = add (code[i], temp);
           move16 (); 
        }
        
        fwc ();                 /* function worst case */
        
        /*------------------------------------------------------------*
         * - Decode codebook gain (MR122) or both pitch               *
         *   gain and codebook gain (all others)                      *
         * - Update pitch sharpening "sharp" with quantized gain_pit  *
         *------------------------------------------------------------*/

        if (test(), sub (mode, MR475) == 0)
        {
           /* read and decode pitch and code gain */
           test();      
           if (evenSubfr != 0) 
           {
              index_mr475 = *parm++;        move16 (); /* index of gain(s) */
           }

           test();
           if (bfi == 0)
           {
              Dec_gain(st->pred_state, mode, index_mr475, code,
                       evenSubfr, &gain_pit, &gain_code); 
           }
           else
           {
              ec_gain_pitch (st->ec_gain_p_st, st->state, &gain_pit);
              ec_gain_code (st->ec_gain_c_st, st->pred_state, st->state,
                            &gain_code);
           }
           ec_gain_pitch_update (st->ec_gain_p_st, bfi, st->prev_bf,
                                 &gain_pit);
           ec_gain_code_update (st->ec_gain_c_st, bfi, st->prev_bf,
                                &gain_code);
           
           fwc ();                 /* function worst case */

           pit_sharp = gain_pit;                                move16 ();
           test ();
           if (sub (pit_sharp, SHARPMAX) > 0) 
           {
               pit_sharp = SHARPMAX;                            move16 ();
           }

        }
        else if (test(), test(), (sub (mode, MR74) <= 0) || 
                 (sub (mode, MR102) == 0))
        {
            /* read and decode pitch and code gain */
            index = *parm++;                move16 (); /* index of gain(s) */
           
            test();
            if (bfi == 0)
            {
               Dec_gain(st->pred_state, mode, index, code,
                        evenSubfr, &gain_pit, &gain_code);
            }
            else
            {
               ec_gain_pitch (st->ec_gain_p_st, st->state, &gain_pit);
               ec_gain_code (st->ec_gain_c_st, st->pred_state, st->state,
                             &gain_code);
            }
            ec_gain_pitch_update (st->ec_gain_p_st, bfi, st->prev_bf,
                                  &gain_pit);
            ec_gain_code_update (st->ec_gain_c_st, bfi, st->prev_bf,
                                 &gain_code);

            fwc ();                 /* function worst case */
            
            pit_sharp = gain_pit;                               move16 ();