---
title: "VTFrameSiloCallBlockForEachSampleBuffer(_:in:handler:)"
framework: videotoolbox
role: symbol
role_heading: Function
path: "videotoolbox/vtframesilocallblockforeachsamplebuffer(_:in:handler:)"
---

# VTFrameSiloCallBlockForEachSampleBuffer(_:in:handler:)

Retrieves sample buffers from a frame silo object.

## Declaration

```swift
func VTFrameSiloCallBlockForEachSampleBuffer(_ silo: VTFrameSilo, in timeRange: CMTimeRange, handler: (CMSampleBuffer) -> OSStatus) -> OSStatus
```

## Parameters

- `silo`: The frame silo object.
- `timeRange`: The decode time range of sample buffers to retrieve. Pass kCMTimeRangeInvalid to retrieve all sample buffers from the VTFrameSilo.
- `handler`: A block to be called, in decode order, with each sample buffer that was added. To abort iteration early, return a nonzero status. The VTFrameSilo object may write sample buffers and data to the backing file between addition and retrieval; do not expect to get identical object pointers back.

## Return Value

Return Value kVTFrameSiloInvalidTimeRangeErr if any time ranges are non-numeric, overlap, or are not in ascending order. Returns any nonzero status returned by the handler block.

## Discussion

Discussion You call this function to retrieve sample buffers at the end of a multipass compression session.

## See Also

### Configuring Frame Silos

- [VTFrameSiloAddSampleBuffer(_:sampleBuffer:)](videotoolbox/vtframesiloaddsamplebuffer(_:samplebuffer:).md)
- [VTFrameSiloSetTimeRangesForNextPass(_:timeRangeCount:timeRangeArray:)](videotoolbox/vtframesilosettimerangesfornextpass(_:timerangecount:timerangearray:).md)
- [VTFrameSiloCallFunctionForEachSampleBuffer(_:in:refcon:callback:)](videotoolbox/vtframesilocallfunctionforeachsamplebuffer(_:in:refcon:callback:).md)