[FFmpeg-devel] [RFC] Public API for RC4 and DES

Reimar Döffinger Reimar.Doeffinger
Mon Feb 2 17:05:08 CET 2009

On Mon, Feb 02, 2009 at 03:58:44PM +0100, Michael Niedermayer wrote:
> On Mon, Feb 02, 2009 at 01:38:43PM +0000, M?ns Rullg?rd wrote:
> > Using the same API for all the encryption types makes sense.
> yes and no
> if it slows 2 of 3 down by a significant amount it wouldnt be that ideal

The slowdown depends mostly on the usage, I think performance-wise the current
design of the AES routines would be quite bad if you were only decoding
a single block each time.
On the other hand, the current DES API means every user has to do the
endianness conversion, CBC and other stuff themselves, and makes it hard
to support 3DES.
I can't see how this change should noticeable affect RC4 speed, and for
the current uses we have DES speed is basically irrelevant and the
implementation is not optimized for absolutely highest speed anyway.
I would not mind a better API, but I doubt there is much choice (except
making the struct structure public).

Reimar D?ffinger

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