freeswitch/libs/silk/src/SKP_Silk_decoder_set_fs.c

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#include "SKP_Silk_main.h"

/* Set decoder sampling rate */
void SKP_Silk_decoder_set_fs(
    SKP_Silk_decoder_state          *psDec,             /* I/O  Decoder state pointer                       */
    SKP_int                         fs_kHz              /* I    Sampling frequency (kHz)                    */
)
{
    if( psDec->fs_kHz != fs_kHz ) {
        psDec->fs_kHz  = fs_kHz;
        psDec->frame_length = SKP_SMULBB( FRAME_LENGTH_MS, fs_kHz );
        psDec->subfr_length = SKP_SMULBB( FRAME_LENGTH_MS / NB_SUBFR, fs_kHz );
        if( psDec->fs_kHz == 8 ) {
            psDec->LPC_order = MIN_LPC_ORDER;
            psDec->psNLSF_CB[ 0 ] = &SKP_Silk_NLSF_CB0_10;
            psDec->psNLSF_CB[ 1 ] = &SKP_Silk_NLSF_CB1_10;
        } else {
            psDec->LPC_order = MAX_LPC_ORDER;
            psDec->psNLSF_CB[ 0 ] = &SKP_Silk_NLSF_CB0_16;
            psDec->psNLSF_CB[ 1 ] = &SKP_Silk_NLSF_CB1_16;
        }
        /* Reset part of the decoder state */
        SKP_memset( psDec->sLPC_Q14,     0, MAX_LPC_ORDER    * sizeof( SKP_int32 ) );
        SKP_memset( psDec->outBuf,       0, MAX_FRAME_LENGTH * sizeof( SKP_int16 ) );
        SKP_memset( psDec->prevNLSF_Q15, 0, MAX_LPC_ORDER    * sizeof( SKP_int )   );

        psDec->lagPrev                 = 100;
        psDec->LastGainIndex           = 1;
        psDec->prev_sigtype            = 0;
        psDec->first_frame_after_reset = 1;

        if( fs_kHz == 24 ) {
            psDec->HP_A = SKP_Silk_Dec_A_HP_24;
            psDec->HP_B = SKP_Silk_Dec_B_HP_24;
        } else if( fs_kHz == 16 ) {
            psDec->HP_A = SKP_Silk_Dec_A_HP_16;
            psDec->HP_B = SKP_Silk_Dec_B_HP_16;
        } else if( fs_kHz == 12 ) {
            psDec->HP_A = SKP_Silk_Dec_A_HP_12;
            psDec->HP_B = SKP_Silk_Dec_B_HP_12;
        } else if( fs_kHz == 8 ) {
            psDec->HP_A = SKP_Silk_Dec_A_HP_8;
            psDec->HP_B = SKP_Silk_Dec_B_HP_8;
        } else {
            /* unsupported sampling rate */
            SKP_assert( 0 );
        }
    }

    /* Check that settings are valid */
    SKP_assert( psDec->frame_length > 0 && psDec->frame_length <= MAX_FRAME_LENGTH );
}