Portable Streaming Encoders Shrink and Grow

As companies launch small-form-factor encoders (SFFEs) for live streaming and (sometimes) recording, one of the biggest questions potential users ask is whether these devices offer the same encoding functionality as larger units.

The short answer is either “almost” or “yes,” depending on specific use cases. In this article, we’ll look at areas where four of these new SFFEs offer parity or enhanced features even while shrinking in size to fit in a messenger bag or even a pocket.

Let’s Connect

In almost any discussion of SFFEs, a number of questions about functionality arise centering on audio and video inputs and overall connectivity.

The miniaturization of these physical devices often means the companies have to decide which input and output connectors to accommodate. Given that some of the devices are smaller than an Apple TV, there’s only so much physical real estate on which to mount connectors.

The good news is that all of the units we reviewed have at least two input connectors, although the second input often pulls double duty with some other function for the SFFE.

Input

The alphabet soup of connectors ranges from CVBS to SDI to HDMI and analog inputs for both audio and video.

Let’s start with the old-school stuff: analog connectors. The presence of analog video inputs, also known as Composite Video Blanking Sync (CVBS), is a welcome addition for field gear, since there’s never a guarantee that the user won’t need to fall back to an analog-only acquisition device. There are also analog audio inputs, via a 1/8" (3.5mm) stereo connector.

On the flip side, digital input options often meet or exceed those on a single PCI Express card. For instance, the availability of Serial Digital Interface (SDI) on some of these SFFE units means they can handle both interlaced and progressive digital content.

One of the units we reviewed for this article capped out at 3G-SDI, which is a single HD-SDI link capable of handling 2.97 Gigabits per second (Gbps) of serial digital information. That means the units can capture 12-bit 1080p30 (progressive 1920x1080 at 30 frames per second) or 1080i60 (interlaced 1920x1080 at 60 fields per second) or 10-bit 4:2:2 10-bit 1080p60.

Every encoder we looked at has HDMI as a base digital input connector. In marketing terms, an HDMI input connector capable of 1080p60 could be either an HDMI 1.4 or HDMI 2.0, but since none of the units we reviewed allow 4K capture, it’s likely that these are HDMI 1.4 connectors.

Output

Almost every device we tested also has an HDMI output connector. Some need this connector for device setup, while others offer local monitoring through the HDMI connector. Audio can be output over the same HDMI connector and, in some cases, via the analog audio connectors.

But not every connector on the devices is functional. For instance, on the Epiphan Webcaster X2 (Figure 1, field-tested on Streaming Media Producer), the company’s site notes that “the AV, TF (SD card), and optical audio ports on Webcaster X2 are not used."

Figure 1. The Epiphan Webcaster X2 (front, back, and side)

On the network front, all of the devices have an Ethernet port for hard-wired connectivity. We recommend this approach, because Wi-Fi can be notoriously finicky when it comes to trying to use the same Wi-Fi access point to send the origin stream and monitor the same stream coming back into the venue.

The two smaller devices, the Epiphan Webcaster X2 and the not-yet-shipping (as of mid-July 2018) Magewell Ultra Stream HDMI (Figure 2, below), both have Wi-Fi connectivity. Only the Webcaster X2 has a reverse SMA connector, allowing an external antenna to boost Wi-Fi signal strength. The Ultra Stream also has Bluetooth connectivity, although it appears to be used only for initial setup and for monitoring the device during streaming.

Figure 2. The not-yet-shipping Magewell Ultra Stream HDMI (front and back)

USB

Each device also has at least one USB 2.0 port, which is required to hook up a keyboard, mouse, or combination of the two. Some devices have as many as three USB ports: one for a USB mouse, one for a keyboard, and a third for a variety of beta features.

While a few of the devices have Bluetooth, which some of these devices use for setup and monitoring, we suggest you follow this rule of thumb if you’re not intimately familiar with a specific SFFE: Carry a wireless mouse/keyboard with a USB dongle to connect for setup and other administrative functions. Connecting via a USB dongle allows both a mouse and keyboard to be used across a single USB connector, freeing up any additional USB ports for recording or other tasks, as well as avoiding any pairing or signal interference with Bluetooth.

This is especially helpful with the second generation of SFFE units, which eliminate all but one USB connector and use a microSD card for recording.