Amiga Genlock

[danbeaver]

Uh, we'll that's a point, but the video timing was set around the clock speed (well vise-versa) and that is why the guys at Newtek chose the Amiga as the Toaster platform. I personally thought you knew that, but I'm sorry to imply otherwise. Let's drop the discussion as it does not relate to the thread. If you like, just start a new thread about the Amiga's development and engineering choices.

[nscaleworld]

Well, I have a SuperGen genlock installed in one of my Amiga 500 towers and it really produces a very nice color composite output. About the same quality as an XBOX hooked up to a TV. Amiga games and classic Amiga programs look great.
 
A genlock is basicly a video mixer. It has two inputs, a thru, and one or two outputs. The Amiga computer attaches to input one, and your video source attaches to input two. You can then record the Amiga's graphics onto your video. Deluxe Paint III is great for creating backgrounds and titles. The genlock color is usually black, but can also be green or blue. The genlock color is called color 0. Video will only show thru color 0 (genlock color). If color 0 is black, then you have to make a copy of black, so that you have two color blacks, Deluxe Paint III allows you to do this. One will be color 0 (genlock color) and the other will be normal black that you paint or draw with. Do not get the two blacks mixed up. There are genlocks that have S-Video inputs and outputs. These produce a clearer picture, with less fuzzyness around the edges. I still use genlocks today, and I just baught a SuperGen SX from eBay. The sliders are a genlocks weakness. They have a duty cycle of only 15,000, so they have to be replaced from time to time.

[amiga-penn-wchester]

a genlock overlays amiga gfx over NTSC or PAL color composite video.  Although the amiga's design lends itself to this type of thing, it's not available out of the box, you need to have a circuit that can reconcile horizontal and vertical timing and add the signals together.  We all spent hundreds on genlocks back in the day, and if they were available directly on the computer, it would have been nirvana.

please see

http://www.textfiles.com/computers/genlock.txt

which was apparently written by a Commodore engineer or tech support person.  You can see from this text that there are a lot of manipulations that need to happen for the overlay to occur.  

genlocks in and of themselves don't always guarantee quality composite video; they were used for vertical scroll titling and captioning.  It highly depends on the make of the genlock.  GVP GLock and Video toaster are the best of the bunch, I'm sure people can name others...

[lassie]

Thanks now i have a pretty good idea what it can do

[psxphill]

We all spent hundreds on genlocks back in the day, and if they were available directly on the computer, it would have been nirvana.

You were paying for the quality of the rgb decoding and encoding, that was the difference between the cheap and expensive amiga "genlocks".
 
An amiga "genlock" is made up of a slave sync generator & a video mixer.

[magnetic]

Dont know why you guys keep calling genlocks "video mixers" a video mixer and a genlock are 2 different devices. A Generator Lock just syncs the computer to the incoming video and allows for overlay, keying, or reverse overlay. A "video mixer" mixes more than 1 video source, sometimes with effects or transitions.

oh and the gvp g-loc is crap. The only good thing is audio mixing, multiple inputs, and software control. Other than that many other genlocks are better.. Supergen, Vidtech, Hama, etc

[psxphill]

Dont know why you guys keep calling genlocks "video mixers" a video mixer and a genlock are 2 different devices. A Generator Lock just syncs the computer to the incoming video and allows for overlay, keying, or reverse overlay. A "video mixer" mixes more than 1 video source, sometimes with effects or transitions.

What is refered to as an amiga "genlock" provides the clock for the amiga chipset to genlock to and then mixes between the two based on the signal output by the amiga. It has no concept of overlay, keying or reverse overlay, thats all internal to the Amiga. The "genlock" then just mixes between the 2 video sources (amiga's output and the external video).
 
Granted the video mixer in the amiga "genlock" doesn't have all the functionality of vision mixers used in tv production. But effects and transistion generators aren't required to mix two video signals.
 
However a genlocking is only for synchronising, it has nothing to do with mixing any signals. You can genlock with only one video source, the sync can come from anything. It's common to genlock to GPS (http://www.dk-technologies.com/downloads/specs/PT8616.pdf)

[JimS]

It has no concept of overlay, keying or reverse overlay, thats all internal to the Amiga. The "genlock" then just mixes between the 2 video sources (amiga's output and the external video).

Gotta somewhat disagree here. The only thing internal to the Amiga is the ability to synchronize to external sync provided by the genlock. The actual overlay is done in the genlock.

[psxphill]

Gotta somewhat disagree here. The only thing internal to the Amiga is the ability to synchronize to external sync provided by the genlock. The actual overlay is done in the genlock.

Genlocking is something that the Amiga can do all by itself, it only is the process of synchronising to an external clock.
 
Just because someone used the word genlock when marketing an external peripheral doesn't change that. They could have called it a video thingy.
 
At which point you'd say that the video thingy plugs into the amiga and allows it to genlock to an external video signal and the video thingy then mixes between the amigas output and the external video signal, based on the signal generated by the amiga.
 
Nobody is going to call it a video thingy though, they are going to call it a genlock. So if someone (like the OP) asks "what is an amiga genlock?" the answer is: it's a video mixer and slave sync generator that allows the amiga to genlock to the external video source.
 
In the real word genlock is a verb, not a noun.
 
So equipment is genlocked if it's synchronised to an external clock.
Equipment genlocks to an external clock.
 
It's unlikely the incorrect usage of the word genlock is going to disappear, so I'm not going to keep arguing the point. You'll either be educated, or you won't. I can't do anymore