An HDMI primer

Electronics makers introduced the High Definition Multimedia Interface (HDMI) just a few years ago with the advent of consumer digital HDTVs. HDMI carries picture and audio on a single cable, and can handle 10-bit video and up to eight channels of audio. Think of it as DVI with multichannel digital audio on a single, small, 19-pin latchless connector.

Employed in consumer HD equipment such as HDTVs, cable set-top boxes, and DVD players, HDMI also has started turning up on consumer and prosumer camcorders, including the Sony HVR-V1U and HC3, Panasonic HDC-DX1, and JVC GZ-HD7, among others. It offers a better quality image than the usual component analog connections without the considerable expense of using a professional HD-SDI interface.

HDMI ports output a decompressed version of compressed footage, in the same way you could save a JPEG as a Photoshop PSD file-delivering the same reduced quality, but taking up more space. If your NLE doesn’t support a given format-say, the new AVCHD format that some cameras equipped with HDMI ports use-you can record the camera’s video output over HDMI into your NLE.

If your NLE supports a format that has issues-like HDV, with its long, slow render times-you can transcode it on the fly by ingesting to a compressed format like DVCPRO HD. While doing this will speed up your workflow, and leave you with CPU cycles to spare for handling more real-time effects, you’ll lose some image detail in the process. Why? The 1440 x 1080 source (HDV’s native size) is upconverted to 1920 x 1080, scaled down to 1280 x 1080 when it’s converted to DVCPRO HD, and then recompressed using a different compression style than it was originally recorded with, causing further quality loss.

If your camera doesn’t have HDMI out-or you can’t or don’t want to use the camera’s native codec-you can use the DeckLink HD Studio card’s component analog inputs to capture NTSC, PAL, 720p, or 1080i footage either uncompressed or transcoded to whatever codec your NLE supports with real-time transcoding. Final Cut Pro, for example, can capture and transcode to DV, DVCPRO50 and HD, PhotoJPEG, IMX, and uncompressed 8-bit or 10-bit. For best quality results, I recommend the latter if you’re capturing via the analog inputs-and if your 8-bit source becomes softened or fuzzy by visiting the analog realm, you should oversample (in bit depth) to best capture the source’s detail.

Installation and setup

Installation of the DeckLink HD Studio card is not nearly as easy as it should be. Unfortunately, the installation instructions that I received were generic. If you remember that the card is PCIe-not PCI-X-you should be able to figure out how to get it into your machine. But the installation instructions never mention the DeckLink HD Studio card specifically, nor do they mention HDMI. You’re on your own when it comes to figuring out which of the two HDMI ports is the input and which is the output. I had to call tech support to get the answer-there’s no indication on the hardware itself. Stamping that info on the hardware or affixing labels would be a big help. At least tech support was prompt and friendly: they guided me to a difficult-to-find web page (http://blackmagic-design.com/products/connections/index.asp?prodID=20) that has things clearly diagrammed.

The card works in the last-generation G5 Macs and in any Mac Pro, but it’s not backwards compatible with PCI or PCI-X machines. The card also will work with Adobe Premiere Pro on the Windows side, but being Mac and FCP-centric, I wasn’t able to test that configuration.

In addition to installing FCP drivers and presets, DeckLink HD Studio’s setup also installs goodies for Adobe After Effects and Photoshop, as well as the ability to output video from the card using any app that supports the QuickTime architecture for previewing video. The setup includes additional utilities for simple capture and output, disk testing, DPX conversion, and Blackmagic On Air 2.0 (which is quite handy).

Performance

How well does it work? To test the various inputs, I tested various frame rates and sizes over the HDMI and component analog inputs, and compared the results to native-recorded HDV from tape and high-quality uncompressed HD-SDI capture. Here are the results.

HDMI capture: Technically, HDMI has very good quality-it is full-raster (the full 1920 pixels wide for a 1080i signal), and this card can do 10 bits per channel. Since it is an uncompressed digital interconnect, it is a perfectly faithful rendition of what you are feeding down the wire. As a practical matter, however, that may not help you too much-current HDMI-equipped cameras aren’t that great, and you’re simply passing on the sins of those cameras’ recorded media.

Capturing over HDMI uncompressed looks just like HDV, albeit with much larger files. Capturing HDV transcoded to DVCPRO HD over HDMI doesn’t look as good as native HDV (but it does give you better real-time editing performance). The only time HDMI will improve the results over native codecs is if you record uncompressed live while shooting-which is inconvenient to say the least, but you will ditch compression artifacts and get a slightly sharper image.

Most HDMI-enabled cameras have less than great lenses and exposure latitude, not to mention noisy imagers. So while the signal over HDMI is uncompressed, uncompressed mediocrity remains mediocre. Still, for unsupported formats like AVCHD, HDMI is your best option-or for greenscreen shoots, capturing HDV and transcoding to DVCPRO HD over HDMI could be well worth doing. Note you only get broadcast frame rates, though-no 24p.

Analog capture: Because you’re converting your image from digital (AVCHD or HDV) to analog and then back to digital, the image quality, especially the sharpness of the image, takes a very noticeable hit, while picking up some noise. Analog capture does work, so it is viable, but it wouldn’t be my first choice. Because you’re using an analog input, you also need to calibrate your card’s setup-putting up color bars and tweaking the Blackmagic PrefPane Video Input will ensure best results. I had to tweak mine a fair bit to line up the targets on the scope. You can transcode on the fly during capture the same way you did with HDMI to other codecs if you need to as well.

In short, here are your image quality options, from best to worst:

First: Live footage captured over HDMI to uncompressed while shooting (inconvenient and awkward).

Second: Native HDV.

Third: Live footage captured over HDMI transcoded on the fly to DVCPRO HD (again, awkward/inconvenient to do).

Fourth: Taped HDV transcoded to DVCPRO HD on the fly over HDMI.

Fifth: Taped HDV transcoded to DVCPRO HD on the fly over component analog.

What’s all this tell us? Keeping your workflow all-digital (HDMI) is preferable to dipping down to analog (component)-and the closer to uncompressed source you can get, the better the resulting image. So while it is nice to have HDMI and component capturing options with this card, they’re not necessarily your best quality options.

Monitoring

If you’re on a tight budget, the HDMI ports really pay off. You can attach an inexpensive HDMI-based HDTV for monitoring signals from the HD Studio card, while still connecting to an analog CRT with component connections at the same time. Though pros who do serious color-correction work won’t be satisfied with one, a large, client-impressing HDTV isn’t that expensive. The all-digital HDMI signal path looks sharp and good, and 24p timelines get converted to 60p or 60i on output as needed by FCP and the card. But for critical color correction work, get a broadcast quality professional CRT and connect it via the component analog connections.

Conclusion

DeckLink HD Studio isn’t suited for bringing in footage from or outputting to professional tape decks with HD-SDI inputs. So if you’re an HDCAM, D-5, or HDCAM SR user, this isn’t the card for you. While some of these decks will let you use analog inputs or outputs, the quality hit (and yes, it’s a big difference) would defeat the purpose of employing these high-end decks in the first place. However, ignoring that small upper end of the market, the card is well suited to FireWire-based ingest (using the port on your computer or on another card, as the DeckLink HD Studio card doesn’t have one), or workflows using HDMI or analog outputs on a camera to bring in footage, so long as it’s using broadcast standards. So if you’re working with DV or DVCAM, DVCPRO, DVCPRO50, DVCPRO HD, HDV, AVCHD, XDCAM, or XDCAM HD, this card is an entirely viable option for you to ingest and monitor with if you don’t require HD-SDI for mastering back out to tape.

Because DeckLink HD Studio costs as much as the Blackmagic DeckLink HD Extreme card, consider whether you need HD-SDI input or output. If you never need HD-SDI I/O because you use FireWire-based ingest, if you want to transcode HDV or AVCHD to uncompressed (for finishing and online work) or to DVCPRO HD (for faster renders and greater real-time performance than HDV), or if you want to monitor on an inexpensive HDTV, then the Blackmagic DeckLink HD Studio is the right card for you.

The GeForce 8 series offers a complete family of graphic cards ready to meet the unique needs of their users. The series features a unified DirectX 10 Shader Model 4.0 & Open GL 2.0 architecture for stunning 3-dimensional graphics and lifelike texture rendering. With 10-bit per channel output, the 8 series produces higher fidelity color and separation. The cards support SLI for multi-card rendering and NVIDIA’s PureVideo HD.

The 8400GS is designed for those who need more graphics processing than their CPU can handle. It processes video data with 16 stream processors fed by 512MB of 64-bit double-pumping GDDR2 SDRAM running at 532MHz to deliver 1920 x 1200 resolution. The core clock runs at 459Mhz and the 400MHz RAMDAC lets you use two monitors for increased workflow or wide-screen gaming.

Video can be streamed via S-Video, Composite or HDTV outputs. An onboard fan aids both board cooling and case airflow so you’re ready to go right out of the box. Choose the NVIDIA GeForce 8400GS card for stellar graphics and versatile video output at a price that won’t break the bank.

Product Details
Amazon Sales Rank: #1691 in Consumer Electronics
Brand: EVGA
Model: 512-P2-N738-LR
Dimensions: 1.60″ h x 7.40″ w x 11.00″ l, 3.00 pounds
Features
PCI-Express video card with 512 MB of 64 bit DDR2 memory
Full support for Microsoft DirectX 10.0 Shader Model 4.0
True 128-bit floating point high dynamic-range (HDR) lighting
PCI-Express and Open GL 2.0 support
2 dual-link DVI outputs support 2 2560 x 1600 resolution displays

Amazon.com Product Description
The eVGA 512-P2-N738-LR NVIDIA e-GeForce 8400GS 512 MB PCI-E Graphics Card features 512 MB of 128 bit DDR2 memory with a 4.26 GB-per-second memory bandwidth. Based on NVIDIA unified architecture with GigaThread technology, the card offers full Microsoft DirectX 10 Shader Model 4.0 support, 16x full-screen anti-aliasing, and true 128-bit floating point high dynamic-range (HDR) lighting, allowing you to experience the latest gaming effects without compromising performance.

Other features include PCI-Express support, Open GL 2.0 support, and HDTV support. It includes a DVI output and supports up to 1920×1200 resolution. This card was built for Microsoft Vista. It measures 2.5-by-6.5 inches (HxL).

22″ widescreen displays perfectly w/ this card
Bought this to fix flickering and distortion on new 22″ Soyo monitor. Previous video setup didn’t offer native resolution setting of 1680×1050, 60hz. The 8400gs card does, and that made all the difference. Setup was smooth, documentation good. Only downside is some extra fan noise since card has its own fan. (Note–before installing, I used Windows Device Manager to disable my old CPU-integrated video adapter.)

eVGA makes great cards
The eVGA GeForce 8400 GS is a nice little card. I used it in a Linux system and had no problem with it. My experience with eVGA graphics cards has always been excellent - great performance, great price, great warranty. They’re always the first ones I look to when getting a new card.

157 million transistors, a 90nm fabrication process, 12 pixel shader processors, 5 vertex shader processors, 512 MB of 128-bit, 4-channel GDDR3 memory. Sound good? View larger.
Performance, by the Numbers
Under the hood you’ll find 157 million transistors on a 90nm fabrication process; 12 pixel shader processors; 5 vertex shader processors; 512 MB of 128-bit, 4-channel GDDR3 memory; and an external bridge chip that supports AGP 4x and 8x interfaces. The card also features a ring bus memory controller for 256-bit memory reads, which is optimized for performance at high-display resolutions.

The Radeon X1600 also supports impressive shader performance with Shader Model 3.0–now you can see incredible details never before visible. The X1600 also allows you to experience simultaneous high dynamic range rendering and advanced adaptive anti-aliasing for incredible enhancements to lighting contour and color details. Take the edge off of jagged wires and strands of hair, while experiencing photorealistic lighting.

Home Theater Compatibility
ATI’s Avivo technology, which is integrated into the X1600, promises a high-definition visual experience, delivering sharper photos, smoother video, true-to-life image representation, and universal display connectivity for driving HD displays. High-definition images come to life with remarkable clarity and color. Plus, Avivo’s universal connectivity allows you to create your ideal display setup. The technology also offers accelerated MPEG-2, MPEG-4, DivX, WMV9, VC-1, and H.264 decoding, encoding, and transcoding. In the display support department you get an integrated dual-link DVI connector, plus compliance with HDMI and HDCP connections. There’s even a component output for direct connections to HDTV displays.

Product Details
Amazon Sales Rank: #26829 in Consumer Electronics
Brand: ATI
Model: 100-437510
Dimensions: 3.00″ h x 9.50″ w x 11.00″ l, 3.00 pounds
Features
157 million transistors on 90nm fabrication process
Dual-link DVI
Twelve pixel shader processors
Five vertex shader processors
128-bit 4-channel DDR/DDR2/GDDR3 memory interface

Fast and affordable
The price on this product was well below what I was expecting. The order went smooth and the product was at my door within days. It’s really helped with the graphics on my 5 month old PC. I couldn’t be happier.

Great product, prompt delivery
Delivery was prompt, product arrived in excellent condition. Will definitely give the vendor future business!