Probably the reason your file is growing is because you are starting with a DV AVI file and rendering to an uncompressed AVI file.

You should not have any black bars if you rendered correctly. Be sure you change your Pixel Aspect Ratio to 1:1. It is probably set for DV aspect.

Dave T2

To reiterate and emphasize what deusx said:

The only thing that determines file size is bitrate.

Everyone (and I mean everyone) makes this same mistake of thinking that 640x480 is going to create a larger file size than 320x240. And, of course, this is with good reason: A still photo that is 640x480 IS larger than 320x240. However, when dealing with moving images, AND when dealing with compression that uses inter-frame compression (i.e., it creates each frame by using information from adjacent frames), the encoder allocates a certain number of bits for each second of video. If you encode higher resolution video, then in order to stay within the budget of "x" number of bits per second, the encoder will use far fewer number of bits to predict the next frame.

As a result, if you try to use a really low bitrate to cram a lot of video into a given size (for instance, putting three hours of 720x480 NTSC DV video onto a single-sided DVD), the image may look great if nothing is moving, but will look terrible during fast moving scenes, dissolves, etc. One "trick" you can use is to encode at 352x480 (a legal DVD resolution). Obviously, since the resolution is lower, the low-motion scenes will not be quite as sharp, but now there will be lots more bits available to provide the information on how to reconstruct each frame during high motion sequences. Thus, you can trade temporal for spatial quality.

So, the bitrate is the only thing that will determine file size. Oh, and that is the average bitrate. The min and max have no effect on anything and usually should be left at the default settings.

great post, John.. and thanks for the 352x480 trick, I didn't know that one. right re all that matters is bitrate... solid answer..

ken

I am rendering to an uncompressed file just like the raw video of my capture. I could not find a way to control rendering bit rate other than best, good, etc in the rendering window. Not an actual bit rate setting. Only at authoring do I seem to have such control if needed.

What really confused me in all of this is that I never change the bit rate when changing between formats but the file sizes grew almost exponentially! I fully underdstand the relation to bit rate and file size, but bit rate remained constant as far as the settings I am using in Vegas. Therefore, I do not understand how file size grew is the bit rate was held at the same setting. Can you please help me grasp this as it is certainly an important concept.

thanks for the very complete and explanitory response, I do appreciate the time, effort and benefit of your experience in unerstanding this issue.

I am rendering to an uncompressed file just like the raw video of my capture.

Anything that you may have captured from a camera or other source was not uncompressed. I can pretty much guarantee that. Video on DV or HDV tape is compressed; just not as much as so-called "delivery formats" like MPEG-2.

When a frame of video is displayed, that frame, for that one moment, is uncompressed because each pixel must be available to light up the corresponding spot (pixel) on the display. As this page

Storage requirements for compressed and uncompressed data

on Microsoft's site shows, uncompressed video is huge: One hour of 720x480 video takes 90 GBytes of disk space, and 1920x1080 60i HD takes 410 GBytes.

Generally, you do not want to save video in uncompressed form, although it does have the advantage of avoiding a generation loss. Usually, however, it is better to simply do everything to your video within one project and then render to the final format (WMV, MOV, RM for the web; MPEG-2 for DVD; and DV AVI or m2t for printing back to tape).

John,

I was unaware that the raw video footage was compressed, that is interesting. When captured into Vegas I fully realize the exceptionally large file sizes associated with uncompressed video but I was unaware that the captured AVI file could grow to the percentages they are growing as the edited files are generally shorter than the original captured AVI.

Where is the setting for bit rate during rendering if it is other than good better best etc.?

I was attempting to stay away form compression at least throught the editing process resulting in a final video ready for compression. I like to use Sorenson Squeeze for the flexibility it offers to accomodate different formats therefore, I need to begin with uncompressed video to begin the compressing process.

Again, forgive me if I am missing something here that is right in front of my face but if the resulting captured raw video AVI file is 5 Gb for a three minute clip with a native format of 720X480 29.97-fsp, how is the video increasing to over 100% by reducing the format size in rendering to 640X480. The overall frame is smaller not larger than the original. Regardless of bit rate which I had stated that I am not changing, the only way the file size can grow to this extreem is that the original AVI (captured file) was actually COMPRESSED (I did not realize this) to a rather dramatic extent considering what I found in reducing the frame size.

If this assumption is not correct please indeed set me straight.

I am now rendering to the 320X240 frame size, uncompressed which eliminates the black bars on either side of the screen. I have found that by leaving rendering out to the native 720X480 frame size then compressing both the frame size in Sorsenson and reducing the bit rate provides a smaller file but one that still contains the bars on each side UNLESS I un-check the perserve aspect ratio button in Sorsenson. Otherwise, the bars are there!

If you could offer me some short cuts to these steps in my attempt to maintain flexibilty, and image quallity, I would certainly be grateful for your wealth of experinece.

Your mention of the 352X480 is indeed something I did not realize and in fact I am trying to visuallized that format. It would seem to be much more narrow than it is tall.

Are there any examples of this that you could point me so I could see it?

Hello there

John has given you all the correct tech info, but forgive me if I say that you may need to learn some basics before it will make enough sense for you to make a decision.

Draft, Preview, Good and best are the quality that VEGAS generates the source video at. That video is then compressed by the codec ( or not for raw video).

The 352x480 format is recognised by the MPEG player and stretched to the correct aspect ratio.

Which to use
***************
Sticking to the codecs in Vegas: for internet use you have two main options: Quicktime or Windows Media.

Which one to use depends on where you want to show it? Can you write HTML? and who is going to view it?

Andrew

What kind of video are you shooting/capturing?

DV is a compressed format that is compressed at 5.1 ratio in the camera. That is, you never will get uncompressed video out of a DV camera, unless you do a hack.

So you do not want to compress this any further. You want DV to To achieve that, you should render to the DV template, not the uncompressed template. 720x480 means you are NTSC. So use the NTSC template.

Also you can render to a lot of formats straight from Vegas, you may not need Sorenson. Perhaps you can get better quality out of Sorenson.

Andrew,

I believe I understand the basics. The good, better, best setting is a relative bit rate setting that controls ultimate file size. Basic stuff.

The low medium and high setting provides limited granularity wouldn't you agree. I wondering if I might have missed a Vegas setting of the actual project bit rate like that found in Sony DVD Authoring and in Sorenson Squeez where acutal bit rates are settable. Again, I understand the basic relationship. Otherwise, why would I be using Sorenson Squeeze?

I am not offended in the least at your suggestion that I "should learn some basics before things will make sense." Feel free to carefully read my last set of questions and responses and feel free to jump in, and comment specifically on the analysis I offered and the feedback I requested.

If you have some specific details that you can offer to this discussion, I would welcome your input. I would ask you to please stick to the specifics of the question and refrain from some predisposition you may have about what I may or may not know. No one knows it all! That's why I value input from the talent within this group.

Buster,

Thanks for the answer. Specifically I have never heard of the 5:1 but from what John said earlier, and what I was finding, I felt certainly some compression was involved in the caputured video. It is entirely possible that I am over-doing it here but I am attempting to maintain maximum quality before compression to the smaller format whcih is my target output. It involves WMV, MOV and even FLV. Vegas unfortunately does not offer the FLV compression and not the level of control over the compression that Sorenson does on all formats. My madness!!

When it is time to compress the files to the format I will need, I am using uncompressed AVI wtih Sorenson to get to the format I need which eliminates the rendering for each type in Vegas.

That flexiblity has been working nicely for me. The thing that started the intial round of this group discussion was the hick-up I noticed when I attempted to change the format of the original 720X480 captured video to 640X480 to eliminate the bars on either side of the finished video. I found that if I did not correct this before rendering, they were with me forever reagardless of the screen size of the rendered file. Begining with the next smallest frame size for 4:3 aspect ratio, (640X480) the bars were gone but this resulted in a file size when renedered that was in execess of 9Gb. This is 2:30 clip so I knew then I had over looked something as I thought the file size was going to decrease. So I thought I would ask if there was input as to more direct steps to reach my goal without sacrificing quality or flexibility an why this was happening.

I know that I can render directly out of Vegas to WMV or MOV using the Quicktime 7 format or even Sorenson 3, but not Quicktime 8 and still, no Flash output. With Sorenson Pro 4 all this and more is possible with many choices for bit rate control of each file type.

If you have not tried it, look at it as a nice edtion to Vegas. If you can offer some guideance to my madeness that may save me some time with sacrafices, please be so kind to share with me.

Thanks for submitting your comments!!

"Low, medium, high" has nothing to do with the bitrate. That controls how much effort Vegas goes through in making each frame look as good as possible.

Bitrate, as discussed in this thread, applies only to compressed video. Therefore there isn't any bitrate setting available when rendering to compressed. Bit rate specifies how many bits per second the compressor is allowed to use when compressing your video. A lower bitrate means more compressed.

I may have missed this somewhere along the way, but why are you rendering to uncompressed?

Yes this all began from a project where I was rendering un-compressed and reducing the frame or format size of the original 720x480 captured video to 640x480 where the rendered file size increased almost an order of magnitude. I put this to the group for a discussion and at one point some offered the setting of bit rate in vegas and like you, I did not recall seeing this. I fully expected the file to be large, but not that much larger than the capture.

Thanks for your time and input!!

Don't worry about it.

Edit, don't resize anything ( if possible, crop if you need to get rid of black lines )render to uncompressed avi and pay no attention to file size because it makes no difference in the end.

Import that into sorenson, and there set your bit rate, resize and add web filters , deinterlace, etc........

I still think you don't have it. You should post your workflow, in very simple steps. We'll let you know if you doing something wrong.

1 Capture DV
2 .....
3......

JKB:

At risk of beating an issue to death, a few more questions and comments:

(1) You are working in NTSC DV, right? Is this stuff all captured from a camcorder? Are there still photos on a timeline?

(2) Why are there black bars? There shouldn't be any black bars in NTSC DV from a camcorder.

(3) As already mentioned, DV is a video format that is already compressed at about a 5:1 ratio when compared to raw "uncompressed" (meaning 3 RGB bytes for each of the 720x480 pixels per frame). There is no reason to ever have to render to an uncompressed avi format unless your follow-on process demands uncompressed. A project pulled into Vegas as DV can undergo literally dozens of serial compress/decompress cycles without any degradation, so there's no reason to go with uncompressed from a degradation point of view. I would assume that Sorenson (or any other commonly-used compression product) would be perfectly happy dealing with 720x480 NTSC DV avi as a source format. I could be wrong on this; I'm usually wrong on at least one thing every day.

(4) If you're throwing video on the Internet, wmv isn't the only game in town. In fact, it's being clobbered by something called the flv format, part of a bag of tricks commonly known as Flash.

I had to go to a baseball game and then shoot a jui jitsu black belt ceremony. That was a first for me. About to render right now.

My comments about bitrate, if you go back and re-read, only apply when encoding using compression, and then only if the compression uses inter-frame compressions. I said that in the original post, but I want to be clear.

As to your file, well, I guess it IS uncompressed, because 5 GBytes for three minutes is exactly the same as 90 GBytes for 60 minutes. As to why it gets larger, I don't know Sorenson at all, but you might want to check the number of bits being used for color. The more bits, the bigger the file. Thus, if you are converting to a larger colorspace, the file WILL get larger. There is no advantage to using more bits/pixel for color depth (you can't make something out of nothing), but perhaps you are inadvertently using a preset that has a larger color bit depth than your original. If so, the slight reduction in going from 720x480 to 640x480 could easily be more than offset by that increase in color depth.

Finally, since my earlier post dealt with compressed video and talked about how the only thing that matters is bitrate, let me again -- as I did in that earlier post, and did at the top of this one -- emphasize that this only applies to compressed video that uses inter-frame compression, like MPEG-2. For uncompressed video, the video is stored as a series of still images, each one completely independent of the other, and in this case, the file size can easily be calculated by multiplying the horizontal bits times the vertical bits times the bits/pixel for color times the frames per unit time. If it wasn't so late, I'd do the calculation for you. It's something like:

720 x 480 x 8 x 30 x 60 x 60 = ?

but that's not quite it. Close though.