[XviD-devel] FDCT constants

[lakshmikanth r]

Hi,

I have gone through the website that you had
reffered.But I am afraid I am not able to understand.
Can you pls take a specfic example of a constant and
explain me to to derive it, I would very thankfull to
you.

Awaiting your response,
With regards,
R.lakshmikanth
--- skal <skal at planet-d.net> wrote:

> 
> 	Hi,
> 
> On Mon, 2004-11-29 at 07:46, lakshmikanth r wrote:
> > HI,
> > 
> > I am a new to the field of MPEG4 encodeing and I
> was
> > going through your xvid reference code and in
> specfic
> > DCT calculation. The following line of code is
> found
> > in dct.c
> > "
> > #define FIX_0_298631336  ((int)  2446)	/*
> > FIX(0.298631336) */
> 
> 	[...]
> 
> > #define FIX_3_072711026  ((int) 25172)	/*
> > FIX(3.072711026) */
> 
> 
> 	these constants are mostly tan[k.pi/16].
> 	Have a look there:
> 
> http://skal.planet-d.net/coding/dct.html
> 
> 	in particular the part where 2d-rotations
> 	with 3 mults are described.
> 
> Skal
> 
> _______________________________________________
> XviD-devel mailing list
> XviD-devel at xvid.org
> http://list.xvid.org/mailman/listinfo/xvid-devel
> 



		
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