[MPlayer-dev-eng] PATCH dynamic link loader for libaf, audio filter package

[Marc Hoffman]

On 6/15/07, Reimar Doeffinger <Reimar.Doeffinger at stud.uni-karlsruhe.de>
wrote:
>
> Hello,
> On Fri, Jun 15, 2007 at 12:20:23AM -0400, mmh wrote:
> Content-Description: message body text
> > This small patch provides the ability to load audio filters at runtime
> > into mplayer.
>
> If anything, please do it as a new af_ like it was done for af_ladspa.
> Ok, I can't guarantee this will actually work, but it seems a lot less
> messy to me.


? Seems clean as an integrated mechanims its a tiny amount of code.  I did
think of doing it as a af-filter itself but that interaction seems too
complex.  Maybe I'm missing something.


> The API for the audio filter is identical to the existing libaf.  This
> > way if a module needs to be provided separately it can be done by
> > providing a shared object which can be inserted at runtime into the
> > audio filter chain.
>
> Why would someone want this though?


1. I need to link at runtime a  module which  can't be integrated with the
code itself directly due to proprietary IP issues.  As long as Mike and the
rest of the crew don't get a hold of the so's.

2. The functionality which I have been asked to add to mplayer is a bit
esoteric and specific to SMPTE time codes.  And I have been asked to make my
work private.

Well I don't want to patch the player thats too complex to do for ever.  So
I was thinking that this would be a good mechanism to tie the things
together for a very long time and minimizing costs etc.


> The only interface change which needs to be provided by the shared
> > object is that it must define a pointer to the info structure which
> > defines the filter.  This is done like this:
> >
> > af_info_t af_info_simple = {
> >         "simple audio filter",
> >         "simple",
> >         "mmh",
> >         "ex: simple",
> >         AF_FLAGS_NOT_REENTRANT,
>
> Why the hell does everyone want to use AF_FLAGS_NOT_REENTRANT?


I just copied this from some place else and got my filter to work.  I would
bet thats what everyone else does as well.

Marc