always have a small area showing the black when edit the recording

[githubcatheaven]

Description

always have a small area showing the black. always.

Reproduction

every time i recording a video , it always have a small black area .

Additional Context

• Cap version: from 0.4.81 - 0.4.84
• Operating system, version: win 11 22631.3155
• Device (optional):

cap-desktop.log.zip

[linear]

CAP-686

[tembo]

This issue appears to be related to a rendering change in PR #1674 (merged 2026-03-21), which coincides with the version range you mentioned (0.4.81+). That PR changed the WebGPU render pass loadOp from "clear" to "load" in apps/desktop/src/utils/webgpu-renderer.ts (lines 302 and 415). The PR review comments specifically flagged this could cause stale/garbage pixels on the first frame or after certain events since loadOp: "load" skips clearing the framebuffer.

Looking at the screenshot, the black area appears at a consistent location which suggests the composite shader may not be covering the full canvas in certain scenarios during editing/playback.

Related issues:

• Issue fix(windows): Cap UI appears as black rectangle in studio recordings (window exclusion is macOS-only) #1737 documents a similar black rectangle issue specific to Windows studio mode (related to window exclusion being macOS-only)
• Issue Video is not displayed, black screen after recording #342 tracks a broader "video not displayed, black screen after recording" issue on Windows with AMD GPUs

Relevant code:

• apps/desktop/src/utils/webgpu-renderer.ts:302,415 - the loadOp settings for both render paths
• crates/rendering/src/ - Rust-side rendering pipeline if the black area persists in exported videos

If the black area only appears in the editor preview (not in exported videos), the fix is likely reverting to loadOp: "clear" with a clearValue as originally suggested in the PR review. If it appears in exports as well, the issue may be deeper in the rendering pipeline.

[githubcatheaven]

it appears in exports as well