Rivergate Software Inc. - makers of DVDAfterEdit

Currently there is no way to preserve a desired layer break with programs such as Toast, Nero, or Record Now. This is because they write a disc from a ViDEO_TS folder, which has no layer break information in it. So they choose the layer break algorithmically, giving preference to a non-seamless cell.

This is even less-likely to follow the author's wishes if he or she chooses to make layer 0 larger than layer 1 for Outside Track Path (OTP), since dual-layer media have no such restriction. Also of course if the disc has lots of room there are likely to be more legal candidates for the layer break.

There is a school of thought that if there are multiple non-seamless cells, it may not matter which one is chosen. But I haven't heard this viewpoint from a DVD author, only from a programmer such as myself, so I can't comment on that. At least we can hope that the current popular programs choose a non-seamless cell. Early reports were that some programs chose layer-breaks arbitrarily anywhere in the video stream.

As much as I wish we could do it, currently the only program capable of writing a dual-layer DVD+-R while preserving the desired layer break, except the original authoring program itself where the layer break was chosen, is Gear Pro Mastering Edition. This requires some calculation to figure out the offset of the desired cell, and there is no visual confirmation of the layer break as in DVDAfterEdit Mastering Edition. However if you know where your desired cell is in the video, you can use DVDAfterEdit ME to display the sector number (it is shown in the cell information of every cell on the disc).

However there is still one area that can trip you up when writing from any program that is not the one that built the VIDEO_TS folder, except for DVDAE ME. That is the desire to put each .BUP file in a different ECC block than its corresponding .IFO file. Unfortunately there is no hard and fast rule for how to do this, so each authoring system is free to choose its own algorithm. This isn't normally a problem if the .VOB file(s) between the .IFO and .BUP are at least 16 sectors long, which almost any video is, but in spec authoring systems there is no rule that there has to be a .VOB file at all in the VMG. DVD Studio Pro puts at least a dummy video in every menu domain to avoid this problem. It is 116K, and contains 1/2 second of black.

DVDAE puts the .BUP file at the next multiple of 16 if it needs to. I have heard of that Toast just adds 16 to the sector number. (I haven't tested that claim). So your results are going to fail on some players if there is a different adjustment made by the original authoring system and the burner program. That is because there are pointers in the Title Map to where the video starts. Those pointers can be ignored by the player, or not, depending on how it implements things. DVDAfterEdit fixes them, but never uses them, for example, since they were only provided as crutches to early DVD player processors with extremely limited memory, and serve no useful purpose for how we keep track of the data.

Another theory that I have is that pointing to the wrong place in the video isn't always noticeable, since it takes so many sectors to display even half a second of video, and some players may be tolerant to starting in the midst of a GOP.

DVD Studio Pro puts two files in each VIDEO_TS folder when it builds it. When that folder is written to DVD-R or DLT, those files are automatically left out. So if you burn with Toast or another burning program, be sure to remove them first. Some players get confused by the extra files.

We have considered putting writing to DVD+-R on our to-do list, but we would be committing to support for lots of different DVD burners, and haven't justified the development and support cost of such a feature yet.

It would be nice if some enterprising burner program provided a way to set the layer break via a text file in the VIDEO_TS folder or something. Then we could arrange to write such a file.

Regards,

Larry