A free broadcast utility that turns a Windows PC + a Blackmagic DeckLink card into a live tally / frame-line / confidence-monitor injector for a camera's viewfinder feed. It captures the incoming SDI, passes the picture straight through (no re-encode) and burns in a coloured tally border, framing lines and operator overlays — driven from a window, a web page, Bitfocus Companion over HTTP, or a TSL 3.1 UMD feed.
Built for standalone Blackmagic URSA Studio Viewfinders, whose single red record lamp is otherwise the only tally available over SDI.
Free, closed-source utility. The compiled application is provided here on the Releases page; the source code is not published. Use it freely — see terms.
⬇ Get the latest release — ThastViewfinder.exe,
self-contained, no installer.
- Requires: the Blackmagic Desktop Video driver (it provides the DeckLink runtime) and a DeckLink card. Just run the exe.
- Verify your download — SHA-256:
da969f21cc0a8f0cdbdc7ec804db5c8c6fd8055e981dc506375c4cf84107e4aa ThastViewfinder.exe
- Tally Router — three independent coloured tally channels (red / green / yellow) drawn as concentric border rings, the physical viewfinder lamp and its arming map, and R+G = Y logic for Sony-style triggers (red + green → yellow).
- Frame Line Inserter — composition, safe-area, aspect-frame and display overlays, burned into the live picture.
- Monitor Injector — the passthrough engine; burns the tally and frame lines in with no decode/re-encode, and shows a NO-SIGNAL slate when the input drops (the physical tally persists through signal loss).
- Signal Monitor — live input / output / reference lock and device status.
- Device I/O — pick which DeckLink card and which physical connector capture and playback use.
It opens a control window and a web page at http://<host>:8090/ that
mirror each other, both driveable from Bitfocus Companion over plain HTTP GET.
It can also take tally straight from a vision mixer's or router's TSL 3.1 UMD
feed over UDP. The console window is hidden by default; launch with --console to
show it.
A standalone URSA Studio Viewfinder ignores the usual Embedded Tally byte (DID 0x51 / SDID 0x52). What actually lights its lamp is the camera-control record-state (Blackmagic SDI Camera Control, Media 10.1 = record), so that is sent as the primary mechanism. Every other tally colour, and all the framing, is painted into the picture instead (the DeckLink card has no hardware keyer) — interlace-safe and low-latency.
Free to use; closed source — see LICENSE.
David Thåst · thåst.se