How does the BD Rebuilder know the format of Bluray disk?

[zhou_heng]

So far as I know, Bluray file format specification(http://www.blu-raydisc.info/format_spec/rom2_specs.php) is not freely and publicly available, then how BD Rebuilder know the format of data in Bluray disk? Did the developers buy the specification(over $2500), or just inverse engineer?

[Guest]

Many people have access to them through their employers, who purchase them.

[setarip_old]

@zhou_heng

Hi!

If you click on the following link, you'll see that there appears to be quite a bit of related information available to the public:

http://en.wikipedia.org/wiki/Comparison_of_high_definition_optical_disc_formats

[jdobbs]

So far as I know, Bluray file format specification(http://www.blu-raydisc.info/format_spec/rom2_specs.php) is not freely and publicly available, then how BD Rebuilder know the format of data in Bluray disk? Did the developers buy the specification(over $2500), or just inverse engineer? I personally did reverse engineering, dumping out files one-at-a-time and looking for familar patterns (like PTS values, packet numbers, etc). Later I exchanged information with other people who had done the same thing (guys like DeanK) and eventually all the information came to light a little at a time. In fact I'm still finding out new things I didn't know about AVCHD formats today (it's not quite as "talked about" as blu-ray).

There is also a lot of information available online via sources such as patent applications and some of the non-confidential BD specs. If you look hard enough and spend enough time digging through hex dumps, you'd be surprised what you can find. I also gleaned a lot of information on file and table formats from open source code (like TSRemux). Other tools such as BDEDIT came in handy too in understanding the structure.

That's the reason it took so long... (the first BD-RB beta was released in Dec 2008, and I started a long time before that).

I can tell you, though, that I wish there was as much information freely available back then as there is now... I could have saved a lot of hours slaving over dumps. I've found that some of the original assumptions I'd made on table formats etc. were wrong or a little off and I've had to rewrite a lot of sections of the original BD Rebuilder code in the last year.

Like they say, if it's not a challenge -- it's really not worth doing.

[zhou_heng]

Thank you very much, jdobbs, for the detailed reply as well as the useful sources mentioned.