[FFmpeg-devel] [RFC PATCH] libavcodec/jpeg2000: Make corrections jpeg2000 decoder

Michael Niedermayer michael at niedermayer.cc
Mon Jun 22 22:22:17 EEST 2020


On Sun, Jun 21, 2020 at 10:55:24PM +0530, Gautam Ramakrishnan wrote:
> On Sat, Jun 20, 2020 at 9:48 AM Gautam Ramakrishnan
> <gautamramk at gmail.com> wrote:
> >
> > On Sat, Jun 20, 2020 at 1:29 AM Michael Niedermayer
> > <michael at niedermayer.cc> wrote:
> > >
> > > On Thu, Jun 18, 2020 at 11:55:20PM +0530, gautamramk at gmail.com wrote:
> > > > From: Gautam Ramakrishnan <gautamramk at gmail.com>
> > > >
> > > > This is with reference to my previous email on the mailing list
> > > > with subject: "query on pixel formats".
> > > > I wish to cleanup some errors in the decoder code. These changes
> > > > would allow the samples p1_01.j2k and p1_07.j2k to be decoded.
> > > > However, I am facing issues with pixel format selection and have
> > > > currently forced the pixel formats to demonstrate the changes made.
> > > > Would be grateful if anyone could suggest modifications to the pix
> > > > format selection.
> > > > ---
> > > >  libavcodec/jpeg2000.c    |  3 ---
> > > >  libavcodec/jpeg2000dec.c | 53 ++++++++++++++++++++++++++--------------
> > > >  2 files changed, 34 insertions(+), 22 deletions(-)
> > >
> > > Its probably a good idea to run this through some fuzzer when checks are
> > > removed, something really simple like zzuf is probably better than nothing
> > >
> > Yes, I shall do that.
> > > thx
> > >
> > > [...]
> > > --
> > > Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
> > >
> > > I know you won't believe me, but the highest form of Human Excellence is
> > > to question oneself and others. -- Socrates
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> >
> >
> >
> > --
> > -------------
> > Gautam |
> 
> When trying to perform fuzz testing, what kind of configuration would
> you recommend using.
> For example, I am taking some of the reference files and setting the
> error rate to 0.01. Is that sufficient?

i tried zzuf with defaults before writing my suggestion and it spotted
segfaults rather quickly, but i dont know if these segfaults where
related to these changes

thx

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

It is what and why we do it that matters, not just one of them.
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