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# kCMSampleBufferConduitNotification_UpcomingOutputPTSRangeChanged

Posted on a conduit of video sample buffers to report information about the range of upcoming output presentation timestamps.

```
let kCMSampleBufferConduitNotification_UpcomingOutputPTSRangeChanged: CFString
```

## Discussion

This information can be important for frame-reordered video and for certain types of decoding where samples are transmitted in a different order from the order they will be displayed. If you need to process frames in presentation order, you can use this information to ensure that you do not process a frame too early (that is, when there are upcoming frames that will have earlier presentation timestamps than a frame to be processed).

The `userInfo` dictionary for this notification contains the [`kCMSampleBufferConduitNotificationParameter_UpcomingOutputPTSRangeMayOverlapQueuedOutputPTSRange`](/documentation/CoreMedia/kCMSampleBufferConduitNotificationParameter_UpcomingOutputPTSRangeMayOverlapQueuedOutputPTSRange) key. If the value for that key is <doc://com.apple.documentation/documentation/CoreFoundation/kCFBooleanTrue>, the dictionary also contains one or both of the [`kCMSampleBufferConduitNotificationParameter_MinUpcomingOutputPTS`](/documentation/CoreMedia/kCMSampleBufferConduitNotificationParameter_MinUpcomingOutputPTS) or [`kCMSampleBufferConduitNotificationParameter_MaxUpcomingOutputPTS`](/documentation/CoreMedia/kCMSampleBufferConduitNotificationParameter_MaxUpcomingOutputPTS) keys providing information about the range of overlapping presentation timestamps.

---

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