AJA & Blackmagic use same UC right?

[Christopher S. johnson]

And the same would go for say DV, or DVCPRO-HD between systems? No dark green RT bars? Because even on the AJA alone, DV files seem slightly different between FW capture and SDI-to DV capture. Cross pollenating DV files from either method results in dark green RT bars.

Thanks guys.

[John Pale]

This is from Blackmagic’s website, explaining that they use Apple’s Uncompressed Codecs starting with FCP 5.0. Apple wanted this standardized among the different manufacturers… I have read that AJA did the same thing, though I have not found that link as of yet. The Googlefest is ongoing, unless Rudy from AJA wants to put this to bed once and for all.

FINAL CUT PRO 5.0
Apple were keen for DeckLink cards to standardize on using Apple’s codecs so that there would no longer be the potential for confusion between the Apple and Blackmagic codecs.

Apple and Blackmagic Design have worked together on this issue and, starting with Final Cut Pro 5.0 and the DeckLink 5.0 drivers, all DeckLink cards use the Apple uncompressed 8-bit and 10-bit codecs for all standard definition and high definition uncompressed 4:2:2 video. The Blackmagic codecs are no longer installed for uncompressed 8-bit and 10-bit 4:2:2 video.

ARE ANY BLACKMAGIC CODECS STILL USED OR INSTALLED?
Yes, the DeckLink 5.8 and newer drivers install the following Blackmagic codecs:

Blackmagic 8-bit (2Vuy) – this is our original 8-bit codec and is still included to support legacy files captured in this format and also is what was used by the Cinewave.

Blackmagic 10-bit RGB – Apple do not currently have a codec with the RGB color space for high definition 4:4:4 dual link video. Blackmagic Design will need to include this codec until such a time as Apple might introduce its own codec for 4:4:4. We would probably discontinue the Blackmagic 10-bit RGB codec at that time.

For the full story check out this link.

https://www.blackmagic-design.com/support/detail.asp?techID=78

[Jeremy Garchow]

Christopher, please explain.

jeremy

[Christopher S. johnson]

What I mean is, I have a creepy feeling that if I capture say…DVCPRO-HD through SDI on my Blackmagic Mac, that my clint, on his AJA Mac, will get a file that is MOSTLY right but is still little different and makes for an RT effect just for him to play aback and edit.

My experience is with AJA and I know that even on that single system a DV file captured over SDI or Component, vs. just FireWire will not behave properly in each other’s Sequences. There is an AJA DV Sequence and a FireWire DV Sequence, and if you transplant, you get a dark green render bar.

It shouldn’t be, but I think this might happen between a BM Mac and an AJA Mac. And that would hurt my relationship with my client.

I’m looking for someone who knows that, not just the Uncompressed, but all of the DV based codecs also playback cross platform and with NO dark green render bars in each other’s timeline/ Sequences.

Thanks guys, this is educational.

-Christopher

[Jeremy Garchow]

[John Pale] “Blackmagic 10-bit RGB – Apple do not currently have a codec with the RGB color space for high definition 4:4:4 dual link video.” via decklink website

This was the original reason that Blackmagic developed an uncompressed codec which was then used by AJA in hardware except that it pertained to HD. Apple’s uncompressed codecs did not differentiate between HD and SD color space back then. Then the split happened, and Blackmagic and AJA had their own uncompressed codecs. Once Apple released the Apple Uncompressed codecs that were ‘hd’ enabled, AJA and Blackmagic started using them, albeit reluctantly, but the codecs were wrapped up in rt extreme. Since Apple doesn’t make a dual link codec, Decklink and AJA are ‘on their own’ in this regard.

Jeremy

[Sean Oneil]

[Shane Ross] “Then why do I hear the argument these days that Decklinks codecs are so much cleaner? IF they are all just Apple codecs….”

If you transcode to Uncompressed from a different colorspace (like 4:1:1 DV25), then apparently the BMD codec does a better job at chroma upsampling.

But if you’re talking about SDI/HD-SDI capture from a 4:2:2 source, then they will be identical.

Sean

[Jeremy Garchow]

Christopher, this shouldn’t be the case and I would triple check your settings. The DV/DV50/DVCPRO HD codec is the same on all machines.

Jeremy

[Joe Murray]

Yes, it should be the same, but I’ve had the same problem as Chris.

Joe Murray

[Jeremy Garchow]

That truly doesn’t make any sense.

Can anyone shed some light on this?

[Mattso]

I’m the ‘CLIENT’ that Christopher is speaking about.

I want to address his concern here, specifically the idea that COMMON codecs are different between machines.

Let’s talk first about a simple, compressed codec, like DV.
If you go sit down and capture a file thorugh firewire in your dual G5, the capture preset you’ll choose in the ‘Log and Capture’ is going to be “DV-48khz” or some such… the common, everyday DV codec that we all know and love.
It is a software-based codec and is uniform from system to system.
HOWEVER. If you sit down at your system and instead of using the firewire, chose to use the AJA KonaLh card you’ve got, and select “AJAKona-to DV25” in the Log and Capture window’s ‘catpure settings’ you’ll also capture a nice little DV file. But THIS file is different from the other file…
I’m not asking- I’m Telling.
It IS different. WHY? HOW? dunno. Is it a Hardware- CODEC? I dunno. But if you take that file and put it in the standard DV timeline, it WILL have at least a dark green bar above it in the timeline.
And the same is true in reverse… if you put a standard DV file in a Kona-DV timline, it will indicate with at least a dark green bar (maybe worse) in the timline.
This is true, and unequivical and repeatable.
My interpretation is that this is a different kind of file. Maybe one field-ordered-one-horizontal-square-pixal different – but different, none-the-less.

NO BIG DEAL… I mean, we aren’t using DV codecs for our upcoming project…

But if is the case with the ubiquitous little DV25 – as it is with DVCPro50… this will almost CERTAINLY be the same with DVCproHD – or any THIRD-party 10bit HD codec being introduced to the mix, no?
I mean, I will bet HARD CASH that if Christopher sends me a bunch of media captured through the BM decklink, that the mechanism by with that media is encoded will have made that codec in it’s prefered image, and will therefore be different enough from the media I’ll have otherwise captured through my Kona as to cost me some real-time in my timeline. Or WORSE?

Please… tell me I’m wrong. and Proove it!

It should be said that the reason Christopher is asking about this is that I’m preparing to buy him a system with a AJA card in it, which he could then use to help do remote work on this project. He’s dutifully trying to argue the cost savings for the Decklink, and this codec issue is our last sticking point.

Thanks gang,

Praising the Cow –
Matt S.
Seattle