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PS4 CFW and Hacks       Thread starter PSXHAX       Start date Jan 20, 2017 at 12:13 AM       39      
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A few years back we saw some PS4 BD-J Homebrew ports followed more recently by PS4 Webkit Emulators, a BDLive Bug and a PS4 JavaScript Emulator demonstration video with some answers to common questions recently by musician and coder Mr_lou. :cool:

To quote: Hello all. Just signed up here, and thought I'd introduce myself (in this thread because BD-J dev is the main reason I signed up, and I don't actually own any PlayStations).

Been working on a BD-J project for 5 years now. Info at www.8bitmemoirs.com

Got the HDCookBook for my birthday, and have studied BD-J a lot. Very little info online about it indeed. Some Japaneese sites are rather good, but requires Google Translate. :)

Is anyone here still interested in BD-J? I think I can answer a few questions from this thread (although it's old), so here goes:

From Lucif3r: Would make more sense if the PS4 supported such a thing from a USB stick or similar... Wasting a blueray disc for a java app? No ty... o.o

Yea, Sony blocked the possibility of booting a Blu-ray Disc from USB, as we all know. But I believe it's still possible to run BD-J stuff from a USB - if you boot from a disc.

So yea, you will still need to burn a disc - but you can settle for having this one disc for booting, and then run whatever Xlets you have on your USB.

I admit I haven't tried this myself yet (because I'm using a Dune HD Smart D1 for testing which lets me run my stuff from harddisk), but from what I've read in HDCookBook it should be possible, because:
  • Xlets can start other Xlets
  • The disc filesystem gets merged with the USB filesystem (for BD-Live).
So, you could (theoretically) "waste" this one boot disc, and then just use USB sticks for various homebrew. But yes, using a re-writable disc is also an option. It'll have a looong life due to the very small size of JAR files.

And of course, while developing, you can use a software player like PowerDVD from Cyberlink. (Other software media-players are also getting BD-J support these days, like VLC and Kodi).

From FreePlay: There's no audio. But I think we already knew that.

I don't think this is because you can't have audio with BD-J. I think it's more a question of the developers didn't bother to port the audio-system to a BD-J compatible one.

From what I've read, the whole Java Media Framework (JMF) should be available in BD-J. I admit I don't have any experience with JMF myself, but a quick look at the docs tells me that it supports playback of Linear PCM WAV, which as far as know, is a RAW format.

The dynamic audio generators usually uses raw format (I think), so it should "just" be a matter of finding a way to feed dynamically generated audio into JMF.

Not claiming this is possible. Just saying I think it can be done, somehow. I'm a musician, and a coder, but I have never experimented with dynamic audio generation yet. But this whole dynamic audio generation is only interesting for emulators.

When we're talking homebrew games, you can always add audio in the form of video-playback. This is what I'm doing in my own project. Plenty of audio there.

From FreePlay: Something else I forgot to mention that you might have noticed in the video: emulators run REALLY FAST on this. Like, around 400% speed. I don't know why.

Without having tried the NES emulator, my guess is that it was created for PS3 with a "dumb" timing setting, which is the easiest way of doing it. The PS4 obviously having a faster CPU will result in a faster execution.

I suppose you could say that the emulator should just have been coded slightly differently.

From incognita: May be you can't hack the PS4 but I think you can do a lot of interesting hombrews.

Absolutely I think so too. My project "8-bit Memoirs" has been a very interesting one so far. Learning a lot of what's possible.

I admit I'm not as much focused on the PS3 as such, but rather Blu-ray Players in genereal (which is why my project has been tested on A LOT of different players).

If you only target PS3, you'll have it easy. Because getting stuff to run on all players requires a lot of patience and work. Blu-ray Players are just as different and buggy as JavaME enabled cellphones.

I would like to add the following. Some people say that Blu-ray Disc Java (BD-J) obviously isn't as powerful as native coding on the PlayStation - and they're of course absolutely right.

You shouldn't expect to be able to code full-blown 3D shooters. BD-J was created for simple menu stuff for Blu-ray movies.

That being said, you shouldn't underestimate what you can do with BD-J either. Take a look at this BD-J demo for example:

Finally, from GregoryRasputin comes the following summary and related BD-J files:

Download: Blu Ray Java

Here are some facts:
  • This is NOT a hack.
  • This is NOT anything major and will not lead to anything major.
  • This will NOT let you run PS4 “backups”.
  • This will NOT give you any access to the PS4’s OS system files.
  • This is NOT illegal.
  • This does NOT void your warranty.
  • This will NOT let you run PC games on your PS4.
  • This will ONLY let you run Java software.
  • This WILL give you Homebrew.
  • This IS totally doable.
Cheers to @GregoryRasputin for the update and @raedoob for the heads-up in the PSXHAX Shoutbox! (y)
PlayStation 4 BD-J (PS4 Blu-ray Java) Homebrew Answers by Mr_lou.jpg
 

Comments

Nice follow-ups, and the only thing that I can think of regarding the PS3 is if the firmware was below 2.50 and then updated to 2.50+ (Sony blocked BD-J on PS3, maybe THIS is a reason why) between your visits? :unsure:
 
Nice follow-ups, and the only thing that I can think of regarding the PS3 is if the firmware was below 2.50 and then updated to 2.50+ (Sony blocked BD-J on PS3, maybe THIS is a reason why) between your visits? :unsure:
No that's not the reason. The only thing Sony blocked was the ability to run BD-J from USB. If you insert a Blu-ray disc, everything must run fine. And this particular disc runs fine on all my other test-players.

But the thing about JavaME is that it can be very tricky. Even though there are specs for the manufacturers to follow, they seem to interpret these very differently. So getting your stuff to run on one player doesn't mean it runs on another. (Same issue with JavaME enabled cellphones).

I would except the PS3 to run almost everything though. It's very puzzling that it is the PS3 that is giving me trouble now. It would be a lot more logical if it was one of my (rather old and slow) test-players.

But I will figure out what it is..... I have borrowed his PS3 now.

EDIT: Also, my other homebrew discs works fine on this PS3. ;-) So I have apparently changed something on this one disc that the PS3 does not like, but all other players don't mind. As I said; not what one would expect.....

UPDATE: Alright, I managed to find the bug that caused the PS3 to refuse to run my Xlet.
So now I can report the following for the PS3:

There's a difference between PS3 and PS4. I'm pretty sure the PS4 allowed for 2-directional buttons to be pressed at the same time - but the PS3 does not. So Erik is right about that: Only one directional button at a time possible on PS3.

The "only 2 action buttons" is not true though. Unless R1, R2, L1 and L2 doesn't qualify as action buttons? Because with PS3 you can catch X and square - but not O like you can with the PS4. So I guess that's what Erik means with "only 2 action buttons". But you can catch R1, R2, L1 and L2 on the PS3 too.

And finally, the best part: The PS3 does, like the PS4, register multiple buttons at the same time. So there's no problem pressing many buttons at the same time. (Like e.g. a direction + L1 + R2 + X).

The biggest downside is that with the PS3 you're apparently limited to creating games where your hero character only moves from side to side or up and down. You can't move right/up or left/down at the same time. This is somewhat disappointing, but for me personally not a huge deal-breaker.

On the PS4 though, it doesn't seem to be a problem. So you can always put: "For PS4 only!" on your commercial version if you really need your hero-character to move in those directions. ;-)

But of course it will be more fun to target both platforms.
 
Below is a Xenforo BBCode table more closely resembling the one HERE with the code I used HERE:

Technology Native Development Blu-ray Disc Java Web
Language C/C++ JavaME BD-J HTML5 Javascript
Platforms reached Playstation 3 _ Yes _ Playstation 3 _ Yes _ Playstation 3 _ No _
_ Playstation 4 _ No _Playstation 4 _ Yes _Playstation 4 _ Yes _
_ Xbox One _ No _Xbox One _ Yes _Xbox One _ Yes _
_ WiiU _ Yes _WiiU _ No _WiiU _ Yes _
Other platforms _ Any platform with a software media player that supports BD-J. Any platform with a modern browser.
Special user-requirements Must jailbreak their PS3 Must own a blu-ray disc burner to create a disc from the ISO file. _
Developer pros Native development will always be superior in regards of speed. Large group of users. Largest group of users. Wide available well-documented technology.
Developer cons Very small group of users. Limited amount of information available. Must own and maintain a webhotel.
 
Below is a Xenforo BBCode table more closely resembling the one HERE with the code I used HERE:
lol when quoting that it looks horrible, but the final result is beautiful, Xenoforo definitely does have the best features, i just can't be bothered changing everything, especially when it will screw up the downloads and the other custom things such as the calendar.

On topic, i just noticed that native part of the Wii U should say 'yes'.
 
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