Review: ViewCast Niagara 2120 Live Encoder

ViewCast's Niagara 2120 is a multiple stream, live H.264 encoding appliance that produced very good quality compared to software-based solutions like Telestream's Wirecast. The sub-5 pound unit is very portable, and can be configured in the home office for one-touch use in the field, and you can log-on remotely to resolve any issues experienced by your on-location streaming crew. With a competitive price of $3,995, the Niagara 2120 should be on the short list of any company or service bureau producing high volumes of on-location live H.264 webcasts.

Hardware Configuration

The Niagara 2120 is a Windows XP computer in a box, driven by a 2.2 GHz Intel Core 2 Duo CPU, with 1 GB of RAM and about 110 GB of free disk space. The unit is about the size of a healthy college textbook; 7.5"x11.5"x1.75," and is is cooled by a noisy fan, so you should locate the box as far from the center of action as possible.

You can attach keyboard and monitor to configure the 2120 directly, or connect the unit to your LAN and configure it from any node on the network. The 2120 accepts SD video only, up to a maximum of 480i, and pushed out a maximum video resolution of 720x480. Video inputs include composite, S-Video and component,
with either balanced audio input via XLR or unbalanced audio via RCA connectors. Using my Canon XH A1 HDV camcorder, I connected via component video and unbalanced audio, setting the component output on the camera to 480i.
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Figure 1. The front end of the Niagara 2120. The blue V tells you that you're streaming video, while the volume meters help ensure good audio levels.

Most connectors are on the back of the unit, with the front containing the power switch, start and stop streaming buttons, a V LED that indicates when the unit is streaming video, and audio meters.

Software

At a high level, you operate the Niagara 2120 via encoder settings that you can combine into groups. If you're encoding via the browser-based GUI, you can start any encoder or group by clicking the red button on the right of the menu. This is how most producers will use the unit in their home offices.

 

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Figure 2. Click the red button on the right to start encoding.

If you're sending the unit out on location with non-technical users sans monitor or keyboard, you designate the desired group of encoding parameters as "active" in the software. When your remote user presses the Stream button on the front of the unit, it executes this active group. If you want only a single stream, you would build a group containing just a single setting, and make that the active group.

Once plugged into the remote network, the unit will acquire an IP address from the network. So long as it's not located behind some firewall, a member of the IT staff should be able to log-in from the home office via that IP address and diagnose any issues encountered by the remote streaming team.

You create the settings in a
screen that contains just the basics, including input, output and audio and video bitrate.

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Figure 3. The basic audio and video settings.

Click the Advanced Settings text and you get three pages of exceptionally detailed and challenging to configure H.264 encoding parameters that will totally intimidate most users, but delight serious compressionists. For example, with profile, where you typically choose either baseline, main and high, you have to input a number instead, and the number options aren't designated in the manual. Viewcast should consider striking a balance, for example simplifying the most common controls, like profile, entropy encoding, b-frame interval and the like, and presenting more advanced controls as they currently are, though with better documentation. No biggie, though, since most users will likely accept the default H.264-related settings, and not even glance at the advanced options.

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Figure 4. The Advanced H.264 encoding options screen.

The encoder screen also contains Streaming Settings, where you point the encoded file towards a streaming server for distribution. There are also multiple options for deinterlacing, including Inverse Telecine and Motion Adaptive deinterlacing. Just below the Streaming Settings (and not shown in the figure) is the option to archive the streamed file to hard disk.

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Figure 5. Setting streaming settings and deinterlace options.

Performance

When analyzing the performance of the Niagara 2120, I considered multiple factors, including CPU efficiency when encoding single and multiple streams, data rate accuracy and stream quality. The 2120 performed quite well in most, but not all, factors.

CPU efficiency was quite good, as shown in Figure 6, where I was encoding two streams simultaneously; 320x240@300 kbps and 480x360@400. On the extreme right edge of the fiture, just above Create New Group, you can see that CPU usage was at 48%, which was plenty of overhead, as ViewCast recommends that you don't exceed 80%.

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Figure 6. CPU efficiency when encoding multiple streams.

I also tried dual file encoding using the 640x480@700 and 320x240@300 kbps presets, which pushed CPU utilization up to 63 - 79%, cutting it close, but still under the limit. The Niagara jumped to 100% when I tried to encode three streams at 640x480, 480x360 and 320x240, but if you configure the streams small enough, you may be able to push three through the system.

In addition to efficiency, you also want your real time encoder to be robust. To test this, I pointed the camera towards my work area, and filmed 3 hours of a typical work day in 640x480@700 kbps and 480x360@400 kbps, storing the files to disk. The Niagara 2100 produced the files without a hiccup, indicating suitability for long form productions.

The only encoding chore where the Niagara disappointed was in data rate adherence, where the results were spotty. If I set the data rate at 600 kbps, the data rate output was very close to that figure, but when I bumped the target to 700 kbps, the Niagara pushed out 800 kbps. If you're streaming from a location with limited outbound bandwidth, you should produce some files to disk under live conditions, and check their data rate to make sure it's at or below your target. That way, when you do go live, you shouldn't have to worry about outbound data spikes. One benefit of Niagara's being an XP box was that I could download and run utility MediaInfo right from the Niagara unit, which simplified my data rate testing.

Video Quality - the Hardware Advantage

Given that Telestream Wirecast costs about $3,500 less than the Niagara, and can produce a similarly configured H.264 stream in real time, I was eager to see how the quality compared. On low motion sequences, the Niagara clip showed a touch of graininess, but also much more retained detail. You can compare the streams yourself at http://www.doceo.com/niagara/Main.html. There is no audio in either clip, and the Telestream file will have to fully download before playing.

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Figure 7. Low motion clips were close, though Niagara showed lots more detail.


On the higher motion shots, the difference was even more striking. For both quality and detail, the hardware solution was clearly superior, albeit at nearly eight times the price.

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Figure 8. The quality difference was striking in this high motion, high detail frame.

Note that I wasn't singling out Telestream; I tried to encode files using the Adobe Flash Media Encoder, but although the files streamed fine, the files stored to disk wouldn't play or load in any of my analysis software. So Wirecast was the only real time encoder, software or hardware, that I could get my hands upon. To be fair, between the price differential, and the titling and switching options that Niagara doesn't offer, the trade-off between the two products is less than the quality difference would indicate.

If quality is your number one consideration, however, the Niagara clearly shines. Overall, the unit was impressive; very good CPU efficiency for single and multiple streams, good ease of use and very high quality live video.


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