DOWNLOAD
Download PETRA
Windows installer 0.1.0 (NSIS, 64-bit only). The first release is unsigned — please verify the SHA-256 as described below and read the SmartScreen notes before installing.
ARTIFACTS
Installer details
SHA256SUMS.txt published with the build, so you can compare them directly and confirm the file is intact and untampered.
If you hit a problem, start with the three verification methods in the section below.
VERIFY
Verify the installer (any one of three ways)
METHOD 01 · POWERSHELL
Get-FileHash
Open PowerShell in the folder that holds the installer and run:
Compare the 64-character hex string with the SHA-256 above; if they match, the file is intact.
METHOD 02 · CMD
certutil
The first line of output is the SHA-256 — compare it with the value above.
METHOD 03 · SHA256SUMS.TXT
The checksum list
The release also provides SHA256SUMS.txt, one line per file in the form <64 lowercase hex><two spaces><file name> (LF, no BOM, sorted), ready to compare with either command above.
SMARTSCREEN
Unsigned installer: SmartScreen and antivirus prompts
STEP 01
Click "More info"
On the SmartScreen dialog, click "More info" to reveal the publisher and app name.
STEP 02
Click "Run anyway"
Once the SHA-256 matches, click "Run anyway" to continue the installation.
STEP 03
Other antivirus software
Some AV tools may report an "unknown publisher" warning; after verifying the hash, choose allow/trust. If it refuses to let the file run, please tell us.
Before you install
- The installer starts with current user privileges; installing the app itself does not need admin rights. Choosing "install for all users" asks for elevation at that step.
- The installer is unsigned, so the first launch shows the SmartScreen "unknown publisher" prompt: click "More info → Run anyway" (see above).
- If your antivirus flags
d3dcompiler_47.dll, allow it — it is a standard component shipped with Electron. - The first launch imports the bundled assets and templates automatically; nothing to do by hand.
- The virtual camera needs one administrator approval: the component installs to
C:\Program Files\PETRA\vcamand is registered for all users, otherwise meeting apps such as Tencent Meeting or DingTalk will refuse to load it. Click "Install component" on the app's "Live streaming" page to trigger that approval. - NDI output requires the official NDI Runtime (free) to be installed separately; without it, the virtual camera and projection keep working.
- If OBS is installed: close PETRA before installing or upgrading OBS (Windows reports the running Electron app as a file lock — that is expected).
SYSTEM REQUIREMENTS
System requirements and hardware
OS
64-bit Windows only
- Windows 10 (21H2 or later recommended) or Windows 11
- Not supported: Windows 7 / 8.1, Windows on ARM64, 32-bit Windows
MINIMUM
Runs reliably
- CPU: dual-core 2 GHz (x64)
- Memory: 4 GB
- GPU: DirectX 11 capable
- Display: 1366×768
RECOMMENDED
Comfortable with several apps open
- CPU: quad-core or better (i5 / Ryzen 5 class)
- Memory: 8 GB; 16 GB when running NDI, OBS and a meeting app at once
- Disk: SSD with 5 GB free
- Display: 1920×1080
- Network: wired gigabit for NDI streaming; Wi-Fi is not recommended
DISK
Installer and assets
- About 190 MB installed, including 60.26 MB of bundled assets (30 image backgrounds, 34 video backgrounds, 14 covers, 6 built-in templates)
- Leave room for your own asset library — 2 GB or more
Features and connectivity
- Free tier: core projection with the built-in Bible and hymn libraries and ready-made static backgrounds; projection works fully offline.
- Pro tier: motion backgrounds and polished transitions, plus virtual camera and NDI output, making online services much easier.
- Only the notice feature goes online — once at startup; failures are skipped silently and never affect projection.
- The download includes image and video backgrounds and 6 built-in templates, so you can start right away.