SolutionBase: Tips for avoiding common DVD-burning blunders

DVD burners present a whole new level of challenges. With so many different options to choose from and a more sensitive media, you've got to know what to do to avoid creating DVD coasters rather than functioning DVDs. Here are some tips and tricks you need to know.

Although DVD burners have been around for a while, they are finally starting to gain popularity because of rapidly declining prices. What a lot of people don't realize though is that burning a DVD isn't quite as simple or reliable of a process as burning a CD. In this article, I will explain why DVD burning can be problematic, and I will give you some tips to maximize your chances of a successful burn.

DVD media

The first consideration that you need to make when preparing to burn a DVD is the media that you are using. Picking out DVD media is a little more involved than picking out blank CDs. When you pick out a blank CD, you basically have two choices, CD-R and CD-RW. Â With DVD though, you have several choices, DVD-R, DVD+R, DVD-RW, DVD+RW, and DVD RAM. DVD RAM is cartridge based. Since DVD players can't generally accept DVD RAM cartridges, I will limit my discussion to the other formats.

DVD-R and DVD-RW were the first recordable DVD formats to be compatible with commercial DVD players. The format is compatible with the vast majority of DVD-ROM drives and DVD players, although some older DVD players will not read this format.

DVD+RW is considered to be better than DVD-RW because it has some extra features such as lossless linking and supports writing both CLV and CAV. Like DVD-RW, DVD+RW is compatible with most DVD-ROM drives and most commercial DVD players, although slightly more DVD players support the DVD-R format than do the DVD+R format.

Today, many DVD burners support all four of these formats. Even so, it is important to check to see exactly which formats your burner supports and to buy media that supports the same format as your drive. If your drive is one of the newer types that support all four formats, but you have been having trouble burning a playable DVD, then I recommend using the DVD-R format since it tends to be compatible with more DVD players than the DVD+R format.

When you shop for DVD media, you should also make sure that you buy good quality media that is rated for the appropriate speed. I've never been one of these people who like to shop for fancy brand names, but when you shop for blank DVD media, brands make a huge difference. Many of the DVD burning compatibility problems are related to the blank DVD media. Purchasing blank media made by a reputable manufacturer rather than going for the bargain basement specials greatly increases your chances of success.

When purchasing blank DVDs, you should also check the rated maximum burn speed. It's OK if a disc is rated for a higher speed than what your drive will support, but you don't want to buy discs that are rated at a slower speed than your drive. Some DVD authoring software will allow you to slow down your burner to the speed that the media is rated for, but it's usually better just to buy media that's rated for the higher speeds. Higher speed media is almost always of a higher quality than lower speed media.

While I am on the subject of the DVD media, I want to take a moment and talk about the proper handling of DVD media. Like a CD, you should handle DVD media only by the outer edges or by the hole in the center. To understand why this is so important, you need to understand how DVDs and CDs work.

Like a CD, a DVD's surface is filled with microscopic pits. The non pitted areas of a DVD's surface are called lands. The DVD player bounces a short wave laser off of the DVD's surface. If the laser strikes a land, then the reflective surface causes the laser beam to bounce back and the player treats that spot on the DVD as a binary 1. If, on the other hand, the laser strikes a pit, then the beam is not reflected, and the result is a binary 0.

So what does this have to do with the way that the disc is handled? We've all seen CDs that don't play well because they are dirty. Dirt, finger prints, and scratches can cause lands to not reflect light well enough to be read correctly. Extreme smudges or scratches can also scatter the laser beam. This is usually only a problem for CDs in extreme cases, but you have to remember that DVDs hold a lot more information than a CD, but do so in the same amount of physical space. This means that the pits and lands have to be even smaller than the microscopic ones found on a CD. Since a DVD's pits and lands are so tiny, DVDs are much more susceptible to interference from fingerprints and dirt than CDs are. My advice is to handle DVDs by the edges only, and to not even try to burn data onto a dirty DVD.

Preparing for the burn

So far I have talked about selecting the appropriate media type for the DVD that you are creating, but there are some other things that you can do to maximize your chances of a successful burn. One thing that you can do is to make sure that your PC is up to the challenge. Although the user interface is fairly simple, DVD authoring is a complex task from the PCs standpoint, and tends to be very hardware intensive.

So what makes writing data to DVD so complex? Data is written to a DVD in a different manner from the way that it is written to hard disk. When your PC writes data to a hard disk, it writes data in blocks. The intricate technical details of data blocks are beyond the scope of this article, but to put it simply, blocks are small, manageable chunks of data. When data is written to a DVD, the computer doesn't have the luxury of using blocks. Instead, the data must be written all at once. The DVD burner will record data at a specific, pre-determined speed. If the computer is not able to supply data to the DVD burner quickly enough to keep up with the burn, then a data underflow error will occur, rendering the disc useless.

Most DVD authoring software contains a mechanism for preventing buffer under run errors. However, some of the buffer under run prevention mechanisms work by pausing and restarting the recording process. Every time the recording process restarts, link information must be written that links the data that's currently being written to the previously written data. These types of buffer under run prevention mechanisms will prevent a buffer under run, but they can waste space and they can make it difficult to make copies of the disc. Buffer under run prevention can also result in poor playback quality since the laser may have to jump around the disc a lot more than it would had the disc been burned in a continuous manner. It's better to prevent a buffer under run condition from occurring in the first place.

The trick to preventing buffer under runs is to make sure that your PC can supply data to the DVD recorder at the necessary rate. The easiest way to accomplish this is through the use of a dedicated, high speed hard disk or disk array. The reason why this technique is so effective is because fragmentation greatly decreases the speed at which data can be read. If you are using a dedicated hard disk, then there is no fragmentation because there is nothing on the disc except for the DVD image.

Having a dedicated hard disk is a good idea for another reason. Creating a DVD takes a lot of hard disk space. Although a blank, single sided DVD only holds 4.7 GB, it takes a lot more than 4.7 GB to create a DVD. My experience has been that if you are filling a DVD to capacity, then the source video will consume somewhere in the neighborhood of 13 GB of hard disk space. The computer will then use some more disk space for the rendering process and then write a 4.7 GB DVD image. Depending on the software that you are using, it can take up to about 30 GB of hard disk space to create one DVD.

A fast hard disk with lots of free space and minimal fragmentation is only one of the requirements for successful DVD authoring. You will also need a CPU that can keep pace. I have successfully burned a DVD on a Pentium III with 256 MB of RAM. However, doing so was an all day job because the machine took so long to render the DVD image.

I recommend at least a 3.2 GHz Pentium 4 with 512 MB or more of memory. I also recommend that you close all applications other than your DVD authoring software and your anti virus software. This will allow as much of the processor's power as possible to be dedicated to the task at hand. Keep in mind that many applications run in the background, and you can use the Windows Task Manager to shut down unnecessary background processes or to boost the priority of the DVD authoring software.

Performing a test burn

Now that you've got the necessary hardware and the correct media type, it's time to make your DVD. If you have been having trouble creating DVDs in the past though, then it's better to perform a sort of test burn prior to creating your actual DVD. This will give you the opportunity to work out the kinks prior to the actual burn.

Most DVD authoring software allows you to write a DVD image to the hard disk rather than burning it to DVD. If your software allows you to create a test image, then doing so is a great idea. The test image will allow you to try out your DVD before you waste a disc. You can make sure that the video looks the way that you expected it to and that your menus work correctly. There have been several times in which I have created test images, and then realized that I made some kind of mistake that I needed to correct prior to creating the actual DVD.

Once you are happy with your test image, you should be able to burn the DVD based directly on the image that you have created. This will save time because your computer won't have to render any data. The only thing that has to happen is that the image data must be dumped to disc. If you have been having a lot of trouble creating DVDs, then I recommend burning to a rewritable DVD. Sure, rewritable discs cost a little more, but using a rewritable disc will give you the chance to work out the kinks without wasting a bunch of blank discs, Once you are satisfied that your DVD is working the way that it is supposed to, then you can burn a permanent copy onto DVD-R or DVD+R media.

Choose the appropriate file system

As you probably know, a computer's hard drive can be formatted to use various file systems such as FAT, FAT-32, or NTFS. What you might not realize though is that DVDs use a file system too. Most newer DVD authoring software will use the UDF 1.05 file system by default. The problem is that most older DVD players do not support UDF 1.05. If you try to play a UDF 1.05 formatted DVD on a player that doesn't support it, you will receive a Disk Error message (the actual error varies from player to player).

To get around this problem, you will have to use a file system that the older player understands. I recommend using the UDF 1.02 file system. Most popular DVD authoring software packages will allow you to use UDF 1.02 instead of UDF 1.05, and almost all DVD players can read the UDF 1.02 format.

The method of selecting the DVD's file system varies greatly among DVD authoring products. If your software prompts you for a UDF partition type (in addition to the UDF version), then you will need to set the partition type to Physical Partition and then set the UDF version to 1.02. Most DVD authoring software will also prompt you as to whether or not you want to use multisession. If you are creating a disc for playback on a DVD player then you should not use multisession.

Firmware update

Hopefully by now, you have been able to resolve the problem that was preventing you from being able to burn DVDs. If you are still having problems though, you might consider checking the manufacturer of your DVD burner's Web site. There have been several cases in recent years in which hardware manufacturers have released firmware updates or special drivers for DVD burners that have corrected various burning issues.