Proxies, rendering, Prerendring and digital interm

Kit wrote on 12/3/2014, 7:13 PM

In the Video Preview Quality thread musicVid10 suggested that I use prerender. So I'd like to ask if there is a difference between prerendering and rendering and proxies and digital intermediates. Is prerendering faster? Gracie mentioned using Lagarith but I don't see that in the prerender dialogue. I feel I'm totally missing something that all you regular Vegas users know and so take for granted. My apologies for asking what must be basic questions. It's very awkward that I can't get help to work with a project open. Almost enough to drive me back to version 12. I want to report this issue but when I try to do so Sony insist on using Japanese and I can't read it. If anyone else has the help/crash issue I'd be grateful if you would report it. Thanks. This forum is what makes Vegas worth using.

Comments

johnmeyer wrote on 12/3/2014, 7:59 PM

They are all related.

All of them involve using a codec to create new video.

All of them involve creating new files on your hard drive, although one form of pre-rendering can be done to RAM.

Pre-rendering is generally done on a small subsection of your overall project. The purpose is to improve timeline performance on a really complicated part of the project (lots of compositing, fX, etc.). Later, when the project is rendered to a final result, the pre-rendered section will render much more quickly, thus saving time. In fact, if your final render is the same format as the pre-render, and if Vegas aligns the moon and stars, you might even get this section to "smart render," and that portion of the render will be nothing but incorporating the pre-rendered video file into your final rendered result.

Proxies are used to create low-resolution versions of ALL of your video in the project. You use these if you want the fastest possible timeline playback performance, and can accept some reduction in the spatial quality (i.e., resolution) during playback. Just before you do the final render, you use a script to automatically replace all the proxies with the original, high-resolution video. To create Proxies in the first place, you usually use a script which creates the proxies from all video files in a selected folder.

Intermediates are similar to proxies, except the video is created at the same resolution as the originals. Like proxies, you usually use a script to create all the intermediate files. Intermediates may be the same resolution as the original video, but a good intermediate codec plays back much, much faster on the timeline than does the video from your camera. I explained why in my earlier post on this subject in the other thread. In addition, if you want to pre-render, or if your workflow requires that you render several times before you get a final result, a good intermediate codec lets you do several renders without getting that "copy of a copy of a copy" degradation that we've all experienced with Xerox machines, and which also happens with video.

videoITguy wrote on 12/3/2014, 9:26 PM

Adding johnmeyers ideas on DI 's - actually there can BE even much more going-on.
For example changing the color space or gamma shift can be helped by using an appropriate DI. In general a DI is chosen because it will transfer as much as you have in the source, preserve it, and be usable in yet a different workflow stage, or different platform, etc and even by different editors such that little to no loss occurs AT all the transfer points. This is far different than a proxy purpose - is a quick and dirty expedite to get edit points established.

johnmeyer wrote on 12/4/2014, 12:00 PM

+1 videoITguy.

3d87c4 wrote on 12/4/2014, 1:31 PM

Ok...dumb questions....

Pre-render:

Does this mean to render a sub section of your project---i.e. a collection of clips on your timeline---then replace the original clips with the new one?

Or, does Vegas know about the "pre-render" and use it automatically?

rraud wrote on 12/5/2014, 9:05 AM

Pre-rendering does not require the user to replace the files. (unlike proxy files, which does)

malowz wrote on 12/5/2014, 1:44 PM

i used for years intermediate files, it speed up amazingly editing, and makes vegas almost crash-free. Sometimes i use some different format, or original avchd files and vegas goes nuts. Then i remember why i use intermediates. ;)

i have a great workflow and everything is optimized to maximum. i do a lot of batch tools to automate processes (a batch to copy files from AVCHD cards and do backup, another to convert to intermediate, another to process files with deshake, another to convert intermediate to blu-ray and dvd files for architect, and so on...)

never going back to native editing. i used proxies in the past, but intermediate is my way now.