[FFmpeg-devel] [PATCH] add init/uninit code to cmdutils.c

[Reimar Döffinger]

On Sat, Sep 25, 2010 at 04:06:02PM +0200, Stefano Sabatini wrote:
> On date Saturday 2010-09-25 15:52:50 +0200, Reimar D?ffinger encoded:
> > On Sat, Sep 25, 2010 at 02:26:09PM +0100, M?ns Rullg?rd wrote:
> > > Stefano Sabatini <stefano.sabatini-lala at poste.it> writes:
> [...]
> > > >> Index: cmdutils.c
> > > >> ===================================================================
> > > >> --- cmdutils.c	(revision 25163)
> > > >> +++ cmdutils.c	(working copy)
> > > >> @@ -56,6 +56,25 @@
> > > >>  
> > > >>  const int this_year = 2010;
> > > >>  
> > > >> +void init_opts(void)
> > > >> +{
> > > >> +    int i;
> > > >> +    for (i = 0; i < AVMEDIA_TYPE_NB; i++)
> > > >> +        avcodec_opts[i] = avcodec_alloc_context2(i);
> > > >> +    avformat_opts = avformat_alloc_context();
> > > >> +    sws_opts = sws_getContext(16, 16, 0, 16, 16, 0, SWS_BICUBIC, NULL, NULL, NULL);
> > > >> +}
> > > >> +
> > > >> +void uninit_opts(void)
> > > >> +{
> > > >> +    int i;
> > > >> +    for (i = 0; i < AVMEDIA_TYPE_NB; i++)
> > > >> +        av_freep(&avcodec_opts[i]);
> > > >
> > > >> +    av_freep(&avformat_opts->key);
> > > >
> > > > Why is AVFormatContext.key special?
> > > 
> > > It is the only FF_OPT_TYPE_BINARY option.
> > > 
> > > > Shouldn't we have a function for automatically clean it up?
> > > 
> > > I suppose a function traversing the list and freeing all
> > > FF_OPT_TYPE_BINARY things might make sense.  Would you like to write
> > > one?
> > 
> > It should also free all FF_OPT_TYPE_STRING.
> > However you can't traverse the option list since you don't have one.
> > I can take this one out if you mind the hack, however I at least
> > won't be writing a proper solution to this any time soon.
> > (the proper solution would probably to free anything in the
> > contexts that is a pointer type and marked as allocated by the
> > user in the documentation).
> 
> We have avformat_alloc_context(), what about adding
> avformat_free_context()?

While that is a good idea, avformat_free_context can _only_!
free things that libavformat has allocated, anything else
could e.g. be a constant array the application has put there,
and trying to free it could abort.
Or in short: That has nothing at all do with this issue.