[FFmpeg-devel] [PATCH 2/2] avcodec/avdct: Clear IDCTDSPContext context

[Michael Niedermayer]

On Mon, Jan 27, 2020 at 06:09:28PM -0300, James Almer wrote:
> On 1/27/2020 5:54 PM, Michael Niedermayer wrote:
> > Fixes use of uninitialized variable and segfault
> > 
> > Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> > ---
> >  libavcodec/avdct.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/libavcodec/avdct.c b/libavcodec/avdct.c
> > index 47e5f7134e..7c761cf39a 100644
> > --- a/libavcodec/avdct.c
> > +++ b/libavcodec/avdct.c
> > @@ -100,7 +100,7 @@ int avcodec_dct_init(AVDCT *dsp)
> >  
> >  #if CONFIG_IDCTDSP
> >      {
> > -        IDCTDSPContext idsp;
> > +        IDCTDSPContext idsp = {0};
> 
> Should probably be a memset() in ff_idctdsp_init(). This is not the only
> IDCTDSPContext user.

this would not work as IDCTDSPContext.mpeg4_studio_profile must be 
initialized but it is also an input to ff_idctdsp_init()

an alternative to the = {0} on the caller side would be to
simply add the mpeg4_studio_profile as an argument to ff_idctdsp_init()
and remove it from the context, its all just internal API so we can
easily redesign this. It should also be documented better ...

What do you suggest ?

thx

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Observe your enemies, for they first find out your faults. -- Antisthenes
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