Video Preview on TV Screen. Complicated. Why?

organism_seven wrote on 1/8/2003, 6:37 PM
Hi,

I have a Matrox Parhelia graphics card installed in my system which is a dualhead card. You can set it up to output and display all video files (MPEG,AVI,QuickTime etc)to display on a secondary screen. In my case, I have a TV hooked up to the second display output. Like most other video editors I like to see what the final output will look like on a normal TV where 99% of my work will be viewed. No other special hardware is required. If you launch a video file it is automatically output to the TV screen.

Great stuff, but............
If I use Adobe Premiere, QuickTime, PowerDVD, Windows Media Player and a dozen other video type applications they all work fine. The video signal is displayed on the TV.
When I use Vegas Video Capture 3.0 the video is also displayed on my TV screen.

But when I use Vegas to edit, the preview window does not work in the same way.
So no video is displayed on the TV.
You have to send the signal out via a firewire device. Why?
With this method I have to mess around changing cable connections and flicking switches when I go from importing to exporting the video signal.
Why doesn't it just use the same method that is used in its video capture program.
I think I have heard it is something to do with DirectX. Maybe so.
But if the Video Capture program can deliver the video signal out, why doesn't the main program use the same method?
Info appreciated.
If VV4 cures this problem, it would be even more appreciated.

Regards
Organism Seven


Comments

videoguy wrote on 1/8/2003, 6:42 PM
man, i am in the same boat. i would like to know the same thing. i have a matrox 6450 and have tried to same thing then finally gave up and went back to using the firewire method of output to my tv from my camcorder. What i would like to know is why when i output back to the tv from my camcorder vegas tells me that it needs to recompress the frames. slows things down a bit.
stepfour wrote on 1/8/2003, 10:20 PM
I'm not sure, but, I have always assumed it has something to do with being able to get a realtime preview of your project without rendering the effects first, and, that the hardware in the camcorder somehow helps. Most of those competing products cannot do that AFAIK. Still, like you, I do wish the preview was easier to work with.
Cheno wrote on 1/9/2003, 12:24 AM
The way I understand it is that Vegas is designed to work with OHCI compliant devices, i.e. firewire, IEEE1394 or what-ever you want to call it - preview to external monitor must be done this way as that is how it was designed. Options are to either use a analog to video converter to go out to your monitor or use a digital camera. Either way it should work fine, provided Vegas recognizes whatever OHCI compliant device you're using...should recognize most of them.

Grazie wrote on 1/9/2003, 12:25 AM
Me too! I get a "Recompresing Frames" red message in the "Black" Preview screen when the moving cursor hits a dissolve or whatever. If it can not do it, then if I know this I'll stop thinking it can and get on with the rest of my life . . . but, if it can and it is User Error, then I'm very willing to learn how to "shape-up" my Veags settings - yes? Simple really! I too use the firewire connection and leave the "monitor" connected - this stops me from doing the camcorder capture. I've tried one of the daisey-chained" ports, but that "appears" to be too slow - blocky pixels and artifacts.

Grazie
DGates wrote on 1/9/2003, 4:32 AM
I don't see why it's so complicated. Every project I edit, ends up going to my D8 camcorder anyway. So it's always hooked up. Kind of a poor man's DVCAM VCR.
JJKizak wrote on 1/9/2003, 7:32 AM
One point you are all missing---Vegas came out way before all of the new
video cards perfected (loosely) the double monitor syndrome.

James J. Kizak
Tyler.Durden wrote on 1/9/2003, 8:05 AM
Hi All,

The process of recompressing frames to the DV spec and passing them out the 1394 port is the best way to see the actual conversion to DV and NTSC (or PAL).

You will need to PRErender (not ram render) any recompressed segments to see full resolution/framerate, but if you want to know what the video will *really* look like, this is the best way.

For fast previews, the internal Vegas window and ram-rendering will give you a quick way to assess sequence, tempo, audio, effect placement, etc.; but for true video quality, 1394 output is best.


HTH, MPH

Tips:
http://www.martyhedler.com/homepage/Vegas_Tutorials.html
DougHamm wrote on 1/9/2003, 4:55 PM
Another quick answer: VV3 doesn't by default use a video overlay to display video in the preview window, and so video cards that 'project' an overlay onto the second monitor won't kick in and display the contents of the preview window.

You could go into the advanced options (using the Shift-key trick) and see if there's an advanced setting to enable overlay; if there is then this might work.

-Doug
organism_seven wrote on 1/9/2003, 5:39 PM
Sorry for appearing dim, butI still don't really understand.
If the Video Capture preview screen outputs to the TV (Does overlay apply here?), why doesn't the main editing preview window do the same?

Regards
Organism Seven
aboukirev wrote on 1/9/2003, 6:49 PM
If you familiar with DirectX/Media programming then the explanation below will mean something to you.
The capture process is most likely simple DirectX capture graph, totally handled by DirectX, including preview window/overlay. Obviously, it's well aware of dual-head card capabilities.
The preview window in VV3 does a lot more than just straight display of DV stream. First, it has to handle skipping frames grcefully and managing resolution (draft/good/best) if you preview a complex transition or composition of layers. So custom drawing is probably the best bet here. Also drawing safe margins directly in preview window, for example, is easier than embedding them into the preview stream.

So there is custom code there, and that code may not be aware of what your video card is capable of.

Even though dual-head cards became very popular, the implementation differs significantly between cards from different vendors. It's probably still not worth the effort to program support for cards from multiple vendors unless you are creating something very simple and/or very 'standard' (in Windows sense).

Go through the camera - makes real difference.

Alexei
watson wrote on 1/9/2003, 8:16 PM
I have often wondered:
People talk about wear and tear on the Camera.
If there is no tape in the camera are the heads really getting wear and tear or is it just the fact that the camera is running electronics?
In that case not much wear and tear would think.

Thoughts?

BillyBoy wrote on 1/9/2003, 9:50 PM
Good question, I was wondering the same thing since I'm not using my Canon ZR45 much as a camera, mostly just as a interface between my PC/firewire and external monitor, then to print to tape to archival reasons.
Chienworks wrote on 1/9/2003, 10:27 PM
Probably the capstan motor runs whether the transport is engaged or not. The camera will also get hot, which will accelerate the drying out of rubber parts and lubricants. Heat will also cause air circulation which could bring more dust inside the camera. In general, running electrons through even solid-state electronic components will cause them to wear out faster than if they are sitting idle.

Granted, these are probably very minor effects compared to actually running a tape through the camera. But they should be considered if you are a stickler about camera life. Personally, i see a camcorder as a tool to be used (though not abused), not a showpiece to be pampered.