Multiple Blackmagic Intensity Pro cards simultaneously - Media Express conf

[Ferggue]

Hi everyone,

I'm running a VHS and magnetic video digitization business and recently built a dedicated capture PC with 3x Blackmagic Intensity Pro cards installed simultaneously.

The good news is that Windows recognizes all three cards correctly, and OBS picks up video and audio from all of them without issues. However, I cannot get Media Express to work with any of the three cards. It detects them but shows no video signal, even though the signal is clearly coming through (confirmed via OBS). My guess is that the three cards are conflicting somehow within Media Express.

My questions:
1. Has anyone successfully run multiple instances of Media Express simultaneously, one per Intensity Pro card? Is this even possible, or is Media Express limited to a single instance?
2. If multiple Media Express instances are not feasible, what would you recommend as the best capture configuration in OBS for VHS digitization?

My current workflow (when Media Express works on my single-card setup) is: capture uncompressed interlaced MOV via Media Express → compress to H.264 and deinterlace to progressive in Adobe Media Encoder. The results are great and I'd love to replicate this quality at scale with 3 simultaneous captures.

Any advice from people who have worked with multiple Blackmagic cards in parallel would be hugely appreciated.

Thanks!

[Brainiac]

Since your setup works for a single card we know that the settings in Media Express (Edit -> Preferences) are correct. Are you using the same settings for the cards in your setup with the 3 cards?

[CaptureCraft]

Here is my experience. I used a couple of different BM cards, but not simultaneously. Now I use 2 different non-BM cards, but simultaneously.
For all the scenarios I used latest (now from 2026) VD2 as a capture software. It comes with H.264, which allows to use it in either lossless or lossy modes.
Keep in mind you need to set VD2 properly to avoid any frame inserts/drops at VD's discretion.
You might need to make sure to capture on different dedicated hard drives (even if you use SSD) as the streams could be quite intensive, especially in lossless mode.
Tip. With H.264 you can set proper video aspect ratio even for initial capture as well as to explicitly specify your video as interlaced with the top field first.

[lordsmurf]

→ compress to H.264 and deinterlace to progressive in Adobe Media Encoder. The results are great

Adobe's deinterlace is pretty terrible compared to QTGMC.

[dellsam34]

compress to H.264 and deinterlace to progressive in Adobe Media Encoder.

This is a terrible mistake results in double loss.

Anyway, to answer your question, I've never run MediaExpress in multi card environment, Even if it's possible, chances are you will get problems with 3 uncompressed streams.

[Ferggue]

Thank you all for your responses!

To Brainiac: yes, I have the same configuration on all 3 cards.

My main issue right now is that OBS always captures progressive, even with no deinterlace filter applied. This forces me to apply a real-time deinterlace filter during capture, which I know is not ideal. Is there any way to capture the interlaced signal as-is in OBS, so I can do a proper post-process deinterlace later?

To dellsam34: could you explain what you mean by 'double loss'? My current workflow is: capture uncompressed MOV → encode to H.264 in Adobe Media Encoder. Since the first step is uncompressed, I assumed there was only one lossy encoding step. Am I missing something?

More broadly, I'd love advice on the right workflow for simultaneous multi-card capture. My current single-card workflow (Blackmagic Intensity Pro + Media Express capturing uncompressed interlaced MOV, then deinterlace + H.264 in Adobe Media Encoder) gives me results I'm very happy with. But simultaneous capture with multiple cards doesn't seem feasible with Media Express, so I need to rethink the whole pipeline. What would you recommend as the correct workflow for capturing from 2-3 Blackmagic cards at the same time, while maintaining the best possible quality?

Thanks!

[dellsam34]

Once you encode to any lossy codec, de-interlacing after becomes a second loss.