[XviD-devel] about the key frame

[lakshmikanth r]

Hi,

I am new to this MPEG4 encoding , I hope you can reply
my question about DCT.

In the XVID software, I have doubts regarding the
implememtation of the DCT algorithm it is as follows,

Can you pls let me how arrive at the following
constants,
#define FIX_0_298631336  ((int)  2446)	/*
FIX(0.298631336) */
#define FIX_0_390180644  ((int)  3196)	/*
FIX(0.390180644) */
#define FIX_0_541196100  ((int)  4433)	/*
FIX(0.541196100) */
#define FIX_0_765366865  ((int)  6270)	/*
FIX(0.765366865) */
#define FIX_0_899976223  ((int)  7373)	/*
FIX(0.899976223) */
#define FIX_1_175875602  ((int)  9633)	/*
FIX(1.175875602) */
#define FIX_1_501321110  ((int) 12299)	/*
FIX(1.501321110) */
#define FIX_1_847759065  ((int) 15137)	/*
FIX(1.847759065) */
#define FIX_1_961570560  ((int) 16069)	/*
FIX(1.961570560) */
#define FIX_2_053119869  ((int) 16819)	/*
FIX(2.053119869) */
#define FIX_2_562915447  ((int) 20995)	/*
FIX(2.562915447) */
#define FIX_3_072711026  ((int) 25172)	/*
FIX(3.072711026) */

I think there are coefficient constants. I want to
specifically know whoe to arrive at the following
constants,
(0.298631336) 
(0.390180644) 
(0.541196100) 
(0.765366865) 
(0.899976223) 
(1.175875602) 
(1.501321110) 
(1.847759065) 
(1.961570560) 
(2.053119869) 
(2.562915447) 
(3.072711026) 

Awaiting your response,

With regards,
R.lakshmikanth
--- zgdragon at tom.com wrote:

> hi,
>     Everyone, i write a xvid encoder(version 1.02)
> with directshow filter, and link the xvid core as
> static library(not use the xvid.dll).
> 
>     the problem is, i test my encoder using this
> process: video capture -> my encoder -> xvid decoder
> -> video render, so, by the USB camer, it work ok,
> but when i chang to use the video card,the video
> render window can see nothing,(use the xvid vfw
> codec all is ok)
> 
>     and ,throught i debug, i find xivd decoder can
> gernal the key frame when using xvid vfw codec, but
> use the encoder i write it can't gernal the key
> frame,.
> 
>     pls help me, thanks a lot.
> 
>                                                
> hugo.
> > _______________________________________________
> XviD-devel mailing list
> XviD-devel at xvid.org
> http://list.xvid.org/mailman/listinfo/xvid-devel
> 



	
		
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