Video Switching is where video inputs are switched usually by hardware known as a video switcher or a video mixer.
Video switchers traditionally were a big and heavy piece of hardware and have become more light weight over the years. The purpose of the switcher is to switch video inputs to an output usually known as the program output or program monitor. The program output is what is transmitted and or recorded or if you like, what the end user the viewer sees.
So, let’s step back a bit video inputs, let’s talk about them. Video inputs are a video capture card which receives the output from a visual device such as a video camera but it can also be anything that has a video signal like a computer, a television, a projector, a tablet and so on. As an example, a video cameras video signal is an output. We can put that output via some sort of cable connection into a video input of a switcher. The switcher will usually have a number of video inputs and it is the video inputs that we are actually switching to the program output.
Traditionally video switchers had a lot of additional hardware added to them is some sort of way to allow for video recording, broadcasting and even for playback footage. This meant a lot of hardware with many cables and much electrical power needed and required a lot of room to accommodate this hardware. This if you like became a video studio with hundreds of illuminated lights form all the different hardware, fans added to keep all the equipment cool.
Who uses video switchers? Well traditionally television stations broadcasting many live shows or even to produce pre-recorded show to broadcast at a later date. A typical talk show with have usually 3 set camera. Cameras 1,2&3 usually went from (1) left to (2) centre to (3) right.
Each of these cameras were connected to a video switcher with 3 camera people operating the cameras controlled by a Technical director and or by a person known as a switcher.
A Technical director.
The Technical director is usually reasonable the broadcast side of things not to be confused with the producer of a show. The Technical director is reasonable for the full audio and visual to be presented to the audience and for each piece of footage to be played and the switching of all cameras. Some Technical directors do the switching themselves and also give commands to the camera operators. Also, usually for more fast switching programs like live news a person known as the switcher operator will press all the physical buttons and line up the view to be switched. The switcher operator will take the commands to switch from the Technical director for example camera 1 “take” or “auto take” or “line up in preview” and so on.
The workload of switching the visuals can be quite fast moving almost like a pilot landing a plane trying to control the aircraft and deal with air traffic control is a very fast and time controlled procedure. So, if you like The Technical director is like the captain and the switcher operator is the co-pilot. Both have a key role to play.
So, what can the average switcher actually do when it comes to live broadcast?
As mentioned above switch all the video inputs and playback footage. Also, when switching there is the ability to switching using transitions.
Transitions or transition switching is where the switch between two visual can be made with some sort of smooth change like a fade, fading between the visuals usually fading one out and one in. In today’s choice of transitions built-in to the switcher there are many to choose from, with flying in and out transitions to blinds, circles and other shapes it can add that extra professional touch to the switch.
Most Switchers but not all! will has a Preview out as well as a Program Out. In traditional Switchers they were only physical outputs that could be connected to monitors for viewing by the Technical director and switcher operator.
The purpose of the preview out (only seen by operating staff) is the setup what will be switched to the program out, it can only be seeing by the operating staff and not by the audience. This is a very useful in know exactly what will be switched to the program out (which the audience will see). It prevents error of switching the wrong camera or playback footage. The Technical director will usually say something like hold camera1 or preview camer1 and the operator with select camera 1 with the preview buttons to be placed in the preview. When ready for the switch from the Preview to the live Program out the command will be either Take camera 1 or Auto Take camera 1.
The Take & Auto Take make the switched from the Preview to the Program out by buttons named Take and Auto Take. Some switchers will have a cut button instead of a Take button in such cases it is likely the verbal command would be cut camera 1 or whatever is to be switched.
The Take or Cut button will without delay and without any transition switch the preview to the program at the blink of any eye. The Auto button or Auto Take button will make the switch between the Preview and Program in a set time in seconds using a chosen transition. As an example, Camera 2 maybe presently in the Program out and now Camera 1 with be faded in over camera 2 in a pre-set time of 3 seconds.
Also used in the Switched process is the most popular Transition Bar.
The Transition bar is where the switch is made manually in a gradual movement by the switch operator using a handle or slider in software or both. The transition bar is used usually when making the switch using a transition like a fade. The Transition bar is different than the auto take button as the operator can stop anywhere in the process. This useful when fading two visuals giving a ghost effect.
Downstream using a switcher.
Not all switcher has the functionality to downstream but for those that do, the downstream options will vary. Downstream options are much more choice in Software video broadcasting programs like Finncast Studio www.finncast.com than those in an only physical switcher.
What exactly is down streaming? Down streaming is where a visual whether it is a camera or an image a chart a piece of video footage is overlaid on the program out. Overlaid meaning placed on top of the existing visual. Unlike the switch which will replace the existing visual with a new one a downstream will be placed over the existing visual with a defined width, height, and position usually setting x position (from the left of the screen moving horizontally) and y position (from the top position moving down vertically). A typical example of a downstream would be a shopping program with a text downstream of a phone number placed on the screen. The most used downstream is logo for the broadcasting company like a Television station. Using the logo as an example of an image being down streamed (overlaid) switching will still take place as normal with the logo remaining on screen. Any video input can be switched (which is technically behind the downstream ) Down streaming is an almost a must for broadcasting especially since online broadcasting is now done by almost anyone who wants to live stream or broadcast professional looking footage.
Effects can also be found in Switchers like old movie, Monochrome, Split screen and so on. Such effects are popular in the making of pop videos.
Most switcher will have some form of audio control or even a built-in audio mixer. The Video switcher may also work in conjunction with a separate audio mixer but the video mixer will at a minimum except the audio output from an audio mixer into the audio input of the video switcher. With that said let us talk about video and Audio inputs and outputs.
Inputs and Outputs
For some inexperienced users starting their hand into the video production world, inputs and outputs can become somewhat confusing and even complicated. So what is a video output? It is a video signal from a device like a camera or as an example let us talk about a desktop computer as most of us will have used one at some stage in our lives.
A desktop computer is usually separated from its monitor and connected via a cable. The desktop computer will have a video card installed which will have a video output or maybe more than one output. Some video cards will have a VGA output and a HDMI output. Whichever, it will have the video signal from the video card. The Monitor used to view this video signal will have a video input again usually of either VGA or HDMI or both. So, the video output transmits the video signal and the video input receives it. The video output is always connected to the video input or at least think of it that way. Output what is to be viewed to input what lets me view it.
The process takes place of course will have to encode and decode the video signal but here I just want to explain inputs and outputs from a connection point of view. And yes, there is formatting and codecs etc but we are only going to focus on the connection of such hardware. Many people asked us is it possible to connect a computer to the inputs in Finncast studio? Yes of course is the answer. The users video capture card might have SDI video input connections and their desktop computer HDMI output. Needless to say HDMI will not physically fit into a SDI input, and this is still possible as there are many video converters some of only cable to carry out this process. Input & Output connections may not be of the same connection type but using specific cables or converters makes this very much possible.
Audio Outputs & Inputs work on a similar principle as video just with audio only. As a quick example the microphone outputs the audio to an input of a sound card and the sound cards outputs the audio to the inputs of the speakers or headphones.
Software’s for broadcasting and Switching such as Finncast Studio hugely eliminate so much of the hardware traditional required. Such software’s have built-in video switching with down streaming, video playback (no need for playback players), Chroma keying for green screen, Lower thirds and even Virtual Sets / Studios. They even have the ability to record without any physical recorder and live streaming over the internet. And it is now video production is at a high with YouTube uploads and live streams and so many people now being not camera shy video broadcasting is all around us online and very one is at it.