←API Reference ←com.nianticspatial.nsdk.playback

PlaybackDataset

A playback dataset loaded from a capture JSON file. Uses on-demand loading for frame images and depth: only the requested frame is loaded and cached (1-frame cache). Create via [PlaybackDataset.loadFrom] with a [PlaybackDatasetSource] (e.g. [AssetPlaybackDatasetLoader]). Use [loadFrom][PlaybackDataset.loadFrom] with a custom [imageDecoder] in unit tests to avoid [BitmapFactory] (not mocked on JVM). Thread safety: This class is NOT thread-safe. All methods must be called from a single thread. The 1-frame cache ([cachedFrameIndex], [cachedImageBytes], [cachedDepthData], [cachedConfidenceData]) is not protected by a lock; concurrent reads and writes will produce inconsistent results. [PlaybackSession] satisfies this constraint by funneling all frame loads through a single coroutine dispatcher. If you introduce additional callers, ensure they are serialized. Cache fields are marked [@Volatile][Volatile] so that a value written on a background thread is immediately visible to any thread that subsequently reads it (e.g. the main thread checking [cachedFrameIndex] before deciding to reload). This is a visibility guarantee only — it does not make compound check-then-act sequences atomic.

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Declaration

class PlaybackDataset

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Properties

Name	Type	Summary
captureRoot	CaptureRoot	-
frameCount	Int	-
frameInterval	Double	-
imageDecoder	(ByteArray) -> Bitmap?	-
source	PlaybackDatasetSource	-

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Functions

Name	Type	Summary
getDepthConfidenceAtIndex	ByteArray?	Loads depth confidence (UInt8 binary) at [index] on-demand. Returns null if not available.
getDepthDataAtIndex	ByteArray?	Loads depth data (Float32 binary) at [index] on-demand. Returns null if this frame has no depth.
getFrameImageAtIndex	android.graphics.Bitmap?	Loads the frame image at [index] on-demand (and caches it). Returns decoded bitmap, or null if no image.
getFrameImageBytesAtIndex	ByteArray	Returns raw image bytes at [index] (on-demand, cached). Use when you need bytes instead of Bitmap.
getFrameMetadataAtIndex	FrameMetadata	Returns frame metadata at [index].
getPlaybackFrameAtIndex	PlaybackFrame	Loads a single frame at [index] as a [PlaybackFrame] (metadata, camera, optional image and depth). Image load failure yields a frame with [PlaybackFrame.image] null; depth is null when not available.
hasDepth	Boolean	True if the dataset declares LiDAR depth ([depthSource] == "lidar").

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