[FFmpeg-devel] Add support for LJ92 compressed MLV files, attempt 02

[South East]

On Sat, 9 Nov 2024 at 00:37, Michael Niedermayer <michael at niedermayer.cc> wrote:
>
> On Mon, Nov 04, 2024 at 06:14:07AM +0000, South East wrote:
> > Hi all - what do I need to do to progress this?
>
> iam a bit overloaded with work ATM, but bayer or interlacing combined with
> jpeg gives me memories of segfaults. So maybe you can run this through some fuzzer
> with some samples that trigger the code pathes
> to check it a bit

Thanks.  I have experience with AFL so this is practical for me.  The
likely output is
a collection of samples that will improve code coverage, focussing on MLV and
DNG files.

Does ffmpeg use AFL for testing already?  I would expect to make local code
modifications to ffmpeg in order to improve speed of fuzzing (see e.g.
__AFL_LOOP).
Would you want those changes?  It should be obvious they do something because
of improved code coverage, perhaps that is enough.

I would expect testing with ffplay (with an ASAN enabled build) would be an
 acceptable scope (there is no encoder for MLV).  Is that assumption correct?

I would guess we are only interested in new problems when the patches are
applied, i.e., if I discover old flaws, that shouldn't have any
bearing on whether
my patches are accepted.

Beyond that, what would you consider evidence of adequate testing?