Review: Kulabyte XStream Live 2.1
As you can see in Figure 3, producing two streams on the HP xw4600 workstation consumed 78% of the CPU, which is high but still within a comfortable range. I tried encoding one 720p stream with one smaller stream, but CPU utilization kept pushing the 100% mark. Again, your results will vary according to the power of the host CPU. And remember, for four simultaneous streams, count on needing an eight-core system.
Figure 4. Monitoring the live stream from the Flash server
I tested the Kulabyte server with some footage from a local square dance. I shot the event with the Panasonic HMC-150, which captures in full resolution, full data rate AVCHD. To test the encoder, I input the video via HDMI, pushing the stream to the Flash Media Server and an archive file. I was able to watch and monitor the stream from the Flash Media Server for the full 60-minute test (Figure 4). I can’t say it was the most intriguing hour I’ve ever spent, but out in the country where I live, honing your square-dancing skills is always a good idea—gives you something to talk about at the next hog slop.
More to the point, the stream played without interruption throughout the test. To assess the quality of the output, I encoded the AVCHD source files from the square dance to the 960x540 parameters using the Adobe Media Encoder and compared the two streams (Figure 5).
Figure 5. Monitoring the live stream from the Flash server.
Encoding is a very search-intensive process as the encoder works to find interframe redundancies that help improve compressed quality. Given that the Adobe Media Encoder produced the video files in roughly 2x real time, I had expected the Adobe stream to look significantly better than the real-time Kulabyte stream. Although there were some quality differences, they were very minor and certainly wouldn’t be noticed by a casual viewer. Overall, though ease of use could (and will) be improved, from a performance and quality standpoint, the Kulabyte encoder performed exceedingly well.
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The encoding giant partners with Kulabyte to create Squeeze Live, a bandwidth-friendly solution for live events.
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