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View Full Version : Is yuy2 better for anime than yv12?


angelyote
1st February 2003, 21:12
I've been using the avisynth2.5 beta for encoding some cowboy bebop.

I've noticed that when I use yv12 colorspace (using mpeg2dec3) The large areas of flat color take on a sort of graininess and there seems to be more obvious signs of mosquito noise (that jittery stuff around edges). I was unable to clean things up effectively using c3d or fluxsmooth.

Then I switched to mpeg2dec for 2.5 that returns yuy2 colorspace and though the encode took over twice as long I was getting a smoother looking picture and less mosquito noise.

Is it possible that the difference in resolution between luma and chroma layers in yv12 can adversely affect the smoothness in large areas of a flat color? I've noticed that chroma seems to play a large roll in anime quality than in live action.

This just a call to see if anyone has experienced similar or opposite results. My one encode doesn't prove anything but it did start me thinking about it.

Dave

P.S. Thank you, Donald. Decimate (mode=3) is the best addition to decomb evah!

sh0dan
1st February 2003, 21:37
Luma is in the same resolution in YV12 as YUY2, so there should be no significant difference between the two formats. Chroma is in half the vertical resolution in YV12, but when compressing to MPEG YUY2 is converted to YV12 anyway.
So unless some of the algorithms for the YV12 are different, there will be a quite small difference between them.

Prettz
1st February 2003, 21:39
Did you use conv3d for both encodes? Its readme says that temporal influence is disabled in the YV12 version (or did I read it wrong?)

angelyote
1st February 2003, 22:16
@shodan
So I guess my idea would only be valid if I was doing some sort of chroma manipulation before compressing to mpeg. Which I wasn't.

@prettz
No, I wasn't using c3d on the yuy2 encode. I tried the yv12 with and without c3d and aside from the general pleasantness that c3d puts on your video it didn't alter the overall difference I'm seeing

Dave

angelyote
1st February 2003, 22:55
!Muppet News Flash!

I was using divx 5.03 for the yv12 encode and divx 5.02 for the yuy2 encode. Seeing the negative feedback on the divx forum concerning 5.03 I would be remiss to continue looking towards colorspace as the culprit.

I'll try stabilizing my codec environment and get back to this :)

Dave

digitize
2nd February 2003, 06:20
@angelyote
Personally I don't like divx 5.x, try a dev build of xvid and see what results you get.

Edit: Well any mpeg 4 codec for that matter, as they all output yv12.

Marc FD
2nd February 2003, 21:51
if i remeber well, a MPEG2Dec will blur chroma a lot during YV12->YUY2 conversion. try to blur chroma in YV12, should do it.

gft
2nd February 2003, 22:32
Make sure divx doesn't turn on the "film effect" without you knowing. That messed me up once.

-gft