DVD-ROM has been described as "a bigger bit bucket" - which essentially means that it is simply a blank slate, an empty page, a large-capacity digital optical publishing medium that can be used to distribute any kind or combination of data, in any file or form. While the "bit bucket" description is apt, and while DVD-ROM's application layer is essentially wide open for interpretation, anyone who's developed multimedia knows that this kind of approach results all too often in "anything goes - but nothing works." With DVD-ROM, it's true that anything that was stable and supported on CD-ROM will also work for DVD-ROM. When it comes to video, especially MPEG 2 video, the infrastructure for DVD on the PC needs definition. A group of multimedia developers, still reeling from the many unhappy returns of consumer multimedia titles that "didn't work", have been diligently attempting to define some guidelines for DVD-ROM playback on the PC, addressing such issues as MCI, DirectShow, and Quicktime, and hardware and software MPEG 2 decoding. In conjunction with the SPA (Software Publishing Association), Intel sponsors ongoing "plugfests" to get hardware and content developers together to see what works, and Microsoft has a staff of evangelists to ease the transition to DirectShow authoring.
All of the read-only DVD formats - DVD-ROM, DVD Video, and DVD Audio - share the same physical and logical levels. The specifications for some of the physical and logical parameters are shown in the following table:
| Spec | CD | DVD |
| Diameter | 12 cm | 12 cm |
| Thickness | 1.2 mm | 1.2 mm (.6 mm x2) |
| Numerical aperture | .60 | .38 to .45 |
| Readout wavelength | 780nm | 650 or 635 nm |
| Track pitch | 1.6 micrometers | .74 micrometers |
| Pit length | .822 to 3.560 micrometers | .400 to 1.866 micrometers .440 to 2.054 micrometers |
| Capacity (per side) | 650 MB | 4.7 GB (single layer), 8.5 GB (dual layers) |
| Scanning speed | 1.2 to 1.4 m/s | 3.49 m/s 3.84 m/s |
| Rotational speed (1x) | 200 to 500 rpm | 570 to 1600 rpm |
| Reflectivity | 70% minimum | 45 to 85% |
| Modulation | 8/14 (8/17 with merge bits) | 8/16 |
| User data rate (1x) | 1.41 Mbps | 11.08 Mbps |
| Error correction | CIRC | RS-PC |
| Error correction overhead | 23/34% | 13% |
| Format overhead | 252% | 136% |
Because of this basic foundation of shared physical and logical formats, any DVD disc can be physically and logically read by any DVD drive. However, because of the differentiated application layers, the content of the disc may or may not be in a form that a given playback platform can play. In the case of DVD Video on the PC, most computer manufacturers have elected to include an MPEG 2 decoder card with every DVD-PC, plus a "DVD Video player" application - essentially a graphic representation of a DVD Video remote control. So, while fewer than a hundred DVD-ROM titles are currently available, there are currently more than 2,900 DVD Video titles that will play on a DVD-PC. Meanwhile, there are an estimated 1.6 million DVD Video players actually installed in America's living rooms - and perhaps nine to twelve million DVD PCs.
