[FFmpeg-devel] [libav-devel] [PATCH] Change behviour of empty AVFilterFormats lists

[Stefano Sabatini]

On date Wednesday 2011-06-08 01:55:53 +0200, Stefano Sabatini encoded:
> On date Tuesday 2011-06-07 17:51:27 +0300, Mina Nagy Zaki encoded:
> > This makes an empty list mean 'all formats supported'. This will simplify some 
> > things for the format negotiation later on. Before the patch, returning an 
> > empty list in query_formats() would simply mean no format supported, which is 
> > non-sensical. This way a lot of unnecessary merging of 'all formats' lists is 
> > avoided. 
> > 
> > 
> > -- 
> > Mina
> 
> > From 46347d6ded4272430a386696065af5a6f9993abb Mon Sep 17 00:00:00 2001
> > From: Mina Nagy Zaki <mnzaki at gmail.com>
> > Date: Tue, 7 Jun 2011 17:42:32 +0300
> > Subject: [PATCH 1/2] lavfi: Make avfilter_make_format_list handle NULL lists.
> > 
> > ---
> >  libavfilter/avfilter.h |    3 ++-
> >  libavfilter/formats.c  |   13 ++++++++-----
> >  2 files changed, 10 insertions(+), 6 deletions(-)
> > 
> > diff --git a/libavfilter/avfilter.h b/libavfilter/avfilter.h
> > index 9b1ea2d..0375a38 100644
> > --- a/libavfilter/avfilter.h
> > +++ b/libavfilter/avfilter.h
> > @@ -233,7 +233,8 @@ typedef struct AVFilterFormats {
> >   * Create a list of supported formats. This is intended for use in
> >   * AVFilter->query_formats().
> >   *
> > - * @param fmts list of media formats, terminated by -1
> > + * @param fmts list of media formats, terminated by -1. If NULL an
> > + *        empty list is created.
> >   * @return the format list, with no existing references
> >   */
> >  AVFilterFormats *avfilter_make_format_list(const int *fmts);
> > diff --git a/libavfilter/formats.c b/libavfilter/formats.c
> > index 101ef09..ec7fca3 100644
> > --- a/libavfilter/formats.c
> > +++ b/libavfilter/formats.c
> > @@ -73,15 +73,18 @@ AVFilterFormats *avfilter_merge_formats(AVFilterFormats *a, AVFilterFormats *b)
> >  AVFilterFormats *avfilter_make_format_list(const int *fmts)
> >  {
> >      AVFilterFormats *formats;
> > -    int count;
> > +    int count = 0;
> >  
> > -    for (count = 0; fmts[count] != -1; count++)
> > -        ;
> > +    if (fmts)
> > +        for (count = 0; fmts[count] != -1; count++)
> > +            ;
> >  
> >      formats               = av_mallocz(sizeof(AVFilterFormats));
> > -    formats->formats      = av_malloc(sizeof(*formats->formats) * count);
> >      formats->format_count = count;
> > -    memcpy(formats->formats, fmts, sizeof(*formats->formats) * count);
> > +    if (count) {
> > +        formats->formats  = av_malloc(sizeof(*formats->formats) * count);
> > +        memcpy(formats->formats, fmts, sizeof(*formats->formats) * count);
> > +    }
> >  
> >      return formats;
> >  }
> > -- 
> > 1.7.4.4
> 
> Makes sense, I'll apply it tomorrow if I see no objections.

Pushed.
-- 
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