Something

    if(param.rc.b_stat_write && !param.rc.b_stat_read) {
        /* Adjust or disable some flags to gain speed in the first pass */
        if(turbo == 1)
        {
            param.i_frame_reference = ( param.i_frame_reference + 1 ) >> 1;
            param.analyse.i_subpel_refine = FFMAX( FFMIN( 3, param.analyse.i_subpel_refine - 1 ), 1 );
            param.analyse.inter &= ( ~X264_ANALYSE_PSUB8x8 );
            param.analyse.inter &= ( ~X264_ANALYSE_BSUB16x16 );
            param.analyse.i_trellis = 0;
        }
        else if(turbo >= 2)
        {
            param.i_frame_reference = 1;
            param.analyse.i_subpel_refine = 1;
            param.analyse.i_me_method = X264_ME_DIA;
            param.analyse.inter = 0;
            param.analyse.b_transform_8x8 = 0;
            param.analyse.b_weighted_bipred = 0;
            param.analyse.i_trellis = 0;
        }
    }