Hi,

We are a software vendor that produces an installation program that is large enough to go on a double-layer DVD -- i.e., we make a "data disk," not a "video disk."

For internal testing purpose, we've been producing ISO images and having the testers worldwide mount the ISO images as hard drive-based DVD-ROM's. Producing and distributing test DVDs would've slowed down iterative testing, and the ISO images contain exactly what the customers will get (data-wise).

In the past, we've shipped master DVDs to the replicator, but are looking into electronic delivery of the data, mainly to speed things up. The replicator is requesting a DDP image of each layer from the master DVD because that's the industry standard. They claim that an ISO image doesn't have the formatting information provided in a DDP image; i.e., they don't want the burden of partly "authoring" the DVD because they cannot guarantee the results if they burned the ISO images themselves.

(1) Are the duplicator's claims true? Does an ISO image contain just the data, plus some basic information like the volume label?

(2) How much does "formatting" matter for a pure "data disk," versus a "video disk"? Surely, things like layer breaks wouldn't really matter for a data disk.

(3) Eclipse Suite 3.0 seems to offer ISO-to-DDP conversion functionality. Does it basically add formatting information to the ISO image, depending on the physical media the user will ultimately ship to customers?

(4) There are tons of free ISO-mounting utilities. Is there a similar utility that can simultaneously load the two DDP images meant for a DVD-9 disk, to emulate a production DVD? (The idea is to aid in quick testing worldwide.)

Thanks a lot.

Hi burner23, and welcome to the forum. I'll answer as much as I can.

1) An ISO image contains a complete disc image (as well as the volume label). For DVD-ROM (non Video) this would normally be enough, but the replicators get both Video and ROM and need some way to know the difference. This is where DDP comes in. If an image is DVD-ROM, the sector size in the image file is usually 2048 bytes per sector. If the image is a DVD-Video that needs CSS, the image is usually 2054 bytes per sector (but could be 2048 or 2064). The extra 6 bytes give instructions on if the sector should be scrambled and how. The DDP spec allows for the author to instruct the replicator on how big each sector is and if it needs CSS scrambling or not.

2) If you are providing a 'true' ISO image, then that should be all that is required (even though it is not). The layer break would normally not matter with a ROM disc.

3) I think that the Eclipse Suite would be VERY expensive for what you need since it is mainly designed for replicators as far as I know.

4) I am unaware of such an ISO mounting utility. ISO files are normally one file that contain both layers. You need something specific to the DDP spec.

*) Check your Private Messages (I've some other ideas). I'll send you a PM as soon as I can (maybe not tonight).