DVD... Disc Capacity as it relates to video projects.

That mainstream video delivery media... that shiny disc we know as DVD - is the acronym for Digital Video Disc.  Some of the folks who created DVD technology tried to make popular the name Digital Versatile Disc as they wanted their technology to be seen for more than just video.

As mentioned in yesterday's article - So, how much data can I fit on that disc? - the single layer DVD has a stated capacity of 4.7 BG (which in reality only will hold some 4.38 GB). In a conversation with a colleague today, he asked "so -- what does that translate into in terms of video time or length of your program?" 

Well, there are many variables here so that is difficulty to answer accurately... let's explore this a little. And the following conversation, when I discuss time/length all concerns SD- Standard Definition video, HD video on Blu-ray discs is another matter altogether for another day.

Single-Layer DVDs

A very over-simplified answer is that a single layer DVD should hold just under 2-hours of video. Now let's mention a couple of the variables - the addition of motion menus (where you have full motion video or animation for the main menu and/or chapter menus does consume some of the capacity and then to fit more data (longer video program) onto the DVD you have options in most of the video editing and DVD authoring software that allows you to adjust the compression setting for both the video and the audio.

If you are working on a video editing application and/or DVD authoring application with individual variable settings for bit-rate, etc.  you may wish to consider employing a Bit Budget Calculator to precisely calculate the projected size of your project so you can make the best settings for your given project. 

There is a bit-budget calculator online - at Kenstone.net that is apparently highly regarded.  But frankly, after I downloaded and opened it, it made me yearn for the simply authoring options in Casablanca Arabesk or Apple's iDVD software.

The long and the short of it is this, the simply answer is plan to get around 1-hour and 50-minutes at the default (normal) setting/s. If you edit with the Casablanca Digital Video Editor, check out this article that specifies the time for each of the settings in DVD Arabesk software

Dual-Layer DVDs

Now dual layer DVDs allow a little less than double the capacity of the single layer DVD discussed above -- however there are a couple of factors to consider here:

• Dual-layer DVD cost between two and three times the price of single layer DVD media
• Dual layer DVD suffer from a slightly lower success rate than single-layer duplication (according to my friends at CAM Audio, Inc. who run all my DVD duplication jobs)
• Lastly, it can be tricky to set the switch point where the laser playing back the DVD switches from one layer to the next (this layer change is invisible on some players, but it can cause the video to freeze for a fraction of a second or up to 4 seconds on other players).
• Older DVD players have difficulty playing back dual-layer DVDs

For now, the video producers I affiliate with are of the opinion that it is better to go with a single layer DVD than a dual-layer disc.

A great website to learn more about DVDs (than you likely even every thought of) is this one:

DVDs De-Mystified: DVD Frequently Asked Questions (and Answers)  The site is maintained by Jim Taylor is SVP and Chief Technologist at Sonic Solutions. Jim is the author of DVD Demystified and Blu-ray Disc Demystified, the best-selling book series published by McGraw-Hill (available through Amazon).com