# ReadPackedFixedString64Delta(FixedString64Bytes, in StreamCompressionModel)

> Reads a FixedString64Bytes delta value to the data stream using a StreamCompressionModel.

## Definition

* **Type:** Method
* **Namespace:** [Unity.Collections](/engine/6000.7/script-reference/unity/collections.md)
* **Assembly:** UnityEngine.ManagedKernelModule

## ReadPackedFixedString64Delta(FixedString64Bytes, StreamCompressionModel)

```csharp
public FixedString64Bytes ReadPackedFixedString64Delta(FixedString64Bytes baseline, in StreamCompressionModel model)
```

### Parameters

**** (\[FixedString64Bytes]\(/engine/6000.7/script-reference/unity/collections/fixedstring64bytes)): The previous `FixedString64Bytes` value, used to compute the diff.**** (\[StreamCompressionModel]\(/engine/6000.7/script-reference/unity/collections/streamcompressionmodel)): [StreamCompressionModel](/engine/6000.7/script-reference/unity/collections/streamcompressionmodel.md) model for writing value in a packed manner.

### Returns

| Type                                                                                          | Description                                                                                                |
| --------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------- |
| [FixedString64Bytes](/engine/6000.7/script-reference/unity/collections/fixedstring64bytes.md) | A `FixedString64Bytes` value read from the current stream, or 0 if the end of the stream has been reached. |