#Sync problems
6 messages in this thread
Heres a few questions for the Video techie inclined folks out there,
1. I have some hardware that needs two video sources to be "sync-locked" in
order to allow overlayed switching. The manual says only "in cases where the
sources can be sync locked to the same time base, it becomes possible…." My
question is: How do I sync-lock two video sources? I thought I might have to
route through a TBC but I'm not sure I can run both video sources through one
TBC. And if I run through two TBC's would the sources be "sync-locked"? I AM
confused!!
2. The hardware also has an input for an external keyer for choma keying. The
manual refers to "feeding the unit signals produced by an external chroma keyer
(sometimes also called color keyer) or any other type of keying device." It
goes on to say "you may find theres keyers from such suppliers as Sony,
Intelligent Memory, etc" Does anyone know of such an animal, what it does or
where a person might pick one up?
3. Last question, I promise. (For now anyway 😉 ). There is a I2C serial
control bus input on the box. The manual says "The VTU has a RJ-type plug-in
jack that will permit the commection of other I2C compatible devices, as well
as external analog control devices, (such as sliders, etc)". What the heck is
an I2C serial control bus and what other devices are out there for it? BTW,
it is I squared C actually.
Any and all comers are welcome to comment, suggest, harrass, poke fun at or
enlighten me. The unit I am referring to is an IV-24 for the Amiga but the
questions refer to the video side of the house. Thanks in advance to any
answers or suggestions on finding the answers.
Dege
1. TBC's
Each video source requires a TBC. TBC's have a reference in connector which
genlocks them to an external source, which could be a black burst generator or
some other source.
2. Chroma keying. Can't help with that one (I use the FAST VM which has its
own chroma and luma keying).
3. 12C. Don't know that one either,
Hope that item 1 helps.
Bob
Robert,
Thanks for the quick response. I have a black burst generator and was
planning to get a TBC. If I understand you correctly, I can sync up the TBC
with my house sync. Then tie each additonal TBC to that the house sync, giving
me "sync-lock" with each video source. Makes sense but man is it going to
cost!! 🙁
Dege
George,
Another alternative in using a TBC with external reference is that if the
TBC has a loop out of the reference signal, you coul use one of your
_sources_ as the reference signal to the TBC, looping its ouput to your
IV24, and then run the second source through the same TBC's video input
and take the TBCd Video Out as the second source to your IV24.
The first source will not be TBCd but both sources will then be in sync.
-John
John,
Thanks for the suggestion. I'll give it a whirl. Thanks for responding.
I am sure this is not the last list of questions I'll be posting! After
computing for 14 years I feel like a newbie again! Actually that doesn't feel
too bad.
Dege
Pop quiz: Two biggest crooks in modern history? (o\_/o)
Answer: Gould & Ali {-I-}
>>>3. Last question, I promise. (For now anyway 😉 ). There is a I2C serial
control bus input on the box. The manual says "The VTU has a RJ-type plug-in
jack that will permit the commection of other I2C compatible devices, as well
as external analog control devices, (such as sliders, etc)". What the heck is
an I2C serial control bus and what other devices are out there for it? BTW,
it is I squared C actually.
The I2C stands for Inter-IC Control according to the specification in a Philips
data book. The I2C bus is a two wire bus (plus ground) used to connect devices
like decoders, encoders, remote parallel ports, and switching ICs together.
It's a slow speed (<100Khz) bus and it is serial so it is good for fairly long
distances. We use it to control IC devices throughout our board designs. The
slow speed means it does not generate much noise, the two wires (or traces)
means it does not consume large amounts of real estate when routing a board. I
had not heard of it being used outside of a board layout, but it appears there
is no reason not to.
Steve Browning