[FFmpeg-devel] [PATCH 1/2] avcodec/sbrdsp_fixed.c: remove input value limit for sbr_sum_square_c()

Michael Niedermayer michael at niedermayer.cc
Wed Feb 6 21:17:50 EET 2019


On Wed, Feb 06, 2019 at 01:57:37PM +0100, Carl Eugen Hoyos wrote:
> 2019-02-03 18:21 GMT+01:00, Michael Niedermayer <michael at niedermayer.cc>:
> > Fixes: 1377/clusterfuzz-testcase-minimized-5487049807233024
> > Fixes: assertion failure in sbr_sum_square_c()
> 
> This changes the output, no?

in normal cases, no it should not
It may be that one can construct a case thats not yet in the range
where the old code was undefined, the new code is defined by 
1 in a Quintillion differently and then the decoder output which is
not 64bit integers still has a off by 1 difference.
That could be, or it might be not, i dont know

You can certainly have a differenceof the old code crashing with
assertion failure though if thst is considered "different"


> Why are the asm implementations not affected?

Please correct me if iam wrong but
i think only the float but not the integer version
of this have been optimized.

thx


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

Republics decline into democracies and democracies degenerate into
despotisms. -- Aristotle
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