Review: Epiphan Pearl Production Switcher

With limited budget, no crew, and keynotes to stream at five conferences per year, upgrading my streaming setup has been a slow process for me. 我做了我的前几个流单相机使用直播广播. The Broadcaster, like the Teradek Cube (which it strongly resembles), 是一个方便的小盒子，通过HDMI连接到你的相机上，事实证明它非常容易设置和使用，对我来说非常可靠. The problem with my Broadcaster streams was the single-source setup, 这意味着我要么跟着演示者走，要么无视演示, capture both in the same shot (and neither very well), 或者在每次演示者推进幻灯片时，将摄像机转向屏幕.

Generally, the approach I followed was to show the presenter only, capture the slide deck separately, and get a quickly assembled, 合成版上线后尽快抹去所有记忆的单源版. Given my other production responsibilities at these conferences, and the glacial pace of video uploads at conference hotels, “越快越好”并不总是够快:2014年，一位主讲人在发表完主题演讲后，在网上看到单摄像头存档流媒体后告诉我, “I had 247 slides that were integral to my presentation! You’ve cost me a TED Talk!”

当时我不知道自己有这么大的能力，我发誓再也不让任何人错过TED演讲了. My next setup involved a couple of variations on the Epiphan AV.io视频采集设备，通过USB 3将DVI源连接到笔记本电脑.0 for switching or compositing in Telestream Wirecast. Since my cameras output HDMI and HD-SDI, 我通常通过演示者笔记本电脑的分割VGA信号来获取演示, 这种设置还需要几个小适配器将信号转换为DVI, 但当我没有将两个源连接到同一USB总线时，它通常工作得很好.

但在实际操作中，我断开和重新连接设备的次数越多，这种设置就越不可靠, 通过HDMI捕获并转换为DVI的摄像机信号在转换过程中似乎总是失去一些活力(Figure 1, below). But certainly, for a sub-$1000 solution (including the 2 AV.io units and the Wirecast Pro software), 事实证明，这个捆绑包是一种非常经济有效的方式，可以提供合格的实时交换流, and by and large, the critics were kind.

Figure 1. On the left, the image of a conference panel captured to SDHC in 50Mbps XAVC by the Sony PXW-X70; on the right, the same image (roughly) captured by the Epiphan AV.通过HDMI/DVI/USB到Wirecast Pro，并在Wirecast的未压缩设置下录制. Note the muted colors and lost sharpness in the image on the right. Click the image to see it at full size.

Enter the Epiphan Pearl

When an Epiphan representative saw me using the AV.去年11月，我在流媒体西部(Streaming Media West)上进行了双摄像头直播采访, he offered to loan me a review unit of the Epiphan Pearl (Figure 2, below), a full-featured production video switcher that takes two SDI, two HDMI, and two VGA inputs, 并允许用户切换和流式传输它们，以及记录ISO和程序馈送.

Figure 2. The Epiphan Pearl Production Video Switcher (MSRP $4875)

Jan Ozer did a 关于如何操作百家乐软件app最新版下载珍珠的有用教程 last September. Jan produced his tutorial within the friendly confines of his own home office; I wanted to test it out in the field at the Computers in Libraries 2016 conference, 面对无情的在线直播观众，以及至少一位未来能否参加TED演讲的知名主讲人(Figure 3, below).

Figure 3. Dave Snowden, CSO Cognitive Edge, 在2016年的计算机图书馆大会上发表了他的直播开幕主题演讲. The Pearl is streaming and recording. Click the image to see it at full size.

As Jan described in his tutorial, 你可以使用Pearl的内置触摸屏来切换媒体源, but the real action happens in the web interface, which you access by connecting the Pearl via Ethernet, going to System Status, noting the IP Address shown, and then typing the following into your browser: http://192.168.0.1/admin (or whatever address appears there plus /admin), then logging in as admin (no password required unless you set one).

Epiphan recommends connecting your laptop to the Pearl via wireless. At the event venue where I tested it, 我的内部A/V技术人员告诉我，防火墙会阻止我通过无线连接到为流设置的网络, 所以他不得不给我提供一个以太网交换机，这样我就可以通过硬线连接我的笔记本电脑和Pearl了. If you’re taking the Pearl on the road, I recommend bringing one along in case it isn’t readily available.