[XviD-devel] New Trellis Quant

Radek Czyz syskin at ihug.com.au
Tue May 13 21:58:10 CEST 2003


Hi,

>         /* quality 6 */
>         XVID_VOP_DYNAMIC_BFRAMES | XVID_VOP_HALFPEL |
>         XVID_VOP_INTER4V | XVID_VOP_MODEDECISION_BITS |
>         XVID_VOP_HQACPRED

Allrighty, I found the problem: even if you're doing BITS refinement,
you should still do sad-based refinement! The code will work without
it, but PSNR _must_ decrease... This is true for 16x16 refinement -
8x8 sad-refinement is automatically deactivated if bits-refinement is
on (it's just faster this way).

It might be (should be?) different with R-D added to bits. I have my
initial code ready (inter only) and it makes wonders - with all BITS
options active, the difference is 0.3dB :))

Please tell me: is it safe to use dequant_inter(coeff, coeff, quant) ?
I just want to dequantize coefficients and I don't have memory space
for extra (third) buffer... I know it's safe with C version, but I
don't want to take for granted all asm versions.

I reviewed the code and found some minor bugs here and there. I'll
commit the changes soon (but without R-D yet) - and Ed will kill me,
because I will have committed it to dev-api-3, and the number of
changes is big....

Regards,
Radek



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