[FFmpeg-devel] [PATCH] mingw memalign hack fix

David DeHaven dave
Thu Nov 27 01:17:52 CET 2008

>>> SSE2 code was segfaulting on my MinGW builds, turns out blocks being
>>> av_realloc'd were losing their alignment. This patch fixes that.
> av_realloc() makes no gurantee about alignment

Then it shouldn't be used for blocks that are being used in MMX/SSE  
optimized code :)

> also several people have already tried to implement a av_realloc()  
> that
> maintains alignment so far with no luck.
> yours looks exploitable ...

At worst you just allocate a new block and copy the data... that's  
what realloc does when it can't extend the block it's been given.  
Ideally this would be fixed in MinGW but I really don't want to dive  
into that pile...

Actually there's something else I didn't catch, the previous patch  
will only realloc up to the previous diff more bytes and not a full 16  
bytes like av_malloc does.


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