Will Java menus work on a BD-9?

[mr_lou]

Hello, noob here. Only discovered BDRebuilder yesterday.

Short version:
I see it's described as "a software to shrink a Blu-ray with all menus and extras". Does that include Java menus?

Longer explanation:
We're a small bunch of hobbyist gamedevs who use BD-J (Blu-ray Disc Java) to make amateurish retro styled games that runs on PlayStation 3, PlayStation 4, PlayStation 5, Xbox One and Xbox Series X (as well as standard blu-ray players). The same disc runs on all those 5 consoles, because it's simply a blu-ray disc. It's all perfectly legal, and no modding or hacking required.
See www.blu-play.com if curious for more info.

We always use BD-R and BD-RE discs, and it all works fine. The problem of course is that very few people own a blu-ray burner, and that requirement turns many away. Therefor it would be awesome if it was possible to use DVDs instead. In fact it would also be ideal, since the ISO files for these games will always be small, and a 25 GB BD-R is a bit overkill.

Naturally I started out simply burning the ISO straight to DVD, thus making what I thought would be a "true" BD-5 and BD-9. It works too on my old Sony player and another old Samsung player I have, but it's identified as "DVD+R AVCHD" which I find a bit strange. Nevertheless, it seems to work on older players.
(It also works on Xbox One - but that's unrelated; because it doesn't care about the media. It works even from a CD-R. I don't think that's because it specifically supports BD-5 or BD-9).

But it doesn't work on PlayStations or newer players in general. I read somewhere that "BD-9 was removed from the BD-ROM specs in 2011" so I assumed that's why.

But then I found BDRebuilder, and noticed it seems to do some patching etc, and is described as "a software to shrink a Blu-ray with all menus and extras." - which sounds very intriguing and that's of course why I'm writing here, curious to hear if this includes Java menus, and if that works on newer players here in 2021.

In the good old days it was actually possible to run a BD-J Xlet from USB on a PS3, but Sony removed that in firmware 2.50. I assume this applies to a BD5 / BD-9 as well, so chances of this working on PS3 is probably slim to none. But I'm still curious to find out if it'll work in other players that I haven't been able to get working so far. :)

If anyone is bored enough to try to make a BD-9 of any ISO at blu-play.com - please feel free! :D

[mr_lou]

I spent all day experimenting with this.

Burning the blu-ray ISO straight to both DVD+R and DVD+R DL and DVD+RW without changing anything.
Changing booktype to "DVD-ROM" before burning.
Running the folder through BDRebuilder before burning.
Running the folder through goBD-tool before burning.
Trying different filesystems, such as UDF2.5, UDF2.6, ISO9660+Joliet.

Mixing all of the above. Then tested on a handfuld of players.

The results:

Burning the ISO straight to DVD, without any fiddling around with tools like BDReuilder and goBD-tool, seems to produce the most compatible result. It plays on my old Samsung and old Sony player fine.

As soon as I try any other method, my old Sony gives up. The Samsung one plays almost anything though.

None of the above will play on any other player I have here, even older ones. In total I tested on 11 players plus a PS3.

So in conclusion: No, Java will (in general) not run on BD-5 and BD-9 discs. Only extremely few players will play them fine.

The question then is: Is that a big loss?

Not really. I've seen blu-ray burners for as little as € 20 EUR nowadays, and there's really no big price difference between DVD+R DL and BD-R media. So... just use BD-R discs.

[Ghitulescu]

There is no true technical reason why it shouldn't work.
However, since no studio would probably release any movie in BD9 then its content (in particular "decorated" with, IMHO, useless java menus), then its content MUST be pirated and consequently usually unplayable.
The only technical reason would be a bitrate higher than a DVDRDL could provide (which is rare, as most BD9 are, as studios already guessed, compressed BD25/50/100s and not true camcorder or other user legit sources).

You should also take into consideration that compressing a BD25 to BD5/9 means that lower bitrates have to be used, and as a compensation, some "tricks" were needed to keep the quality - a true BD-specs-abiding player may not play the content for "stupid" reasons like a too long GOP, or higher B-pyramid level or any other thing. Also the type of media used may be a problem - many new players really want that a DVD+R be marked as such, and not as DVD-ROM which was used for very older DVD-players. Others do not care. DVD-R had a better acceptance than +.

I tested a lot of players some 10 years ago for compatibility with various codecs, encodings and media. If the MKV support would have not been so stupidly implemented in many integrated players (like ignoring the muxed subtitles which have to be external) then I would have said that the MKV way would be the best.

[mr_lou]

I know there are no technical reasons stopping this. Blu-Play games never use high bitrates. They're just small amateurish hobby projects. They're never 25 GB anyway. We're usually talking MB. Like "Ukko's Journey" is only 80 MB, and "The UFO Game!" is only 2.3 GB. Both using very low bitrates for the m2ts files. Shouldn't be a problem at all.

It looks very much like an intentional design: Don't play blu-ray if on a DVD - and I agree it's their silly idea of stopping piracy - which will sadly always hit us non-pirates too.

The trick goBD-tool does, adding some extension data to the index.bdmv file to trick the player into thinking it's an AVCHD - but then still execute the BD-J Xlet; could be done on a PlayStation 3 even from USB back in the good old days. But Sony prohibited that in a firmware update. I don't understand their reasoning, if there even is one. As if it was ever a threat to anything.

I'd love to discover some hidden secret that allows blu-ray playback from a DVD-R / DVD+R / DVD+RW. Because I agree: Logically it should just play. But I think it's an intentional block for silly reasons.

Plenty of small downloadable (and yes - perfectly legal) ISO files to test with at blu-play.com if you're up for the challenge. ;)

[jdobbs]

There's no reason why Java Menus would not work under BD Rebuilder when targeting a BD-25. The menu structure stays unchanged on a full backup. But, as mentioned, there are exceptions when trying to shrink it to a BD-5/9. Some players just don't like BD-5/9.

[mr_lou]

There's no reason why Java Menus would not work under BD Rebuilder when targeting a BD-25. The menu structure stays unchanged on a full backup. But, as mentioned, there are exceptions when trying to shrink it to a BD-5/9. Some players just don't like BD-5/9.

Yea, a BD-25 is not a problem at all. But I don't need to use BD Rebuilder for those.
My conclusion regarding BD-5/9 discs though, are that most players don't like them.