Avoiding problems with double layer DVDs

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Avoiding problems with double layer DVDs

Post by ckhouston »

Burning to DL DVDs causes even more problems than emcontered with SL discs. Here are some tips to make it go as smoothly as possible.

1. Use good quality discs, they will have fewer failures, so will be cheaper and cause you less stress in the long run.

Verbatim +R DL DVDs are almost universally recommended to be the most reliable and compatible with more burners and players. Buy those made in Singapore if possible, they are better quality than those made in India, and stick with the 2.4x max speed ones rather than 8x if possible, they are compatible with more burners and players. Always burn either one at the lowest speed offered for best results.

http://www.digitalfaq.com/reviews/dvd-media.htm gives links to online sources to buy them if you can't find them in local stores.

2. Burning near the outer edge of SL discs usually causes problems because disc quality is lower there and that problem is magnified even more with DL discs. The chance of there being a proper layer break point is also reduced in that case. So avoid putting so much material on them that the converted size almost fills the disc (meaning disc occupancy near 100%).

The Automatic encoding option in ConvertXtoDVD will usually avoid this problem unless you try to put too much material in a project, maybe more than 5 or 6 hours -- use the 2 pass encoding option in that case.

If you do decide to put a lot of material on them, you should use a custom target size lower than the default DVD9 size, maybe 7600 or 7800 MB. That will compromise converted quality but you have to make a choice between quality and the likely chance of a bad burn. See Note 1 below.

3. Establishing proper layer break points is a common problem with DL discs. Following tip 2. will help alleviate that problem in most cases. But most layer breaks have to be set at the beginning of chapter points, so avoid using widely spaced chapter points. Use the default 5 minute chapter spacing at a minimum, you may have to set it even lower if you try to put too much material on the DVD.

4. As always, keep your burner firmware up to date and use the latest program versions for both conversions and burning.

Note: VSO programs used 8100 MB for the default capacity of a DL DVD at the time this topic was written. That has since been changed to the 7700 MB value recommended In Note 1 below, and there seems to be fewer DL burning problems as a result.

Note 1: CX2D uses conservative target values for both single layer (SL) and double layer (DL) DVDs in order to prevent burning too close to the outer edge of the discs where quality drops due to uneven dye distribution there. Conservative values also allow conversions with a small overflow of the target size to still be burned. However, the margin of safety provided by default target values is less for DL than SL discs when it should actually be more due to the additional complexities of their construction and of writing to them.

+R SL discs have a capacity of 4483.63 MB which is a little smaller than that of -R SL discs, so the default target value of 4300 tries to prevent writing more than 95.9% of capacity. -R DL discs have a capacity of 8147.88 MB which is a little smaller than that of +R DL discs, so the default target value of 8100 only tries to prevent writing more than 99.4% of capacity.

A target value of 7814 would have to be used for DL discs in order to provide the same margin of safety as that used for SL discs. But, considering the additional complexities of burning DL discs, a value of 7700 MB is probably more appropriate for them. That may seem to be an excessive reduction, but remember that it is spread over two layers, a 200 MB reduction for each layer in other words.

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