In addition to the standard HDSDI output on the Merlin card, Previzion has a low latency preview output that is generated through the 2nd DisplayPort output connector on the nVidia Quadro card. This has a much lower latency (1-2 frames, depending on the camera), but shows significant visual artifacts (tearing, etc.) and does not have embedded timecode, audio, or any HDSDI metadata. It’s meant as a high speed preview for camera operators, with the regular synchronized HDSDI signal being used for recording and editing in post.
The way it works is to create an extended desktop with a DisplayPort device connected to the output, then run Previzion. Previzion will recognize the second device, and write a full size copy of the current preview window to the second desktop. If a device such as an AJA HA5 HDMI to HDSDI converter is connected, the result is a very rapid HDSDI composite preview.
Connection and Screen Setup
- Exit Previzion before changing desktop mapping settings.
- Connect the AJA HA5 to the second DisplayPort connector, using a DisplayPort to HDMI converter cable.
- Right click on the desktop, and select nVidia Control Panel
- Under Display->Set Up Multiple Displays, select Clone. The red light on the AJA will light.
- Reboot the machine.
- When the machine comes up, right click the desktop and select nVidia Control Panel again, then Set Up Multiple Displays. If it does not default to DualView, select DualView and confirm. The ‘DVI 1920’ remains the primary monitor display.
- You can verify the extended desktop by sliding a window over to the right; it will appear on the HDSDI stream.
- If necessary, return the main display to 1920×1200 or 1600×1200 with the Change Resolution panel in the nVidia Control Panel.
- Exit the nVidia Control Panel.
- Now start Previzion. The output will appear on the secondary display, with the same low latency that the primary UI window has.