By Oliver Peters, August 3, 2006
Blackmagic Design is one of a handful of innovators that has driven the desktop video revolution, making it possible to edit uncompressed standard definition-and now high definition-video on a Mac or Windows workstation.
Starting with the basic DeckLink card, which provided easy capture and output of uncompressed SDI, Blackmagic Design has expanded its family of products to cover SD, HD, Dual Link 4:4:4 and even 2K resolution film files. Blackmagic launched the DeckLink capture card in November 2002, making working with true 10-bit, uncompressed video on a Mac OS X system an affordable reality. IBC 2004 saw the launch of DeckLink Multibridge, a bidirectional analog converter and breakout box. At NAB 2004, Blackmagic launched DeckLink HD Pro, a 10-bit/12-bit Dual Link 4:4:4 and 4:2:2 video capture card for Mac OS X and Windows XP systems. DeckLink HD Pro was upgraded to PCI Express in February 2006, making it an uncompressed HD Dual Link 4:4:4 card that also handles 4:2:2 video and SD.
I recently tested two Blackmagic products-DeckLink HD Pro and Multibridge Extreme-on an Apple Power Mac G5 Quad workstation. When Apple introduced Power Mac G5 PowerPC-based workstations in quad and dual configurations in October 2005, it also migrated the bus architecture to PCI Express, sending all the vendors who had been making PCI and PCI-X cards scrambling. Blackmagic Design was one of the earliest to respond, quickly offering PCI Express versions of its popular cards.
PCI Express communicates in 250MB/s "data lanes," so cards and slots are defined by their bandwidth and are typically identified by the number of lanes they use (one, four, eight or 16 lanes). A four-lane PCI Express slot can transfer data equal to the 133MHz PCI-X slots in the previous generation of Power Mac G5s.
Design Diversity
Although part of the same overall family of products, DeckLink and Multibridge offer radically different designs. DeckLink cards are standard PCI-style cards that install inside the computer, plugging into one of the PCI Express slots. I tested DeckLink HD Pro, which is a digital I/O card. There are four SD/HD-SDI connectors for up to Dual Link 4:4:4 capture and output, as well as a multi-pin connector for a breakout cable. This breakout cable adds S/PDIF and AES digital audio I/O, VTR remote control, sync and analog monitor outputs. Other DeckLink products offer different combinations of I/O capabilities, including some that are SD-only or for use in analog rather than digital installations.
In contrast, Multibridge Extreme fulfills two roles: as a capture card and a standalone format converter. It uses a very small, L-shaped PCI Express card that does nothing but connect to the slot and provide a connector on the back of the computer. A tether cable connects the computer to the externally mounted Multibridge chassis that houses the Blackmagic Design electronics and serves as a breakout box with various analog and digital connectors. Connections include I/O for balanced analog audio and composite/component video, SD/HD-SDI (up to Dual Link 4:4:4) digital video with embedded audio, unbalanced analog audio monitoring, AES digital audio via a DB-25 connector, VTR remote control and a DVI-D (Dual Link) or HDMI video monitoring port. In addition to the tether, Multibridge Extreme offers a USB port to connect to the computer for control functions. When the tether is connected and the computer is powered up, Multibridge Extreme acts much like DeckLink and functions as an analog and digital capture and output card that can be used with applications including Final Cut Pro and After Effects.
Value Added
If you disconnect the tether or turn off the computer, Multibridge turns into a standalone format converter. Its functions and configuration can be controlled from any computer over USB as long as the Multibridge Utility application and the Blackmagic control panel are installed. In the converter mode, Multibridge Extreme handles a variety of A-to-D and D-to-A conversions within the NTSC, PAL and HD formats. It can also provide HD-to-SD downconversion with the usual aspect ratio choices (squeezed, 4:3 center, letterbox).
Each of these products comes with an installation CD that includes a number of extra utilities. In addition to drivers, codecs, control panel, Final Cut Pro setups and enablers, and the Multibridge Utility, you also get Deck Control (a separate capture utility), Disk Speed Test and FrameLink.
Deck Control allows you to capture video or output to a tape deck independent of any NLE software. Since the media files it stores to disk are QuickTime movies, you can use this utility in conjunction with any QuickTime-compliant compositing or editing software, such as Adobe After Effects or even the software version of Media 100 (Media 100 sw).
The FrameLink utility allows users to access any Windows AVI or Blackmagic uncompressed QuickTime file as a virtual volume of numbered DPX image files
. Mounting is instant, and frames can be opened and saved in any order. Any frames modified will be automatically written back into the movie when the frame is saved. The image files can be opened in any application that supports DPX. For example, FrameLink enables you to use an application like Photoshop for dirt and scratch removal.
Working with Video
I put both cards through their paces using Final Cut Pro. After the installation, you'll see plenty of new listings in the Easy Setups, view options and capture settings; these are the additional Blackmagic Design settings for various codecs, sizes and frame rates. Neither card actually accelerates effects. In the past, Blackmagic's codecs enabled some effects to operate in real time, but with the introduction of Apple's Dynamic RT engine in FCP 5 and Apple's newer, faster machines, there is actually no speed difference between designating Blackmagic or Apple to handle effects in Final Cut's settings. The video I captured looked great due to the high-quality internal processing of these cards. Even Blackmagic's preset for HD using the PhotoJPEG codec looked pretty good at full screen on the Sony LCD, making this a viable HD offline editing codec, but with a much smaller storage footprint than DVCPRO HD.
Both DeckLink HD Pro and Multibridge Extreme work in all the frame rate and format variations of SD (NTSC and PAL) and HD, including VariCam, Sony 24p and 3:2 pull-down removal and insertion. Opening the Blackmagic control panel in OS X's system preferences gives you total control over the cards. Blackmagic preferences include options for genlock timing, video output behavior with custom gamma curves to load or save LUTs, preserving blanking data or VANC (allowing three-line timecode, VITC, subtitle info or any other VANC data to be preserved during capture), and I/O configurations.
In addition to the ability to work with SD, 720 and 1080 formats and downconvert HD to SD on output, Multibridge Extreme can downconvert inbound HD signals and capture them as SD media. There is no upconversion option, but the cross-conversion utility allows 720p mastering to 1080i broadcast decks.
To get full-resolution conversions, you must be working in compatible frame-rate groups. For example, I tried to view some 720/23.98p video as downconverted NTSC. I thought there was a problem because the video lacked resolution; I later received this clarification from Blackmagic Design's support engineers: "You can use HDTV 1080/29.97i or 720/59.94p with 29.97fps NTSC. With 1080, we have an Easy Setup to go from 23.98 to 59.94, so you can downconvert 1080/23.98p, but for VariCam, just use the full frame rate." When you follow the instructions, the NTSC downconversion is a full-quality 720x486.
I was happy with the performance of this system-both the Apple workstation and the Blackmagic Design hardware. Multibridge Extreme and DeckLink HD Pro are high-quality products, but if you purchase Multibridge Extreme, make sure your reseller includes a couple of additional items. The AC adapter does not ship with a power cord. Also, there is no breakout cable harness for the DB-25 digital audio connector. If that's a requirement in your shop, you'll have to make an additional purchase. Admittedly, this may be nitpicking, because either card makes a great system addition for any editing professional.
Installation
This was one of the easiest products I've ever installed. It was literally only several pain-free minutes for each card. Simply open the computer, place the card in the slot, run the installer disk and get ready to edit.
My testing system was configured with an Apple 23-inch Cinema Display as the primary monitor and a Sony 23-inch LCD connected to Multibridge Extreme's DVI-D port for video monitoring. When I changed to the DeckLink HD Pro card, I used one of its SD/HD-SDI outputs for monitoring, connecting this same Sony LCD via a separate HD-SDI-to-DVI converter. In both cases, I have plenty of other monitoring options, including SDI and various analog configurations, but the Sony LCD gave me a high-quality HD image. Multibridge Extreme supports Dual Link DVI, so you can connect an Apple 30-inch Cinema Display to the DVI-D port and view 2K film files full screen at their native resolution.
Be careful of the order in which you do your installation. Multibridge Extreme definitely wants to be installed in the proper sequence, and make sure you reboot when you are instructed to do so. As with most of the Mac cards, the video output can be used as an extension of the desktop display, which is handy for viewing Photoshop graphics or even a PowerPoint presentation on a video monitor.
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