DVDA2 size of file problems

dan4dvd wrote on 12/8/2004, 7:18 AM

I have just begun entry into DVDA2 and have run into a problem.
I am using the DVD Architect STUDIO version (aka cheaper one).

I imported 2 mpg2 files (that I edited via Vegas Movie Studio) into DVDA2, but when I did their size "grew."

The files were 2.32 GB and 1.44 GB, but after importing them became 3.27GB and 2.04GB, respectively.

I know that I can optimize my files and lower their bitrates, but it doesn't seem that I should have to do this and it also takes about 5 times as long to burn a DVD then.

I think I read somewhere that lowering my bitrate in the optimize files section would decompress and then recompress my files and thus diminish the quality of my files significantly.

I have Vegas Movie Studio+DVD (the $100 version) and cannot figure out how I might lower the bitrate there.

Does anyone know what happened here?

This would limit my overall time per 4.7GB DVD by 40%.

Thanks.
Dan

Comments

ScottW wrote on 12/8/2004, 7:40 AM

What are you looking at that tells you they grew? The project size as shown by DVDA, or the file size on the optimize screen?

In the case of the project size, if there was an AC3 file with the same name and in the same directory as the MPEG file, then the AC3 file will be reflected in the total size as well.

In addition, DVDA is showing you sizes in base 10, windows is showing you sizes in base 2. In computers, 1K is 1024, not 1000.

So for example, a 1.49GB file as shown in size by windows will show as 1.7GB on the optimize screen in DVDA.

Basically, you need to make sure that the sum of all your file size as shown by windows (MPEG and AC3) does not exceed 4.37GB - and that assumes no special menus or other fancy stuff like animated thumbnails. As soon as you start adding in various "features" you'll need to start reducing that 4.37GB value.

You should always use a bitrate calculator to figure out what your optimum bit rate will be (do a google search on "bitrate calculator" - the first hit should be a java calculator at videohelp.com) when you get ready to render from Vegas. Obviously this gets more complex as you start to make complex menus - so sometimes if I can, I'll actually create a dummy menu and prepare the project, add up the sizes of the files in the VIDEO_TS folder and then subtract that from 4.37, which leaves me with the amount of space I'll have left for my content.

You're much better off doing this from Vegas rather than doing a "fit to disk" and having DVDA re-compress. If you're in a hurry, you can render from Vegas back to DV AVI, then use those in DVDA and let it "fit" - you won't lose from recompression, but you won't have as much control over compression either.

<edit> Sorry, I just re-read and noticed you were using studio. Well, your only option might be to let DVDA do the optimize thing with the AVI files.

--Scott

dan4dvd wrote on 12/8/2004, 7:59 AM

I have the DVDA STUDIO version and don't know if this will make a difference.

You were right - I forgot to add the audio files.

So, my file (including audio) in Windows is 2.92GB and thus in base 2 would be 2.99GB. Yet the optimize screen shows 3.27GB for the file itself - not counting any menus or extras.

Is this merely a safe guess for the program?

Also, the default bitrate appears to be 8.0. How much could I lower it without truly effecting noticeable quality (I realize this is a subjective question)?

I think I read somewhere that lowering my bitrate in the optimize files section would decompress and then recompress my files and thus diminish the quality of my files significantly. Is this true?

If so, I guess I should lower my bitrate before I import it into DVDA2.

I have Vegas Movie Studio+DVD (the $100 version) and cannot figure out how I might lower the bitrate there.

ScottW wrote on 12/8/2004, 8:13 AM

DVDA can be pretty bad at project size estimates, but actually showing a file size it should be ok at, though I don't think I've personally ever verified it. I usually end up just worrying about what Windows is saying since project size estimates can be way, way off.

If your source material is MPEG, then recompressing in DVDA will cause the file to be decompressed and then recompressed at the new rate - so yes, this can cause a loss in quality since you aren't working with the original source material. Hence the suggestion that it might be better for you to just use AVI files in DVDA (since I don't think you can control the bit rate during render using MovieStudio)

I routinely use 6,000 as my average bit rate and the material looks fine - it depends on the material. I don't like going much lower than 6,000 though (in terms of an average), but I have gone as low as 4,800 and things didn't look too bad (granted, the source material wasn't in that great a shape to begin with).

--Scott