Window capture recording screen region instead of window content (0.4.84)

[mrfelton]

When selecting a specific window to record, Cap is capturing the screen region that the window occupies rather than the window content itself. This means that switching tabs, moving other windows over the top, or any other activity in that screen area gets captured in the recording, which is not the expected behavior.

Expected behavior: recording a window should bind to that window's content only, unaffected by anything else on screen.

Actual behavior: Cap records the screen region the window occupies, so anything that appears in that area (other windows, tab switches, etc.) is included in the recording.

Environment:

Cap version: 0.4.84
macOS: Tahoe 26.4.1
This was working correctly in a previous version of Cap before updating to 0.4.84
Happy to provide any additional info or test builds if helpful.

[linear]

CAP-689

[tembo]

Thanks for the detailed report. Looking at the codebase, I can see the architectural reason for this behavior:

Current Implementation:
For recording, Cap uses display-based capture with crop bounds (as_content_filter_excluding_windows) in crates/recording/src/sources/screen_capture/macos.rs:222-228. The window bounds are calculated relative to the display in crates/recording/src/capture_pipeline.rs:368-389 and used to crop the display capture.

Contrast with Screenshots:
Screenshots use sc::ContentFilter::with_desktop_independent_window() in crates/recording/src/screenshot.rs:859, which captures the window content itself regardless of what's overlaid on screen.

Fix Direction:
To get true window-only recording (not affected by overlapping content), the recording pipeline would need to use with_desktop_independent_window for window targets, similar to how screenshots work. This would require changes in ScreenCaptureConfig::to_sources() to create a window-specific content filter rather than a display filter with crop bounds.

Related Context:

• Issue Screen capturing crashes when capturing window of 2nd screen #836 covers window capture crashes on secondary screens, which may share some capture pipeline code paths
• Issue fix(windows): Cap UI appears as black rectangle in studio recordings (window exclusion is macOS-only) #1737 relates to window exclusion being macOS-only

The user notes this was working in a previous version before 0.4.84 - this would be worth investigating whether the behavior changed intentionally (perhaps for performance/stability reasons) or if there was a regression.