[FFmpeg-devel] On libavfilter: A Summary of Issues

[Reimar Döffinger]

Stefano Sabatini <stefasab at gmail.com> wrote:

>On date Sunday 2012-10-07 14:18:15 +0200, Michael Niedermayer encoded:
>> Hi
>> 
>> On Sat, Oct 06, 2012 at 07:38:36PM -0400, Derek Buitenhuis wrote:
>> [...]
>> 
>> > 
>> > 
>> > It's a Monolithic Library
>> > -------------------------
>> 
>> is it ?
>> all filters are registered through avfilter_register()
>> one could load a filter by whichever means and register it, it would
>> work.
>> A patch actually implementing such dynamic loading is welcome!
>> but see below also, there are other options ...
>
>The problem is that an external C filter can't access all the
>internal utilities in libavfilter, which *are* required for a sane
>implementation, the alternative is to copycat all the utilities in the
>userspace code, which kinda sucks.

This issue is not well solvable since this code will be completely impossible to access from loaded plugins if e.g. lavfi was linked statically and even otherwise would mean bloating the symbol table massively.
Unless you intend to pass all function and data pointers in a structure at filter load.