Multicam

Multi-camera support in the Camera SDK refers to the ability to use multiple cameras, for example one from the back and one from the front, at the same time. The SDK is able to:

• detect which cameras can be streamed at the same time
• configure them with proper resolution and frame rate
• compose the two streams on screen, using a layout arrangement of your choice
• let you take picture and videos

Device sets

The SDK abstracts the multi-camera complexity away with the CameraDeviceSet class. Device sets work just like regular CameraDevices: you can take pictures, snapshots and use them as a source for video recording. The only difference is that you have dedicated APIs in CameraManager.

Choosing a device set

To choose between regular devices, as explained in the devices documentation, you'd use the property CameraManager.devices. For device sets, simply use CameraManager.deviceSets instead:

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val manager: CameraManager = ...
val multicams: List<CameraDeviceSet> = manager.deviceSets

swift
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let manager: CameraManager = ...
let multicams: [CameraDeviceSet] = manager.deviceSets

If the returned list is empty, the current device does not support multi-camera captures.

Opening a device set

To open regular devices, as explained in the devices documentation, you'd use the CameraManager.openDevice function. For device sets, simply use CameraManager.openDeviceSet instead:

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suspend fun openDeviceSet(id: String? = null): CameraDeviceSet = ...

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func openDeviceSet(id: String? = nil) async throws -> CameraDeviceSet { ... }

If no id is provided, the engine will simply open the first available set.

Observing the current device set

To observe regular devices, as explained in the devices documentation, you'd use the CameraManager.currentDevice property. For device sets, simply use CameraManager.currentDeviceSet instead:

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val current: CameraDeviceSet? = manager.currentDeviceSet.value
val flow: StateFlow<CameraDeviceSet?> = manager.currentDeviceSet

swift
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let current: CameraDeviceSet? = manager.currentDeviceSet
let publisher: AnyPublisher<CameraDeviceSet?, Never> = manager.currentDeviceSetPublisher

Arrangement

With device sets, you have the option to choose how they will be composed on all the target surfaces: on screen, on picture and snapshot targets and on video outputs.

To do so, use the CameraDeviceSet.arrange() function and pass one of the arrangement options above:

• arrange(Arrangement.SplitVertically)arrange(.splitVertically): screen is vertically split in half.
• arrange(Arrangement.SplitHorizontally)arrange(.splitHorizontally): screen is horizontally split in half.
• arrange(Arrangement.Overlay(Shape.Oval, 1F))arrange(.overlay(shape: .oval, aspectRatio: 1)): one of the streams is fullscreen; the other is overlaid on top with the given shape and aspect ratio.

Flip

In some cases, especially when using Arrangement.OverlayArrangement.overlay, you may want to swap the streams (so that, for example, fullscreen stream becomes the small overlay). This can be done with the flip() API:

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manager.currentDeviceSet?.flip()

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manager.currentDeviceSet?.flip()

Unlike toggling between regular cameras, this operation is extremely fast.

Configuring constituent devices

By design, a CameraDeviceSet has no notion of things like zoom or white balance, because each sensor has different capabilities and constraints. However, you can access and configure the devices that constitute a device set by using CameraDeviceSet.children:

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val (primary, secondary) = deviceSet.children
primary.configure { ... }
secondary.configure { ... }

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deviceSet.children[0].configure { ... }
deviceSet.children[1].configure { ... }

Capturing media

Capturing media with CameraDeviceSet is identical to CameraDevice. Please check the regular documentation for pictures and videos as it applies to device sets too. The only difference is that functions must be invoked directly on the set:

• For pictures, use CameraDeviceSet.takePicture(encoding: Picture.Encoding, meterIfNeeded: Boolean = true)CameraDeviceSet.takePicture(encoding: Picture.Encoding, meterIfNeeded: Bool = true)
• For snapshots, use CameraDeviceSet.takeSnapshot(encoding: Snapshot.Encoding)
• For videos, the CameraRecorder will automatically record from the current device set, if any of them is open