No proxies, just changing project settings. If I was using proxies then the behaviour would be perfectly logical.

Bob.

You got me interested, Bob - would like to test this approach.. So what you do is basically edit HD stuff (like the 1920x1080/25p mxf's) in an SD project; after you're done cutting etc. - what do you do next? Just change the project setting to HD and render out to HD, or render to HD without even changing project settings?

me wanna know too!!!!

have three large hd projects just digitised.....

leslie

yeah, i know i could try for myself, but the only thing i ever found about about being on the cutting edge was that i bled a lot....

I just set up PAL Widescreen project and put an HQ 1920x1080/25p mfx clip on the timeline; I am only getting 12 fps ! Is this the "advatage", or am I missing something :(

That's a damn good question!

I opened a PAL 16:9 SD DV project just like you and dropped 1440x1080 50i HDV onto the T/L, preview set to Preview/Auto. Playback at 25fps. Then I added a wave file with 4 tracks of 24/48K, still 25fps. This made syncing much easier, moreso once I nutted out the tip I posted. Then I'm happily doing my cuts only editing, add a few volume envelopes and realise my fps are back down to 12fps. Drop Preview down to Draft, yeah yuck but I'm back to 25fps.
Got all my cuts done and just for giggles switch my Preview back to Preview/Auto and resize the window a bit bigger and I have playback back to 25fps! Truly wierd and makes no sense which is why I really posted this, in the hope that maybe others could make some sense out of it and maybe make things a bit easier.
Sometimes we get in a rut, the anarchist in me likes to throw the odd Molotov at the T/L just to see what'll happen and I think I found something, maybe.

So now I've switched the project back to HDV and it's rendering out while I get some rest.

Bob.

Yeah, well... Too many variables/unknowns. For the starters, when I am talking framerates I ALWAYS assume Best/Full (I have now this monster 50" plasma hanging above my desk, so I won't compromise for any lower settings - unless I really have to).

Bob,

I am unable to reproduce any of this on my computer. In fact, I get quite the opposite (and I think, expected) result. I expect that what you are seeing may have to do with how video is being scaled for the preview window. As you change the project settings, you may be causing the preview window to scale up or down slightly to whatever preview resolution will fit. This in turn is the product of many different settings: Do you have preview set to draft, preview, good, best? Do you have it set to Auto or Full? Do you have the preview set to display project aspect? Is the preview set to scale or only show discrete resolutions?

Frame rate can also play a role. You didn't mention at what framerate your HDV was shot. 24p? 60i? Something else?

In trying to duplicate what you did, I put some 29.97 interlaced 1440x1080 footage from my FX1 onto the timeline. This is a native m2t file, and I'm using Vegas 7.0d. I started out with a standard NTSC 4:3 template. The preview window was set to Preview (Auto), Simulate Device Aspect, but NO scale video to fit preview. I sized the display to get 655x480x32. Playback fps bounced around, but averaged about 23 fps on my slow computer.

I then started playing around with the project settings while leaving EVERYTHING else the same.

When I set the project settings to NTSC DV (widescreen), I achieved full 29.97 fps playback. At first this seemed to confirm what you saw.

I then realized that when I changed to this setting, the preview window was now 436x240x32. Hmmm ... I'll bet this is what is happening to you. The previous preview was 655x480 which is 314,400 pixels. This new resolution of 436x240 computers to only 104,640 pixels, which means Vegas only has to display 1/3 the number of pixels.

I then resized the display larger until it "popped" to the next resolution which in widescreen is 837x480 which is 401,760 pixels.

Not surprisingly, I got about 20.5 fps.

So, I think you need to look carefully at the total number of pixels in the preview box and make sure that no other settings are changed. My guess is that you will find that there is no free lunch. In particular, the total number of pixels displayed (while holding everything else the same) will determine playback speed: increase the number of total pixels, regardless of project setting, and the playback speed will decline.

Oh, and when I set the project properties to HDV 1080-60i, I ended up with a 640x360 display (230,400 pixels) and got just about 29.00 fps (once in awhile it would hit 29.97).

Finally, being a terminal nerd, I put these results into Excel and plotted the results and ended up with a very nice straight line (total pixels vs. fps). So, it's a pretty direct correlation, and doesn't depend on the project setting, other than how that causes the number of display pixels to change.

Thanks for putting so much time into this. Having slept on it you're right. I suspect getting full fps playback has a bit of an event horizon to it as well. Once it can't just quite keep up overheads increase and the drop in performance has a bit of bump down. Also we really notice dropped frames!

Bob.

2 stupid follow-up questions:
1. So the smaller the preview window, the better fps playback I'm going to get? So I may get better fps playback at Preview/Auto at 436 x 240 than Draft/Half?

2. When rendering, does the size of the preview window matter? I've been trying to remove any issues that may slow down the render, and I minimize the preview window to a thumbnail. It seems to help, but that may just be a visual placebo.

When rendering, does the size of the preview window matter?
No.