Inaccurate disc space read out

trea wrote on 4/3/2008, 11:37 PM
I am using DVD Architect 4.5 and I recently discovered that when trying to burn a DVD movie with a single file of 700 MB, that the DISC SPACE indicator says over 5 GB. I am using a DVD with MAX capacity of 4.7 GB so when I go to prepare, it says I have to optimize. I do that and take the bitrate way down to make it fit. After the perpare process is complete, the DISC SPACE indicator shows an accurate 525 MB of disc space used. (after compression of the video i assume) Why is this read out so "off" in the beginning? I originally wanted to put TWO 700MB files on this DVD but because of the read out, I did them on two DVD's. Now I have two wasted DVDs that have hardly any media on them. Please email me with any suggestions on WHY this is happening and how to fix it. Thx!

Comments

bStro wrote on 4/4/2008, 7:51 AM
The number on the bottom right of DVDA's screen is an estimate of the project's eventual size. If DVDA intends to re-encode any of your videos, this estimate will be based on the default bitrate or, if set, the bitrate that you have set specifically for any of the project's media. Note that unless you change it, the default bitrate is 8Mb/sec, which is generally more than necessary.

Granted, DVDA has always had a habit of over-estimating the final project size (and this error can be cleared up to some extent by simply saving your project, exiting DVDA, and re-opening the project), from 700MB to over 5GB is bad even for it. So my suspicion (assuming Save / Exit / Re-Open doesn't clear things up) is that your 700MB was not DVD compliant, and DVDA was going to re-encode as necessary. You can see which files, if any, need to be re-encoded (DVDA calls it "recompress") by going to File -> Optimize DVD.

If, on the other hand, DVDA does not report the need to recompress (ignoring menus since menus almost always have to be recompressed) and you know that the files are small enough to fit, then just do the Save / Exit / Re-Open steps mentioned above. If DVDA still has some wacky estimation, ignore it.

What are the specs of your original video? How long (in minutes) is it? What's its framesize? What format is it (MPEG2, DV AVI, Divx AVI, etc)? What bitrate is it encoded at?

Quick tip: Always use re-writeable media until you're happy with the output.

Rob
johnmeyer wrote on 4/4/2008, 8:43 AM
I don't think this is related to DVDA's lousy estimation because, bad as it is, it doesn't think that a 700Mbyte file will take more than 4.37 Gbytes.

Here are "gotchas" that can cause a project to balloon in size, even though you have only added one video file (this is something I posted a long time ago, and I'm too lazy to edit it):

As for the project being too large, did you add subtitles, multiple audio channels, or multiple instances of the same file? Did you use any of the video for animated buttons or menu backgrounds? If these things are done incorrectly, you can end up using the same assets twice (which will make the project size explode) rather than just having two pointers to the same media (which adds virtually no size to a project).

trea wrote on 4/4/2008, 9:53 AM
Thx for the reply. I have not tried saving, and reopening yet but will. What I noticed is that after the preparation is complete, the estimate changes to something that looks more normal. So what I am currently doing is ignoring the warning about exceeding the the disc space and continuing anyway. As for the video I was burning, 700 MB, Divx .AVI, about 1:30 runtime, 137 KB bitrate, 24 bit, 23 frames a sec. It does tell me that is has to "compress" the audio and video so I assume that it is not DVD compliant and that it is converting it which I guess is where some of the inaccuracy came from. I fairly new to this program and have only burned one project which all of the files were rendered by me. That project turned out well, this one is just a basic burn of some preexisting files that someone else rendered.

The other thing I noticed is that the preparation time takes a while for alot of these projects. It seems that 3 hours is the norm for preparation of any of my projects before burning. Is this normal?
bStro wrote on 4/4/2008, 10:33 AM
Well, there's your answer. ;-)

You're correct -- Divx (or AVI of any kind) is not DVD compliant. The only DVD compliant format is MPEG2. So, yes, DVD Architect has to re-encode any Divx files you give it. As I mentioned the default bitrate for DVD Architect to encode at is 8 megabits per second.

A ninety minute (1:30) video at 8 mebabits per second is approximately 5400 megabytes (90 minutes = 5400 seconds, 8 megabits = 1 megabyte).

5400 megabytes is approximately 5.4GB.

In fact, I'd be curious to know how you got this project back down to, what was it you said, around 500MB?

Rob

(Note about the above calculations to any nit-pickers in the peanut gallery: Yes, due to the binary nature of computer storage, some of those figures aren't exact. I rounded down, and it's close enough enough to make my point. ;)
trea wrote on 4/4/2008, 12:39 PM
Well, the first time I tried this I got it on the DVD and played back. The first 3 mins or so were fine, after that the screen went black and had audio only. I just prepared it again and this time the entire thing was black with audio only.

I am currently rendering it as a mpg2 through vegas 8 and going to try again after that. I am hoping that with the file being re-rendered as an mpg2, it will not cut out the video during the preparation process since it shouldnt have to reencode anything.
Terje wrote on 4/4/2008, 3:52 PM
It seems that 3 hours is the norm for preparation of any of my projects before burning. Is this normal?

Going from one highly compressed format to another compressed format is CPU intensive, so yes, this is going to take a long time. Compare this to compressing DV-AVI files which are very lightly compressed, on modern hardware that will typically happen in near real time or even faster than real time. So compressing 30 minutes of video will take 30 minutes or less.

Starting with heavily compressed video will not give you good results, it will take a long time to re-compress. Since you are putting a lot of video on here, it will probably look pretty bad too.
johnmeyer wrote on 4/4/2008, 8:08 PM
Oh, it's DivX. As others have said, since a DVD must be MPEG-2, DVDA (or any other authoring app) will have to recompress. Just use the "fit to disc" option and let DVDA take care of figuring out what to do.
tdsilk wrote on 4/28/2008, 7:59 AM
I finally found something that works for me. What I did was render my file using the MPEG2 setting and disabled the audio. I rendered the auido separately as AC3. When I openend the file in DVDA 4.5b it worked just fine. I hope this heps.
tdsilk wrote on 7/13/2009, 7:45 AM
Hello Everyone,

It looks like this problem is back. As I stated in my last post the problem went away after I modified one of the MPEG2 render settings and disabled the audio. However, I had a recent hard drive crash and in addition to loosing all of my notes I had to reinstall Vegas Pro 8. Now, when I render to mpeg2 and look at the file in the exporer window it shows a smaller size than what dvd Arc reads. For example, I have a file that's 4.5 gig in explorer, but when I try to add the file to dvd arc it says 4.9gig. I've tried playing with a couple of custom settings to try to get back to what was working prior to the crash, but no dice so far. Anyone else experiencing this?

Thanks,
tdsilk
bStro wrote on 7/13/2009, 10:00 AM
Everything in my first reply of this thread still applies, particularly the 2nd and 3rd paragraphs. First check the Optimize DVD dialog to see if DVD Architect intends to re-encode that 4.5GB file. If yes, then it is not DVD compliant for some reason. If no, ignore the estimate and try burning the disc anyhow.

Rob