# Internals
Functions here are not exported.

```@docs
DSP.os_fft_complexity
DSP.os_prepare_conv
DSP.os_conv_block!
DSP.os_filter_transform!
DSP.Windows.makewindow
DSP.Windows.padplot
DSP._zeropad
DSP._zeropad!
DSP._zeropad_keep_offset
DSP.Filters._polyprep
DSP.Filters.freq_eval
DSP.Filters.build_grid
DSP.Filters.lagrange_interp
DSP.Periodograms.coherence_from_cs!
DSP.optimalfftfiltlength
```