[XviD-devel] fdct porting questions

[Christoph Nägeli]

On Feb 11, 2004, at 10:37, Christoph Nägeli wrote:
> Hi all,
>
> Perhaps you know that I'm trying to optimize xvid for ppc altivec.
> Because idct are a little complicated, Edouard told me that it's 
> better if I port the idct from libmpeg2 at sourceforge.
> So I did this and it worked fine, though the PSNR and MSE are a little 
> different than these from the C function,
> => the ieee 1180 test seems to tell that these are ok (and image 
> quality is good, too)
>
> I thought it would be best to port fdct from another project, too, so 
> I choose ffmpeg and actually I could just copy-paste the fdct_altivec 
> file.
> But now running xvid_bench has an error (like this):
>
>  ===== test fdct/idct =====
> PLAINC -  1.911 usec       PSNR=13.291  MSE=3.000
> ALTIVEC -  0.473 usec       PSNR=-49.310  MSE=5460077.000 | ERROR

The image doesn't look like a picture, I forgot to relink my video app 
before encoding a test movie...

--
Christoph