[theora-dev] DCT-coefficients in

[Alexander Lubyagin]

Why for white-pixel image, oc_enc_fdct8x8_c() returns
the matrix with non-zero AC-coefficients?

_x[64]:

* 107 107 107 107 107 107 107 107
* 107 107 107 107 107 107 107 107
* 107 107 107 107 107 107 107 107
* 107 107 107 107 107 107 107 107
* 107 107 107 107 107 107 107 107
* 107 107 107 107 107 107 107 107
* 107 107 107 107 107 107 107 107
* 107 107 107 107 107 107 107 107

_y[64]:

*   3426      1      1      1      0      0      0      0
*      1      2      1      1      0      0      0      0
*      1      1      1      1      0      0      0      0
*      1      2      1      1      0      0      0      0
*      1      1      1      1      0      0      0      0
*      0      1      1      1      0      0      0      0
*      1      1      1      1      1      0      1      0
*      0      0      0      0      0      0      0      0

This is - error of butterfly-method?

P.S. My program dct.py returns:
   1016      0     -0      0      0      0     -0     -0
      0     -0      0      0      0      0      0     -0
      0     -0      0      0      0     -0      0      0
      0      0     -0      0      0      0     -0      0
      0     -0      0     -0      0      0     -0     -0
      0      0      0      0      0      0      0      0
     -0      0     -0     -0      0      0     -0     -0
     -0     -0      0      0     -0     -0      0      0