Ive spent some hard earned time today with the Decklink Intensity Card.
It most definitely works with a computer driven DVI source with a DVI-
>HDMI adaptor or cable, so the YUV "consumer" HDMI vs RGB DVI
computer colorspace "issue" is not a problem per se for the Intensity
card as was speculated. I have only tested with my MacBook Pro, but I
would be surprised if this was an issue with other systems.
jit.qt.grab finds the card just fine and will work with colormode
argb or uyvy and produce proper results either way.
Currently the Decklink drivers support only one card. Even though
their On Air software sees both cards we have installed, quicktime
does not. Decklink is aware of this and will be supporting 2 cards
eventually with a software update, so I am told.
I havent been able to quantify, but there is a noticeable frame lag
from the output device to the intensity card input and display. It
seems like 3-5 frames delay, not huge, but there.
My laptop sees the Intensity card and can drive it at 1920x1080
Interlaced or 1280x720 Progressive. I dont think all systems will be
able to see and drive the intensity card properly. A friends 12"
Powerbook did not properly see the 720P, it output 720 interlaced, so
it would not lock up at that resolution.
Back to Jitter:
jit.qt.grab on a 2 x 3.0 Ghz Intel Mac Pro with 8GB ram, x1900 with
@colormode uyvy @1920x1080 to a videoplane @uyvy = 60fps
@colormode uyvy to the cc.uyvy2rgba.jxs shader, to a jit.gl.slab
@file td.sinefold.jxs, then mixed with the original texture using one
of the composite shaders to a videoplane @ rgba, is 60 fps.
the above, but at colormode rgba sans uyvy/rgba conversion shader is
a paltry 30 fps. :)
720p @ colormode argb with the above shaders ran at 50 -55 fps, and
looks lovely being progressive and all.
Everything else (colormode uyvy, etc) ran at 60fps, but the ARGB
progressive mode has a much much nicer image quality. Drastically
superior, why would anyone want to deal with Interlacing in this day
and age anyway?
Color differencing (using RGB color mode @720P)
There are very slight color shifts. Using Final Cut Pro to output
SMTPE video bars @720p. I measured the color accuracy using the
Digital Color Meter supplied by Apple.
Local 720p Bars (in RGB as percentage)
Red : 70.6% 0. 0.
Blue: 0. 0. 70.6 %
Green: 0. 70.6 0%
After Intensity /Jitter to the Mac Pro displayed via GL
Red: 73.3 0. 0. %
Blue: 0. 0. 73.3 %
Green: 0. 73.3 0.%
Blacks were super black at 0% on both systems
Pedestal was 2.0% local, 2.7% on intensity card, so some luma/gamma
The colors after going through Intensity card look really good, and
the shifts were not noticeable in any way, but they are there. Not
sure if this is a Jitter issue on a Quicktime/Decklink issue, but, at
the end of the day they are not really an issue. More testing could
reveal the source of the issue.
I was also able to record using jit.gl.texture to jit.matrix
readback, which considering the PCIe bandwidth did not significantly
lower performance. I had a greater fps hit dropping in a pwindow that
had use onscreen 1 enabled. Recording the 720p content to motion jpeg
lowered my framerate to about 35 fps all while driving a full screen
display @ 1280x720 progressive with slab effects enabled and mixing.
Could not Test video out ironically because we had no HDMI viewing
monitor. Once they have the second (or hopefully more) card
supported, this will make a wonderful platform to use for HD.
This is really good news.
I hope this is helpful to the list.
I hope to test on a PC shortly, but it may be sometime.
v a d e //