How to Test Your DVD and Avoid Common Problems
I've authored my disc and played it back on my computer several times. It looked great, so I ordered 100 copies, but when I put one in my set-top DVD player and tried to watch it on my TV, the disc is wrong, all wrong! What happened?
No matter how many discs you've authored, there is always a feeling of relief when your client approves the final DVD. The best defense against delivering an unplayable DVD is to thoroughly test your final DVD, then package and handle it properly.
Come Up with a Plan
Let's face it, by the time you're done authoring and testing your DVD, you've seen it so many times that you're sick of it. It's hard to rigorously test a DVD that you've already watched many different versions of: you tend to skip past parts that worked correctly in a previous iteration, such as menu navigation. Don't fall into this trap--although it's fine to spot check changes, any final disc must be tested completely, from top to bottom, to ensure there are no nasty, last minute surprises.
To help you reliably test your discs, you should make a test plan. As a starting point for a test plan, we recommend you check the following:
- Menu navigation: Does each and every button highlight when selected and take you to the correct sub-menu or video point? Can you get back to previous menus? Do your remote buttons (such as "Top Menu") do what they are supposed to do?
- Video: Does the video play smoothly and have good audio sync? Do you see any dropouts or noticeable macro blocking? Watch every single second of the video on the final disc before you consider it done. This takes a long time, but ensures a good result.
- Audio: Does the audio sound good and have comparable levels to commercial DVDs? Is it stereo? Have you made sure it's not MPEG layer-2 audio (which some players don't support)?
The key to good testing is to check your DVD in the exact same way that your viewers will watch it. For the vast majority of discs, that means testing it on a set-top DVD player hooked up to a standard television set. Testing on computers has its place (more on that below), but you haven't really tested a disc until you've checked it on an actual DVD player and TV.
Because TVs are interlaced and computer monitors are progressive, the video and menus will look different on a television than on your PC. Pay particular attention to menu flicker from narrow horizontal lines or very fine details. Also be sure that the motion video quality is okay--field dominance problems are often harder to see on a computer.
If you have problems with video stuttering on an old player, it may not necessarily mean you have a problem. Some older players don't like DVD-R media, resulting in periodic pauses or stutters. But if your DVD doesn't play properly on at least two different, new, highly rated players, you've got a problem. If in doubt, test more.
Because you're authoring your DVD on a computer, it's common to also do your initial testing on your computer. There are many DVD player software packages available, and some are more accurate than others. Many authoring programs also offer a simulation mode that lets you preview the DVD before you burn the final DVD. This is a useful preview, but should not be trusted to faithfully represent the final DVD in all details. To be positive you have a good disc, you must burn a DVD-R and test it on an actual set-top player.
Some DVDs are intended to be used in a computer, such as instructional videos. If this is the case, you should run through your complete test plan on your computer as well as on a set-top player. You should test your DVD on both Windows and Mac computers with the default DVD player software to ensure it will work for a wide range of viewers.
As mentioned in other articles, there are several mistakes you can make which will render your final DVD unplayable. Please review these articles to make sure you understand audio formats, bit rates, and MPEG encoding options.
Media and Labels
Even if you've produced a perfectly good DVD image on your computer, you can easily burn a bad DVD, label it in such a way as to cause problems, or damage the final DVD. To avoid this:
- Use only high quality media. Cheap, unbranded media is often of questionable quality and may not play reliably. Saving a few dollars isn't worth the headache of unplayable DVDs.
- Verify each copy. During the burning process, make sure to turn on the verification pass as well. Even high-quality media occasionally fails on a burn, and the verification cycle can help catch these errors.
- Check data integrity. If you have a DVD that you think may be damaged, a good way to check to see if the data is intact is to put it into a computer and copy the entire disc to the hard drive. Your computer requires each bit of data to be readable and verified during this copy process, so if there is a physical glitch in the DVD, this will make the computer stop and tell you that it couldn't copy the disc. Burn a new DVD and toss the damaged one.
- Hands off! DVDs are extremely delicate. Touching the surface of the disc leaves fingerprints that can render a disc unplayable. If you need to clean a DVD, first try using a soft, lint free cloth and gently wipe from the hub outwards in a series of straight lines toward the edge. Do not wipe in a circle: This can cause a scratch along the data path, which can also leave the DVD unplayable. For really dirty DVDs, you can buy special solutions and cleaning devices that work fairly well. However, if your disc is that dirty, burning a new one is a better plan. You may want to preemptively warn clients about proper disc handling. People are familiar with audio CDs, which are much more tolerant of dirt and fingerprints, and often abuse DVDs without knowing it.
- Pack carefully. As indicated above, DVDs are delicate, so carefully putting them in proper packaging is critical. Amaray-style cases are always a good choice, as are CD jewel cases. Avoid sleeves that come in contact with the face of the DVD. And steer clear of clever "auto ejecting" cases that push the DVD out of a slot in a sealed case. These make it impossible to remove the disc without putting fingerprints on it, and often scratch the surface as well.
- Make a backup! DVD-R media is inexpensive, so save yourself some grief by burning at least four copies of your final DVD. Send two to your client, and keep two for yourself. If one of the discs is damaged, you or your client has a backup. While you're at it, make sure to back up all of the original files you used to author the DVD in the first place, in case your client asks for "minor changes" in the future.
"Do not use adhesive labels. Labels add weight to the discs that frequently causes playback problems. Most importantly, they can disturb the balance of the disc, and cause erratic tracking, making the laser misread the data. Drive manufacturers specifically recommend avoiding labels entirely. For best results, you should print directly on to the disc faces with a dedicated inkjet or thermal printer. For masters being sent to replication, simply writing on the face (or hub) with a permanent marker is better than a DVD sticker."
-- Bruce Nazarian, Gnome Digital
Author of DVD Studio Pro 2.0: The Complete Guide to DVD Authoring
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