[MPlayer-users] MPlayer-1.0pre4 bug with divx4 multipass filter

[Vladimir Mosgalin]

On Mon, 13 Sep 2004, D Richard Felker III wrote:

DRFI>> His methods must be incorrect (well, not really, but they aren't showing
DRFI>> the real situation, because this is comparsion of the worst case with
DRFI>> the best case). With the method "encode with qp=2 and compare the
DRFI>> difference in filesize" I get insignificant difference. Up to 1%, maybe.
DRFI>
DRFI>your test is not valid. you need to compare the psnr for both files
DRFI>too. the psnr for the incorrect-sized file will be much worse
DRFI>because the partial blocks at the edge don't encode well!

I understand this, but doesn psnr really matter as long as they look
good? Say, with height 360 352 pixels must be the same, remaining 8 must
be encoded _worse_ and lower overall psnr, but they look ok - so there
are no problems with it.

PSNR test must be mathematically correct, but video isn't about math..
The psnr difference isn't meaningful in this case, just like in many
others.

DRFI>mod4 is useless, and mod8 barely helps. at least you're not stupid

Not really. Who knows, maybe I'm encoding interlaced video and don't
want any chroma problems?

DRFI>at this point, you've repeatedly insisted on doing things that are
DRFI>proven to lower quality significantly, and then you complain about
DRFI>lavc being low quality without any proof, when all my experience has
DRFI>shown the opposite. this conversation is getting really stupid. if you
DRFI>want to continue it, post a sample "challenge" file with your xvid
DRFI>encode and the original, and i'll encode with lavc.

OK, just wait a few more days. I barely have free time right now. And I
waste half of it on these mails...

-- 

Vladimir