Possible?

mark30 wrote on 3/8/2004, 5:01 AM
HI all,

Just tried something that might (??) make rendering almost real time? But I can't believe it until you guys tell me I'm not talking nonsense..
Lets say I have this DV/Firewire IN/OUT box/converter thingie..
Normally I use it to have extrernal firewire preview and for capturing from my camera.

Now.. I switch the in- and outputs. So that means I'm having the firewire cable from my pc to the INPUT of that box. On the firewire OUTPUT I have my camera. I push record on the camera and press play in Vegas. I didn't render anything yet, it's just the timeline playing - cuts only.
Now my camera is actually recording this. So it becomes a sort of PTT without rendering first. Now that's cool, but there's no audio yet.

Now It's cool to have the camera record it, but what if I have a second pc, and I don't connect the camera but this pc. Do you think that vidcap.exe would capture the timeline that's playing on the first pc?
That way it's just a case of capturing the played timeline, put all the audio under it and print to tape all very fast.

Am I missing something here or could it save some time? I know it gets harder when playing effects, but if you don't have many effects and you prerender them it will play fine on the first timeline. And audiorenders are very fast anyway. Just copy them under the new captured avi..

Do I lose quality? This way it's just 2 * realtime to have a PTT..

What do you think?
grtz,
Mark

Comments

pb wrote on 3/8/2004, 5:15 AM
I think you may get "unrecognized DV device" problems. I have inadvertently tried this when swapping 1394 drives around and ending up with both PCs connected to each other via the daisy chain. Good luck though. You will improve your render speed through buying the fastest PC you can afford; RAM does not appear to affect speed after you get over 512 Meg. I added a gig to one of your machines for an entirely different reason and quite frankly see marginal improvement render speed wise.

Peter
Chienworks wrote on 3/8/2004, 5:19 AM
No quality loss in the slightest; it's just a plain ol' DV data stream and it's exactly the same data you would have if you printed to tape or rendered. Make sure you disable DV device control both in Vegas on the sending computer and in VidCap on the receiving computer. Of course, you'll have to start capturing before you start printing so you'll end up with some extra cruft at the beginning you'll have to delete, especially if you want to resync the audio. I suggest you start your project with a single white frame at 00:00:00;00. This will make it easy to locate that frame and trim everything before it.

However .... reality sinks in. Print to tape is real time, yes. But, this assumes that your project is ready to print and anything that needs rendering is already rendered. If this is the case, then rendering directly to a DV .avi file is usually faster than realtime. In any case where your preview to PC method beats rendering, it's doing so because you are dropping frames and i think that's something you would want to avoid. On top of all that, rendering includes the audio in sync.

So, while your method would work, i can't see that it is any advantage. Good try though :)
mark30 wrote on 3/8/2004, 5:35 AM
FIrst.. the 'unavailable dv device thing..' that problem is solved because the DV in/out box is seen as that device.. So that's not the problem..

Chienworks.. Maybe you're right about the dropped frames, but I never have those in previewing external monitor.
Syncing the audio is not a real problem I think for me. If I render the audio tracks as a wave file it usually takes a very short time to do so.
I'll give this a try when I have my project at full length (24 minutes I think it's going to be).
I'll try to do it this way before rendering and see how much time it will cost.
If I don't have dropped frames and I can render the .wav and export the video to the other pc (or camera even) in less time than Vegas needs to do it's render then... It wouldn't save me time anyway because I'd have to do an audio included PTT so haha you're right after all grrrrrrr

thx guys
farss wrote on 3/8/2004, 5:40 AM
If you've only cut straight cuts then there's nothing to render anyway.
If you've got a lot to render then PTT doesn't start UNTIL it's rendered so you gain zip, sorry.
Chienworks wrote on 3/8/2004, 5:49 AM
Mark's not talking about PTT, so having the PTT process render first isn't even in the equation. But, just the same, to have this process work smoothly anything that isn't straight cuts would have to be prerendered, which amounts to the same thing, or possibly even worse because prerenders are manual and will eat up more of your time. And after that's all done, a simple render at that point will still be faster than previewing. On my 866 P3 i usually get a render like that about 30 to 50% faster than real time.
taliesin wrote on 3/8/2004, 6:05 AM
If you have filter applied to your clips - in most cases the external preview will NOT playback with full framerate of 25 fps (for PAL) if you also use full PAL resolution (means preview quality is set to "Best - Full").
In this case (having filters added and best and full preview quality) watch the information display on the lower field of the internal preview while you are playbacking the video external. There you will see the playback rate is going down.

The method you describe is o.k. for non-filtered stuff or - if filter are applied - for a kind of draft output. I sometimes does it this way (printing to tape by just manually set the dv recorder to record and starting the timeline playback) if I need a quick output to show someone via dv tape but only if playback rate doesn't matter for it.

Marco