<!--
{
  "availability" : [
    "iOS: 4.0.0 -",
    "iPadOS: 4.0.0 -",
    "macCatalyst: 13.1.0 -",
    "macOS: 10.7.0 -",
    "tvOS: 9.0.0 -",
    "visionOS: 1.0.0 -",
    "watchOS: 6.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "CoreMedia",
  "identifier" : "/documentation/CoreMedia/CMBlockBufferIsEmpty(_:)",
  "metadataVersion" : "0.1.0",
  "role" : "Function",
  "symbol" : {
    "kind" : "Function",
    "modules" : [
      "Core Media"
    ],
    "preciseIdentifier" : "c:@F@CMBlockBufferIsEmpty"
  },
  "title" : "CMBlockBufferIsEmpty(_:)"
}
-->

# CMBlockBufferIsEmpty(_:)

Returns a Boolean value that indicates whether the buffer is empty.

```
func CMBlockBufferIsEmpty(_ theBuffer: CMBlockBuffer) -> Bool
```

## Parameters

`theBuffer`

`CMBlockBuffer` to examine. Must not be `NULL`.

## Return Value

False if the `CMBlockBuffer` is `NULL`.

## Discussion

Determines whether the given `CMBlockBuffer` is empty, i.e., devoid of any `memoryBlocks` or `CMBlockBuffer` references. Note that a `CMBlockBuffer` containing a not-yet allocated `memoryBlock` is not considered empty.

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)