How much quality video can you get onto a DVD?

One of the questions we answer on a regular basis is “how much quality video can you get onto a single layer DVD?”

In general, the short answer is about 90 to 120 minutes.

Now for the long answer -Once you have the source material shot and edited, the DVD Video quality will be a function of two main variables, the quality of the Video Compressor you are using and the bit rate that you set for the compression.

1. Bit Rate – If you have a very short video program you won’t have any constraints on the bit rate and therefore no constraints on topping out on the high end for quality.  Where you run into problems is when you have a video program over 90 minutes or so.  Once you get into this area, you only have about 4.4G of data that you can store on a single layer DVD.  So you have limit your bit rate, to minimize the amount of data that can be read in a given period of time.  The lower the bit rate, the less fine detail of your video can be interpreted and delivered to your video screen.

2. Compressor Quality – there are many types of video compression programs.  Some are software based and some are hardware based.  In general the more elaborate programs, i.e. the more costly, the better the compression.  However, there are several consumer level compressors such as iDVD and Toast, just to name a couple that do a pretty good job at a low cost.

There are a few obvious consideration that you have to take into account when trying to work out this “video quality vs. run time” equation.  The first is the actual content of the video.  If, for example, the video content is a lecture, where most of the background is static and there is little movement on the screen, you will not need as high a bit rate as say, a blockbuster action motion movie that has considerable movement on the screen.  I have seen very good quality 160 minute lectures with static backgrounds that fit on one DVD.

The second important consideration is to consider that a bit rate that is too high(too close to the max spec for compression standards) may cause some DVD players to “choke” because they cannot process that much data fast enough.  This happens mostly in two circumstances, with old computers or when using DVD+/-R.  It takes more processing power to play a DVD+/-R so the high bit rate on top of that will sometimes cause playback issues.

So this has been a very basic look at the issue of DVD Video quality vs. run time.  There are many more fine details and issues regarding this topic, but I have chosen to just discuss some of the more basic concepts here.

If you have more questions regarding this process, or would like more info on DVD Duplication after you job is authored, please contact us.  You can ask for me, Brian.