Problem with shifted chroma

[McCauley]

Hi,

i have a problem with some interlaced footage from a DVD i'm trying to encode.
The chroma is shifted four pixels to the right, see the sample (http://www.mediafire.com/?xm7zl8jwjde).

It shouldn't be hard to fix that, but i found nothing in the Avisynth docs and on the forums.

Looking forward to help on this.

Regards and thanks in advance
McCauuley

[martino]

ChromaShift (http://www.geocities.com/siwalters_uk/chromashift.html)

[IanB]

And if you need sub-pixel accuracy in the movement :-X=3.2 # Move chroma left 3.2 pixels
Y=-1.6 # Move chroma down 1.6 pixels
MergeChroma(Spline16Resize(Width(), Height(), X, Y, Width()+X, Height()+Y))

[McCauley]

Thanks for the fast replies to both of you, i will try it when getting home.

Regards
McCauley

[McCauley]

Can i add that to wiki, or have i missed something?


#ChromaShift_SP: Shift chroma with subpixel accuracy

function ChromaShift_SP (clip clp, float "X",float "Y") {

X = default(X, 0.0) # positive values shift the chroma to left, negative values to right
Y = default(Y, 0.0) # positive values shift the chroma upwards, negative values downwards

w = clp.Width()
h = clp.Height()

clp.MergeChroma(clp.Spline16Resize(w, h, X, Y, w+X, h+Y)) }

Regards
McCauley

[l33tmeatwad]

I had a need to shift U and V separately so I modded ChromaShiftSP to allow that, figured I'd throw it in here in case anyone else needed it.

#ChromaShiftSP2: Shift U & V chroma separately with subpixel accuracy, based on the ChromaShiftSP function by IanB & McCauley

function ChromaShiftSP2 (clip clp, float "UX",float "UY", float "VX",float "VY", string "ResizeMethod") {

UX = default(UX, 0.0) # positive values shift the U chroma to left, negative values to right
UY = default(UY, 0.0) # positive values shift the U chroma upwards, negative values downwards
VX = default(VX, 0.0) # positive values shift the V chroma to left, negative values to right
VY = default(VY, 0.0) # positive values shift the V chroma upwards, negative values downwards
ResizeMethod = Default(ResizeMethod, "Spline36")

U = clp.UToY()
U = Eval("U." + ResizeMethod + "Resize(U.Width(), U.Height(), UX, UY, U.Width()+UX, U.Height()+UY)")

V = clp.VToY()
V = Eval("V." + ResizeMethod + "Resize(V.Width(), V.Height(), VX, VY, V.Width()+VX, V.Height()+VY)")


YToUV(U, V, clp) }