> ## Documentation Index
> Fetch the complete documentation index at: https://docs.xbox.com/llms.txt
> Use this file to discover all available pages before exploring further.

# ButterflyDIT4_1

> ButterflyDIT4_1

Don't use; internal use only.

## Syntax

```cpp theme={null}
void ButterflyDIT4_1(  
         XMVECTOR& r1,  
         XMVECTOR& i1  
)  
```

### Parameters

*r1*   \_Inout\_\
Type: XMVECTOR&

Don't use; internal use only.

*i1*   \_Inout\_\
Type: XMVECTOR&

Don't use; internal use only.

### Return value

Type: void

Don't use; internal use only.

## Remarks

Don't use; internal use only.

XDSP uses DirectXMath based digital signal processing (DSP) functions for audio, which they are primarily FFT. All buffer parameters must be 16-byte aligned. For more information about the DirectXMath API and library, see [DirectXMath](https://learn.microsoft.com/windows/win32/dxmath/directxmath-portal).

## Requirements

**Header:** xdsp.h

**Supported platforms:** XBOX One family consoles and XBOX Series consoles

## See also

[xdsp](https://docs.xbox.com/reference/audio/xdsp/xdsp_members.md)

[FFT](https://docs.xbox.com/reference/audio/xdsp/functions/fft.md)

[Fourier Transform](https://www.techopedia.com/definition/7292/fourier-transform)

[Game for Windows and the DirectX SDK blog](https://walbourn.github.io/xdsp-h-digital-signal-processing-helper-functions/)


## Related topics

- [XDSP](https://docs.xbox.com/reference/audio/xdsp/xdsp_members.md)
- [ButterflyDIT4_4](https://docs.xbox.com/reference/audio/xdsp/functions/butterflydit4_4.md)
- [FFT4](https://docs.xbox.com/reference/audio/xdsp/functions/fft4.md)
- [FFT](https://docs.xbox.com/reference/audio/xdsp/functions/fft.md)
- [FFT16](https://docs.xbox.com/reference/audio/xdsp/functions/fft16.md)