---
title: vDSP_biquad2
framework: Kernel
role: symbol
role_heading: Function
platforms: [macOS 10.9+]
path: kernel/1532195-vdsp_biquad2
---

# vDSP_biquad2

Applies a single-precision stereo biquadratic IIR filter.

## Declaration

```occ
void vDSP_biquad2(const struct vDSP_biquad_SetupStruct *, const float *, float *, size_t);
```

## Parameters

- `Parameter 0`: The data structure that stores the biquadratic filter state and coefficients.
- `Parameter 1`: A pointer to the single-precision interleaved stereo input data.
- `Parameter 2`: A pointer to the single-precision interleaved stereo output data.
- `Parameter 3`: The number of elements per channel.

## Discussion

Discussion Use this function to apply a stereo biquadratic IIR filter to the input and write the filtered result to the output. The input and output are interleaved so that even elements correspond to the left channel and odd elements correspond to the right channel.

## See Also

### Biquadratic Infinite Impulse Response (IIR) Filters

- [vDSP_biquad2_CreateSetup](kernel/1532224-vdsp_biquad2_createsetup.md)
- [IIRChannel](kernel/iirchannel.md)
- [vDSP_biquad2_CopyState](kernel/1532220-vdsp_biquad2_copystate.md)
- [vDSP_biquad2_ResetState](kernel/1532215-vdsp_biquad2_resetstate.md)
- [vDSP_biquad2_DestroySetup](kernel/1532201-vdsp_biquad2_destroysetup.md)