off topic - can raspberry pi do HDMI capture?

David Röthlisberger david at
Sat Feb 1 01:39:48 PST 2014

On 31 Jan 2014, at 20:51, Chuck Crisler wrote:
> I am currently evaluating a Blackmagic Intensity Pro

I've had no end of trouble with the Blackmagic Intensity Pro. The
drivers are closed source but I assume that you already understand the
hassle that causes. At one point the drivers were overwriting memory
that belonged to a *different process* than the process with the
GStreamer decklinksrc; this went away when I upgraded the driver from
9.7 to 9.7.3.[1]

Also the Blackmagic card has a stability problem when you have more than
one of them in the same PC: After about 24 hours the card will "lock up"
and stop working until you reboot the PC. I tried all sorts of device
powerdown/unbind/reset tricks, but nothing worked other than rebooting
the PC. However perhaps my use case is different to yours: I use these
to capture video from a set-top box for automated testing, so although
the Blackmagic cards are in use 24/7, they are stopping & starting
frequently (capture video for 2 or 3 minutes; stop for a few seconds;
start again...). Maybe with a single long-running capture you won't have
the same problems. Also note that when you're using a single Blackmagic
card per PC it's quite stable.

Unfortunately these cards might be the best option you have. You could
try the ViewCast Osprey 820e, but it's much more expensive. It has
open-source drivers, but they're not upstream in the Linux kernel. In
our tests something like 0.5% of video captures came out with a blue

In the end we found that the best option (for us) is to use a
video-capture device that streams the video over the network, like the
Teradek VidiU -- the video quality isn't great (only 5Mbps) but it's
sufficient for our needs, it's rock solid, and you avoid any driver


[1] Rough notes & scripts to reproduce here:

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