Colorspace conversion

[Sharc]

The 2 scripts below do not produce identical outputs. Is this expected behavior due to the lossy YUY2->YV12 conversion, or is one (or both) of the scripts flawed?
Script 1 converts the interlaced frames to YV12
Script 2 converts the separated fields to YV12

Script 1:

AviSource=YUV422.avi     #720x576i, yuv422 interlaced
converttoYV12(interlaced=true)
Even = AssumeFrameBased().SeparateFields().SelectEven()
Odd = AssumeFrameBased().SeparateFields().SelectOdd()
Interleave(Even,Odd).Weave()
converttoRGB32(interlaced=true)

Script 2:

AviSource=YUV422.avi    #720x576i, yuv422 interlaced
Even = AssumeFrameBased().SeparateFields().SelectEven().ConvertToYV12(interlaced=false)
Odd = AssumeFrameBased().SeparateFields().SelectOdd().ConvertToYV12(interlaced=false)
Interleave(Even,Odd).Weave()
converttoRGB32(interlaced=true)

[Selur]

Scripts look fine to me and I would have expected them to have the same output.

The 2 scripts below do not produce identical outputs

How did you compare them?

Using:

LoadCPlugin("I:\Hybrid\32bit\avisynthPlugins\ffms2.dll")
Import("I:\Hybrid\32bit\avisynthPlugins\Histograms_in_RGB_&_CMY.avsi")
# loading source: F:\TestClips&Co\files\interlaceAndTelecineSamples\interlaced\YUV422_sample.avi
#  input color sampling YUY2
#  input luminance scale tv
A= FFVideoSource("F:\TESTCL~1\files\INTERL~1\INTERL~1\YUV422~1.AVI",cachefile="E:\Temp\avi_1deca8d5573c8cb8cd8489678b764f38_853323747_1_0.ffindex",fpsnum=25,colorspace="YUY2")
B = A
A = A.ConvertToYV12(matrix="Rec601", interlaced = true)
AEven = A.AssumeFrameBased().SeparateFields().SelectEven()
AOdd = A.AssumeFrameBased().SeparateFields().SelectOdd()
A = Interleave(AEven,AOdd).Weave()
A = A.ConvertToRGB32(interlaced  = true)
BEven = B.AssumeFrameBased().SeparateFields().SelectEven().ConvertToYV12(interlaced=false)
BOdd = B.AssumeFrameBased().SeparateFields().SelectOdd().ConvertToYV12(interlaced=false)
B = Interleave(BEven,BOdd).Weave()
B =  B.ConvertToRGB32(interlaced=true)

D = A.HistogramRGBParade ().Subtitle("Histogram A")
E = B.HistogramRGBParade ().Subtitle("Histogram B")
return Interleave(D,E)

it looks like you are right the histogram seems to be shifted by one line, but I'm not sure whether 'Histograms_in_RGB_&_CMY.avsi' (http://avisynth.nl/index.php/Histograms_in_RGB_%26_CMY#HistogramRGBParade) is suited for interlaced content,...

At least:

LoadCPlugin("I:\Hybrid\32bit\avisynthPlugins\ffms2.dll")
# loading source: F:\TestClips&Co\files\interlaceAndTelecineSamples\interlaced\YUV422_sample.avi
#  input color sampling YUY2
#  input luminance scale tv
A= FFVideoSource("F:\TESTCL~1\files\INTERL~1\INTERL~1\YUV422~1.AVI",cachefile="E:\Temp\avi_1deca8d5573c8cb8cd8489678b764f38_853323747_1_0.ffindex",fpsnum=25,colorspace="YUY2")
B = A
A = A.ConvertToYV12(matrix="Rec601", interlaced = true)
AEven = A.AssumeFiedBased().SeparateFields().SelectEven()
AOdd = A.AssumeFrameBased().SeparateFields().SelectOdd()
A = Interleave(AEven,AOdd).Weave()
A = A.ConvertToRGB32(interlaced  = true)
BEven = B.AssumeFrameBased().SeparateFields().SelectEven().ConvertToYV12(interlaced=false)
BOdd = B.AssumeFrameBased().SeparateFields().SelectOdd().ConvertToYV12(interlaced=false)
B = Interleave(BEven,BOdd).Weave()
B =  B.ConvertToRGB32(interlaced=true)

C = Subtract(A, B).Subtitle("DIFF")
A  = A.Subtitle("A")
B  = B.Subtitle("B")
return Interleave(A,B,C)

seems fine.

Cu Selur

[Selur]

Think I got it:

LoadCPlugin("I:\Hybrid\32bit\avisynthPlugins\ffms2.dll")
Import("I:\Hybrid\32bit\avisynthPlugins\Histograms_in_RGB_&_CMY.avsi")
# loading source: F:\TestClips&Co\files\interlaceAndTelecineSamples\interlaced\YUV422_sample.avi
#  input color sampling YUY2
#  input luminance scale tv
A= FFVideoSource("F:\TESTCL~1\files\INTERL~1\INTERL~1\YUV422~1.AVI",cachefile="E:\Temp\avi_1deca8d5573c8cb8cd8489678b764f38_853323747_1_0.ffindex",fpsnum=25,colorspace="YUY2")
A = A.AssumeBFF()
B = A
A = A.ConvertToYV12(matrix="Rec601", interlaced = true, ChromaOutPlacement ="DV")
AEven = A.AssumeFrameBased().SeparateFields().SelectEven()
AOdd = A.AssumeFrameBased().SeparateFields().SelectOdd()
A = Interleave(AEven,AOdd).Weave()
A = A.ConvertToRGB32(interlaced  = true, ChromaInPlacement = "DV")
BEven = B.AssumeFrameBased().SeparateFields().SelectEven().ConvertToYV12(interlaced=false, ChromaOutPlacement ="DV")
BOdd = B.AssumeFrameBased().SeparateFields().SelectOdd().ConvertToYV12(interlaced=false, ChromaOutPlacement ="DV")
B = Interleave(BEven,BOdd).Weave()
B =  B.ConvertToRGB32(interlaced=true, ChromaInPlacement = "DV")

D = A.HistogramRGBParade ().Subtitle("Histogram A")
E = B.HistogramRGBParade ().Subtitle("Histogram B")
return Interleave(D,E)

seems fine.

Important thing is setting 'ChromaInPlacement' when converting to Yv12 and setting 'ChromaOutPlacement' when converting to RGB32. (Didn't first think of this since I haven't filtered DV content for ages,...)

Cu Selur

[Sharc]

Scripts look fine to me and I would have expected them to have the same output.

Yes, I thought the same …….

How did you compare them?

The differences are small and difficult to see by interleaving or subtraction alone. So in practice they should not really matter, I think. I was just wondering as to why there is a difference at all

I compare like this:

subtract(A,B).Levels(127,1,129,0,255)

If A,B are identical this should give a homogeneous gray picture.

Another check I made is like

A=A.converttoYV12(interlaced=true).colorYUV(analyze=true)
B=B.converttoYV12(interlaced=true).colorYUV(analyze=true)
stackhorizontal(A,B)

You will see that the luma of A and B are almost identical but there are small differences with U and V.
Not sure whether my test methods are really valid though.

[Selur]

you missed my last post.

[Sharc]

you missed my last post.

Yep indeed. Now it's ok. I pulled my hair.
Does it affect your new release of Hybrid? Seems like issues always pop up just after a new release is out.

[Selur]

Does it affect your new release of Hybrid?

Yes, this would affect all previous releases of Hybrid, including the latest. (Like I said I never use DV content so I never stumbled of this.)
Will add an option to add the chroma placement.

Seems like issues always pop up just after a new release is out.

That just happens because then people play around more.

Cu Selur

[Sharc]

Will add an option to add the chroma placement.

Can it perhaps be automatically added, based on the source analysis?

[Selur]

Can it perhaps be automatically added, based on the source analysis

I could probably add it automatically if the source is DV or MPEG-1 video. -> I'll look into it.

-> send you a link to a new dev version for testing

Cu Selur