FreeCalypso > hg > gsm-codec-lib
view libtwamr/ex_ctrl.c @ 394:2af94ba0c075
libtwamr: integrate syn_filt.c
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Mon, 06 May 2024 18:49:17 +0000 |
parents | 3f27ca24c620 |
children |
line wrap: on
line source
/************************************************************************* * * GSM AMR-NB speech codec R98 Version 7.6.0 December 12, 2001 * R99 Version 3.3.0 * REL-4 Version 4.1.0 * ******************************************************************************** * * File : ex_ctrl.c * Purpose : Excitation Control module in background noise * ******************************************************************************** */ /* ******************************************************************************** * MODULE INCLUDE FILE AND VERSION ID ******************************************************************************** */ #include "namespace.h" #include "ex_ctrl.h" #include "typedef.h" #include "basic_op.h" #include "no_count.h" #include "cnst.h" #include "memops.h" #include "gmed_n.h" #include "sqrt_l.h" /* ******************************************************************************** * LOCAL VARIABLES AND TABLES ******************************************************************************** */ /*-----------------------------------------------------------------* * Decoder constant parameters (defined in "cnst.h") * *-----------------------------------------------------------------* * L_FRAME : Frame size. * * L_SUBFR : Sub-frame size. * *-----------------------------------------------------------------*/ /* ******************************************************************************** * PUBLIC PROGRAM CODE ******************************************************************************** */ /* ************************************************************************** * * Function : Ex_ctrl * Purpose : Charaterice synthesis speech and detect background noise * Returns : background noise decision; 0 = no bgn, 1 = bgn * ************************************************************************** */ Word16 Ex_ctrl (Word16 excitation[], /*i/o: Current subframe excitation */ Word16 excEnergy, /* i : Exc. Energy, sqrt(totEx*totEx)*/ Word16 exEnergyHist[], /* i : History of subframe energies */ Word16 voicedHangover, /* i : # of fr. after last voiced fr.*/ Word16 prevBFI, /* i : Set i previous BFI */ Word16 carefulFlag /* i : Restrict dymamic in scaling */ ) { Word16 i, exp; Word16 testEnergy, scaleFactor, avgEnergy, prevEnergy; Word32 t0; /* get target level */ avgEnergy = gmed_n(exEnergyHist, 9); move16(); prevEnergy = shr( add (exEnergyHist[7], exEnergyHist[8]) ,1); test (); if ( sub (exEnergyHist[8], prevEnergy) < 0) { prevEnergy = exEnergyHist[8]; move16 (); } /* upscaling to avoid too rapid energy rises for some cases */ test (); test (); if ( sub (excEnergy, avgEnergy) < 0 && sub (excEnergy, 5) > 0) { testEnergy = shl(prevEnergy, 2); /* testEnergy = 4*prevEnergy; */ test (); test (); if ( sub (voicedHangover, 7) < 0 || prevBFI != 0 ) { /* testEnergy = 3*prevEnergy */ testEnergy = sub (testEnergy, prevEnergy); } test (); if ( sub (avgEnergy, testEnergy) > 0) { avgEnergy = testEnergy; move16 (); } /* scaleFactor=avgEnergy/excEnergy in Q0 (const 29 below)*/ exp = norm_s (excEnergy); excEnergy = shl (excEnergy, exp); excEnergy = div_s ((Word16) 16383, excEnergy); t0 = L_mult (avgEnergy, excEnergy); t0 = L_shr (t0, sub (20, exp)); /* const=30 for t0 in Q0, 20 for Q10 */ if ( L_sub(t0, 32767) > 0 ) { t0 = 32767; move32 (); /* saturate */ } scaleFactor = extract_l (t0); /* test if scaleFactor > 3.0 */ test (); test (); if ( carefulFlag != 0 && sub(scaleFactor, 3072) > 0 ) { scaleFactor = 3072; move16 (); } /* scale the excitation by scaleFactor */ for (i = 0; i < L_SUBFR; i++) { t0 = L_mult (scaleFactor, excitation[i]); t0 = L_shr (t0, 11); excitation[i] = extract_l (t0); } } return 0; }