Vegas AVI PRE-Render

Movick wrote on 4/22/2006, 12:07 AM
Of late I've been editing ever more complex pieces, and the need to pre-render sections such as montage openings is becoming unavoidable. For whatever reason, when I pre-render a timeline section as an .AVI out of VV5, it looks discernibly poorer in quality than sections not pre-rendered after the final render. Does anyone have a clue as to why I am having this issue? I notice this difficulty predominantly where text or still images are incorporated into the pre-render. Is there any solution to get a clean pre-render which will equal the other sections of the timeline once the final render is completed?

Thanks,

Movick

Comments

JJKizak wrote on 4/22/2006, 5:27 AM
Make sure in the options your prerender files are not going to your "C" drive.

JJK
Movick wrote on 4/22/2006, 8:27 AM
Where should they be saved? Why would that matter?

Movick?
Zulqar-Cheema wrote on 4/22/2006, 8:40 AM
If I remember right what ever the setting the preview window is on, it will pre-render in that quality, so if you are in draft, then it will render in draft.
Movick wrote on 4/22/2006, 8:55 AM
I've always used the highest possible settings within the custom settings when rendering to .AVI. Does anyone know whether I should obtain clarity equal to non-pre rendered sections of the timeline when creting .AVI files?
Udi wrote on 4/22/2006, 9:29 AM
If the problem is in Text/Image - might be you pre-render with "good" setup and final render in "best".
What you can do - render the section to a new track, place on top - this way you control the setup and the re-render.

Udi
winrockpost wrote on 4/22/2006, 9:32 AM
should be the same,, make sure you are prerendering the files to the same quality as the final. good,best etc.
rmack350 wrote on 4/22/2006, 10:59 AM
My guess would be that you're choosing a dv25 format for your prerender. Try uncompressed.

Rob Mack
Movick wrote on 4/23/2006, 9:00 PM
Hello all.

Sadly, after taking all of the steps outlined here, I still have a discernably less clean .avi after a pre-render as compared to sections not pre-rendered after the final video file is created. I had always thought the using the uncompressed setting and making sure all render settings set to best would yield proper results, however this is not the case. I am exceedingly frustrated with this issue, as I will be forced to add one fairly complex timeline to another even more complex timeline to get the result for which I am looking. I notice a less sharp, slightly fuzzy appearance to pre-rendered sections after dropped in a timeline and rendered to the final. Is there anything else which may be the culprit? This issue essentially makes Vegas a less than useful editing system, especially where one works with large and complex timelines .

All suggestions are greatly appreciated.

Thanx,

Movick
rmack350 wrote on 4/23/2006, 11:42 PM
Don't know what the issue is but if your prerenders are uncompressed and yet you lose quality on the final render then something is wrong with your process. Could you spell it out in detail?

Rob Mack
Movick wrote on 4/24/2006, 12:19 PM
Here are screenshots of what I've done. Thanks to all!

http://www.programmedremotes.com/vegas.htm

Movick
Former user wrote on 4/24/2006, 12:28 PM
What type of file is your final render (uncompressed, DV etc)?

You probably already know this, but there are SETUP options for the PRE-RENDER files that is seperate from the final render. Is that the screenshots you posted, or is the screenshot for the final render?

Dave T2
Movick wrote on 4/24/2006, 2:41 PM
Those shots are of the final render to .avi.

Movick
Former user wrote on 4/24/2006, 3:16 PM
And your PRERENDER settings are the same?

Dave T2
Movick wrote on 4/24/2006, 3:25 PM
From where are the pre-render settings accessed? Why is this setting relevant to the final output?

Thanks,

Movick
rmack350 wrote on 4/24/2006, 4:07 PM
Well, it shouldn't be relevant. In fact I just did a test by prerendering a clip in DV25 format and then doing a real render at uncompressed. Vegas very properly ignored my dv25 prerender.

You create a prerender by keying shift+M. Vegas then shows you a dialog asking what format to make the prerender. After the prerender is made, Vegas displays a little thin mark above the prerendered area. I don't see the mark in your shots (It could have been lost when the screens were resized though), and the fact that you're asking how to access this setting makes me wonder if you are doing something other than this type of prerender.

What you were describing sounds like a render to DV25. That would screw up the test and graphics. However, a prerender like that should get included in the final render if the formats don't match. That is how V6 behaves and I'm sure V5 does the same.

Incidentally, Vegas prerenders aren't very robust anyway. It's a prerender of timeline coordinates and it dissappears when you change the media at those coodinates. Very dissatisfying.

Rob Mack
Movick wrote on 4/24/2006, 5:00 PM
Forgive me, but I'm not clear on the explanation you've just offered. Isn't the function of a timeline “pre-render” to view that section in real-time when your computer starts to lag on playback?
What I am looking to do (perhaps I misused the term "pre-render) is render out segments of a piece which are complex, such as an intro montage, into portable single video chunks which I may place into another timeline with zero loss in quality. Quite often, I will create a separate timeline for an intro montage - allowing me to focus on the 30 second segment without the potential fuss of messing with the main piece itself. I simply wish to render out a montage for example, then add it into the timeline for the remainder of the piece as a single video chunk. Does that make sense?


Thanx,

Movick
Chienworks wrote on 4/24/2006, 5:04 PM
Movick, are you doing a Shift-B prerender?
rmack350 wrote on 4/24/2006, 5:08 PM
Try the shift+M command, for starters. Maybe you have already.

Now, it sounds as if you are rendering footage to a new track, or making render files to use elsewhere. The symptoms you describe sound like you're using a DV template. That would account for the bad looking titles because the DV format only samples color every fourth pixel. The three pixels in between are just averaged.

In any case it sounds like you've got a format missmatch in there that's chewing up your text and graphics.

Rob Mack
Movick wrote on 4/24/2006, 5:09 PM
File/render as
Movick wrote on 4/24/2006, 5:17 PM
Where's the mismatch? I used the uncompressed template... no ntsc dv. I'm lost here
Chienworks wrote on 4/24/2006, 6:32 PM
File / Render As does not make prerenders. That is only used for final renders.
Movick wrote on 4/24/2006, 8:42 PM
Forgive me for saying, but for whatever reason whenever I post a question here I get fragmented responses which are at best more confusing than helpful. I appreciate the fact that some here are trying to help, but unless I'm completely insane; it seems we keep rehashing the subject without resolve.

I am asking a simple question here – what is the best way to create a single chunk clip to use in another timeline. I feel I've more than clearly explained this, yet I keep getting these fragmented replies which seemingly serve more to pontificate than to assist.

Could someone please tell me the correct way to get a clean one chunk piece of video to use in a timeline outside of the original with no loss in quality...please? Does it matter whether the render is “final” or “pre-rendered” for use in another timeline? When I create files outside of Vegas, I final render as an .avi, and the files seem to work just fine…why is it different if I final render in VV5?

Movick
PeterWright wrote on 4/24/2006, 9:17 PM
You didn't say what format you started with, but if it was DV, then you should be able to render an avi without losing any discernable quality.

"Good" is normally fine for rendering quality - if you've done some resizing in your project, then you may need to set this to "Best" to get optimum quality. (Will take longer to render, but is worth it)

If you are still getting inferior quality going from DV avi to DV avi, there must be a setting causing this.
rmack350 wrote on 4/24/2006, 9:31 PM
Okay, your question is a bit clearer. Render your files for use in subsequent projects as uncompressed avi files. Make sure you are using or adjusting your template so that the media stays in the same format throughout -- Same dimensions, same pixel aspect ratio, same field order. Flopping field order can make things look blurry under some circumstances.

Now, uncompressed files are huge and you can compromise by using Sony YUV, which is a 4:2:2 sample scheme, rather than the 4:4:4 scheme of an uncompressed file. However, don't go back to DV, which is 4:1:1 and throws out way too much data for the sake of small files.

If you feel that you are already doing this and yet the media is degrading then I'd say you're doing something wrong or missing something along the way.

Why not post some frame exports of "before", "during", and "after" shots?

Rob Mack