Review: Epiphan Pearl Production Switcher

Recording

Finally, if you want to record your switched program, click the Recording button. You have fewer choices here. You can choose to record internally, which makes the files you record available for download to your laptop via the web interface. You can also change the recording format, plus filesize and time limits, as shown in Figure 7 (below). But you can’t record your program feed at a higher (or lower) bitrate than you set for your stream.

Figure 7. Recording options

If you want to record an ISO, or isolated, feed—say, a clean feed the slide deck, or a composited version of the program instead of a switched one—you can create a new channel, create your layout and choose your source(s), set new encoding parameters, and start recording. This will allow you to record at a higher bitrate than you’ve set for your stream, although not with the program feed you’ve created by switching your show live. In terms of processor load, the Pearl seems to have no trouble streaming one feed and recording the same one or a different one simultaneously. At no time did it drop a stream I’d started, even with another recording going on, although I did find, at times, that I couldn’t get a stream to start, but with no real explanation of the single word “error” on the touchscreen.

One thing I did note with recording, in limited tests, was that the encoding quality seemed to be not as good as the encoding quality on the streams I delivered, with the same bitrate. I was dealing with fairly low-motion video, but the image on the recorded feed did degrade surprisingly when the speakers moved. When I wanted to trim and polish up a recorded stream for archival use, I found that the archived stream on Ustream, when downloaded at full quality, looked better than the version I recorded internally at the same biutrate on the Pearl. Encoding the live streams at 720p30 and 1.5Mbps with the Pearl delivered fine results for the presentations I was capturing, and the switches were smooth and easy to implement with the web interface. Below is an example of an archived stream of the Day 3 keynote.

Live streaming video by Ustream

One other issue I noted with the videos recorded internally on the Pearl (as well as the FLV archives downloaded from Ustream) was that they were encoded at variable frame rate. This meant I needed to convert them to constant frame rate in Handbrake before editing them in Premiere Pro to avoid audio sync issues. For more information on this fix (a common issue with certain encoding sources), see this tutorial.