[xine-devel] DVD Navigation / SPUdec

[Eduard H. <ed...@ao...>]

Hello.

I know, there is an own project for DVD navigation at sourceforge,
but it has no ML associated with it. So I assume we should still
such issues here.

In order to prepare xine for navigation I made some "research" how
navigation buttons are implemented with my dxr3. They are actually
very easy to implement, but need an extension to xine.

The dxr3 intercepts menu SPUs the same way as the usual subtitles.
It knows that these SPUs don't have a duration and doesn't show
them immediately.

For activating one button following actions have to be performed:

1) Selecting the button colors (from the CLUT) and the transparency
	values (4 colors, 4 trans-values)

2) Setting the top,bottom,left and right borders of the button

3) Activating (showing) the menu spu.

As this actions have to be performed immediately, queueing them
in some queue might be too slow. Therefore some kind of function
call (callback function) is needed. 

What I can think of:
*) The spu decoder registers a callback at the input plugin
*) the spu interface is changed and a plugin function for
	menu buttons is introduced.

Using this method the (very comfortable) modular design
can be kept. And it is IMHO not bad when the libspudec behaves
the same way as the spu decoder of the dxr3 does.

When doing this enhancement, setting the clut
should word with an callback too. There might be movies, where
the CLUT changes while playing.

Although the navigation logic will be concentrated in the input
plugin a couple of changes have to be done to xine.

Just to give some input
*) language selection (not just the track number)
*) multi angle (maybe only in input needed)
*) spu language selection, how to distinguish a menu spu from
	an subtitle?

Any comments?

greetings,
-- 
Eduard Hasenleithner
student of
Salzburg University of Applied Sciences and Technologies