[xine-devel] stillframe skipped away? (was: Re: [xine-user] DVD menu problem)

[Michael R. <mr...@us...>]

I am taking this over to the xine-devel mailing list, because I think it 
uncovers a fairly serious problem.

> >I get a similar result with the DVD 'Miss Congeniality': When
> > navigating with the user interface, at the title menu I just get a
> > black background and the pointer, but you cannot see at which item
> > it's pointing at.
>
> I get this too.  I think I know why (to some degree).
>
> It's most prominent on my Back to the Future DVDs, where all the
> menus are preceeded immediately by the white flash of the time
> machine hitting 88mph.   The screen remains white instead of
> progressing to the menu. Essentially, I think it's not displaying the
> correct frame on still frame menus, but instead stopping a couple of
> frames too early.  Menus which are animated seem to be fine.

There are certain situations in the interaction of xine engine and 
libmpeg2 where frames can be skipped. If the engine realises, that the 
decoder is falling behind with decoding (maybe because your machine is 
slightly too slow), it advices the decoder to skip some frames. 
Unfortunately, if this happens right before a stillframe, this very 
important frame will be skipped and the last completely decoded frame 
stays on the screen.

It would be very helpful, if one of you could confirm this theory by 
doing:
* get yourself a configured xine-lib source tree by downloading the
  latest release tarball and ./configure-ing it or alternatively using
  an old build tree, if you have it still around
* cd to the src/libmpeg2 directory
* edit the file decode.c: remove the lines 44 and 46 in that file
  (the comment marks around "#define LOG", this will enable logging)
* type "make install" in that directory
  (this should install a logging-enabled libmpeg2 xine plugin)
* run xine as usual
* you should now see a lot of console output when playing a DVD, have a
  look at the output at the critical moment and watch out for any
  messages of dropped frames

To the developers: Is there any nice solution to prevent skipping on 
stillframe situations?

Michael

-- 
"Hey, it's Unix! I know this!" 
	-Lex, Jurassic park.