View Full Version : Live Switching - Cameras, Component, DV and more

09-12-2003, 09:41 PM
Hey all:

I'm writing this to those toasters who do a lot of live switching. One of the main reasons I bought the Toaster was to be able to offer the ability to do live switching as part of my companies services and increase cash flow. (By the way has this been the case with you?)

Well, to do live switching you need multiple cameras so I've been looking around. Of course the BOB has these wonderful component inputs but it would seem that the only cameras these days with the outputs are Beta SP cameras and decks. The prosumer DV cameras have DV, composit, and Y/C. Of course, from what I've read I can now use strickly DV via firewire inputs with the VT[3] (Note: Upgrading soon) But there goes the Uncompressed quality. (Some would say the quality difference is insignifiacant) Also, prosumer DV cameras don't send SMPTE color bars. Well, I really don't know where I'm going with this. I guess I have the following questions:

1.What cameras are you using for your live switching?
2.What COM system are you using to communicate with the cameramen?
3. Are you using an external audio mixer before going into the VT or are you using just the VT audio?

I'll take any advice I can get on live event switching with the VT.

Thanks for the help.


09-13-2003, 03:46 PM
While I am far from expert, we use the JVC GY-DV500s cameras. We like them pretty good so far. I'll probably pick up a DV5000U in a few months.

09-14-2003, 11:55 AM
Thanks J,

The JVC DV5000 was one of cameras I was looking at.


09-14-2003, 01:34 PM
I'm not an expert on this, but when I posted a question over a year ago asking if the analog output of a DV camera/camcorder was coming before or after the signal had been compressed to DV, the answer I got was that it was after the compression. So using the DV5000 as a "camera only" via its analog outs, the signal will be compressed about 6:1 by the DV CODEC and have been effectively changed to 4:1:1 color.


09-14-2003, 06:13 PM
Thanks John:

I'll have to look into that. Looks like if you want to do uncompressed you've got to go Beta.


09-15-2003, 06:40 AM
There's a tiny chance I'm wrong about this, but I don't think so. The analog outs on pretty much any video camera worth more than $500 should NOT be a compressed video signal. There would be no reason whatsoever for the signal generated by the camera head to be compressed for DV recording prior to the analog outputs. That would result in an extra signal processing step to convert it back from a compressed DV signal for output on the analog connections rather than taking it from between the camera head and the recording mechanism.

09-15-2003, 10:27 AM
Cameras over 2K are compressed at the analog output.
You have to ask the manufacturer.
Why? Dunno

09-15-2003, 01:44 PM
Hmmmm..? Well JReble makes sense. Why go through the trouble to compress video to DV and than out to analog. It is most likely the same card(DV compressor) sending the DV to both the recording head and the analog outputs at the same time. This would save space inside these small cameras.

The point is that I really want uncompressed and it doesn't look like I'll find it in these prosumer cameras. Heck, I can't even find SMPTE color bars in a prosumer camera. This is unfortunate because it is very expesive to by the professional cameras.



PS - I still need to research the DV5000

09-15-2003, 06:15 PM
JVC Streamcorder. Clean clean picture and no compression
at the analog outputs.
Price? Under 3K I think.


09-16-2003, 08:44 AM
Thanks Bob. I'll look into it.


09-16-2003, 10:44 AM
From what I understand most all semi-pro and pro camera's analog output is more or less directly from the head or chips. The DV compression only comes into play when it goes to tape.

I could be wrong but I would assume it would more depend on the camera design. Best bet is to ask the manufacturer of your favorite camera. And then ask about 5 other people at the manufacturer just to make sure.

09-16-2003, 03:51 PM
I sent an email to the West Coast JVC pro video rep. He said he would check to make sure, but he thought the analog video out was after the DV CODEC. Why? So you can monitor what is or will be on the tape, not the camera head. I am still waiting for a final word.


09-16-2003, 04:02 PM
On the GY-DV500, their is a "monitor out" and a "test out" (BNC connections). There is also a Y/C out. Would it not make sense, if the reason for the signal being post-CODEC is to see what's going on the tape only, to send it out on the monitor output and send an uncompressed signal to the other outs. I know that, to me, this makes sense, but that means nothing in the real world.

Explanations and thoughts would be appreciated. Thanks for checking this out.

09-16-2003, 04:19 PM
test out is before codec and monitor out is after codec i am not sure about the y/c out

09-16-2003, 06:25 PM
With GY-DV500, if you do a fast pan while viewing both Y/C out and Test out, is there a delay in the Y/C? If Yes, this would probably indicate the time lag caused by compression to DV and then uncompression back to analog. I don't see mention of a separate Test Out connection for the DV5000. Maybe there is a menu option to select the type of Monitor output?


09-16-2003, 06:44 PM
to tell you thr truth i have never used the yc out on our 4 dv500s

09-23-2003, 07:42 PM
I have tried with the VT3 using two Cannon GL1's with firewire out. The picture quality was not the issue that I had. I was shooting the feed out onto a screen and what a time lag. When I went to the Y/C output, the delay went down to within a frame. Is there any difference in the firewire cards or is the delay inherent to the camera or computer hardware. I am running a Dual Xenon 2.2 machine with WIN2K.

Brian R
09-23-2003, 08:16 PM
This is a question that has come up many times.
Remember, when you are using the IEEE1394 (Firewire) outputs from a camera it is data, not video. When you want to switch it it must be converted into something that is switchable and this takes time to do, hence the delay. There is no magic here just trying to combine the digital and analog worlds and this is not always a real time proposition!
Stick to switching composite video or better yet, Y/C and the delay will be limited to the processing of your switcher.

09-24-2003, 12:34 PM
Very true.
Also remember if it comes in via firewire it has to be decoded into video by the computer. This takes some time. Coming in via analog you get the VT's 2-3 frame delay "through" and no CPU overhead.

09-24-2003, 01:35 PM
Hey Pat!!!

Got a couple words for you below:

Aardvark Q10

Still here?? :eek: ;) :D

10-04-2003, 06:15 PM
Don't know what your budget is like, but you might take a look at the Panasonic AW-E300A or AW-E600 convertible camera system.

"Convertible" is Panasonic's way of saying that the camera will work either on a remote pan/tilt system, or on a proper studio tripod. But don't let that mislead you, it's a darn good camera with all the bells and whistles you'd expect in a studio setup.

It comes with composite and Y/C outputs standard, and has an option card slot to insert a component card if desired. It also supports the use of a CCU, so you can align and genlock multiple cameras from one operator's position.

Lenses are avaliable either motorized or manual, and with a manual lens you can attach a tripod-mounted manual focus and zoom controller- something lacking in most camcorders.

Panasonic's array of accessories and packages is somewhat mind-bending, but basically you'll need the camera, lens, studio handgrip controls, viewfinder bracket, viewfinder, a studio card (composite or component), and CCU.

The studio cards, composite or component, give you:
1) The video output of your choice
2) A tally output
3) A signal to drive the viewfinder
4) Intercom I/O to the CCU

As others have mentioned, FireWire is probably a poor choice for live studio work. Like any other compression system, DV has some degree of latency to it, which will cause you problems when it comes to audio sync.