also check the size of the file, whereas a DVD-R disc is rated at 4.7 gigs there is only like 4.47 gigs of usable space on the disc. perhaps you went a little over that? i tend to try to target my disc images to be 4.3-4.4 gigs to be safe.

hope this helps, DVD-A is a great product

I created a DVD project in DVD-A 1.0 with 12 separate video clips. Most of the video clips were 9 minutes at 26 seconds long (which is a 2 GB file in DV format). In "optimize DVD" I adjusted the bitrate to fit, with 4% margin just in case.

"Optimize DVD" reports

Project-wide settings
Estimated size: 4,618.0 MB (96.0% of 4.700 GB media)
with Default bitrate at 5.640 Mbps

Individual media assets
Name Duration Estimated Size
VX2k-01-01 00:09:26 404.0 MB
VX2k-01-02 00:09:26 404.0 MB
VX2k-01-03 00:09:26 404.0 MB
...etc

Now, 16 rendering hours later, the final project will not fit on a DVD. Yikes! Why is this? Let's look a little closer. Looking inside the VIDEO_TS folder, we see each VOB is actually a bit smaller(!) than DVD-A estimated:

filename file size (Windows) Average bitrate (BitRate Viewer)
------------------------------------------------------
VTS_01_1.VOB 402 MB (421,595,136 bytes) 5322 kbps
VTS_02_1.VOB 402 MB (421,175,296 bytes) 5317 kbps
VTS_03_1.VOB 401 MB (421,398,528 bytes) 5319 kbps

...etc.

so bad estimation is not the problem. In the entire VIDEO_TS folder there are 13 VOB files, most of them about 400 MB, which take up a total of 4.48 GB (4,815,058,944 bytes), plus 26 other files (.IFO, .BUP) each about 20 k, which take up a total of 610 KB (624,640 bytes) in total.

The complete VIDEO_TS folder is 4.48 GB in size (4,815,579,136 bytes). Of course
this does not fit on a DVD-R which can only hold 4.377 GB (4,700,000,000 bytes).

How did this happen, even though in every case the actual VOB size was slightly smaller than DVD-A estimated?

Let us suppose that the authors of DVD-A had not read the DVD specs or even the DVD FAQ, http://www.dvddemystified.com/dvdfaq.html#7.2 and did not know that a DVD size of 4.7 Giga-bytes is specified in metric units (1 giga = 1x10^9 bytes) and assumed instead a computer "gig" of 1024*1024*1024 or 1,073,741,824 bytes. On this imaginary DVD-R we could then store 5,046,586,572 bytes and in fact my VIDEO_TS would only fill 95.4 % of the disc, almost exactly as predicted on the Optimize DVD page. Aha!

So, Sonic Foundry... could we fix this, please? Thanks!!

In the meantime, the workaround is to be sure to plan no more than 92.6% usage on the disc, to account for the difference between a metric Giga (1 billion bytes, 10^9) and a computer gig (2^30 or 1,073,741,824).