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# FFEffectDownload(_:)

Places the effect on the device. If the effect is already on the device, the existing effect is updated to match the values set by the FFEffectSetParameters method.

```
func FFEffectDownload(_ effectReference: FFEffectObjectReference!) -> HRESULT
```

## Parameters

`effectReference`

An opaque reference handle to an effect object. This is obtained from a previous call to FFDeviceCreateEffect.

## Return Value

If the method succeeds, the return value is FF_OK or S_FALSE. If the method fails, the return value can be one of the following error values:

## Discussion

FFERR_INVALIDPARAM

FFERR_DEVICEPAUSED

FFERR_DEVICEFULL

FFERR_INVALIDDOWNLOADID

FFERR_INTERNAL

FFERR_EFFECTTYPEMISMATCH

If the method returns S_FALSE, the effect has already been downloaded to the device.

## Discussion

It is valid to update an effect while it is playing. The semantics of such an operation are explained in the reference for FFEffectSetParameters.

---

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