[FFmpeg-devel] [PATCH] install aes.h, des.h and rc4.h

Måns Rullgård mans
Sun Mar 8 22:27:12 CET 2009

Michael Niedermayer <michaelni at gmx.at> writes:

> On Sun, Mar 08, 2009 at 08:24:43PM +0100, Reimar D?ffinger wrote:
>> On Sun, Mar 08, 2009 at 07:19:55PM +0100, Michael Niedermayer wrote:
>> > On Sun, Mar 08, 2009 at 09:38:33AM +0100, Reimar D?ffinger wrote:
>> > > Is there a way we can go forwards with this or should we just give up on
>> > > making this public API.
>> > 
>> > Where was the problem with just saying in the docs that the struct must be
>> > aligned so that all user level instructions on the platform can access it.
>> > Or for portable applications align by 16 byte
>> > or something similar
>> > ?
>> We also need an implementation of it that works fine for asfcrypt.c.
>> Or in other words, coming up with a public API is not enough, we must
>> also come up with a way to actually use it within FFmpeg.
>> Which is not really a problem since I don't mind if the structure of
>> AVDES/AVRC4 is public and AVAES is always on the heap so far, it
>> just seems bad to be inconsistent with AVAES and to have no concept of
>> how to allocate AVAES on the stack (unless we decide there is never any
>> need to allocate them on the stack).
> what is the problem with DECLARE_ALIGNED() ?

That it doesn't work reliably for alignment greater than 8.

M?ns Rullg?rd
mans at mansr.com

More information about the ffmpeg-devel mailing list