Review: Telestream Episode Engine
For VP6 and H.264 encoding, Telestream’s Episode Engine is fast and produces equal or better quality than most other streaming encoders. For those producing shiny optical discs, MPEG-2 performance and quality is also quite good. However, Windows Media producers should look elsewhere because Engine’s encoding speed is slow and the output quality is subpar.
Episode Engine runs only on Macs and consists of two applications and a configuration window that you access from the System Preferences window. You create all presets in a standard copy of Episode (which is included) and then monitor and create encoding jobs in the Episode Engine Admin panel.
Episode Engine comes in two versions: standard ($3,950) and pro ($8,450). Part of the difference relates to output formats, with the pro version providing support for high-end formats such as DNxHD, DVCProHD, XDCam HD, and GFX. The standard version can input most of these but can’t output them.
In addition, the pro version adds several features, such as Split-and-Stitch, a High Availability option, and SNMP support for monitoring the system remotely over a network. Briefly, Split-and-Stitch is a technique for very fast file rendering during which Episode Engine divides each file into multiple components, encodes each separately, and then stitches them back together (Figure 1).
Figure 1. The Episode Engine Admin panel encodes a job via Split-and-Stitch.
High Availability relates to running multiple Engines in a cluster. That is, you can combine multiple Engines into a cluster controlled by a "master" on one of the encoding stations. Once you go beyond five or six computers in a cluster, Telestream recommends that you use a dedicated master that doesn’t compress and doesn’t charge a license fee for that server.
The master allocates work throughout the encoding cluster, and if any encoding station fails, the master reallocates all work to the remaining servers. However, if the master fails, you’re out of luck. With the High Availability option, you get an extra master on a cluster, so if the first master fails, the second takes over.
Input/output format compatibility is a strength for both product versions. For example, though you can’t output all of these formats with the standard version, you can input GXF, MXF (including XDCam HD and MPEG-4 Proxy), AVID DNxHD, Blackmagic 8- and 10-bit, and many others, including all relevant SD formats. The only notable exception is AVCHD, which neither version can import.
On the output side, format support is equally vast, including all of the most relevant streaming formats—such as H.264, Windows Media, VP6 (S and E), and presets for relevant devices such as the iPod and iTunes—and most relevant broadcast formats, though you’ll need the pro version to output many of these formats. For more details, check out the Format Support document at www. telestream.net/episode-engine/literature.htm.
Speaking of presets, I’ve got a lot of minor issues with Episode’s settings in general. The language is overly complex and obscure to most users, and many settings are flat-out suboptimal. For example, most templates add letterboxes to convert SD source material to 4:3 output, which is seldom the desired technique, and key frame settings always opt for key frames at scene changes only, whereas most producers use periodic key frames and key frames at scene changes (Figure 2).
Figure 2. Templates can be set up in Episode, which uses somewhat obscure controls.
These flaws are much more serious in the Episode desktop product because the typical user may not be (and shouldn’t have to be) a compression expert and should be able to trust the company to choose the most usable settings. In the context of a product such as Episode Engine, which an experienced compressionist will set up and most users will interface with via watch folders, the problems aren’t nearly as significant.
This real-time hardware encoder offers strong output. If only it weren't beset by limitations and technical snafus.
Companies and Suppliers Mentioned