Decklink video input

[efxmaster]

ok, I am doing an event that has a live video feed from a very nice Ross video switcher. It sends out 1080i 59.94fps. So the decklink card will take it, and I can bring it up on the catalyst. I thought that it would drop some frames or have a latency problem, but what it looks like is that it is only playing back at 30fps. I changed the catalyst to 60fps and it did not change what it looked like. Is this something in the catalyst or is it the decklink card?

8X3.0 GHz Mac Pro
Nvidia 8800 ( I think )
SSD for content.
Decklink extreme hd 2 with an hd-sdi in.

Thanks for the help.

[Mr_P]

The catalyst playback rate will have no effect on the speed of a video input...

the Catalyst playback rate applies only to movies (ie the speed at which they playback)
So you will see no change in the video input.

The Decklink '1080i 59.94' is 30fps...
59.94 is the frequency of the interlaced fields, which equals 30 frames per second (an interlaced frame is made up of 2 fields)
See: http://en.wikipedia.org/wiki/Frame_rate

Decklink at 59.94 and Catalyst set to 30fps (not 60fps) would be ok...

What exactly are you trying to achieve?

Simon

[efxmaster]

Ok that makes sense. Here is what is happening. There is a blended screen on the catalyst. There are two other screens being sent a signal straight from the Ross switcher. If I have any video signal coming from the Ross switcher that has any real motion in it, it does not look right, blured or I guess more a lag. Is that the decklink card?

Thanks for the reply.

[Mr_P]

Blurred when moving could be because its an 'interlaced' image
http://en.wikipedia.org/wiki/Deinterlacing

Try selectig the 'de-interlace' button on the video input window to see if that helps.

Blur would be seperate from lag/delay.

The decklink cards inherently frame buffer as they are designed for NLE rather than live input (this is why Active Siicon cards are better)
There is no way to turn off the buffering - try a lower resolution and see if that makes a difference. (720p if possible)
It usually happens when the PCI bus is busy as HD-SDI capture takes a lot of bandwidth compared to SD.

What other cards do you have installed?
What hardware version is your mac?

S

[efxmaster]

The video card and the decklink are it. I will have to find something that will down convert it.

Maybe I will just have to get the Active Silicon card.

[Mr_P]

Do check the latency from your Ross switcher too...