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Edit Review: Digital Rapids DRC-Stream 1500

Feb 1, 2007 12:00 PM, Reviewer: Jan Ozer

Hardware encoder handles a multitude of video formats.

Digital Rapids' DRC-Stream 1500 is a hardware encoder that converts live video and video files to MPEG-2 and web-friendly formats such as QuickTime, MPEG-4, and Windows Media 7, 8, and 9. The DRC-Stream 1500 provides great connectivity with standard-definition (SD) broadcast formats, excellent audio and video preprocessing, and competent software that's somewhat unpolished — at least for those coming from the NLE space.

It's ideal for those broadcasting live or capturing live events, but file-to-file batch encoding functions that didn't involve the unit's hardware preprocessing capabilities were below average for Windows Media encoding. Otherwise, the DRC-Stream 1500 produces excellent-quality compressed video.

The DRC-Stream 1500 supports one channel of SD input. The PCI board-based unit includes an audio/video breakout cable, or you can buy an optional rackmountable breakout box (with the same I/O capabilities) for $495. I/O includes two component inputs (three BNC each), two S-Video connectors (mini-DIN), and four composite connectors (BNC). There are also two SD SDI connectors and a DV connector on the PCI board.

Audio connectivity includes four XLR balanced audio connectors and four unbalanced RCA connectors, with embedded SDI audio and two XLR AES connectors. Digital Rapids supplied the board to us in a rackmountable Windows XP workstation driven by a single-processor 3.0Ghz Intel Xeon with hyper-threading. The CPU, rather than the board, performs most encoding functions, so you definitely should consider a faster home for your DRC-Stream 1500.

Software

There are three tiers of software available. The base-level Stream LE supports live encoding and file-based transcoding to Windows Media 7, 8, and 9; SMPTE VXC-1; QuickTime; RealNetwork's Helix 9 and 10; and MPEG-1 and MPEG-2 (to file only) encoding. None of the software versions can encode to Apple's H.264 or H.263 codecs, though other H.264 codecs are available. MPEG-4 was available, but it worked poorly in our tests.

StreamPro software is a $1,995 upgrade that includes RS-422 deck control and standalone logging. Interestingly, no version of Stream includes DV deck control, which certainly would have been helpful in my tests, and is ubiquitous in most other programs capable of video capture. StreamPro also supports batch encoding to multiple formats from a live capture stream, and it adds a software overlay feature that gets your logo on the video.

The Pro version offers watch folders for automated transcoding and FTP distribution, and email notification. It also supports formats such as the Sorenson Media ACE codec package, which includes Sorenson Video 3, SWF, and FLV output and MPEG-4 (AVC/H.264) formats. The Flash output is based on Sorenson Spark Pro, not On2 Technologies, so it offers less quality than the On2 upgrade discussed below.

StreamEnterprise, which costs an additional $2,995, includes all the features of StreamPro, plus remote control and management tools.

Additional codecs are available on an à la carte basis. I tested Flash 8 encoding based upon the On2 codec, which included variable-bit-rate and two-pass encoding. Though the module was in beta, it worked well, and upon its release it will cost $1,795 for both live encoding and encoding to files. I also tested an AVC encoder powered by the Nero Digital codec, which also appeared stable, and will cost $495 upon its release.

Workflow

DRC-Stream 1500's workflow is straight-forward, but frustrating. You start by selecting a codec profile, either from the canned profiles Digital Rapids supplies or from a custom profile you create. While Digital Rapids exposes all relevant encoding parameters to you, the company doesn't standardize the look and feel of the presets, as with Sorenson Squeeze and even the Adobe Media Encoder. Controls for scaling, de-interlacing, and other parameters are presented on different screens depending upon the codec, which can get confusing.

On the other hand, you can customize each encoding profile extensively; for example, you can add standardized file names, FTP or email destinations, and encryption information. However, Digital Rapids should consider a pre-encoding check function, because if any configuration information is wrong or missing, you won't know until after you start the encoding process.

For example, if there's a file with an identical name in the target archive folder, Stream won't let you know when you configure the profile (as Sorenson Squeeze does). Instead, once you begin the encoding session, it starts processing all files and then errors out with a cryptic error message that doesn't identify which profile is causing the problem. Conversely, in other tests, the software overwrote several files without warning, spoiling the results of several hours of encoding. It's definitely functional, but you have to be both precise and careful.

After choosing your profile(s), you select an input source. For file-based encodes, you then choose output file names and click the start button. For live encoding, you have many more options, including access to the DRC-Stream 1500's hardware-based video filtering, noise reduction, brightness and color adjustments, and audio EQ and dynamic range compression.

When encoding to multiple profiles, you have several options based on video source and the software version. For file-to-file encodes, you can batch-encode to multiple targets in StreamLE and StreamPro, which is called Queued mode. For live encodes to multiple files, both programs offer Concurrent mode, which attempts to encode to all selected profiles in realtime.

However, if you select too many encoding profiles for simultaneous encoding, the system will start dropping frames. On the test bed that Digital Rapids provided, this happened when the machine was encoding five simultaneous streams of 320×240 video (encoded to Windows Media, RealPlayer, QuickTime MPEG-4, Flash, and the Nero AVC codec), and two streams of 640×480 video (encoded to RealPlayer and Windows Media).

To avoid dropped frames, StreamPro offers a Batch mode that captures the file in realtime in an intermediate format that you can specify, which it then transcodes to all selected formats in non-realtime. This may not work if you're attempting to broadcast multiple streams in realtime, but it is an efficient way to produce multiple streams.

Similarly, if you are web-casting live in one format, and later want to produce others, you can render to your broadcast format and an intermediate file format in realtime, then later set up a batch encode of the intermediate file to any number of presets. Encoding times for all non-realtime encoders depends on processor speed.

Preprocessing

Hardware features such as de-interlacing, scaling and noise reduction (video), and compression and equalization (audio) are the special sauce. I found these functions particularly effective within the DRC-Stream 1500.

In high-motion video, the ability to customize de-interlacing based on clip content is absolutely critical to encoding quality. Digital Rapids' motion-adaptive de-interlacing produced excellent quality in my tests, as evidenced in Figure 1 on p. 49.

The center image shows the output of real-time encoding with the DRC-Stream 1500, which easily bests the output of Microsoft's Windows Media Encoder in live streaming. Digital Rapids' realtime encoding also produced better results than the non-realtime file-to-file based encoding.

In Figure 1, the image on the left was produced from the original source DV file. When we used Batch mode to recapture that file from the DV camera, then encoded to Windows Media format, the results matched the quality of the center image because we de-interlaced during capture, not during encoding.

Digital Rapids performed well in most other file-to-file encodings, particularly with the new On2-based Flash module, but to get the best out of the DRC-Stream 1500, you have to capture and de-interlace with the board.

I also tested the board's temporal noise reduction feature with concert footage I shot under poor lighting conditions, encoding to Windows Media with and without the filters. I noticed that the filter eliminated most of the mosquito-type artifacts in the video, but as always, the filtering produced some minor loss of detail.

The DRC-Stream 1500 also offers brightness, saturation, contrast, and hue adjustments, as well as color gain, color balance, and gamma. On the audio side, the board offers both dynamic range compression/expansion and equalization. Again, the controls were basic across the board.

To be fair, Digital Rapids sells most units to the broadcast space, and the software's look and feel is customized for engineers and others working in that market. If that includes you, you'll like Stream's controls just fine. You're probably used to color adjustments that provide only red and blue controls, and audio compression controls with just a couple of threshold sliders.

If you're spoiled by such cushy rides as Adobe Premiere Pro or Apple Soundtrack Pro, you'll probably find the controls primitive and lacking niceties such as on/off toggle switches, splitscreen previews, and multiple presets. These features become crucial for highly technical tasks such as equalization and audio compression. Given Digital Rapids' target market — and pricing, I'd have to guess that most users fall into the broadcast category. Otherwise, be forewarned.

Compressed quality

I'll live with a coarse interface if a compression product delivers great compressed quality, which the DCR-Stream 1500 bundle did, except for file-to-file encodes in Windows Media format. To test this, I compressed a 42-scene clip to four different formats — On2, Flash, Windows Media, RealPlayer, and Sorenson H.264 — and to two different parameters, 30fps 320×240 at 300kbps and 30fps 640×480 at 500kbps.

I compared these clips to those prepared in non-realtime in other available encoders — On2 Flix Pro, RealNetworks RealProducer, Sorenson Squeeze for H.264, and Windows Media. The compressed quality of all the clips the DCR-Stream 1500 produced was at least as good as the file-based encodes the other encoders produced — and the DRC-Stream 1500's Flash quality was particularly impressive.

The unit had trouble producing the target data rate accurately using QuickTime's MPEG-4 codec. I discovered errors in many of the Nero-encoded AVC files, but the Nero was still in beta during our tests. Otherwise, the DRC-Stream 1500 hit the data rate targets, proved very stable, and produced excellent-quality compressed video.

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bottomline

Company: Digital Rapids
Ontario, Canada; (905) 946-9666
www.digital-rapids.com

Product: DRC-Stream 1500

Assets: Great connectivity with SD broadcast formats, excellent audio and video preprocessing.

Caveats: Must capture and de-interlace with the board, software unpolished.

Demographic: Mainly geared for the broadcast market.

PRICE: $3,495 (DIRECT)

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© 2008 Penton Media, Inc.