v1.4.1 — Streaming reliability fixes

This release fixes streaming reliability issues found in an audit of the HEVC, H.264 and AV1 paths, presets and diagnostics.

• Codec bitrate backoff: experimental H.264/AV1 sessions treat the requested bitrate as a ceiling. SteamVR's own rate control can now lower it after bad-link events, instead of the session holding a rate the link cannot carry.
• 232 Mbps check for codec sessions: H.264 targets above 232 Mbps are refused on a verified original driver, as they already were for HEVC. Install the bitrate patch first. An unrecognized driver produces a warning.
• HEVC restore: ending a codec session puts back your previous bitrate, automatic bandwidth, link-joining and stream-width settings, including after an interrupted session.
• Session lifetime: quitting SteamVR ends a codec session without relaunching SteamVR. The 90-minute limit no longer stops a running game; HEVC is restored when SteamVR exits, or automatically before the Frame administrator session's two-hour limit.
• Lower PC overhead: the codec companion watches SteamVR through Windows process handles instead of starting PowerShell about twice a second, and the PC adapter no longer re-queries its encoder preset on every frame.
• HEVC encoder controls: a rate-control setting that NVENC rejects at startup falls back to Valve's configuration instead of preventing the stream from starting. Conflicting advanced settings are rejected individually, and a VBV-only override no longer rejects every other advanced setting.
• Presets and Back to stock: tracking, OSC, eye-tracking sharing, NAT, dashboard, shutdown and volume preferences are no longer saved, removed or reapplied. Out-of-range values from older releases no longer block Back to stock or saving a preset. Apply validates the whole request before a preset stops SteamVR or changes the driver patch.
• Diagnostics: encoder-stall capture now includes SubmitFrame, reconfigure and submit-to-start warnings, and frame-ID stream resets are recorded. One failing source no longer freezes the dashboard, OpenVR reads stop waiting after three seconds, and an unreadable codec status or driver backup no longer blocks actions or closing the app.

If a codec session from an older version is still running, select HEVC and apply before starting a new session, so the updated companion is used.

Validation: 65 managed tests, six native encoder test suites, 18 codec-companion and three Frame root-helper tests, and 25 compositor-timing assertions passed. The PC codec adapter encoded and independently decoded H.264 and AV1 at 90 and 120 Hz on the development PC's NVIDIA GPU. The self-contained package's contents, codec runtime imports and decoder fingerprint were verified. Patcher fixture tests were not run for this build, and the codec-session changes have not yet been exercised in a live headset session.

Download SteamLinkVRSettings-SteamFrame-win-x64.zip, extract the entire folder and run SteamLinkVRSettings.exe. SHA256SUMS.txt verifies the ZIP. The bundle includes the codec companion/runtime and the experimental decoder's corresponding source; it excludes personal configuration, credentials, captures and original Valve binaries.