I’ve started recently to play around with DVD+R DL because they start becoming cheaper and some applications really need them 🙂
I was very surprised that the current version of growisofs / dvd+rw-tools (7.1) advertises layer break position setting support but in reality I couldn’t get it to break where I want.
Looking at the code (especially from growisofs_mmc.cpp) I found very strange that the « -use-the-force-luke=break:NNNN » option wasn’t really used either in calculations or cuesheet sending.
Investigating a little bit more in the code I produced the following patch that I have sent upstream to get it included somehow in the next version.
It allows a user (who should be careful of what it does 🙂 ) to manually force a layer break position for DVD+R DL burning. (For those of you who haven’t had this problem yet please notice that : DVD-R DL (minus) DO NOT allow layer position to be changed, that said you should know what to do … only DVD+R DL (plus) allow that)
For this patch to work you have to specify « -dvd-compat » on the command line, otherwise the cuesheet sending code is not called (I didn’t understand exactly why…) and the layer break wouldn’t be set …
In any case the output of growisofs command should tell you where the layer break is going to be set.
I’ve tested it succesfully for a dozen of DL burns with or without layer break so it should be safe enough (the patch is not very intrusive anyways ; I also tested without the option to see if the normal behavior was preserved…)
Use it this way :
growisofs -dvd-compat [your other options here] -use-the-force-luke=break:XXXX [where XXXX is the layer break in sectors] -Z /dev/[your device]=[image.iso]
for example 🙂 :
growisofs -dvd-compat -use-the-force-luke=break:2084960 -use-the-force-luke=dao -Z /dev/sr0=/home/johndoe/m.iso
note the dao option usage that will close the session, otherwise the disc would remain « open » if it’s not full and depending on what you burn you’d really want to close the session trust me 🙂
Have an happy dual layer with positionned break burning !
Attachment : dvd+rw-tools-7.1-layerbreaksetup.patch
Note: use a command similar to apply (change to -p 1 depending on where you are) :
patch -p 0 < dvdrw-tools-7.1-layerbreaksetup.patch