---
title: AVAudioEngineManualRenderingMode.realtime
framework: avfaudio
role: symbol
role_heading: Case
path: avfaudio/avaudioenginemanualrenderingmode/realtime
---

# AVAudioEngineManualRenderingMode.realtime

An engine that operates under real-time constraints and doesn’t make blocking calls while rendering.

## Declaration

```swift
case realtime
```

## Discussion

Discussion You can only use the block-based render mechanism in this mode. See manualRenderingBlock.

## See Also

### Constants

- [AVAudioEngineManualRenderingMode.offline](avfaudio/avaudioenginemanualrenderingmode/offline.md)