CapturedSurfaceResolution

concepts

1. Surface Resolution

   Sites can read the captured screen's native resolution + scale factor. Lets remote-desktop apps render UI hit-boxes at the right DPR.

2. Bandwidth saver

   The explainer's motivation made interactive: capture twice — once at default, once at logical resolution via applyConstraints() — and watch the pixels-per-frame drop by dpr².

3. Resolution Budget Calculator

   Pick a bitrate budget — 1080p call, 720p archive, 480p with-camera, 2 fps doc share — and the calculator picks downscaleFactor and frame-rate constraints to match. Start a capture and compare requested vs. delivered.

4. Retina renderer

   High-DPR remote desktop scenario: reads screen DPR to size the canvas at physical pixels (not CSS pixels) for a 1:1 pixel-perfect capture. Side-by-side shows blurry (DPR ignored) vs sharp (DPR applied) — the problem CapturedSurfaceResolution solves.

why it shipped

This feature allows applications using screen capture to save resources by sending the video of a screen capture using their logical, or device independent, resolution. It is common for a screen to have zoom applied via the operating system. We refer to the resolution before applying the zoom as the logical resolution. An video-conferencing application can save resources by sending the video of the screen capture at the logical resolution by removing the zoom applied to it, and reapplying the zoom after receiving it on the remote side. Since the logical resolution is normally lower than the ac

references

• ChromeStatus entry
• Spec