Feature request: HDV selectivfe prerender

Laurence wrote on 5/17/2007, 8:01 PM
This has gone from being a "bug report" to a "feature request":

I would love to be able to use the "selective prerender" function in an HDV project. The Cineform Neo and Connect HD codecs smart-render in Vegas. They should be able to selectively prerender as well. The selective prerender function used to really help systems that weren't quite up to the task of previewing SD transitions in realtime. Now all the current PCs fly through SD transitions and hardly need this function at all. Currently, HDV projects are more of a challenge and the selective prerender function would be as useful for many of us in HDV projects as it used to be on slower systems with SD. It really should be an HDV feature, especially on smart-renderable Cineform codec projects. It would also speed up the rendering of smart-rendered Cineform masters.

For those of us trying to make due with older single core systems, adding this feature would be invaluable.

Comments

[r]Evolution wrote on 5/18/2007, 2:21 PM
What is 'Smart-Render'?

Is this where the Timeline would Render in the Background?

Laurence wrote on 5/18/2007, 10:09 PM
Smart-rendering is where any part of the video that isn't changed is just file copied. In other words, if you add titles, color correction, a filter, etc., any of those parts would need to be rendered. But the parts in between these changes where nothing has changed are just bit copied into the new edited file.

This has two advantages: one, you don't lose a generation for the parts that are smart-rendered. Two: it is WAY faster: I'm talking forty or fifty times faster on an older machine like mine.

Smart rendering and selective prerendering are related in that the parts of a project that can be smart-rendered also tend to preview very easily. What a selective prerender does is to render proxies of just those sections where something has changed. Then when you are previewing the project, when you get to these difficult sections, the proxies play and your preview stays smooth. This has two postive results. One: your previews are really smooth after a selective prerender. Two: the proxies of the difficult parts can be used in the final render. This means that rendering out a master of a selectively rendered project goes lightening fast.

All this works beautifully in a standard definition DV project. The problem is that it doesn't in an HDV project. Connect HD or Neo based projects smart-render beautifully, but they don't selectively prerender. They should, and if they did, it would make working with Cineform in a Vegas project VERY easy and fast, even on a borderling system.
[r]Evolution wrote on 5/18/2007, 11:20 PM
Sometimes I run into the problem of wanting/needing to show a project/timeline but can't because it continues to drop frames in spots where I've added Titles, Graphics, Composites, Layers, etc.

I wish I could Render my timeline like in FCP or Premiere so I could play it all the way through without dropping frames in at least Preview Quality. At current w/ 4GB Ram I can still only Ram Render so much of the timeline.

It would be nice to be able to Render the timeline out to a Temp file directory then we could just delete the Temp files. Ram Render is cool... but I personally would like a little more Render Power/Control on my timeline.
Grazie wrote on 5/19/2007, 12:38 AM
Synch? Have you tried a test, a Nested Preview Project? I don't know IF this would assist you, but:

#1 - Create a Copy of your MAIN Prject: CopyMainProj.veg ( this is a test, so to safeguard the underlying project I do TEST copies when I'm . .er . . testing!!)

#2 - Open a NEW instance of Vegas and Import the CopyMainProj.veg - this will create a Nested proxy file. I find the proxy file will take time to build, but less than other ways.

See if this is a help to your workflow? You may like it. Only an idea, but it may just get you to "see" and Preview your edit decisions better? Yeah? And if you are finding that it is slick to do this then you RIGHT click on the nested file and go straight back to the CopyMainProj.veg - in which you can edit and then save and tab back to the Nested and see if your edit fits what you want.

Grazie
Laurence wrote on 5/19/2007, 4:12 PM
>It would be nice to be able to Render the timeline out to a Temp file directory then we could just delete the Temp files. Ram Render is cool... but I personally would like a little more Render Power/Control on my timeline.

That is exactly what a selective prerender does. It's a little different in Vegas than in other apps though. In Vegas, what it does is go through the timeline and render anything that needs to be rendered to preview smoothly into temporary proxies in a user assignable temp directory. Unlike FCP which renders transitions that can be moved, this is a timeline based render made up of a series of short proxy renders. If you change anything like move a transintion a little forward in time for instance, you need to rerender the proxies from point that was changed through to the of the project. In actual practice, this works quite well as most of us tend to work from the beginning to the end of the project.. Change a timing at the beginning however and it needs to start the process again.

Anyway, all this works fine in standard definition. It just doesn't work properly in HDV resolutions. If you try a selective prerender in an HDV project, it will render the whole project including the video between the transitions. This takes a whole lot longer and uses a whole lot more space. With native m2t files this is probably unavoidable, but with smart-rendering Cineform AVIs, there is no reason this feature should not work.

If a selective prerender did function properly in an Cineform HDV project, the result would be that if you were doing a typical workflow of working from the beginning to the end of a project, your previews, titles and filter effects would all preview smoothly even on borderline systems, and the rendering of a final Cineform master would be almost as quick as a direct file copy. You could do selective prerenders every time you took a few minute break, and the overall process would be very similar to what many of us went through when we used to have systems that were borderline for SD projects.

None of this would do much for people with lightning fast quad cores, but for those of us with slower systems, it would make all the difference in the world.
Laurence wrote on 5/21/2007, 6:40 AM
>It would be nice to be able to Render the timeline out to a Temp file directory then we could just delete the Temp files. Ram Render is cool... but I personally would like a little more Render Power/Control on my timeline.
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You can do this with the selective prerender by looping the section you want to prerender and running the selective prerender function with the "pre-render looped section" tab checked.
JJKizak wrote on 5/21/2007, 7:51 AM
I am behind the times but I noticed in 7.0E when video options set to 1394 and "rendering to player" that with widescreen the media player will output through my video card HDTV section. If I render anything to player in 720P or 1080i HDV vegas opens a second vegas and puts the rendered file on the timeline and will not activate "Media Player" I assume because media player cannot play m2t files. Is this normal?

JJK
Laurence wrote on 5/21/2007, 10:22 AM
Media player plays m2t files just fine. If you have a fast CPU, it will play them smoothly without any special effort. If you have a slow computer but a competent graphics card, nVidia's Pure Video will offload the mpeg decompression onto your graphics card. That's what I do. Pure Video is an nVidia program, but it works with ATI graphics cards likw my Radeon 9500 as well.
JJKizak wrote on 5/21/2007, 12:03 PM
Laurence:
Why does your media player play m2t files and mine says no way? I have media player 11.

JJK
Laurence wrote on 5/21/2007, 2:33 PM
m2t files are just mpeg files with some extra transport data. You should be able to play them. How smoothly they play back might be an issue, but they should play back.
JJKizak wrote on 5/21/2007, 4:40 PM
In reference to my previous posts 7.0d would open up media player (1394 firewire) when preview rendering to 1080i or 720p but the player would just stutter or hang up. Now with 7.0e vegas doesn't bother to open media player it opens a second (completely new empty) vegas project and puts the rendered file on the timeline. Just a wonderment . Is that something new in vegas that is telling me that it cannot do because the media player won't play m2t files? I also have Quicktime & Nero player installed.
JJK