How do I open an .aca file?  
Author Message
Will Merydith





PostPosted: HD DVD Interactivity Authoring, How do I open an .aca file? Top

Can I open my .aca files



Audio and Video Development2  
 
 
Andy Pennell MSFT





PostPosted: HD DVD Interactivity Authoring, How do I open an .aca file? Top

You refer to the content of aca files using specially crafted URIs in markup/script e.g.

file:///hddvddisc/ADV_OBJ/myfile.aca/foo.jpg

i.e. treat the aca file as if it were a directory.



 
 
wmerydith





PostPosted: HD DVD Interactivity Authoring, How do I open an .aca file? Top

So are you saying I can create the uri in windows explorer (to that jpg) and view it I tried that (png file actually) and it did not work.

"Windows cannot find <path>"




 
 
Andy Pennell MSFT





PostPosted: HD DVD Interactivity Authoring, How do I open an .aca file? Top

Sorry, I misunderstood you. Windows has no concept of .aca files so cannot decode them.

I thought you were wanting to consume them from HD DVD code.



 
 
wmerydith





PostPosted: HD DVD Interactivity Authoring, How do I open an .aca file? Top

Is the ECMA script obfuscated when written to archive



 
 
Peter Torr - MSFT





PostPosted: HD DVD Interactivity Authoring, How do I open an .aca file? Top

The CreateACA tool shipped with iHDSim does not do any obfuscation; an ACA is simply an archive file like a ZIP file (but without the compression). If you opened it up in a binary editor, you would see all the raw text after some header information. If you have the HD DVD spec, it would be fairly trivial to write a de-ACA program.

If you have an AACS-protected disc, then you have the option of encrypting the script code (both inside and outside of ACAs).



 
 
wmerydith





PostPosted: HD DVD Interactivity Authoring, How do I open an .aca file? Top

I wanted to check out some of the javascript on the Serenity and Million Dollar Baby HD-DVDs, but when I open the aca in a hex editor, I can read the xml but not the javascript.

So I assume that obfuscation is intentional


 
 
Peter Torr - MSFT





PostPosted: HD DVD Interactivity Authoring, How do I open an .aca file? Top

Yes, in that case they have used a different tool and have AACS-protected their script. The XML is only protected against tampering (modification), but the script is also protected against viewing (so you don't copy their code).