Compression settings in Vegas...

[Gregory Stevens]

Hey all,

I have never been able to fully understand compression settings, between the fact that there are just so many options and that you almost always find someone telling you "these settings are the best!" I want to better understand what every setting means. I understand this will probably entail a lengthy response but if you have the time or have a website that goes into full detail - I'd really appreciate it.


Also, I use a Canon XH-A1 for my shootings, when I want to upload to a site such as YouTube or Vimeo using the "Windows Media Video V11" codec - What are the best settings to optimize quality and reasonable file size? I've also read "HDV 1080-60i (1440x1080, 29.970 fps)" format does not have a "true" HD pixel ratio which I do not understand - maybe my project settings for my XHA1 should be "HD 1080-60i (1920x1080, 29.970fps) ??

Please help someone super confused.

[Don Bloom]

I'll see if I can address the firswt part of your question regarding compression.
Compression is something that HAS to be done to the project if it is to fit propery on a single layer DVD which is what I believe most people are using. Please note that I am referring to STANDARD DEFINITION finished product. While there are many out there doing BluRay again I think the majority of people are still doing SD finsihed product so let's talk about that.
A single layer disc used for SD DVDs is only 4.7 gigs and with the disc formatting (automatic no need to do anything) it will actually only hold 4.34 gigs of material. Now here's where it gets tricky. Not really. All compression is time based. IOW a project that runs 60 minutes will not need to be compressed, it will fit nicely on a single layer disc for SD DVD delivery at the following bitrate; 8, 6, 2 (all in millions) as set in the Vegas RENDER AS (MPG2) menu using AC3 audio. However a 120 minute project will not fit on the disc at those rates because of the size of the project based on lrngth of time. Make sense? According to the handy bitrate chart from Edward Troxels Vegas newsletter from June of 2003, the proper bitrate for a 120 minute project going to single layer disc for SD delivery using AC3 audio, would be; MAX 8; AVG 4,826; and LOW 2 again all followed by enough zeros to equal million. Also keep in mind that these numbers are using VBR or Variable BitRate which allows the program to go thru the project and use different BRs as needed.
Now using those numbers the 120 minute project will fit on the DVD.
Hope that helps with compression. I'll leave other to expand on this and answer the other.

[Don Bloom]

See, it's too early and I forgot to finish my thoughts about this.
OK so it has been determined that the PROPER bitrate for any project that is to be delivered in SD format via single layer DVD is determined by the length the project in time AND the type of audio you want to deliver to the authoring program. DVDA really wants AC3 and will re-render audio back to that anyway so might as well start with it when rendering in Vegas.
All of these settings are adjustable ans savable in Vegas. Remember to go thru the render as menu for MPG and see the various settings. Single pass, 2 pass will not affect the bitrate settings. I suggest you get a bitrate calculator either Edwards or one online and use that. Remember that the bitrate is determined by the length of time of the project.

OK now I think I got it. ;-) Back to sleep for me.

[Steven Davis]

What is this "sleep" you speak of? Very nice explanation by the way.

[Don Bloom]

I will look up the definition of that word as soon as I get some so my brain can work properly. Wait, that will never happen.

Thank you for the kind words. I bet if I was fully awake I could have written 2 or 3 more pages ;-)

[Garrett Low]

Hi Gregory,

Just a note to add to Don's answer. Going from an HD source to an SD file using the encoder in Vegas will lead to less than a stellar looking DVD. This is mostly due to the scaling algorithm that Vegas uses when converting your 1080 content to a 720x480 video. There have been posts here on how to get a better end product. Here is one thread that discusses it:

http://www.dvinfo.net/forum/what-hap...d-quality.html

By using Virtual Dub or VDub you can get a much better quality picture. The downside is time. Depending on your computer it will add a lot of time but for me the improvement in end quality is very much worth it.

For your YouTube Vimeo upload question, both of those sights like MP4 or H.264 files. From my experience they pretty much destroy WMV when they process them for posting. I attached a template I use for uploading to YouTube. Your project setting for Vegas should match whatever the majority of your source files are. Since your using a Canon XH A1 it should be 1440-x1080. Since you have 60i material you'll also have to remember to convert to 30p (or really 29.97p) for web upload or you'll see really bad banding in high motion scenes. For most video I shoot progressive so either 30p or 24p. That just makes it easier for web upload and I personally like the look in general. But there are situations when 60i is preferred. You're camera just doesn't shoot square pixels so but it is HD. the 1440 pixels wide is just the HDV standard.

Hope that helps,
Garrett

[Mike Hammond]

Hi Gregory,

To answer the last part of your question about uploading to Vimeo & You Tube, I use the Sony AVC MP4 setting with the HD 30F template. It looks great and is made for web play.

Here is a sample of one of my vids:

CSX Iona Island Autumn on the River Line on Vimeo

-Mike

[Garrett Low]

Hi Mike,

I've only played with the Sony MP4 render engine for some Blu-ray burns. Never for web uploads. I noticed in your clip at around 26 seconds there's some noticeable macro-blocking in the mountain areas. Is this something Vimeo is doing? Also, could you post a screen shot of your setitngs you're using?

Thanks,
Garrett

[Mike Hammond]

Hi Garrett,

Here you go.

These settings aren't perfect, but I use them for wedding highlight reels as well and they turn out pretty good.

Vegas renders this template pretty quick so that's a big plus for me.

[Brian Karr]

Originally Posted by Gregory Stevens

Hey all,
I've also read "HDV 1080-60i (1440x1080, 29.970 fps)" format does not have a "true" HD pixel ratio which I do not understand - maybe my project settings for my XHA1 should be "HD 1080-60i (1920x1080, 29.970fps) ??

Please help someone super confused.

1440x1080 does not use square pixels as 1920x1080 does. The non-square 1440 pixels fill the same space as 1920 square ones do. This is done as a way to compress data (there are 1440 pixels instead of 1920). Your project can be set as 1920x1080 square pixels (i.e. pixel aspect ratio = 1.0), keeping in mind that your original 1440x1080 data will be converted (interpolated) to 1920x1080.

As far as compression. One way to simplify things is to keep in mind that bandwidth rules. The video bitrate will have more of an effect on overall video quality than anything else. The trick is whatever is decoding the video has to be able to handle the video bitrate, so there are limits as to how high you can go.