[LAU] AV i/o hardware

[Len Ovens]

On Tue, 25 Nov 2014, Simon Wise wrote:

> "Expensive" was referring to their range (which probably include the same 
> chips etc) in the context of the DIY approach we are talking about here.

I agree it is a bit pricey compared to what most DIY setups are. I am 
looking at what the SW I have tried can do and what we used in The TV 
station where I worked in the early 80s had in even on air, but not much 
different in production.

We had basically two hard switchers that each had one push button for each 
source available in the station. At the right side was a T handle fader 
that faded from one switch output to the other. That fade could be verying 
amounts of each signal (fade to black or whatever) or could be a wipe (a 
moving pre-selected shaped key) or a chromakey (what it was called then). 
What I have seen in live stream SW has the switcher part, but not the fade 
or keying except being able to key in a box in a set place on the screen. 
The idea of a wipe, even timed so a physical fader is not needed, is not 
there. Maybe someone can suggest SW that has some of these things, but the 
only solution I saw was with HW. What SW does have, is the ability to sync 
unrelated video streams at the cost of added latency. We used to call it a 
frame storer.

Unfortunately, the newer DSLRs don't seem to have a DV output to firewire 
as some of the old video cameras did. Maybe this is still more common than 
I know. However with the OPs comment about having remote students speak on 
the screen the cameras in question will likely be webcams of various 
quality (the $3 dollar store ones are surprisingly good if you add some 
light) then the SW switching and being able to add a second video box to 
the screen may be enough for what is needed. I think that any of the 
cameras I have (including the DSLR) video out to a video capture card are 
not going to look any better... though the DSLR does have a nicer zoom and 
can focus. Having worked in the video business, I have never been 
interested in family video "taping" and so do not have a video 
camera/recorder to play with. I have a young boy who may change that, he 
has already done some stop motion animation and finds it easier to tell a 
story that way than with words. However, for most of what he would do, 
recording to file(s) and then mixing/switching/fading/etc. in post 
production rather than real time is more likely.

I meantioned the keyer on a card only in case something more than what was 
available in SW was wanted. I think it is still cheaper than a full HW 
keyer, but yes it costs more than most of us wants to pay (or can).

--
Len Ovens
www.ovenwerks.net