DejaVu

Your last 5 to 25 minutes, always recorded. One key saves it.

Like ShadowPlay, except it never turns itself off, survives crashes,
and keeps Discord out of your clips.

one exe · any GPU · no account · no uploads · no telemetry

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The whole app in 10 seconds

1. A red dot in the corner means your screen is being buffered. It starts with Windows and stays on.
2. Something clip-worthy happens.
3. Press Alt+F10 and eldenring_2026-08-11_224513.mp4 lands in Videos\DejaVu. A short chime plays and a balloon confirms it; clicking the balloon opens the file. The chime matters more than it sounds: Windows hides balloons while a game is fullscreen, so the sound is the confirmation you actually get mid-match.

That's the entire app. There is no main window and nothing to set up; every setting lives in the tray menu. You don't have to wait for the buffer to fill either: press the key ninety seconds after launch and you get a ninety-second clip.

Get it: DejaVu.exe from the latest release, or scoop bucket add blancodagoat https://github.com/blancodagoat/scoop-bucket then scoop install dejavu. If your browser saved it as DejaVu (1).exe next to an old copy, run it anyway: on launch it deletes the stale copies beside it and renames itself back.

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Why it doesn't let you down

The usual pain	DejaVu
ShadowPlay turns itself off silently, so you press the key and nothing was recording	Always on; if capture breaks it falls back to the main display, keeps going, and tells you so
OBS makes you remember to start the buffer every session	Buffering starts the moment the app launches, including at boot
A crash eats your clip, because RAM buffers lose everything	The buffer lives on disk in crash-safe segments; after a crash, the next launch saves what survived
Discord pings and voice chat leak into shared clips	Capture a game window and the clip carries that game's audio, nothing else. Monitor capture excludes Discord from the mix by default
Replay_2024_final(3).mp4 filename chaos	Clips are named after the game that was on screen
Saved clips eat your disk forever	An optional cap rolls the oldest clips off past 10/25/50 GB, and the newest is never touched

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Everything you can change (all in the tray menu)

Setting	Options
Buffer length	5 / 10 / 15 / 20 / 25 min
Capture	Auto (follows your game), any monitor, or one window
Quality	Low / Medium / High. Constant-quality encoding: action gets the bits, menus cost almost nothing
Frame rate	30 to 240 fps, offered up to what your display can actually show
Capture method	Windows Graphics Capture, or Desktop Duplication. Windows 10 paints a yellow border around anything the first one records and gives no way to turn it off; the second draws no border, at the cost of recording whole displays only
System audio	On or off
Microphone	Off by default. On mixes your default mic into the clip's audio
Captured app audio only	On by default. With a window captured, the clip carries that app's audio alone, even when a virtual mixer like SteelSeries Sonar routes the app to its own output device
Keep Discord out of clips	Applies to monitor capture; one click puts voice chat back into the mix
Save sound	A chime when a clip saves, a low buzz when a save fails. Off if you prefer silence
Replays folder	Open it or move it somewhere else, both from the menu
Clip folder cap	Off / 10 / 25 / 50 GB
Hotkey	Click-to-rebind dialog
Corner indicator	Off, the red dot, or the app icon. It sits on the display being recorded, stays above fullscreen games, and never appears in your clips
Notify about new versions	Off by default, so the app stays silent on the network. On, it asks GitHub a few times a day; on a scoop install, clicking the update balloon runs the whole update and restarts the app

Yellow border on Windows 10? That is the OS telling you something is capturing the screen, and Windows 10 has no setting for it. Switch Capture method to Desktop Duplication in the tray menu — it records displays rather than single windows, and draws no border.

Admin games: if the hotkey stops working while a game with anti-cheat has focus, hit Restart as administrator in the tray once. That's a Windows rule, not ours.

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vs the big two

	ShadowPlay	OBS Replay Buffer	DejaVu
Stays on	silently dies	manual start	always, and self-heals
Crash survival	RAM, all lost	MKV remux dance	auto-recovers on boot
"Saved" feedback	sometimes nothing	none natively	balloon, click to open
Discord-free audio	no	manual per-app setup	default
Install	NVIDIA App + overlay	full OBS + scenes	one exe (~160 KB)
GPU	NVIDIA only	any	any with a hardware encoder

_{Based on each tool's design and widely reported user complaints; both evolve, so verify against current versions.}

Honest numbers: while buffering 1440p60 at High, DejaVu's measured working set is about 160 MB, most of it the hardware encoder's own working space, and shrinking it further is an active work item. Paused, it's a tray icon. There is no overlay, no background service, and no FPS tax from an in-game UI. On modern GPUs (RTX 40+, RX 7000+, Arc) it records AV1, which gets you the same quality in roughly a third smaller files; everywhere else it falls back to H.264 on its own — including mid-session, if the encoder turns out to produce AV1 the container can't hold.

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How it works under the hood

• The capture engine is our own: frames go straight into a Media Foundation hardware encoder (AV1 where the GPU can, H.264 otherwise), never leave the GPU, and there are no third-party components in the app at all. Two sources feed it — Windows.Graphics.Capture by default, and DXGI Desktop Duplication for displays where the Windows 10 capture border has to go, which arrives without a cursor so one is drawn back in.
• Capture never stops. The encoder rotates between one-minute fragmented-MP4 segment files, so a seam costs at most one frame, and killing the power mid-write still leaves playable files. Old segments delete themselves, which keeps disk use flat.
• Saving stitches the segments covering your window into one standard MP4. It's a lossless remux, no re-encode, done in a couple of seconds.
• Segments on disk at launch mean the last session died, so they're stitched into recovered_*.mp4 automatically and you get a balloon. A recovered clip that won't decode is thrown away rather than handed to you.
• If a capture source delivers zero frames, the buffer drops it for the main display and says so. A sleeping or locked screen just idles until you're back. Repeated hard failures pause it for a minute at a time between retries, and it reports that too; it never stops silently.
• Replay audio matches what you capture. A captured window records that app's audio: through the app's own output device when a virtual mixer (SteelSeries Sonar, per-app output settings) routes it there, through include-mode process loopback otherwise. Monitor capture records the system mix with the audioExclude process trees removed (Discord, Canary, PTB, and Vesktop by default). Either way it's encoded to AAC live, muxed per segment, with the default mic mixed in when Microphone is on, and the route each session took is written to the log.
• Everything the app does gets a line in %APPDATA%\DejaVu\log.txt, so a problem in the field leaves a trace instead of a vanished balloon.

Runs on old PCs, and that's the point

DejaVu is built for roughly 2015 machines and up:

• Windows 10 2004 or later. The same build provides the process-loopback audio device, so Discord exclusion works everywhere the app runs.
• Any GPU with a hardware H.264 encoder: NVENC since 2012, QuickSync since 2011, AMD VCE since 2013. Without one, encoding falls back to software and costs CPU.
• The buffer lives on disk instead of RAM by design. On an old 8 GB machine, RAM is what your game needs, and the buffer takes none of it. The disk writes are light enough for a 2015 hard drive.

Privacy

• The buffer lives in %LOCALAPPDATA%\DejaVu\buffer and is wiped on a clean exit. After a crash it becomes your recovered clip instead.
• Nothing leaves your machine. No uploads, no account, no telemetry. The app never phones home; the update check in the tray menu runs only when you click it. The one exception is opt-in: turn on "Notify about new versions" and it asks GitHub a few times a day, which means GitHub sees your IP.
• Failure balloons offer "click to report": that click only opens a prefilled GitHub issue in your browser (with the log tail, usernames scrubbed) for you to review and submit, or just close. The app itself sends nothing, ever.
• Pause buffering any time from the tray; the dot turns grey.
• The mic is off unless you turn it on, and Discord voices are kept out of the mix by default.

Files & config

Where	What
Videos\DejaVu	your saved replays
%APPDATA%\DejaVu\config.json	all settings (missing keys fill themselves in; out-of-range values are clamped in memory without rewriting your file)
%LOCALAPPDATA%\DejaVu\buffer	the rolling buffer

Config keys: bufferMinutes (5 to 25) · quality · fps · saveHotkey · saveRoot · captureTarget ("auto" or \\.\DISPLAY2) · showIndicator · indicatorStyle ("dot" or "icon") · systemAudio · microphone · appAudioOnly · clipCapGB · audioExclude · saveSound · updateNotify · captureBackend ("wgc" or "duplication")

Building & tests

dotnet build src/DejaVu/DejaVu.csproj
dotnet run --project tests/DejaVu.Tests            # unit tests
dotnet run --project tests/DejaVu.Tests -- smoke   # + live capture / crash-recovery / audio-exclusion proof
dotnet run --project tests/DejaVu.Tests -- soak 12 # crash-kill soak: hard-kills a recording process at
                                                   # random moments, then proves every recovered clip
                                                   # decodes head to tail ("soak 500" = overnight run)

The smoke test records the real screen and plays a test tone to prove exclusion strips it from the captured mix. It skips itself if the screen is locked or asleep, since a sleeping desktop delivers no frames.

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MIT license · sibling of Memento, the screenshot tool that stays out of your way