The new adaptive preview feature.

farss wrote on 5/29/2009, 6:51 AM
I've been pretty curious about this. We seem divided over this, some love it and some hate it. Here's what I have found.

It can work very, very well. I put a HQ EX clips onto the V9 T/L. Plays out nicely, add CK FX and switch on adaptive preview. Quality drops but fps holds up. I added a similar clip minus any FX after it. Kind of wierd watching the quality jump up after the cut but what else could Vegas do here.

So I started adding more tracks and clips, all composited via CKs. Now things gets messy. Vegas is forced to spend a lot of time decoding the source mpeg streams. The adaptive preview seems to get muddled and frame rate jumps up and down. If this is what others are seeing then I can understand their complaints. The underlying problem I believe is that the mpeg-2 system and probably AVCHD, has no mechanism to half decode i.e. use less CPU and give a lower resolution frame. If this is what's bugging users then two choices seem to present themselves. Get a much faster system or turn the feature off.
Other systems do seem to create proxies that can gracefully degrade when being decoded. I doubt too many of us would want Vegas forcing us to go down that path like they seem to do. On the other hand maybe we can have such as system as an option.
So my view is this new feature in V9 is a plus, it works very well when it works. It would seem like it can turn ugly when pushed beyond its limits and maybe there's some scope for further fine tuning. Overall so far I see it as a big step forward, if nothing else it's an acknowledgement of the users complaints.

Bob.

[edit] One other thing I seem to have noticed. With adaptive preview on the size of the preview window seems to make quite an impact. If you're really having issues, try making it bigger or smaller. There does seem to be some sweetspots. Whatever you do don't just throw it out the window in the first minute. Play around with it a bit.

Comments

megabit wrote on 5/29/2009, 6:57 AM
"It can work very, very well. I put a HQ EX clips onto the V9 T/L. Plays out nicely, add CK FX and switch on adaptive preview. Quality drops but fps holds up. I added a similar clip minus any FX after it. Kind of wierd watching the quality jump up after the cut but what else could Vegas do here"

Actually, I never witnessed Vegas rising up the quality, once it found it necessary to lower it down. E.g. even with a clean clip (no FX), when there is a single glitch (like I/O busy when starting playback), it will go to Half from Full, and stay there for ever. Sort of one-way street...

When I switch the feature off, it will happily play the clip at full res and fps!

Piotr

AMD TR 2990WX CPU | MSI X399 CARBON AC | 64GB RAM@XMP2933  | 2x RTX 2080Ti GPU | 4x 3TB WD Black RAID0 media drive | 3x 1TB NVMe RAID0 cache drive | SSD SATA system drive | AX1600i PSU | Decklink 12G Extreme | Samsung UHD reference monitor (calibrated)

Grazie wrote on 5/29/2009, 7:22 AM
Bob, yes.

My "hurrah!" for the Preview thing was that this appears to be Madison further declaring acknowledgement of our wishes, and maybe, just maybe, we are starting along the road of some form of "intelligent" Previewing. What this will become in the next 2 to 3 years - I can't wait! But the future is looking promising.

Grazie
Steve_Rhoden wrote on 5/29/2009, 7:49 AM

You made a very good point there Grazie.....
That just maybe theory of yours, there will be something there.
jabloomf1230 wrote on 5/29/2009, 6:24 PM
Piotr,

That's my experience also. I just turned the option off.
farss wrote on 5/29/2009, 6:46 PM
"My "hurrah!" for the Preview thing was that this appears to be Madison further declaring acknowledgement of our wishes,"

This new feature and other changes made / features added in V9 show what looks like a signifcant change in the Vegas landscape. Everyone of them is something that has been mentioned here over the years. I feel that the money I've paid for the V9 upgrade has been much better spent than what I paid for the V8 upgrade.

The best marketing tool that SCS has for Vegas seems to be it's users. They did seem to have lost sight of that for a while, good to see that the ship might be back on course.

Bob.
Harold Brown wrote on 5/29/2009, 7:35 PM
Good analysis farss. In some cases (details you mentioned) it does a pretty good job. I can only see this getting better over time and with the ability to turn it off it could be a handy tool from time to time.

I am running a quad 2.4 right now but plan to upgrade late next year to a faster machine (and new OS). This one is only 15 months old so it will become my everything else machine.
rmack350 wrote on 5/29/2009, 10:58 PM
Last I looked it was resetting back to a higher quality preview when I stopped playback...

Okay, looked again. put a few clips on the timeline, overlapped a couple, applied an effect to the center one. It seemed like the first time I played through this the preview adjusted down and stayed there even on the last section of clip that was just raw DV. Preview popped back up to good/full when I stopped playback. All subsequent times I played back the region the preview dropped to Preview/full and then back up to good full over the raw sections during playback. I didn't need to stop and start. I can't make the section drop to preview/full and stay there, which makes me doubt that I ever saw it.

It appears to drop up and down as I play. If it did that rapidly over a barely rough patch then it might not be too pleasant. Seems like that ought to be something they could fine tune over the next few letter patches. Generally, I like the better playback over the transitions and effects, even if the quality is a little less.

(Edit: I just changed my RAM preview setting and then played the loop again. The first time I played it it dropped to preview/half and stayed there forever. After a stop and a start the preview quality was able to pop back up to good/full. I'm kind of wondering how Vegas' frame caching is working with this? My assumption has always been that Vegas caches frames at whatever your preview settings happen to be. If Vegas is automagically downgrading your preview quality does it then cache frames at that quality?)

Rob Mack