---
title: kVTVideoDecoderSpecification_EnableHardwareAcceleratedVideoDecoder
framework: videotoolbox
role: symbol
role_heading: Global Variable
path: videotoolbox/kvtvideodecoderspecification_enablehardwareacceleratedvideodecoder
---

# kVTVideoDecoderSpecification_EnableHardwareAcceleratedVideoDecoder

A Boolean value indicating whether VideoToolbox uses a hardware-accelerated video decoder, if available.

## Declaration

```swift
let kVTVideoDecoderSpecification_EnableHardwareAcceleratedVideoDecoder: CFString
```

## Discussion

Discussion You set this key in the decoderSpecification passed in to VTDecompressionSessionCreate(allocator:formatDescription:decoderSpecification:imageBufferAttributes:outputCallback:decompressionSessionOut:).  Set it to kCFBooleanTrue to allow hardware-accelerated decoding.  To specifically prevent hardware-accelerated decoding, set this property to kCFBooleanFalse. This property is useful for clients doing realtime decode operations because it allows VideoToolbox to choose the optimal decoding path.

## See Also

### Hardware Acceleration

- [kVTDecompressionPropertyKey_UsingHardwareAcceleratedVideoDecoder](videotoolbox/kvtdecompressionpropertykey_usinghardwareacceleratedvideodecoder.md)
- [kVTVideoDecoderSpecification_RequireHardwareAcceleratedVideoDecoder](videotoolbox/kvtvideodecoderspecification_requirehardwareacceleratedvideodecoder.md)