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# kAudioFileStreamProperty_PacketToFrame

Obtains the frame number corresponding to a packet number.

```
var kAudioFileStreamProperty_PacketToFrame: AudioFileStreamPropertyID { get }
```

## Discussion

Obtains the frame number corresponding to a packet number. Pass an `AudioFramePacketTranslation` structure with the `mPacket` field filled in, and a value in the `mFrame` field is returned on output.  (The `mFrameOffsetInPacket` field of the `AudioFramePacketTranslation` structure is ignored.) For more information on the audio frame packet translation structure, see [Audio File Services](/documentation/AudioToolbox/audio-file-services).

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