F.A.Q.

• What is a Frame Synchronizer?
• What is Audio-Follow-Video?
• What is Genlock?
• What is Interlacing?
• Why Linux?
  • What is Linux?
  • What the heck is Open Source?
  • Does that mean we have to put Synergy code on the web?
  • Why not just use Windows?
  • Do customers have to know Linux then, will it affect their IT department?
  • If anyone can add to it, why isn't it even worse than Windows?
  • But is it compatible with Windows? I heard that Linux doesn't run all Windows programs.

What is a Frame Synchronizer?
A Frame Synchronizer is an electronic device used to align two or more video signals. The Frame Sync has a reference input to which a common house reference is fed (see GENLOCK definition). The device delays the signal by storing the image information in memory. The reference determines the time at which the device begins to output the video. By doing this to all signals using the same reference, the signals can now be mixed, dissolved, etc. together without timing errors. This is only required for signals coming from devices that are not already GENLOCKED or have had signal delaying circuitry added prior to the mix device.

What is Audio-Follow-Video?
In production settings, a video signal is commonly accompanied by an audio signal. These signals may come from the same device or from separate sources. A fair comparison would be a server (stores both video and audio information) to a studio camera with a separate boom microphone. During editing, it is often necessary to be able to access either signal independently while maintaining the relationship between the two. Audio-follow-video mixers allow accompanying audio to "follow" the video when switching sources.

What is Genlock?
A method of synchronization in which a signal producing device is locked to a common reference. When many devices in a system are "genlocked", it is possible to then mix signals without timing errors. In a video switcher, a timing error may be seen in the form of a jump when a transition (wipe, fade, etc.) occurs. Not to be confused with Frame Sync (another definition).

What is Interlacing?
A system developed for television which divides each video frame into two fields. This is done by first drawing one field consisting of an image's odd scan lines (1, 3, 5 all the way to 525) and then drawing the remaining even scan lines (2, 4, 6...and so on), interweaving both fields. Interlacing reduces the perception of screen flicker. Interlacing is not without its imperfections; it can cause unwanted effects with images (such as computer generated text and graphics) when transferred to video.

Why Linux?

What is Linux?
Linux is an open source operating system that allows applications to have a GUI interface with a mouse and windows much like Windows or Mac OS. It also allows easy addition of tricky stuff like Networking, USB, hard drives, and real time software control.

What the heck is Open Source?
If you work on Linux, you have to "give back to the community". In other words, by using the free stuff you have to make your source code free if you make any additions or changes to the code. In this way, Linux keeps doing more things for free.

Does that mean we have to put Synergy code on the web?
Not Synergy code itself, but yes for any changes we make to the operating system. Whether anyone uses those changes is up to the people "out there".

Why not just use Windows?
Well, inside Synergy MD we can have up to 24 separate operating systems running in the frame talking with each other. Microsoft would of course charge hundreds of dollars, per operating system in use. This would add thousands to the cost of a system with no added functionality. Also, because we have the source code, we can (and did!) optimize Linux to our real-time and dedicated hardware needs and comb through it when we have problems. This would be impossible with Microsoft.

Do customers have to know Linux then, will it affect their IT department?
Nope. Synergy MD connects perfectly to their Windows network as a normal peripheral with an IP address. After that, it's just a black box that's running software inside just like Synergy SD.

If anyone can add to it, why isn't it even worse than Windows?
There are teams of people who get together to make "approved" versions. Some teams are in companies (like Red Hat) and others are part of non-company "consortiums". These people are very particular about ensuring that the quality is there.  Linux is certainly well known for its stability, which proves that the model works.

But is it compatible with Windows? I heard that Linux doesn't run all Windows programs.
Hey, we're not running any Windows programs - we're running Synergy code. All the outside world needs to see is Ethernet, USB, RS-422, HTTP, and a windows-compatible directory structure on our hard disk. All of that works just fine - you'd never know the difference. Remember that the user interface for Synergy is on our traditional control panel, not the rack frame.