As Dual Layer DVD blanks come down in price, DL projects, and confusion are more common – hopefully this will help.
A DL DVD (the type most commonly used for retail movies) requires the DVD player to change direction at the layer break – think of as a turntable’s arm reaching the end of the record, then imagine that instead of just staying near the label, the arm started working its way back out towards the outer rim. That’s sort of the way DL DVDs work, and when the player changes direction at the layer break, there is a slight pause – authoring a DL DVD you try to make that pause as un-noticeable as possible.
There are 2 types of DL blanks, for video +RDL is preferred, and the way that data is written depends on whether the blank is +RDL or –RDL. The +RDL blanks are newer, and many people use a trick when burning: Every DVD you burn includes a small ID code to tell the player what it is – changing this code to an older type of disc can increase compatibility in [often older] players that might not know about +RDL.
While it’s just too much info to try and include here, you can find resources on-line explaining the +RDL & -RDL burning processes, media brands & their compatibility, & that trick I mentioned, changing the book type, which is now automatic for some drives using Imgburn. However as a DVD author creating a DL project, the only thing that really changes is that you have to be concerned with the Layer Break, which is just what it says: the point where data is first written to that second (reversed) layer.
During the process of burning your finished DVD onto a blank disc, there’s only one long stream of data, one large file if you want to think about it that way – the hardware player will split it all back up into the various files. The concept of this big, single mass of data is important, because your job is to place the layer break right in the middle of it, or as close to the middle as possible.
From an Engineering standpoint this is pretty simple – pick the 50% point and Bam! But you’re not an Engineer, you’re an Author, and you’ve got to make sure no one notices that slight LB pause. How far you go is up to you (& your clients) in your pursuit of perfection.
The simplest way is to let software [DVDA, Imgburn, etc] decide… Depending on the choices they suggest – you’ll usually get some choice – the next step up the ladder is to change the order of the menus and media in your project; you can arrange it for example so that all or most of your menus are before or after your main, video content. Having the LB at the start or end of a title is really ideal. [Note: re-ordering your assets can have an effect on DVD playback when using the remote’s “Next” button.]
When you have to have the LB occur during your video, it has to be at the beginning of a cell. A cell is just a portion of video, & it’s included only in a Video DVD’s instructions to the player. A cell is a start and end time – a place on your DVD – and each piece of video you include makes up at least 1 cell; remember that everything on a DVD is considered video, even the menus, so they have cells too. Each video can also include, be split up into many more (up to 99) cells.
Since the LB has to be at the start of a cell, when software gives you a choice on where to put it, you’ll usually get a list of chapters & ideally a title – this is because chapters point to cell start times, and every title is at least one cell. When you have to choose a chapter, you try to pick one where any pause is less apparent. If you don’t have a good choice, or if it’s still a ways from the middle, add a new chapter marker in DVDA, which will automatically create a new cell when you render the DVD.
Creating a new chapter may still not be ideal though… While it’s done at the end of the process, & so will not be in any scene menu, it’s not where you chose to have a chapter in the first place – it may for example be during a scene with a natural pause. The answer is to create a cell without a chapter pointing to it, one that to the viewer is invisible, doesn’t exist.
One way to accomplish this is to go ahead and create the chapter in DVDA, creating the cell break, then after rendering to hdd changing the chapter numbers along with which cells they point to. Another way would be to split an existing cell after render.
With a reminder that my resources for compatibility testing are limited, so test, test, test… The first method seems to work well using PgcEdit: Open the DVD [on hdd] in PgcEdit, Select the title in the left pane, Click the button on the lower left corner, “Edit PGC”. Then Click the button, “Edit Chapter (PTT) table”, at the bottom of the window that opens. You’ll see a list of all of your chapters, each one next to a “Program #”, which corresponds to the cells in that title. Select the line for the Program # that’s the same as the cell you added for the LB, then select every line below that – Click the button for “Increment programs”, then Click the button for “Delete last chapter”, & Click OK.
If you look towards the bottom left in the “PGC Editor” window, you’ll see a column of chapter numbers, and the cells they go with… You should see a gap, with your LB cell without any chapter associated with it. If all is good Click OK and close the window, saving your PgcEdit edited layout, otherwise Cancel & try again.
You can at the same time, while in the PGC Editor window set the cell flags for the LB, but I *think* it might be easier to let PgcEdit set whatever in the next step… Minimizing PgcEdit test your saved DVD on hdd, & assuming it passes, restore PgcEdit, going to the File menu, selecting Burn DVD / Create ISO – during this process PgcEdit will set the cell flags for the LB. Of course can use your preferred method for burning etc – I’ve had very good results with Imgburn.
This is intended to approximate the results you’d get using high dollar DVD authoring software, creating a cell break without a chapter attached for LB purposes. It’s not necessary -- I’d classify it more along the lines of potential optimization – play with it at your discretion. :?P
A DL DVD (the type most commonly used for retail movies) requires the DVD player to change direction at the layer break – think of as a turntable’s arm reaching the end of the record, then imagine that instead of just staying near the label, the arm started working its way back out towards the outer rim. That’s sort of the way DL DVDs work, and when the player changes direction at the layer break, there is a slight pause – authoring a DL DVD you try to make that pause as un-noticeable as possible.
There are 2 types of DL blanks, for video +RDL is preferred, and the way that data is written depends on whether the blank is +RDL or –RDL. The +RDL blanks are newer, and many people use a trick when burning: Every DVD you burn includes a small ID code to tell the player what it is – changing this code to an older type of disc can increase compatibility in [often older] players that might not know about +RDL.
While it’s just too much info to try and include here, you can find resources on-line explaining the +RDL & -RDL burning processes, media brands & their compatibility, & that trick I mentioned, changing the book type, which is now automatic for some drives using Imgburn. However as a DVD author creating a DL project, the only thing that really changes is that you have to be concerned with the Layer Break, which is just what it says: the point where data is first written to that second (reversed) layer.
During the process of burning your finished DVD onto a blank disc, there’s only one long stream of data, one large file if you want to think about it that way – the hardware player will split it all back up into the various files. The concept of this big, single mass of data is important, because your job is to place the layer break right in the middle of it, or as close to the middle as possible.
From an Engineering standpoint this is pretty simple – pick the 50% point and Bam! But you’re not an Engineer, you’re an Author, and you’ve got to make sure no one notices that slight LB pause. How far you go is up to you (& your clients) in your pursuit of perfection.
The simplest way is to let software [DVDA, Imgburn, etc] decide… Depending on the choices they suggest – you’ll usually get some choice – the next step up the ladder is to change the order of the menus and media in your project; you can arrange it for example so that all or most of your menus are before or after your main, video content. Having the LB at the start or end of a title is really ideal. [Note: re-ordering your assets can have an effect on DVD playback when using the remote’s “Next” button.]
When you have to have the LB occur during your video, it has to be at the beginning of a cell. A cell is just a portion of video, & it’s included only in a Video DVD’s instructions to the player. A cell is a start and end time – a place on your DVD – and each piece of video you include makes up at least 1 cell; remember that everything on a DVD is considered video, even the menus, so they have cells too. Each video can also include, be split up into many more (up to 99) cells.
Since the LB has to be at the start of a cell, when software gives you a choice on where to put it, you’ll usually get a list of chapters & ideally a title – this is because chapters point to cell start times, and every title is at least one cell. When you have to choose a chapter, you try to pick one where any pause is less apparent. If you don’t have a good choice, or if it’s still a ways from the middle, add a new chapter marker in DVDA, which will automatically create a new cell when you render the DVD.
Creating a new chapter may still not be ideal though… While it’s done at the end of the process, & so will not be in any scene menu, it’s not where you chose to have a chapter in the first place – it may for example be during a scene with a natural pause. The answer is to create a cell without a chapter pointing to it, one that to the viewer is invisible, doesn’t exist.
One way to accomplish this is to go ahead and create the chapter in DVDA, creating the cell break, then after rendering to hdd changing the chapter numbers along with which cells they point to. Another way would be to split an existing cell after render.
With a reminder that my resources for compatibility testing are limited, so test, test, test… The first method seems to work well using PgcEdit: Open the DVD [on hdd] in PgcEdit, Select the title in the left pane, Click the button on the lower left corner, “Edit PGC”. Then Click the button, “Edit Chapter (PTT) table”, at the bottom of the window that opens. You’ll see a list of all of your chapters, each one next to a “Program #”, which corresponds to the cells in that title. Select the line for the Program # that’s the same as the cell you added for the LB, then select every line below that – Click the button for “Increment programs”, then Click the button for “Delete last chapter”, & Click OK.
If you look towards the bottom left in the “PGC Editor” window, you’ll see a column of chapter numbers, and the cells they go with… You should see a gap, with your LB cell without any chapter associated with it. If all is good Click OK and close the window, saving your PgcEdit edited layout, otherwise Cancel & try again.
You can at the same time, while in the PGC Editor window set the cell flags for the LB, but I *think* it might be easier to let PgcEdit set whatever in the next step… Minimizing PgcEdit test your saved DVD on hdd, & assuming it passes, restore PgcEdit, going to the File menu, selecting Burn DVD / Create ISO – during this process PgcEdit will set the cell flags for the LB. Of course can use your preferred method for burning etc – I’ve had very good results with Imgburn.
This is intended to approximate the results you’d get using high dollar DVD authoring software, creating a cell break without a chapter attached for LB purposes. It’s not necessary -- I’d classify it more along the lines of potential optimization – play with it at your discretion. :?P