PostHog/posthog-js @posthog/types@1.390.1

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1.390.1

Patch Changes

• #3885 5392a55 Thanks @pauldambra! - feat(replay): capture canvas at reduced resolution

  Adds session_recording.canvasCapture.resolutionScale - a (0, 1] fraction of the canvas display size to capture replay frames at. The captured bitmap is downscaled (pixel-area savings are quadratic) while the canvas's true display size is still recorded, so playback stretches the smaller frame back to the correct dimensions and aspect ratio - only sharpness drops, never layout. It defaults to 1 (full resolution, matching today's behaviour), and the latest defaults bundle (2026-05-30) opts new installs into 0.6.

  The canvas's true display size travels with each frame through the encode worker (as required message fields), so the encoded reply is always drawn back to the correct dimensions — no per-canvas state is retained on the main thread, and downscaling can never mislabel a canvas's dimensions. At full resolution the captured pixels are unchanged (the quality resampling hint is only applied when actually downscaling); the emitted drawImage now always uses the explicit destination-size form, which is pixel-equivalent on replay.

  Mechanically, @posthog/rrweb's canvas FPS-snapshot observer takes an optional canvasResolutionScale record option and downscales each captured frame accordingly. (2026-06-19)