Priority Alert

The Priority Alert system is built-in to the DiscoverVideo media systems.  Priority Alert delivers live or recorded video, text messages, or web pages to viewers desktops and cell phones without the viewer needing to take any action.  It simultaneously displays your alert on selected Digital Signage displays.

This is seriously cool.

Most of us spend our day facing a computer screen, walking the halls of a building, or at least carrying a cell phone.  The best way to notify people in an emergency is to show the information where they are looking.  People may not read email in time or at all or they may be away from their desks. Phone calls take time and often go unanswered.  And audio public address systems may not be available, may not reach everywhere, or may be inappropriate for the situation.

Let’s explore some use cases, starting with the most obvious:


Educational organizations, companies, and government agencies and departments today need to alert everyone in a security emergency.  The information people need may be fluid and unique to the situation.  During such an emergency, an authority can press a button.  The button may be a web page button, a physical “panic button”, or an existing 3rd part alarm system triggered by existing procedures.  When the alert is initiated, one, some, or all computer screens show a live video of an authority giving instructions.  Or showing a prerecorded video, or a color-coded large text message.  If the organizations has a special web page that give information, that may automatically appear.

At the same time, one, some, or all Digital Signage displays switch to the same announcement.

To be sure the alert is widely distributed, groups of people can receive a text message on their cell phone.  The text message headlines the alert and displays the video, text, or web page, the same as the desktop alerts and the Digital Signage displays.

When the alert ends, desktops automatically close the alert and Digital Signage displays return to their normal operation.

Morning Announcements

It can be frustrating when announcements don’t reach the intended audience.  A teacher in a classroom may be distracted with other duties at the appointed hour and can’t “click” on a video to show the class.  A busy employee may miss the CEO “Town Hall Meeting” despite email alerts and calendar invites.

When a live video event is scheduled to begin at 7:30 AM, it might not start until 7:32 AM and everyone would prefer to just start to watch when it actually begins, right?

Just create a Priority Alert for only your intended audience.  Traders can receive the “Morning Call” broadcast while the IT staff does not.  The middle school gets their “Morning Announcement” and the High School gets theirs.

Weather Emergencies

If there is an immediate weather emergency, such as a tornado, alert everyone to seek shelter.  Provide a recorded video reminding them what to do.

Early closing because of snow or other events is displayed everywhere.

Fire / Drills

Fire alarm systems are pretty loud, and flashing strobe lights help to inform those who may not hear it. Augment your alarms with Priority Alert and you can also provide specific instructions like “Use the South Exit, not the North Exit”.


Priority Alert is well suited for “Paging” uses.  Simply send a text alert “Mr. Jones please call the office” to  desktops and Digital Signage displays.

Special Events

  • Inspire your sales team with instant, fun notifications of wins.
  • Broadcast local sporting events and alert interested parties
  • Many more uses…


The Priority Alert video system uses multiple protocols. It can scale to deliver live video to any number of viewers via IP multicast.  If multicast is not available, the system automatically rolls over to three different unicast protocols. This gives you the best chance of reaching your audience in virtually all circumstances.  The network load is very small and there is minimum dialog before, during, and after an alert is active.

Easy To Deploy

We’ve taken special care to make it easy to deploy.  Users can install Priority Alert on their computers.  The desktop .msi installer can be pushed to desktops and everything is setup automatically so the user need do nothing. You can even prevent the user from making any changes.

Easy To Trigger

In an emergency, you don’t want to spend time logging in to a system and navigating to trigger button.  You can trigger an alert several ways:

  • From a logged-in web page
  • From a desktop App single button press
  • From a desktop App and a USB physical button or foot switch
  • From a Web API
  • From a dry-contact closure


Priority Alert has been completely redesigned and improved in our DEVOS system (V4.8 and above).  We are excited about it and all of the new features.  The DiscoverVideo Priority Alert system has been serving our customers for about a decade, and it is now better than ever.




It’s Not Just An Encoder

For years, I would haul around a video switcher, audio mixer, streaming encoder, power strips, cameras and microphones to capture and stream events. One camera typically aimed at the speaker, one camera focused on the audience, another camera capturing a wide shot of the event, and the fourth video feed would be the presenter’s laptop or presentation. These four video feeds get connected to my video switcher which has frame buffers to allow for hitless switching. The audio feeds from the cameras, plus the feed from the PA system get connected to my audio mixer. The output of the video switch (“Production Board”), and the output of my audio mixer, goes to my encoder which can both stream and record.

As the event unfolds, I select cameras. The switcher has a A/B side-by-side effect and a Picture-in-Picture effect. I use these effects when the presenter starts his talk and uses PowerPoint. To keep it interesting, I make quick cuts to the audience from time-to-time, and cuts to the wide shot of the stage.

The audio is from the speaker’s microphone, but I mix in the audience applauce from a camera microphone when appropriate.

There is a handheld microphone that is passed to the audience to ask questions. I cut to the audience camera as they speak, and if the presenter referrs to a slide again, I cut to that.

If my cuts are not right for some reason, I know I can grab the files from each camera and later edit the production, as long as I remembered to start the recording in each camera too.

A Better Way

There are all-in-one audio/video switchers that have a built-in encoder, but they are rather expensive and complex. What I really want is an encoder with built-in mixing and switching, not a switcher with a built-in encoder. I want to stream and record each video independently, and also stream and record the produced output. I want a simple built-in audio mixer, and some simple buttons to switch feeds and to produce desired Picture-in-Picture effects. Oh, and I want it to fit in my coat pocket.

Spider is exactly what I want. Four HDMI video inputs each with optional analog input. Each input has its own independent encoder, so not only can I stream each input but I can also record each input in .mp4, .ts, .mov, or even .avi format. Each live stream can be a push to Arcus, DEVOS, YouTube, Facebook, or virtually any streaming service. Each input could also be delivered on the network as a HLS, RTSP, or UDP/Multicast stream. Each one. Cool! If someone wants to monitor just the audience camera backstage on their cell phone, they can.

The selected video, or the Picture-in-Picture, is encoded by a fifth buit-in encoder which can also stream and record the same as each of the inputs. Built-in text and graphics overlay for each input and for the program output too.

One HDMI output provides a quad view of the four inputs so I know which camera to switch to, and one HDMI output shows the production feed that I’m streaming and recording.

I don’t need to worry about disk space for recording because it is done via USB 3.0 to my portable drive. A 2TB drive costs under $200 now, and I have several.

I can run the whole show using only the buttons, or I can plug in keyboard/mouse and configure and control it from the monitor. Or I use the Spider’s web page user interface from my laptop or tablet.

The Spider is amazing, and you can learn more about it here.


Back in 1997, I set out to build the world’s first video appliance. Together with an incredible team, we produced the “video brick” — a stand-alone appliance that compressed and streamed live audio/video. We built a company around the notion of simplicity and plug-and-play reliable appliances, and it really took off. No “blue screen of death”, no virus threats, simple and reliable, but packed with advanced features most customers would grow into. Streaming locally via multicast and on the public Interent using Windows Media or MPEG-4, the appliances became a staple of the industry.

With success comes competition. The leader always has arrows in their back. As expected, low cost cheap encoders begain to appear. In Network Cameras, in software, and in under $1000 boxes. Some very good, some just terrible.

When YouTube and others begain to support live streaming, consumer volumes became possible and even cheaper encoders begain to appear. Free Open Source software encoders became popular and new uses, such as streaming video games, became not only possible but formed a whole new industry. Much of the attention shifted to software encoding giving the user the illustion of “free” because they don’t count the cost of the computer required to run the software. Quite sensible when you stream events from your computer, but perhaps not so sensible for more constant and dedicated uses. And while there are great systems based on a PC with special PCIe cards, nothing beats a fully embedded dedicated system.

Dedicated appliance encoders are great, and there are several good ones. But I am confident you will find the Spider to be the best choice for simplicity, quality, flexibility, and most importantly, for value.


Rich Mavrogeanes


There are two categories of encoders: File Encoders and Streaming Encoders

File Encoders

File Encoders seek to make a compressed video file that can be delivered from physical media or over a network.  A File Encoder uses a uncompressed video file as an input and produces a compressed video file.  When a file is processed, File Encoders can analyze the entire input file, frame-by-frame, and use multi-pass techniques to produce an output that is highly optimized.  They can use time to apply various pre-processing “tricks” (such as noise reduction, color optimization, deinterlacing, etc.) to ensure the output is as good as possible.  These encoders are often less than real time, where it takes longer than 1 hour to process a 1-hour video.

File Encoders are typically included in video authoring/editing tools, such as Final Cut, Vegas, Media Studio, and Premier, and are invoked when you select “Render” or “Save-As”.

A File Encoder is what is used by Hollywood studios to make DVDs and BluRay disks, and by NetFlix and similar providers to create files at various bit rates and resolutions.

Stream Encoders

Stream Encoders seek to make a compressed video stream that can be delivered live over a network.  A Stream Encoder uses a live video input, such as a HDMI or SDI feed.  Because a live encoder must produce the compressed video immediately, there is little opportunity for quality improvment.  That is, multi-pass encoding techniques are not possible.  Live encoders may try to improve quality by conducting deinterlacing and some noise reduction of the input, but generally the quality of the output is more reliant on the quality of the input and the compressing technique (i.e. the quality of the H264 encoder itself and the settings used).  Stream Encoders may also record, where the live stream is saved locally.  The quality of the recording can be excellent, but would not be as good as those produced by a File Encoder which can perform quality improvment “tricks”.  For most use cases, the difference may not be visible espeically when the Stream Encoder can record at different settings than used for live streaming. Unlike a File Encoder, rate control is more important.  For a file, during periods of high motion you can maintain quality by increasing the bit rate.  But for a streaming encoder that is trying to maintain  a constant bit rate, you have to apply backpressure to the encoder and there are many techniques for this.  So a Stream Encoder is more complex.  To answer the question “Which produces a quality video?”, the answer would have to be a File Encoder.  To answer the question “Which produces a better stream?”, the answer is only a Stream Encoder.

A Stream Encoder is what is used by live services such as Sling and similar “Live TV” providers, often at various bit rates. All Discover Video encoders are Stream Encoders.


You will want to use H.264 video compression (A.K.A. MPEG-4 Part 10).  Next-generation compression H.265 does not provide much improvement for streaming at the bit rates of interest for most people (at very high data rates and for commerical producers it has real value).  While other codecs have their advantages, H.264 is supported on virually all platforms (browsers, mobile devices, set top boxes, Roku receivers, Samsung TV’s, etc.).

Like with anything, you can have poor H.264 and good H.264.  What makes it good?  Well, it’s a bit technical but things like rate control, motion estimation, and processing requirements.  A compressed video of a non-moving image will look pretty much the same from virtually any encoder.  But at any given bit rate, and with the “knobs” twisted to the right values, the differences begin to appear.  How blocky is the video? How much CPU is needed?  Simply put, not all H.264 video encoders are created equally.

Hardware Appliance vs. Software

Back in 1997 we set out to create the world’s first video appliance at a company I founded.  It used MPEG-1 and delivered live video over ATM and over Ethernet/IP.  It was a great success and was followed by MPEG-2, MPEG-4, Windows Media, and H.264 appliances and it launched a whole new industry.  Today there are many video appliances.  Howerver, the motivation for hardware-based vs. software-based encoders has changed.

Mantis_encoder_FrontIt was almost laughable to expect a cira 1997 x286-based CPU running Windows 95 to be a reliable platform for video streaming.  Machines in those days could barely play a video, let alone create one.  When 3rd party cards begain to appear the PC could actually do some useful video things. But not for long before the infamous blue-screen-of-death would appear.  An appliance, however, is engineered specifcially for video encoding.  Using dedicated chipsets, it can be made to be reliable, compact, and purposeful.  It does not relay on a general-purpose CPU for encoding, but uses video compression chips and optimized D/A input devices.




We have come a long way since the the first video appliance.  Today we have more computing power on our phones than the astronauts had to land on the moon.  Encoding video on a univeral computer platform is today perfectly reasonable, and there are many software video encoders for Windows and Apple computers.  Software encoders can take advantage of Intel or Nvidia technologies to lower the CPU load and produce video of the same quailty that used to be only the domain of video appliances.  Of course, a computer does not come with any video inputs…excpet for maybe a built-in webcam.  To bring in video sources, you need a USB device (MISO) or a capture card (Captiva).




StreamEngine Rack Mount Server

All encoders use software.  Many of the popular 3rd party encoders use the Windows operating system even though it is not exposed to the user.  Hardware-based encoders, however, use dedicated chips (DSPs) to perform the actual video encoding.  Using dedicated hardware in a multi-channel encoder allows high channel density and lower per-channel cost.  DV StreamEngine, for example, can encode up to 12 simultaneous video inputs and both stream and record the content in HD H.264.

How To Choose

  • For occational use (e.g. daily 30-minute broadcast), a desktop software encoder is ideal, provided your computer has the horsepower necessary (think Core i7 class machine).
  • Add the cost of your computer (e.g. $1000) to the cost of the software plus the cost of the capture device (USB or PCIe card), and you may find that using a PC as a dedicated encoder is more expensive than an appliance.
  • Use an appliance for continuous streaming, as is done for IPTV applications
  • Use an appliance to get an “Easy Button”, and when the size and complexity of a PC is simply not warranted
  • For 360-degree video, use a dedicated 360-degree camera that has built-in streaming and file encoders



Rich Mavrogeanes




It’s The Bandwidth

A few years ago, a major hospital contacted us to help them stream a large event.  They were convinced they wanted to use our streaming service, Arcus, to stream live video to thousands of viewers.

“Can you say where the viewers might be located?” I asked.

“Oh, right here in our building.  We want all employees to watch” she said.  “Maybe a few at home too, but mostly the viewers are here on the campus.”

“You really should have a local server in this case” I offered.  “Unless you have a ton of inbound internet access, a premises solution is better for you.”

Read more

360 Video

DiscoverVideo was the first enterprise system to support 360 degree video for live, recorded, and uploaded video.  Our Insta360 camera can be scheduled and controlled from the DEVOS system, bringing amazing flexibility and giving viewers an experience they deserve.

Stream and record directly from the camera or connect the camera to a Mantis or other encoder via HDMI.

No More PTZ

Conventional solutions might use Pan/Tilt/Zoom cameras that require an operator, or attempt less-than-perfect object tracking.  With 360 video, each viewer can decide what they want to see.


Because 360 video is capturing all angles all the time, it streams and records in full 4K resolution.  There is sufficient resolution that viewers can even zoom-in on objects, such as whiteboard notes, at any time.

Lecture Capture

Simply place the camera in the classroom.  The system captures the entire lecture including the instructor, the whiteboard or projector, the student asking questions, etc.  No worry if the instructor moves around, the viewer can always follow.  Audio may come directly from the camera’s built-in microphones or from a room audio system.  Stream it live or record it for VoD viewing.

Special Events

Watching a concert in 360 captures the excitement.  Sporting events in 360 allows the viewer to follow the action. Capture the participants at the meeting table or board room.

Closed Captions

Captions Are For Everyone


Closed Captions for broadcast televsion was one of the most successful and rapidly deployed and least controversial legislations of all time. The Television Decoder Circuity Act of 1990 required all TV’s to support Closed Captions and shorly thereafter, CC was everywhere.

A decade later, media started to be important on the public Internet, and by 2010 the Twenty-First Centry Communications Act included requirements for closed captions for internet video.  The U.S. Government had long required CC, via Section 508.  And in 2014, the U.S. FCC approved quality standards for CC.

Adding captions to a video-on-demand has always been easy, but required a human operator and a lot of time.  Stanards such as WebVTT and SRT make captions portable…get a video and the .vtt file and you have captioned video.

Make Captions

It is very easy to add captions manually.  In a system like DEVOS, you upload the video, then play it as you listen:  start to type the words you hear and the video pauses; press enter and you have added a caption line and the playback continues.  In this way, you can caption a video in just a little bit more time than it takes to play the video.

Artificial Intelligence (AI)

AIWith advances in AI and huge investments in things like Siri and Alexa, it is now possible to do a reasonably good job creating CC using only machines.  AI now has the ability to pick voices out of background sounds and to even identify different speakers.

But AI is still not at the near-perfect level.  What more, it may not understand technical terms (say Sphenopalatine ganglioneuralgia), and needs the assistance of a human to achieve near-perfect transcriptions.

That human assistance can come in several forms:  you can allow the machine to perform the transcription to captions and then manually edit it (if needed) in the DEVOS system, or you can use the built-in services of Ceilo24 to create near-perfect captions automatically.

Do You Need Captions?

Captions are not just for the hearing impaired. While you should take the high moral road while meeting regulatory requirements, studies show that captions are very useful for better comprehension of the content and for searching and finding the desired content.


Caption Search

When you have thousands of videos, you can search by title, desciption, date, and entered tags.  But how can you find all the videos where someone mentioned “science” or “Discover Video”, or any other word for phrase?

The DEVOS system supports powerful search tool and you can rapidly find any video by searching the full text of the captions.



Live Captions

The Discover Video DEVOS and Arcus system also support live captions where you or a 3rd party may enter live text which is displayed in the live player.  For “IPTV” (TV Distribution applications), simply turn on the captions in the TV Set Top Box to display captions.


Want To Know More?

We are always happy to help.  Just ask.




Rich Mavrogeanes