view libgsmefr/weight_a.c @ 477:4c9222d95647

libtwamr encoder: always emit frame->mode = mode; In the original implementation of amr_encode_frame(), the 'mode' member of the output struct was set to 0xFF if the output frame type is TX_NO_DATA. This design was made to mimic the mode field (16-bit word) being set to 0xFFFF (or -1) in 3GPP test sequence format - but nothing actually depends on this struct member being set in any way, and amr_frame_to_tseq() generates the needed 0xFFFF on its own, based on frame->type being equal to TX_NO_DATA. It is simpler and more efficient to always set frame->mode to the actual encoding mode in amr_encode_frame(), and this new behavior has already been documented in doc/AMR-library-API description in anticipation of the present change.
author Mychaela Falconia <falcon@freecalypso.org>
date Sat, 18 May 2024 22:30:42 +0000
parents b651adfce60d
children
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/*************************************************************************
 *
 *  FUNCTION:  Weight_Ai
 *
 *  PURPOSE: Spectral expansion of LP coefficients.  (order==10)
 *
 *  DESCRIPTION:
 *      a_exp[i] = a[i] * fac[i-1]    ,i=1,10
 *
 *************************************************************************/

#include "gsm_efr.h"
#include "typedef.h"
#include "namespace.h"
#include "basic_op.h"
#include "no_count.h"
#include "sig_proc.h"

/* m = LPC order == 10 */
#define m 10

void Weight_Ai (
    Word16 a[],         /* (i)     : a[m+1]  LPC coefficients   (m=10)    */
    const Word16 fac[], /* (i)     : Spectral expansion factors.          */
    Word16 a_exp[]      /* (o)     : Spectral expanded LPC coefficients   */
)
{
    Word16 i;

    a_exp[0] = a[0];                                    move16 (); 
    for (i = 1; i <= m; i++)
    {
        a_exp[i] = round (L_mult (a[i], fac[i - 1]));   move16 (); 
    }

    return;
}