YV24 question

[bxyhxyh]

I do sometimes 720p YV24 rip from bluray source.
By downscaling luma plane and upscaling chroma planes.

Today I checked it to to be sure.
And these two have different placements on chroma.

ConvertToYV24(matrix="Rec709").Spline36Resize(1280,720)
Spline36Resize(1280,720).ConvertToYV24(matrix="Rec709")

First one's placement is exactly same as "upscaling chroma" method.
But second one was bit off.

Why?
Blurriness or detail loss aside shouldn't their chroma placement be the same?

[Gavino]

I expect this is due to the deficiency which exists in Avisynth's horizontal resizing of YV12, producing a chroma shift. See this post and surrounding discussion. As far as I know, this has never been fixed.

Resizing in YV24 works fine, so doing the conversion before the resize produces correct results.
See this thread where a similar problem to yours was discussed.

[bxyhxyh]

Ok. Thanks.

So "upscaling chroma" method seems correct then, since it is done in Y8 colorspace, (or on the luma plane if we used utoy()).

[Sparktank]

Does this affect only internal resizers or does it affect cretindesalpes's Dither_package as well?
Most of those posts are old.

[colours]

Dither_resize16 has a cplace parameter for you to specify the chroma siting, and it defaults to MPEG-2.

[Reel.Deel]

For the internal resizers there's mawen1250's Resize8 (https://www.nmm-hd.org/upload/get~8y1IjaaqvoI/Resize8_v1.2.avsi) script which correctly handles chroma placement.

[TheSkiller]

Does this affect only internal resizers or does it affect cretindesalpes's Dither_package as well?It does not affect Dither_Resize16, I tested it myself not too long ago, see here (http://forum.doom9.org/showthread.php?p=1706510#post1706510). Only the built-in resizers are affected by this chroma shift while resizing in horizontally subsampled color spaces (YV12, YUY2, YV16, YV411).

[Sparktank]

That's good to know.

see here (http://forum.doom9.org/showthread.php?p=1706510#post1706510).

Ahhh, I remember watching that thread for awhile.
I forgot about all the good info that one.
Thanks for the refresh.