---
title: MERAWProcessor
framework: MediaExtension
role: symbol
role_heading: Protocol
platforms: [macOS 15.0+]
path: mediaextension/merawprocessor
---

# MERAWProcessor

A protocol that defines the requirements for a RAW processor.

## Declaration

```swift
protocol MERAWProcessor : NSObjectProtocol
```

## Overview

Overview This protocol provides an interface for Video Toolbox to create and interact with MediaExtension RAW processors. MERAWProcessor objects are instantiated by Video Toolbox and are closely linked to a corresponding MEVideoDecoder object that produces RAW video output. note: Developers who wish to build MediaExtension RAW processors using this API need to include a RAW processor entitlement, provisioning profile, and specialized dictionary in their Info.plist file when building their extensions. For more information, see Entitlements, Create a development provisioning profile, and RAW processor property list dictionary. Once a user installs and runs the host app, embedded RAW processor extensions become available to any app on the user’s system that opts in to using them by calling VTRegisterProfessionalVideoWorkflowVideoDecoders(). important: MERAWProcessor objects run in a sandboxed process without access to the filesystem, network, and other kernel resources. MediaExtension RAW processor’s operation and life cycle closely tie to VTRAWProcessingSession. Creating a raw processor An instance of the MERAWProcessorExtension factory object is created the first time the given processor is opened by Video Toolbox in a process. The makeProcessor(formatDescription:pixelBufferManager:) method on the MERAWProcessorExtension object will be called once for each processor instance needed. The processor can evaluate the provided CMVideoFormatDescription at this point and confirm whether it is able to process the specified format. If the processor cannot process the format, the factory routine should return MEError.Code.unsupportedFeature. This sequence of calls will happen inside of VTRAWProcessingSession. Configuring pixel buffer requirements At any point after instantiation, the processor can call back into the provided MERAWProcessorPixelBufferManager object to notify Video Toolbox of its output pixel buffer requirements. The processor extension may make multiple calls if output requirements change in response to properties being set or due to observed bitstream characteristics. Processing frames Calls to processFrame(fromImageBuffer:completionHandler:) are serialized. A new frame is not sent to the processor until the last processFrame(fromImageBuffer:completionHandler:) has returned, but may be submitted before the processFrame(fromImageBuffer:completionHandler:) completion handler is called if the processing is happening asynchronously. These calls correspond to VTRAWProcessingSessionProcessFrame calls on the parent VTRAWProcessingSession. RAW processors must write their output frames into CVPixelBuffers allocated through the makePixelBuffer() interface. Returning CVPixelBuffer from any other source may result in degraded performance or other issues. If the processor’s internal processing queue is full, and it cannot process more frames, it should return NO when the isReadyForMoreMediaData property is queried. This property should return YES again when the processor is able to accept new frames – generally after an earlier asynchronous frame processing operation is completed.

## Topics

### Inspecting a RAW processor

- [metalDeviceRegistryID](mediaextension/merawprocessor/metaldeviceregistryid.md)
- [outputColorAttachments](mediaextension/merawprocessor/outputcolorattachments.md)
- [processingParameters](mediaextension/merawprocessor/processingparameters.md)
- [isReadyForMoreMediaData](mediaextension/merawprocessor/isreadyformoremediadata.md)

### Processing RAW frame

- [processFrame(fromImageBuffer:completionHandler:)](mediaextension/merawprocessor/processframe(fromimagebuffer:completionhandler:).md)

### Extension requirements

- [RAW processor property list dictionary](mediaextension/raw-processor-property-list-dictionary.md)
- [RAW processor entitlement](mediaextension/raw-processor-entitlement.md)

### Instance Properties

- [metadataForSidecarFile](mediaextension/merawprocessor/metadataforsidecarfile.md)

## Relationships

### Inherits From

- [NSObjectProtocol](objectivec/nsobjectprotocol.md)

## See Also

### RAW processors

- [MERAWProcessorExtension](mediaextension/merawprocessorextension.md)
- [MERAWProcessorPixelBufferManager](mediaextension/merawprocessorpixelbuffermanager.md)
- [MERAWProcessingParameter](mediaextension/merawprocessingparameter.md)
- [MERAWProcessorNotification](mediaextension/merawprocessornotification.md)
- [RAW processor property list dictionary](mediaextension/raw-processor-property-list-dictionary.md)
- [RAW processor entitlement](mediaextension/raw-processor-entitlement.md)