Using VLC to Capture from Blackmagic Intensity Extreme on Windows XP

This took a while.

And I'm still not sure I totally understand it.

But to get a "Perfect" capture and Preview on Windows XP SP3 with Thunderbolt and a Blackmagic Intensity Extreme.

Here are the manual steps:

1. Open VLC

2. Go Tools > Preferences > Video 

3. Use the drop down for "Display ----- Output ----> [Windows GDI video output]"

The default "automatic" will produce a blocky chunky slow video window with multiple artifacts all over the place, so be sure to manually set the "Display Output method to Windows GDI video output"

4. Save

5. Media > Open Capture Device...

6. Video device name: Decklink Video Capture

7. Audio device name: Decklink Audio Capture

8. Video size: 720x486

9. Advanced options: check, Device properties


B. Play

C. First "popup" Properties > Video Format

D. Use the drop down for Video Format: (Scroll Up to pick the First: NTSC - 8 bit 4:2:2 YUV)

The default identical looking (NTSC - 8 bit 4:2:2 YUV) is an accidental abbreviation for NTSC "Progressive" which appears to be improperly rendered on Windows XP at the moment. The "Top" position in the list is actually the same "Interlaced" which takes less time for VLC to process and display.

VLC has its own internal software De-Interlacing options which appear to work without the long delay or lag of the Intensity Extreme "profile".. so I am uncertain what is going on.

Also the Blackmagic Control Panel applet is responsible for actually setting up the Intensity Extreme for input.. so it could be the pop up panel is confusing the DirectShow pin that feeds VLC and it may be mininterpreting the input as Progressive when it actually is not.. I do not know for sure.

For now.. just do it.

E. Apply: OK

F. Second "popup" Properties > Audio Format


It takes about 1 or 2 seconds for the window to launch, audio and video are "rock solid" and in-sync.

All  of this was figured out by trial and error.

Windows XP SP3

Blackmagic Intensity Extreme

HP Thunderbolt laptop

VLC Player 2.2.6 Umbrella

Pressing the [o] red dot "Record" button saves the currently viewing Preview as a Lossless .AVI file to:

C:\Documents and Settings\{my-username}\My Documents\My Videos

The videos are lossless, but the audio, video playback are very far out of sync.. and the file information reports a frame rate of 21.xx below 29.97

So I don't know if its a difference in format interpretation or dropped frames or samples.. or something else I do not understand.

Blackmagic went to a lot of trouble to not playback audio while capturing in Media Express and calls the process out as harmful to maintaining sync while capturing. VLC plays back audio while its capturing.. perhaps introducing a delay in the audio stream when writing to disk.

I am not entirely sure how to disable audio playback in VLC while capturing both audio and video. It could be a challenge.

VLC Preview however the audio and video are in lock step.