Frame Recompessed?

stepfour wrote on 5/31/2002, 11:33 PM

I'm previewing by firewire to camcorder to TV. Up til now the preview quality has been excellent, but after the latest editing session the preview quality and has gotten bad. It's now a jerky, poor-quality preview. I notice that the difference between this revision of my project and the one just prior to it is that when I play this one a red message, "Frame Recompressed" appears below the message "Preview on External Monitor" in the preview window in VV3a. What might be causing this?

Comments

tserface wrote on 6/1/2002, 1:48 AM

I'll take a stab at answering this, but this is mysterious to me so this is mostly my opinion of what is happening given what I've seen.

If you send DV to the IEEE 1394 device (in my case a Director's Cut box) then there is nothing for it to compress (DV is a kind of compression). When you try to composite things with the DV (titles, graphics, track motion, etc.) then VV has to recompress the DV that it is sending out to the device. This takes some time because it is effectively rendering on the fly. The preview that I get when doing a lot of compositing is usually choppy and grainy, but it renders fine for the final output. The real rendering chore takes much longer. So, effectively, VV is recompressing the DV as it is being sent out to the external monitor. It doesn't really need to do that when it's displaying it locally since the local version doesn't need to be compressed DV to display on the computer in the preview window.

Funny thing. One time I was viewing my output on an external monitor and I liked the choppy look, but when I rendered the final video it always came out slow. I wish I could figure out a way to do a 10fps effect, but still have real DV output. Perhaps another filter???

I hope this helps some. Like I said, I'm taking a stab at it.

Tom

stepfour wrote on 6/1/2002, 10:07 AM

Thanks tserface. I think with this last revision my project now has so many effects and things in it that the preview can no longer be full quality. I rendered a small section of the project and the quality of the DV-AVI is incredible, so there's definately nothing wrong with the project itself. Vegas is so zippy on rendering that I might go ahead and render the whole thing.

I remember reading something about some sort of RAM capacity setting that can be made in VV3. I have P4 1.8Ghz w/ 1GB so maybe that RAM setting, wherever it is, would help me keep a high quality preview without rendering. Anyway, I am excited about the pristine AVI on that small render. Of course, the quality on that should be excellent since it's basically DV to DV but the transitions, titles and things also look great.

tserface wrote on 6/1/2002, 10:13 AM

Cool. VV3 does do a great job compositing. When you think about all the work it is doing to overlay track upon track upon track with all of the various rules and techniques, it really is quite amazing. I'm glad it worked for you. Even if the preview doesn't look exactly like the final, it is still useful to use the TV as an external monitor because then you can see what is really showing on the screen, a better representation of the colors, etc.

Tom