It's a collaborative community space for promoting Java content on blu-ray disc (BD) players. We also wish to promote content for GEM-based platforms other than BD-J. This project is hosted by a few developers at Sun who are enthusiastic about the technology.

The hdcookbook project provides several things:

1. A source code repository containing various Java-based tools and sample code.

2. A set of binary files built from the source code repository.

3. An active discussion forum about BD-J authoring.

4. A set of Wiki pages to provide information about content development.

Anyone interersted in Java-based content authoring for TV, of course!

In reality, this project seems to attract interesting mix of blu-ray content authors. On one spectrum, there are independent developers wishing to run their first Java application on a BD player they have purchased. On the other spectrum, there are content authors involved in commercial BD title production. The latter audience have access to industrial-strength BD authoring tools already, but they join this project because sometimes our tools provide functionality or fill the need that commercial tools do not necessarily cover. Then, there are audience who fall in between those two spectrums, such as those who are evaluating BD-J as a business opportunity and using our tools for doing experimental work.

We are beginning to see interest from the OCAP community, as well. Most of the framework code is directly applicable to an OCAP environment, or to other GEM-based environments, like MHP. Also, a Blu-ray player is an attractive device for people who are prototyping application ideas and services that might ultimately deploy on OCAP or MHP, because Blu-ray players are inexpensive, and they have performance characteristics that are similar to real OCAP/MHP devices.

Our tools are divided into two sections, DiscCreationTools and AuthoringTools. DiscCreationTools consists of tools mainly for assembling a valid BD structure, whereas AuthoringTools are the tools to ease and enable innovative content authoring. Most likely, you'll be using only a subset of the tools in the repository, depending on what you're trying to do.

All our samples are under the "xlet" directory in the hdcookbook.

"hdcookbook_discimage" is by far the most complete BD image sample. This disc image includes three xlets demonstrating typical features that a typical movie-like disc might want to do, such as having a menu to allow scene and subtitle selection, a bonus game, a feature to connect to the internet to download a new image, etc.

We also have many samples for GRIN. GRIN is an application framework tool provided under AuthoringTools.

There are also independent examples and test cases, in which we've built over time, usually for some specific BD feature.

All samples come with an ant build setup, and can be made into a complete BD image so that one can run on a player. By default, the build setup for samples require hdcookbook tools to be pre-built.

Sometimes we built the tools because we needed them. In many other cases, we built, or enhanced, our tools, when someone we're working with had a need.

At minimum, we expect you to be reasonably familiar with Java as programming language to get started. Also, our source code repository is built with ant, so some knowledge on ant build script will be handy.

Please note that this project currently do not provide tutorial-type writeup on how to do BD-J programming. We hope that hdcookbook's sample disc images and their build system setup can serve as examples.

I suggest you to start with a xlet/HelloWorldXlet sample, because it is the simplest Blu-ray Disc image example we have in the hdcookbook source code repository. Once you have that image running successfully on your Playstation 3, then you can try changing the application to suit your need. The build setup for samples require hdcookbook tools to be pre-built.

If you are searching for a way to execute your Java application from a USB stick, then you need to convert a BD image to another format called AVCHD before placing it on a memory stick. There is an experimental tool under AuthoringTools/experimental that can do this BD to AVCHD conversion for you. Unfortunately, we have been informed that the support for running Java application from a USB stick has been discontinued in Playstation 3 firmware update v2.50 altogether.

At miminum, you'll need to add these two items:

1. A set of classes (BD-J compilation stubs) to compile your application against.

2. An environment to test your BD image on.

If you are new to a concept called a scene graph, it might be hard to see the power of GRIN right away. Note that you don't need to know about GRIN to write your first BD-J application. In fact, you don't have to rely on GRIN at all to do BD-J authoring if you choose to.

That said, we believe that GRIN is a wonderful application framework that can free you, content authors, from Java programming details and allow you to focus on the design and the behavior of the content instead. GRIN provides a way to declare content as a scene graph - what we call a Show file. It is a scene graph implementation architected and developed primarily for the BD platform, and it is highly efficient. GRIN runs on top of our animation framework, which handles all the complicated frame refreshing logic for you so that your content looks good together with the video plane running behind Java's graphics plane. Each scene can include logic for handling user input. You can declare all the scene nodes statically, or call into Java layer.

Definitely. Tools under AuthoringTools are generic and we are aiming them to be applicable to GEM based platform overall. Many tools under DiscCreationTools directory might be BD specific, meanwhile. See also question #3, "target audience for this project".