Artifacts when scrolling in browser recordings with version 0.4.5

[tpiecora]

Description

Exported videos have artifacts at any resolution, frame rate, and quality. Disabling hardware acceleration also did not affect the output. It artifacts manifest in parts of the video where scrolling in a browser occurs as a flashing or "jumpy" effect. Watching the raw video in the .cap package, these artifacts are not present.

Downgrading to 0.4.1 resolved the issue.

Reproduction

Capture a screen recording of Chrome. Export a video.

Additional Context

• Cap version: 0.4.5
• Operating system, version: Tahoe 26.2
• Device (optional): Mac Book Pro

[linear]

CAP-638

[tembo]

This appears to be related to the ongoing flickering/artifact issues tracked in #1557, which has reports from multiple users on both macOS (including M4 on Tahoe 26.2, same as your setup) and Windows. Several users there also confirmed that raw recordings in the .cap package are fine but artifacts appear after export, matching your description.

Key observation from your report: The regression between v0.4.1 and v0.4.5 narrows down when this was introduced. Looking at the commit history, several rendering and decoder changes landed between these versions:

• PR Editor video playback performance #1473 refactored frame processing and the WebSocket frame pipeline
• PR Windows hardware acceleration and NV12 rendering optimizations #1482 added NV12 rendering optimizations and hardware acceleration changes
• PR Fix camera orientation on Windows, improve playback stability, and add frame capture support #1487 modified playback stability and decoder logic

Since the raw recording is unaffected and only the export shows artifacts during scrolling (high motion content), this likely points to the export rendering pipeline rather than capture.

Relevant code areas for investigation:

• crates/rendering/src/decoder/ - frame decoding and caching logic
• crates/export/src/mp4.rs - MP4 export settings
• apps/desktop/src-tauri/src/export.rs - export orchestration

Potential workaround: In the export settings on macOS, there's an experimental "Force FFmpeg decoder" toggle (added in PR #1506) that might help as a fallback if the hardware decoder is involved.

For debugging: A cap-desktop.log file (found in your Cap data directory) from an export that shows the artifacts would help identify whether any decoder warnings or frame timing issues are being logged during the export process.

[richiemcilroy]

Hey! Should be fixed now in 0.4.6 :)