Calculation of optimum Q_bwe_exc differs between encoder and decoder

This is a follow up of !2851 (comment 111222).

The calculation of optimum scaling factor Q_bwe_exc in IVAS modes is different between encoder and decoder SWB TBE functions swb_tbe_enc_fx() and swb_tbe_dec_fx(). While at the decoder, the length of the signal on which the scaling factor is computed equals to L_FRAME32k + NL_BUFF_OFFSET:

/* ----- calculate optimum Q_bwe_exc and rescale memories accordingly ----- */


    Word16 sig_len = L_FRAME32k + NL_BUFF_OFFSET;
    move16();
    IF( st->element_mode == EVS_MONO )
    {
        sig_len = L_FRAME32k;
        move16();
    }

    Lmax = 0;
    move32();
    FOR( cnt = 0; cnt < sig_len; cnt++ ) // note: this differs from the encoder where the length is always L_FRAME32k
    {
        Lmax = L_max( Lmax, L_abs( bwe_exc_extended_fx[cnt] ) );
    }

the length at the encoder is L_FRAME16k:

/* ----- calculate optimum Q_bwe_exc and rescale memories accordingly ----- */


    Lmax = L_deposit_l( 0 );
    FOR( cnt = 0; cnt < L_FRAME32k; cnt++ )
    {
        Lmax = L_max( Lmax, L_abs( bwe_exc_extended[cnt] ) );
    }

Edited Mar 03, 2026 by vaclav