HD capture devices

resources
#1

Hi everyone,

We need to capture a video signal that should be at least XGA resolution. It could be analog (VGA, components) or digital (DVI/HDMI).

We have already used PAL signal capture devices that are easily handled with OF, but we don’t what is the best option to capture higher resolution signals.

In a first search we have found that Blackmagic devices are pretty popular for this purpose, does anybody have any experience with those or some other device in OF?

We could work under Windows or Linux platforms, but would prefer Windows+CB if possible.

Regards.

#2

For a non-OF project we just got the DVI2USB to use to encode 1024x768 video for a streaming server. They are expensive but were the only devices I found that specs claimed to compress higher resolutions to USB with a decent framerate (am using a mac).

http://www.epiphan.com/products/product.php

I have yet to plug it into OF but I should get a chance next week

#3

quick followup - just tested with

Windows Machine playing Netflix mirrored display at 1280x1024
DVi->VGA ---- VGA->DVI -> DVI2USB -> Mac Pro Quad Core (2006)

Using the basic ofVideoGrabber at 1280x1024 I was getting 30fps according to this RateTimer class,

https://github.com/jvcleave/PS3EyeWindow/blob/master/src/testApp.h

OF was at about 800fps

Another interesting thing I wasn’t aware of is that epiphan has an SDK for the device
http://www.epiphan.com/products/dvi-frame-grabbers/dvi2usb/development/

#4

Hi jvcleave,

Just a question about those tests.

Is the captured video signal changing somehow or it is a more or less stable desktop background?

I ask because at that resolution those framerates seem difficult to achieve within a USB 2.0 bus, and I only see it could be possible if the image is changing very little to apply some compression. Am I wrong?

There is a recent Blackmagic capture device with USB 3.0 port, that can support much more bandwitdh, but it seems to work only under Windows 7, so we have finally purchased a PCIe version that works fine in our first tests.

Regards.

#5

I think for the ofVideoGrabber test I was playing Tron.

Actually I kept messing with their SDK where I was getting the best video performance at 1024x768. For that I was was playing “How the Universe Works”

I have a little addon/wrapper I wrote during the process here:
https://github.com/jvcleave/ofxEpiphanPlayer

Using the addon I got the best video performance but the app framerate dropped quite substantially (30/60fps as I recall). I would stick with your setup if that is working for you

#6

there’s 2 addons for blackmagic devices, for windows:

http://github.com/jamezilla/ofxBlackmagic

and for linux

http://github.com/arturoc/ofxBlackmagicGrabber