[FFmpeg-devel] [PATCH 2/2] tta/x86: add ff_ttafilter_process_dec_{ssse3, sse4}

Christophe Gisquet christophe.gisquet at gmail.com
Tue Feb 11 14:07:54 CET 2014

2014-02-11 Paul B Mahol <onemda at gmail.com>:
>> Well, I don't feel confident, but it makes sense it works. I don't
>> know what opinion other people have, nor a way to mitigate a potential
>> issue. I fear leaving a comment along the declaration of the TTA*
>> struct about the need for a total size multiple of 16, and making sure
>> the tables addresses in TTAFilter remain aligned might help, but not
>> failproof at all.
> What about all those ALIGNED macros that are put into c code of various structs?

I don't know how that works for a structure inside a structure (rinse
and repeat) that is (av_)malloc'ed, even more so if it's an array of
structs. I would wager it only means "reserve padding" so that the
address relative to the start of the struct/stack is aligned as

If the top-level structure size is not a multiple of 16, I don't think
that'll help for instance.

I'm not about to inspect the ISO C specs.


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