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Portable Field Transcoding with Small-Form-Factor Computers

What if you need to transcode files when you're in the field, in between production shoots or as a way to push digital dailies out to local clients? Recognizing the need for portability in such a scenario, we ran a number of tests to determine the ideal balance of size and speed, and we share those results here.

Hardware, aka Small Boxes

Since we were interested in assessing in-the-field transcoding, we wanted to test devices that were either fully portable and self-contained or at least could be mounted in a shallow, AV-style fly-away rack. We found both types to test, plus one that is small enough to mount directly behind a portable monitor via standard VESA mounting points.

For the fully portable version, we used a 2013 MacBook Air 13" (aka version MacBookAir 6.2) with 4 GB of RAM and a 256MB SSD (the APPLE SSD SD0256F unit that uses PCI-express connectors that are slightly newer and faster than standard M-SATA connectors.

We used this unit for two reasons First, we had a baseline for this MacBook Air against other Streaming Media Producer testing. Second, as the lightest 13” laptop around, we expect this to be more readily available than some of the heavier or bulkier laptops that are power by either the Macintosh or Windows operating systems 

For the two small boxes, each of which would require external keyboard, video, and mouse (KVM), we opted for very small form factor units that used outboard direct current (DC) power supplies, ranging from 12v to 19v inputs.

The idea here is to use a unit that could be powered by an external battery, in locations where there may be limited alternating current (AC) power available. Mind you, if there were loads of 120v (or 240v) power outlets around, you probably wouldn’t even consider one of these units to do the heavy lifting of transcoding. But we wanted to explore a workflow that could hold up just as well in a fly-pack or a remote broadcast van as it could in a traditional production studio.

Finally, when it came down to it, we also wanted to explore a build-versus-buy scenario. So we chose to build a unit from a variety of readily available parts, as well as to review a test unit that could readily be purchased from an Amazon or NewEgg.

For the build-your-own solution, we chose an Intel i3 processor that runs at 3.59 GHz—the i3 4130—which has an integrated HD4600 graphics processor. If you buy one of these off the shelf at your local Fry’s or via mail order, the Haswell-based i3-4130 should set you back about $135. We also used the Gigabyte GA-H87TN (thin mini ITX) which uses an M-SATA slot for its primary drive and also has two SO-DIMM RAM slots. We used this thin mini ITX motherboard to fit one of our design criteria: any unit needed to be able to fit in no more than one rack space (1RU or 1.75” height).

We chose an Inteset case to house the motherboard, RAM, M-SATA and something extra: a larger capacity data drive. With the Inteset (see full review here), which allows for the addition of a 2.5" SSD in its very tight confines while still allowing airflow, the physical unit is small enough that we could mount two of these units side by side, giving us the potential to install two transcoding devices in a standard 1RU width rack space.

For the almost-ready-to-go unit, we chose a very compact unit from Intel’s Next Unit of Computing (NUC) product line. It’s an i5-based unit called the NUC D54250WYK that comes in two flavors: one with space for a 2.5” HDD or SSD and one without. We couldn’t get Intel to provide the unit that houses the HDD/SSD—designated as a D54250WYKH—but they did provide the standard NUC, which has both a 7-pin SATA data and 15-pin SATA power connector. By leaving the base off the NUC when we put in the M-SATA primary drive and two low-voltage (1.35v) SO-DIMM RAM chips, we were able to replicate in functionality what the D54250WYKH provides.

(For a further review of these two units, comparing form factors and specifications, including why an i3 versus an i5, see our Small Box Field Transcoders review).