gecko/media/libopus/silk/fixed/LTP_scale_ctrl_FIX.c

/***********************************************************************
Copyright (c) 2006-2012 IETF Trust and Skype Limited. All rights reserved.

This file is extracted from RFC6716. Please see that RFC for additional
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***********************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "main_FIX.h"

/* Calculation of LTP state scaling */
void silk_LTP_scale_ctrl_FIX(
    silk_encoder_state_FIX          *psEnc,                                 /* I/O  encoder state                                                               */
    silk_encoder_control_FIX        *psEncCtrl,                             /* I/O  encoder control                                                             */
    opus_int                        condCoding                              /* I    The type of conditional coding to use                                       */
)
{
    opus_int round_loss;

    if( condCoding == CODE_INDEPENDENTLY ) {
        /* Only scale if first frame in packet */
        round_loss = psEnc->sCmn.PacketLoss_perc + psEnc->sCmn.nFramesPerPacket;
        psEnc->sCmn.indices.LTP_scaleIndex = (opus_int8)silk_LIMIT(
            silk_SMULWB( silk_SMULBB( round_loss, psEncCtrl->LTPredCodGain_Q7 ), SILK_FIX_CONST( 0.1, 9 ) ), 0, 2 );
    } else {
        /* Default is minimum scaling */
        psEnc->sCmn.indices.LTP_scaleIndex = 0;
    }
    psEncCtrl->LTP_scale_Q14 = silk_LTPScales_table_Q14[ psEnc->sCmn.indices.LTP_scaleIndex ];
}