[vlc-devel] [PATCH] core: add a callback to init/release data for picture pool of opaque formats

[Rémi Denis-Courmont]

Le lundi 20 avril 2015, 16:38:07 Steve Lhomme a écrit :
> There's no object instance you can use in video_format_t so
> picture_NewFromFormat() is not an option. And that's what is used in
> vout_InitWrapper() to create the decoder pool (in this case the
> decoder already has its pool), the display pool (which needs to be
> initialized with the same handles as the decoder pool).

The video output can, and typically does, survive the decoder. The pictures 
can also survive the current decoder output format (especially with threaded 
decoding).

So I don't see how non-serial data in video_format_t (or alongside it) can 
ever work. FWIW, that issue was already brought up to solve a completely 
different problem - multiple video output windows.

To take a simple and concrete example, how do you compare the video formats 
when there is an opaque pointer inside? Pointer comparison only works if you 
know that the two pointed objects were concurrent in memory, such that they 
cannot be two distinct objects with the same address.

-- 
Rémi Denis-Courmont
http://www.remlab.net/