FreeCalypso > hg > gsm-codec-lib
view libtwamr/int_lsf.h @ 458:e26b974f7ba3
doc/AMR-study-utils: update for the current situation
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Fri, 10 May 2024 18:45:36 +0000 |
| parents | 693ea1d5cf1e |
| children |
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/* ******************************************************************************** * * 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 : int_lsf.h * Purpose : Interpolates the LSFs * ******************************************************************************** */ #ifndef int_lsf_h #define int_lsf_h "$Id $" /* ******************************************************************************** * INCLUDE FILES ******************************************************************************** */ #include "typedef.h" /* ******************************************************************************** * DEFINITION OF DATA TYPES ******************************************************************************** */ /* ******************************************************************************** * DECLARATION OF PROTOTYPES ******************************************************************************** */ /* ************************************************************************** * * Function : Int_lsf * Purpose : Interpolates the LSFs for selected subframe * Description : The 20 ms speech frame is divided into 4 subframes. * The LSFs are interpolated at the 1st, 2nd and 3rd * subframe and only forwarded at the 4th subframe. * * |------|------|------|------| * sf1 sf2 sf3 sf4 * F0 F1 * * sf1: 3/4 F0 + 1/4 F1 sf3: 1/4 F0 + 3/4 F1 * sf2: 1/2 F0 + 1/2 F1 sf4: F1 * Returns : void * ************************************************************************** */ void Int_lsf ( Word16 lsf_old[], /* i : LSF vector at the 4th SF of past frame */ Word16 lsf_new[], /* i : LSF vector at the 4th SF of present frame */ Word16 i_subfr, /* i : Pointer to current sf (equal to 0,40,80 or 120) */ Word16 lsf_out[] /* o : interpolated LSF parameters for current sf */ ); #endif