---
title: vDSP_biquadm_CopyStateD
framework: Kernel
role: symbol
role_heading: Function
platforms: [macOS 10.10+]
path: kernel/1580000-vdsp_biquadm_copystated
---

# vDSP_biquadm_CopyStateD

Copies the filter state from one dopuble-precision multichannel biquad IIR filter object to another.

## Declaration

```occ
void vDSP_biquadm_CopyStateD(vDSP_biquadm_SetupD __dest, const struct vDSP_biquadm_SetupStructD *__src);
```

## Parameters

- `__dest`: The vDSP_biquadm_SetupD object whose state you wish to overwrite.
- `__src`: The vDSP_biquadm_SetupStructD object whose state you wish to copy.

## Discussion

Discussion Both src and dest objects must be valid single-precision multichannel biquad setup objects created by previous calls to vDSP_biquadm_CreateSetupD. Both objects must have the same number of channels and sections.