HD-DVD's menu software was built primarily by Microsoft and didn't require Java or even support Java. It's menu system was loosely HTML-based XML with some support for CSS-like stylesheets and optional Javascript. Just about everything a movie menu needs (including support for rich animations) could be done entirely declaratively and JS scripting was entirely optional (and rarely used/needed).
It could have been cheaper than Java runtimes needed by Blu-Ray players, but one of the requirements they decided they needed in the menus was live previews of movie content and that wanted multiple active streams of video decompression. These days Blu-Rays fake it with effectively just using animated GIFs in the Java menus, but HD-DVD menus would actually play the movie in things like scene thumbnails (which was neat, but maybe unnecessary). Needing hardware that supported multiple active streams of video decompression to support that is often considered the big reason HD-DVD wasn't cheaper than Blu-Ray especially given the licensing costs and expense of BD-J Java systems.
Thats fascinating! Thank you for the history! It would be cool to see the best implementation of this JS based system however I feel like it would suffer from the some of the same problems as the Java system: namely with so many vendors, how can you ensure that each implementation will contain a robust JS rendering engine? Feels like that would just lead to publishers using off the shelf templates that do the bare minimum as we are seeing on Blueray.
How would the HD-DVD laser cope with having to read multiple streams? or does it read it ahead of time and just cache it somehow? One of the biggest annoyances of DVD was the fact that some player implementation had horrific seek times and so the menu transitions were mind numbingly slow.
I wish they would have watched AVGN's comedic take on DVD and Blu-Ray formats and just created a format that met all those specifications. Have you seen these videos?
> It would be cool to see the best implementation of this JS based system however I feel like it would suffer from the some of the same problems as the Java system: namely with so many vendors, how can you ensure that each implementation will contain a robust JS rendering engine?
Like I said the primary rendering engine was primarily XML driven and XML-based. So far as I'm aware the only implementation in HD-DVD's history was Microsoft's (which was a small complaint among the hardware vendors that there was only one firmware for the "base OS" of HD-DVD players), and it was incredibly performant (because it wasn't using scripting to run animations and such). It supported JS for scripting, but that scripting was almost never used in the vast majority of disc menus, and it was probably a very bare JS engine at that and never needed to guarantee performance. The JS could be under-powered because it was an optional add-on for small bits of interactivity like "games and quizzes", it was not driving hardly anything in day-to-day menus. Think "early days of the web" (or maybe HN itself): almost everything is basic HTML and JS is used sparingly for a minimum for just a small subset of interactive features. But if you built an HTML specifically to be a nicely animated Table of Contents for a movie and had years of DVD movie menus to compare for best practices.
> How would the HD-DVD laser cope with having to read multiple streams? or does it read it ahead of time and just cache it somehow? One of the biggest annoyances of DVD was the fact that some player implementation had horrific seek times and so the menu transitions were mind numbingly slow.
Good questions. I'm not as much a hardware person as a software person, so I don't know the answers beyond that I just recall the approach chosen by the HD-DVD standard was considered expensive in contrast to DVD or to Blu-Ray hardware standards at the time. As a user of HD-DVD, there was some noticeable seek lag in the menus, as I recall, but it was kind of magic when it worked.
It could have been cheaper than Java runtimes needed by Blu-Ray players, but one of the requirements they decided they needed in the menus was live previews of movie content and that wanted multiple active streams of video decompression. These days Blu-Rays fake it with effectively just using animated GIFs in the Java menus, but HD-DVD menus would actually play the movie in things like scene thumbnails (which was neat, but maybe unnecessary). Needing hardware that supported multiple active streams of video decompression to support that is often considered the big reason HD-DVD wasn't cheaper than Blu-Ray especially given the licensing costs and expense of BD-J Java systems.