FAQ & Common Fixes

System Requirements

What are the minimum specs?

Onset Engine requires a minimum of 8GB RAM. It runs on Windows 10 64-bit or newer.

Is there a Mac version?

Not yet. Onset Engine is currently available for Windows only, so please don’t buy it for a Mac. A version for Apple Silicon Macs is planned. Leave your email and we’ll send you one email when it’s ready.

Do I need an NVIDIA GPU?

No dedicated GPU is required, as Onset Engine works great on CPU (using fallback inference). However, an NVIDIA GPU (CUDA) will significantly speed up AI-powered clip analysis and hardware encoding. Read more.

Installation Issues

Is the installer safe?

Yes, when it comes from onsetengine.com. Every Onset Engine installer is signed by Onset SAS. To check yours, right-click the file, choose Properties, open the Digital Signatures tab and confirm the signer is Onset SAS. If there is no Digital Signatures tab, or it names anyone else, don’t run the file.

The installer you download, OnsetEngine-Setup.exe, is small because it fetches the rest of Onset Engine when you run it. It downloads only from Onset Engine’s own download server, and checks that the download is exactly the file we published before running it. If the check fails, nothing is run.

SmartScreen warnings

Windows may show “Windows protected your PC” when you run the installer. Choose More info and check that the publisher is Onset SAS, then choose Run anyway. The installer is signed; Windows shows this warning for files that haven’t been downloaded widely yet.

What is OnsetEngine-Setup.tmp?

It’s the setup program itself. Like most Windows installers, Onset Engine’s setup copies itself into a temporary folder and runs from there, so Task Manager and antivirus software may show these names instead of the file you downloaded:

• OnsetEngine-Setup.tmp - the installer you downloaded, while it runs
• OnsetEngine-Setup-Full.exe and OnsetEngine-Setup-Full.tmp - the full installer it downloads, while it runs
• OnsetEngine-v1.2.6-Setup.tmp, with your version number - if you downloaded the full installer directly

They live in a folder in your temp folder (%TEMP%) whose name starts with is-, and setup removes them when it finishes.

The installer seems stuck

• During the download: the window shows the download’s progress. It’s about 2 GB, so on a slow connection it can take a while. Keep the window open until the setup appears.
• After the download: the full installer starts and Windows asks for permission to make changes. If nothing appears, look for a flashing shield icon on the taskbar: the permission prompt may be waiting behind other windows.
• Can’t connect: if the installer can’t reach the download server, it offers to open the download page, where you can get the full installer instead.
• Still running after Onset Engine is installed: if Task Manager still shows OnsetEngine-Setup.tmp once Onset Engine is installed, choose End task. It holds a temporary copy of the download (about 2 GB), so then open %TEMP% and delete the folder starting with is- that contains OnsetEngine-Setup-Full.exe.

Antivirus warnings

Some antivirus software flags installers it hasn’t seen many copies of yet, or the AI models and video tools Onset Engine includes. First check the signature. If the signer is Onset SAS, restore the file from your antivirus quarantine or allow it, and add the installation folder (C:\Program Files\Onset Engine) to your antivirus exclusions. Please let us know which antivirus flagged it at [email protected].

FFmpeg not found

Symptom: FileNotFoundError: ffmpeg or ffmpeg is not recognized

Fix: FFmpeg is bundled with Onset Engine in the ffmpeg/ folder. If you receive this error:

1. Verify the ffmpeg/ folder exists in your Onset Engine installation directory
2. If missing, re-extract the application from the original download archive
3. Restart Onset Engine

libmpv-2.dll missing (DJ Mode)

Symptom: DJ Mode button is grayed out or crashes immediately

Fix: MPV is bundled with Onset Engine in the mpv/ folder. If you receive this error:

1. Verify the mpv/ folder exists in your installation directory with mpv.exe and libmpv-2.dll
2. If missing, re-extract the application from the original download archive
3. Restart Onset Engine

CUDA not available

Symptom: RuntimeError: CUDA not available during ingest

Fix:

1. Verify you have an NVIDIA GPU: open Device Manager → Display adapters
2. Update to the latest NVIDIA driver from nvidia.com/drivers
3. If using a laptop, make sure Onset Engine is running on the discrete GPU (NVIDIA Control Panel → Manage 3D Settings → add OnsetEngine.exe → select “High-performance NVIDIA processor”)

Note

A current NVIDIA display driver is the only requirement - everything else Onset Engine needs to talk to your GPU is bundled with the application.

Tip

Without a compatible NVIDIA GPU, Onset will fall back to CPU inference (slower but fully functional).

First Run

Where are my clips stored?

In the Library folder of your projects folder (output_clips inside %APPDATA%\Onset Engine unless you’ve chosen another). ⚙️ Global Preferences shows where it is, with Browse… to change it and Open to look inside.

How long does ingest take?

It depends on the video length, your hardware and your analysis settings. As a reference, 10 minutes of 1080p footage takes under a minute with the default Standard analysis, with or without an NVIDIA GPU. High Quality analysis takes about the same time on an NVIDIA GPU, but around 4–5 minutes on CPU only. See the measured timings.

What is ViT-B-32 vs ViT-L-14?

These are the two AI models used for clip analysis, shown in the ingest settings as Standard (ViT-B-32, the default) and High Quality (ViT-L-14). High Quality gives somewhat better clip matching. On an NVIDIA GPU both take about the same time; without one, High Quality is several times slower. Keep one model for your whole library: clips analyzed with the other model can’t be compared with the rest, so clip direction and search leave them out. The Add Videos window starts on the model your library uses and asks before you mix them, and New video matches it automatically. To switch a library to the other model, re-ingest its footage. Read more.

Ingest Issues

Ingest is very slow

Possible causes:

• CPU-bound decode: Large 4K files may decode slowly on CPU. Ensure you have a modern multi-core processor for best performance
• Antivirus scanning: Windows Defender may scan every extracted clip file. Add your clips directory to the exclusion list
• Mechanical HDD: Ingest is I/O heavy. Use an SSD or NVMe for the clip output directory
• First ingest: the first ingest downloads the visual analysis model once (about 300 MB, or about 860 MB for High Quality). Later ingests load it from your computer

Ingest stops entirely when one file fails

Symptom: Ingest aborts partway through a library, with no clear indication of which file caused it.

Fix: Update to v1.0.15 or later. Earlier versions treated any single unreadable video - a truncated download, a file still being copied, a format this build of FFmpeg can’t open - as fatal to the whole run. Bad files are now skipped, the run continues, and every skipped file is listed with its reason at the end. Re-running ingest retries only the ones that failed.

Clips are too short / too long

Scene detection thresholds are adjustable in config.yaml:

# Adjust scene detection sensitivity
min_clip_duration: 1.5    # Minimum clip length in seconds (default: 1.5)
max_clip_duration: 12.0   # Maximum clip length in seconds (default: 12.0)
scene_threshold: 27.0     # FFmpeg scene detection threshold (lower = more cuts)

Lower the scene_threshold to get more clips (finer cuts). Raise it if clips are too fragmented.

Rendering Issues

Why is rendering slow?

Rendering speed depends on your export settings and hardware. CPU rendering takes significantly longer than hardware encoding.

How to get 60fps?

Pick a 60fps option from the Quality dropdown at the bottom of the Editor’s settings panel. 60fps requires Core tier or higher - the free Demo is capped at 720p/30fps.

What codecs are used?

Onset Engine uses H.264 or HEVC for video encoding.

NVENC vs CPU encoding

NVENC is a hardware encoder on NVIDIA GPUs that drastically speeds up exports. If no compatible GPU is found, Onset Engine falls back to CPU encoding, which takes longer but produces identical quality. Read more.

Render crashes with OOM (Out of Memory)

Symptom: Onset Engine crashes, or encoding fails partway through a long render

Fix: Onset Engine renders in chunks to prevent this, but if you’re still hitting OOM:

1. Close other GPU-intensive applications (games, browsers with hardware acceleration)
2. Turn off the most expensive VFX for that render - Cutout Pop Transitions, Depth Effects, and Smooth Motion are the heaviest
3. Render at 1080p instead of 4K for the initial pass

Render finishes but produces no file

Symptom: The render runs to the end, then fails at the final stitch and writes no MP4. Only occurs on some Windows machines, and only when the output is watermarked - the free Demo, or a paid build with the watermark switched on in Preferences.

Fix: Update to v1.0.12 or later. Drawing the watermark text relied on a font configuration that is present on many Windows installs but missing on others; where it was missing, the final stitch failed with no output. The watermark now uses a font bundled with the application, so it no longer depends on anything being installed on your system.

If your watermarked renders have always worked, your machine had the font configuration and you were never affected.

The clip library is stuck on “Loading…”

Symptom: On startup, the library sits on “Loading…” and never populates until you press refresh.

Fix: Update to v1.0.11 or later. In earlier versions the background library scan could fail to hand its results back. Pressing the refresh button is the workaround on older builds.

The window freezes / menus come up blank on large libraries

Symptom: After a big library loads, most clicks stop responding, and right-click context menus open blank or missing items. DJ Mode keeps working normally.

Fix: Update to v1.0.14 or later. Each source video’s row in the library panel used to cost five separate on-screen elements, and Windows caps how many a single program may create at 10,000 - past that, it silently refuses to build any more menus. A row now costs about a fifth as much, so this no longer happens until well past 3,000 source videos.

Render output has no audio

Symptom: The rendered MP4 has video but silent audio

Fix: This usually means FFmpeg couldn’t find the music file during the final stitch:

1. Ensure the music file path has no special characters (spaces are fine, emoji are not)
2. Check that the music file is a standard format (.mp3, .wav, .flac, .ogg)
3. Re-run the render with the same music file selected

Colors look wrong in rendered output

Symptom: Output is oversaturated, undersaturated, or has a color shift

Fix:

• Check your preset’s color grading settings - the PRESTIGE preset applies neutral clean grading and the AGGRESSIVE preset desaturates
• Some media players apply their own color management. Try viewing in VLC or MPV instead of Windows Media Player
• If rendering at high quality, NVENC CQ17 preserves more color detail.

DJ Mode Issues

DJ Mode shows black screen

Possible causes:

1. libmpv-2.dll not found - see installation fix above
2. No clips in library - run ingest first (minimum 50 clips for DJ Mode)
3. Virtual clips with moved source files - if you ingested with Don’t make copies of clips on and then moved the source files, the pointers are broken

Clips play with a flash at the start

Symptom: Brief flicker of the first frame before the clip plays from the correct start time

Fix: This affected virtual (pointer-only) clips, where playback has to seek into the middle of a large source file. It is mitigated in current builds - make sure you are on the latest version. If you still see it, switching that library to physical clips avoids the seek entirely. See Physical vs Virtual Ingest.

Keybinds don’t work

DJ Mode keybinds only work when the MPV window has focus. Click inside the playback window, then use:

• ↑/↓ - Energy tier
• ←/→ - Force clip transition
• / - CLIP text query
• G - Gold star clip
• B - Block clip
• ? - Show help overlay

Performance Tips

Speed up rendering

1. Use draft for previews - FFmpeg direct stitch at 720p, renders in ~30 seconds
2. Close Chrome - Chrome’s GPU process competes for VRAM with NVENC
3. Use physical clips - Virtual clips require FFmpeg seek per clip, which is slower than direct file reads

Speed up ingest

1. Use an NVMe SSD for both source files and the clips output directory
2. Ingest in pointer-only mode for large archives - skips the clip export step entirely
3. Start working during ingest - DJ Mode activates at 50 clips, the Editor at 1 clip

Reduce disk usage

1. Use virtual ingest (Pointer Only mode) - zero disk usage beyond the SQLite database
2. After rendering, delete the chunks/ temp directory if it wasn’t auto-cleaned
3. Use draft quality for iterations, high quality only for final exports

Licensing

How to activate?

Click the tier badge button in the upper-right corner of the GUI to open the License & Activation dialog, paste your key, and click Activate.

Can I use on multiple machines?

The Demo tier allows 1 activation. The Core and Studio tiers allow up to 2 simultaneous activations.

What happens when license expires?

Onset Engine will revert to the Demo tier, capping exports at 30 FPS and 720p resolution. Read more.

Related Articles

• Autopilot
• DJ Mode