Has anybody some experience with I/O graphic hardware accelaration

zedociel

As the title say… Has anyone used some of those stuff, like the matrox MXO2 or the blackmagic intensity as output for Isadora. Does it work ? Does it really accelerate the rendering process ?

Thanks in advance
J

mark

Dear J,

It isn't going to accelerate the process necessarily. The thing is about the Blackmagic output, it is _not_ a graphics card, i.e., it doesn't support OpenGL. What it does, it does really well: present frames with extremely accurate timing and with excellent color. But Isadora can't render to it directly.

The way Isadora can output to this device is via the "External Video Out Device" in the Output menu. (You can read up on this feature in the manual.) When you select one of these devices (whether it is Blackmagic, or a DV camera, whatever) Isadora will copy the image on the stage to the device. So it works something like this

1) Render to the stage

2) Copy the stage image to a bitmap buffer in normal RAM

3) Send that bitmap to the Blackmagic or other device.

So, as you can see, there is always an extra step involved. And, the thing about graphics cards is, the are meant to have data flow _into_ them (i.e., from the CPU/Application into the card.) They are far less efficient when going the other direction. So step #2 can be costly performance-wise.

So, really, the best thing to do is to go out of a Graphics Card if at all possible. Many models now have HDMI outputs, so you can go directly to an HD monitor or whatever. Unless you really need the Blackmagic output, a normal graphics card will always be better.

Best Wishes,

Mark

mockej

Thanks Mark, I had a similar question in the back of my head, as I may be getting a BM Ultrastudio 3D soon (for a sterescopic film project, but figure I may as well use it for existing stage projects with Izzy). I picked up in some other thread that you were using one of these, is it for the Coppola project? In any case I will be trying it out soonish, will appreciate tips and will be asking more specific questions when I get my teeth into it.

cheers, m

zedociel

Dear Mark,

Thanks a lot for the answer. It brings some enlightement to my understanding of the whole process. It wasn't about the connection, but really about the acceleration part, so I got my answer.

Thanks again for the help.

All the best

Jérôme