However, there are times when it’s just not convenient or practical to have an extra monitor involved. This came up recently in a thread in the Wirecast support forum. Someone wants to capture the screen of a number of Mac Mini’s in order to bring multiple Skype video calls into a streaming production. They run the Mac Mini’s headless, accessing the Mac desktops using a software screen sharing application.
Over the last couple of years I’ve been exploring the realm of webcams. Along the way I’ve encountered some confusing things involving the Microsoft LifeCam Studio. To be more specific, some have claimed that it’s capable of delivering 1080p video, while Microsoft’s own information suggests otherwise. My recent experiments using vMix have shed some light into the actual capabilities of this inexpensive little webcam. I thought them worth sharing.
“You cannot change the laws of physics, Captain.” – Montgomery Scott
Remember that a USB 2.0 connected webcam is bandwidth limited to delivering a maximum of 480 mbps (60 Mbytes/sec) to the host computer. Because of this fact, and given that the video frames from the webcam are uncompressed, the USB 2.0 link can only deliver 720p30.
My 60 day trial of vMix HD came to an end last week. My experience using vMix was so much better than recent experience with Wirecast that I decided to purchase a license.
That said, it wasn’t clear which version of vMix was appropriate. The trial license is the “Pro” version, which is all-bells-&-whistles enabled. The “Basic” version is free, but limited to SD resolution and the number of inputs that it can accept. The “Basic HD” version, just $60 USD, adds the ability to operate at resolutions up to 1920x1080p.
The company lists the limitation on the “Basic” editions to “4 Total Inputs” and 3 “Capture Inputs.” This terminology is not exactly obvious. So, I began by purchasing the Basic HD license to see if it would meet my needs.
For the past several weeks I’ve been experimenting with vMix HD, a software based tool for real-time video production on the desktop. I’ve been running the free 60 day trial version of vMix HD, which runs on Windows.
It now seems very likely that I will purchase a license for the Basic HD version, since it’s very capable and costs only $60.
To understand why I’m so very appreciative of vMix HD, it helps if you know what I’ve been using in this role for the past few years…Telestream’s Wirecast.
Vaddio has today announced that their RoboSHOT 12 camera is now shipping. This device is notable for supporting both streaming H.264 over IP and delivering uncompressed 1080p60 over a USB 3.0 interface. It also has an HDMI output. All three output methods are simultaneously live.
The various specifications of the RobotShot 12 are all top-of-the line. The camera is aimed at enterprise installations. It will surely find it’s way into video conference suites, surveillance/monitoring, and even tele-production.
Remember that to deliver 1080p video* any USB 2.0 attached webcam must compress the video using either MJPEG or H.264. Only by compressing the stream in-camera can it deliver the that resolution over the 480 Mbps USB 2.0 connection. Once the video is delivered cross the USB link, in many cases it must be decompressed to allow further manipulation before final delivery to it’s ultimate destination.
If my first approach was too much for my desktop, then perhaps I could split the workload between my desktop and my laptop. This presents a different set of problems, but ultimately makes the process more robust.
In this arrangement my laptop joins the JVB session. It’s running VoiceMeeter, Chrome & Bria. It provides the audio mix-minus feeds.