BDedit - BD structure edit

[Lowpro]

I encountered an issue recently while working on my "Universal Blu-ray Authoring Template". Thought I'd give everyone a heads up. Not sure if it's a limitation of the Blu-ray specification or a bug with the BDedit software. Either way, something good to know. I was restructuring the navigation commands for part of my template, the IG for the TOP MENU. After 2 hours of work I mux'd (*.m2ts) out. When opening the Blu-ray fresh at that point I found the IG could no longer be read, the below error being given, the status bar reading "ERROR Reading page 0".

"Access violation at address 00406C1C in module'BDedit v0.59b10.exe'. Write of address 40002E38."

Fortunately I saved (*.mnu) the menu and created a copy of the current M2TS file prior to muxing out and reading the Blu-ray fresh. As such, I reverted back to the prior M2TS file, opened the IG, then loaded (*.mnu) the problematic IG. Muxing out again at that point resulted in the same error. I then opened a second instance of BDedit and compared the problematic IG with the prior version. After much trial and error I finally figured out what the issue was.

When restructuring the navigation commands the number of commands residing on one of the buttons had been increased significantly. It was the only thing which stood out. The updated version of the button contained 240 commands. Prior no button within the IG contained more than 200 commands. When noticing this I recalled an issue I had a couple months ago, the issue involving a hardware based Blu-ray player and number of commands on a button within an IG. As such, I decided to see if the same issue was at play here. Sure enough it was.

The magic number was 231 in this case. Your mileage may vary. :-P So long as the button did not contain more than 231 commands the resulting IG once mux'd could be opened successfully after reading the Blu-ray fresh. Increasing the number of commands above 231 would break the IG each and every time. Thankfully I had saved (*.mnu) the menu so I didn't lose any of my work. I just needed to bring the number of commands for the button in question down below 231. In this case I offloaded a large portion of the commands to several other buttons. Muxing out at that point the IG could then be opened once reading the Blu-ray fresh.

So this begs the question, what is the maximum number of commands allowed on a button within an IG per the Blu-ray format? Is the magic number 231 or is what I'm encountering a bug within BDedit? Whatever the case may be there is a limit, at least from a hardware perspective. The related issue I encountered a few months ago was specific to playing a given Blu-ray using a hardware based Blu-ray player. The Blu-ray player would become non-responsive when attempting to read the Blu-ray, then powering off. I hard reset was then required to bring the Blu-ray player back to life.

In that case the number of commands residing on a button I had just updated was the issue. The number was well north of 231 commands. Reducing the number of commands on the button in question below a certain level resolved the issue. At the time I didn't bother trying to determine what the threshold was as doing so would have involved lowing the number of commands by one, re-burning to BD-RE, testing, rinse and repeat, a hard reset needing to be performed each time prior to trying again. In any event, just an FYI for everyone. Not sure if anyone else is using BDedit as an authoring tool as I am. If you are just make to always backup your current IG before muxing out.