HD playback from BMSD card

[David Roth weiss]

[matt short] “The problem was I was setting the Veiw to an SD setting when you need to set it to a corresponding HD setting.”

Matt,

You’ve got it a little confused, and I think you may have misunderstood the guys at BM. BTW, they don’t seem to know much about downconversion anyway, so its easy for users to remain confused after discussing it with them… See my explanation below, I think it will help you to understand not only how it works, but why it works. And BTW, its not really magical, most of SD the Kona cards can do the same.

First, keep in mind that FCP is capable of playing both SD and HD on the timeline without a capture card installed. So, if someone sends you an HD file, you can play it back in FCP and monitor on your computer monitors without any video hardware at all.

Second, your SD BM Extreme card is capable of downconverting from HD to SD on the fly. So, when you play an HD signal on the timeline and route it through the BM card, the HD signal passes through the card and is downconverted in realtime by an onboard video chip. Then, the converted SD video signal travels out of the card through the component/composite cable to either a display, VCR, or both. This is where the part comes in that I think you are confused about…

The View Settings — what is this signal traveling out of my computer card and what devices are attached that can read it.

Although you may want to argue with me over this, I can assure you that, having lived with a BM Extreme card for the last 18-months (before recently switching to a Kona HD card), I know its capabilities and operation quite well. What confuses most people is that Easy setup requires an HD setting, while the view setting needs to be set independently to the proper SD settings and framerate. I think this may be the part that you have not got your brain wrapped around entirely.

Since the SD card has only HD input, but no HD output (this is what separates the SD and HD cards), and the down-converted signal is SD, you must think of the output like you would any other SD signal, and monitor it accordingly. Your SD monitor and SD tape deck are expecting just one thing, an NTSC SD signal at 29.97mhz — anything else will not work. So, the view settings should not in fact be set to HD, but rather to SD.

BTW, the BM card will in fact display DVCProHD to an SD monitor as well — I worked on an HD project that way for many months. The setups are not all labled absolutely perfectly, especially the ones that display 23.98 HD as 29.97 SD. But, with enough guesswork and testing you will get it to do exactly what you want. Keep in mind that DVCProHD is an 8-bit signal, so just cycle through every 8-bit SD setup and tinker with framerates until you find the one that works for your HD format and framerate.

Hope this helps,
DRW

[Matt Short]

[David Roth Weiss] “What confuses most people is that Easy setup requires an HD setting, while the view setting needs to be set independently to the proper SD settings and framerate.”

This is what I was doing (unsuccessfully) before I talked to tech support. When I switched the View settings to the corresponding HD settings, it worked.

[David Roth Weiss] “BTW, the BM card will in fact display DVCProHD to an SD monitor as well — I worked on an HD project that way for many months. The setups are not all labled absolutely perfectly, especially the ones that display 23.98 HD as 29.97 SD. But, with enough guesswork and testing you will get it to do exactly what you want. Keep in mind that DVCProHD is an 8-bit signal, so just cycle through every 8-bit SD setup and tinker with framerates until you find the one that works for your HD format and framerate.”

Good to hear. This is what I need.
Thanks for the advice.

[Matt Short]

[David Roth Weiss] ” with enough guesswork and testing you will get it to do exactly what you want.”

I figured out how to do it with DVCproHD media. The sequence has to be set to the plain DVCproHD not the Blackmagic DVCproHD and the view settings need to be set to the corresponding (size & framerate @ 8bit) Blackmagic HD setting.

[David Roth Weiss] “Since the SD card has only HD input, but no HD output (this is what separates the SD and HD cards), and the down-converted signal is SD, you must think of the output like you would any other SD signal, and monitor it accordingly. Your SD monitor and SD tape deck are expecting just one thing, an NTSC SD signal at 29.97mhz — anything else will not work. So, the view settings should not in fact be set to HD, but rather to SD.”

This makes alot of sense but, (sorry David) it doesn’t work that way. I’m sure you’re right in that it’s not sending an HD signal to my monitor but, the View setting does need to be HD to playback.

Thanks for helping me figure it out.
Matt

[Kristian Lam]

[David Roth Weiss] “ince the SD card has only HD input, but no HD output (this is what separates the SD and HD cards), and the down-converted signal is SD, you must think of the output like you would any other SD signal, and monitor it accordingly. Your SD monitor and SD tape deck are expecting just one thing, an NTSC SD signal at 29.97mhz — anything else will not work. So, the view settings should not in fact be set to HD, but rather to SD.”

Hi David,

This is incorrect. The view settings should be on HD even if you’re workin with an SD DeckLink card as the down conversion is handled in the Blackmagic drivers and not by Final Cut Pro.

regards

Kristian Lam
Blackmagic Design