Review: Telestream Episode Engine
In terms of the feature set, Episode lets you encode in either VP6-E or VP6-S formats, as well as single- and dual-pass VBR. You can also produce files with an alpha channel and choose between Best and Normal quality. I used the former for all quality and performance tests as described below.
The only sour note was encoding WMV files, which were of slightly lower quality than those produced by Carbon Coder and other tools, with some dropped frames at high-motion sequences. Nothing major, but when combined with the slow encoding times experienced below, Episode Engine would not be my first choice for Windows Media encoding.
Like the Mac and Windows versions of Episode, Engine doesn’t offer access to Windows Media SDK 11 tweaks, and since Engine runs exclusively on Macs, you can’t manually change the registry settings or use the Windows Media Power Toy to accomplish the same. I don’t know what percentage of Windows Media producers actually tweak the quality settings, but if you’re in that group, this deficit is significant. On the other hand, Engine can produce multiple-bitrate files, though I didn’t test this feature.
So Engine is very good quality in two of the most relevant formats and subpar on the third. Now we turn our attention to performance, where Episode’s results were also bipolar.
Performance
I tested Episode Engine on a 2.8 GHz Dual Processor, Quad-Core workstation with 8GB of RAM that Telestream supplied. In the other corner was Rhozet Carbon Coder running on a 3.33 GHz Dual Processor, Quad-Core HP xw8600 workstation running 64-bit Windows Vista with 16GB of RAM.
In my experience, processor speed almost always translates to linearly faster performance. Accordingly, because Carbon Coder was running on a workstation that was 19% faster, it should be 19% faster than Engine. To make the results more comparable, I adjusted Episode’s times down by 19% in all performance tables shown later.
SD Tests
Even without the adjustments, Engine performed very well in three of four tested output formats, besting Carbon Coder’s raw encoding time in DVD-compatible MPEG-2, H.264, and VP6. However, even after adjustment, Engine’s Windows Media encoding time was nearly triple that of Carbon Coder. You can see that in Table 1.
Note that in these single-file encoding trials, I used Episode Engine Pro’s Split-and-Stitch feature, which breaks the file into separate components, encodes them using separate "jobs," and then stitches the file back together at the end. In addition, note that Telestream lets you choose the number of simultaneous encoding jobs per rendering station, much like Carbon Coder. Though the manual recommends allowing the Engine to balance the number of jobs per encoder node, I used five simultaneous jobs upon the advice of my Telestream representative.
When encoding with Carbon Coder, I set the number of transcoding slots to either the maximum number of jobs in the encoding run or the number of processor cores, whichever was lower. For example, for single-file tests, I used one transcoding slot for maximum performance. When encoding 16 files for the next test, I set the number of transcoding slots to eight.
The next series of tests involved encoding 16 1-minute DV files to the VP6, H.264, and VC-1 formats. Here, I did not use Split-and-Stitch because it adds overhead, and my goal was completing the entire job, not individual files. Again, in two of three formats, Episode Engine didn’t disappoint. In particular, Episode Engine’s VP6 encoding speed was very impressive (Table 2).
