punktfunk/docs/releases/v0.20.1.md

Update whenever it suits you — the app and the machine you stream from can still be updated one at a time, and everything already paired keeps working. This release is entirely fixes and hardening on top of last release's session⇄game work — nothing new to opt into.

Fixed: installing or updating the Windows host

Three separate reports came in within hours of the last release, all blocking install:

• winget install could fail outright if you'd ever had another streaming host on the machine — even one you had since disabled or mostly uninstalled. A leftover, disabled service or an empty folder from an old install was enough to trip the "conflicting host" check and abort. Only a host actually set to start on its own counts now.
• Installing through a package-manager app (like UniGetUI) could fail with a file-path error before the install wizard ever appeared, because of a broken setting the installer passed itself. Fixed.
• The package source instructions were incomplete. winget install unom.PunktfunkHost says "no package found" until you've pointed winget at Punktfunk's own source, once per machine — the command for that is now spelled out.

Fixed: Moonlight compatibility no longer turns on without asking

A fresh Windows install used to enable Moonlight-app compatibility silently, with no checkbox ever shown — even though that mode pairs over a less secure connection and the host warns about it on every start. It's opt-in now. Existing installs are untouched either way; Punktfunk's own clients were never affected.

Fixed: switching into Steam's Game Mode on Linux could black out the machine

Last release shipped the permission needed to properly take over the screen for Steam's Game Mode — and surfaced a few sharp edges that only show up once that takeover is actually live:

• The takeover could kill Punktfunk's own background service a few seconds later, leaving the display dark with nothing left to bring it back except a physical console or SSH.
• It could also hang waiting on a permission prompt nobody could see, delaying recovery until well after the stream had already dropped — or act on a leftover marker file from months ago and jump the machine to the desktop for no reason.
• Restarting the host mid-stream — including a routine update — could leave the display stuck off, since nothing told the screen to come back.

All three are fixed. Recognizing the machine's built-in Steam Game Mode may now need a one-time permission on some distributions; installing or updating normally takes care of it.

Fixed: a laptop with its built-in screen turned off stuttered constantly

On a laptop with two graphics chips and the internal screen switched off — a common setup for streaming from a laptop docked to a TV or monitor — streaming stuttered roughly every two seconds, for the whole session. Punktfunk now recognizes a dark-but-connected laptop screen as the cause and points at the actual fix, instead of pointing at an external monitor that isn't the problem.

Fixed: latency creeping up over the course of a fast, high-bitrate stream

On a fast local network, especially at higher bitrates, latency could climb steadily over a long session instead of staying flat. Several separate causes are fixed at once: the stream's internal clock sync could get starved by a busy connection and let the two ends' clocks drift; a stream mode could put more data on the wire than its bitrate setting actually allowed; a slow-to-decode moment could build up a backlog that took a while to work through instead of catching up immediately; and the one-time startup speed test could be mistaken for real network congestion and permanently cap the stream below what the connection could actually handle.

Fixed: missing cover art looked broken

A library entry with no cover art showed as an empty grey box, which read as something that failed to load. It now shows a controller icon instead, so "no art yet" looks intentional rather than broken.

Improved: the Windows app now keeps its own log file

The desktop app writes its own log to %LOCALAPPDATA%\punktfunk\logs\client.log now, instead of only printing to a console window that a normal launch never shows. If you're ever asked to send logs for a problem, this is where they are.

Under the hood (for developers)

• Nothing changed on the wire or at the API boundary. Streaming protocol stays at version 2, the embeddable C ABI at 13, the Windows virtual-display driver protocol at 6 — 0.18–0.20 hosts and clients keep mixing freely.
• Windows conflict detection now keys on the competing service's Start registry value (0–2 = boot/system/auto only), matching the tray's own dormant-is-harmless logic from last release; install directories no longer count.
• The winget Log switch used the literal string |LOGPATH| instead of winget's actual <LOGPATH> substitution token, so Inno received an illegal filename on any install that requested a log (UniGetUI does by default). Guarded by a new manifest check.
• gamestream installer task lost its default-checked flag; a silent/unattended install now lands PUNKTFUNK_HOST_CMD=serve. /MERGETASKS=gamestream opts in. Fresh installs only — GamestreamParam already omitted the flag on upgrades.
• The gamescope display-manager takeover now calls privileged systemctl verbs non-interactively (--no-ask-password) so a headless polkit prompt can no longer block the stream's own recovery thread; session_select_requested's sentinel baseline is now recorded at takeover time as well as at successful launch, closing a window where a months-old ~/.config/steamos-session-select write could false-positive a session-select honor; and punktfunk-host now handles SIGTERM/SIGINT by restoring the display manager it stopped (20 s grace) before exiting, so a systemctl --user restart or package upgrade mid-takeover can't strand the box. The takeover also now ensures the invoking user has systemd lingering enabled before touching the display manager — without it, stopping the DM stops the user's own service manager ~10 s later and takes the host down with it.
• A new internal_panel target class lets the exclusive-topology stall detector name a deactivated eDP/LVDS laptop panel as a disturbance suspect; previously the suspect list was filtered to external physicals only, so the one display responsible on a hybrid laptop reported as none. EvtIddCxMonitorI2CTransmit/Receive now answer every DDC/CI probe against the virtual monitor with an immediate STATUS_NOT_SUPPORTED, so third-party brightness/monitor tools stop occupying win32k's serialized physical-monitor path on it. The swap-chain drain thread now falls back to TIME_CRITICAL priority if MMCSS registration is refused, and raises IddMinimumVersionRequired 4 → 10 to use IddCxSetRealtimeGPUPriority.
• Clock re-sync now spaces its probe rounds ~7 ms apart, tracks a running best-RTT guard band instead of a static connect-time floor, and applies the best batch of a rejection streak after three consecutive rejections rather than drifting unbounded.
• A new per-frame WireBudget (shared between encoder backends) tracks the real bitstream-to-wire inflation ratio for datagram-aligned PyroWave sessions and deflates the rate-control target by it, so the configured bitrate pin holds on the wire rather than on the raw codec bitstream.
• The pre-decode frame channel now drains to the newest AU for all-intra (PyroWave) streams, since those have no reference chain forbidding a mid-stream drop — capping any standing backlog at roughly one frame instead of ratcheting between the coarse jump-to-live thresholds.
• The ABR capacity probe's first post-probe report window is now discarded outright, rather than measured, so the probe's own deliberate overload can no longer read as session congestion and permanently end slow-start early.
• New display-disturb dev tool for reproducing DDC/CI and modeset-class display disturbances on demand during stall-immunity testing; not shipped to end users.