I think that the following is correct, but I want to make sure. I need to convert from Rec.709 to RGB24 and expand the luma range, so I use this:
Then I can work in RGB. As I understand it, Rec.709 and Rec.601 only relate to YUV. Once one has converted to RGB correctly, there is no longer a distinction, so I can work in RGB and then convert to Rec.601 using this:Code:ConverttoRGB24(matrix="pc.709")
Does anyone know if HCenc converts YV12 to YUY2 internally? If it does, it might be better to use ConverttoYUY2() because HCenc certainly accepts YUY2 as input.Code:ConverttoYV12()#compresses luma range and assumes Rec.601
On a related note, given a Rec.709 YUV source, is
the same asCode:ConvertToYUY2(matrix="rec709")#keeps the luma in the TV range
and if not, which would people recommend. (I am not really concerned with the clamp parameter: I want to know if the overall conversion produces the same result.) Thanks for any help. I am nearly clear on this sort of thing.Code:Colormatrix(mode="rec.709->rec.601",clamp=0) Convertoyuy2()
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Anonymous344Guest
Last edited by Anonymous344; 2nd May 2011 at 15:47.
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Not quite; Rec601/709 refers whenever conversions are done between RGB<=>YUV
If you don't specify a matrix in avisynth, Rec.601 is used
On a related note, is
Code:ConvertToYUY2(matrix="rec709")#keeps the luma in the TV range
Code:Colormatrix(mode="rec.709->rec.601",clamp=0) Convertoyuy2()
The 2nd depends on how you converted RGB to YUV (colormatrix doesn't work on RGB) -
Anonymous344Guest
Thanks for your help, poisonsdeathray. : )
Other way around; It accepts YUY2 or YV12 input and outputs YV12 . (You can export YUY2 also, but this is invalid for DVD)
Not quite; Rec601/709 refers whenever conversions are done between RGB<=>YUV If you don't specify a matrix in avisynth, Rec.601 is used
No it doesn't, assuming your source is RGB, the 1st converts RGB to YUY2 using rec709 matrix
The 2nd depends on how you converted RGB to YUV (colormatrix doesn't work on RGB)Last edited by Anonymous344; 2nd May 2011 at 15:16.
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What I want to know is once you have converted to RGB is all RGB is the same i.e. if you have a Rec.709 source and convert it to RGB would it be qualitatively different from a Rec.601 source converted to RGB (leaving aside luma ranges and alpha channels for a moment)? (There are no vestiges of the video having been rec.709 originally left, so when you have finished working in RGB you can convert to whatever YUV colorspace you like.)
How you convert to RGB determines whether or not you get the same thing. If you converted with proper matrix you get the same thing (nearly; there are rounding differences)
Sorry, I didn't envisage an RGB source. I envisaged a Rec.709 one being converted to YUY2. When I said on a related note, I was trying to distance this part from the first half of the post. I was just trying to avoid starting a thread for every question I have.
Remember this and you won't go wrong:
The matrix only takes effect when you do RGB<=>YUV conversions
Colormatrix() filter is unique because it can do changes in YUV (staying in YUV) -
Anonymous344GuestIf you start with Rec.709 YV12 source, and use ConvertToYUY2() , it's still Rec.709 because you are still in YUV
Remember this and you won't go wrong:
The matrix only takes effect when you do RGB<=>YUV conversions -
To be more precise, Rec601/709 only refers to how that YUV video was derived. ie. what matrix was used to convert from the original RGB source to YUV to make that video. The RGB might be a master format. As an end user, you usually only have access to YUV video (e.g. DVD, blu-ray, HDTV caps)
Remember this and you won't go wrong:
The matrix only takes effect when you do RGB<=>YUV conversions
In that case, hypothetically, if I had a Rec.709 source and Rec.601 source and wanted to work in YUY2 and splice them together I would have to use colormatrix(mode="rec.709->rec.601") on the former, then ConverttoYUY2() and then splice them. Got it!
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Anonymous344GuestTo be more precise, Rec601/709 only refers to how that YUV video was derived. ie. what matrix was used to convert from the original RGB source to YUV to make that video. The RGB might be a master format. As an end user, you usually only have access to YUV video (e.g. DVD, blu-ray, HDTV caps)
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If by expand the luma range, you mean go from luma 16-235 to RGB 0-255, then you would use matrix="Rec709".
If you use matrix="pc.709", it will map luma 0-255 to RGB 0-255.
On a related note, given a Rec.709 YUV source, is
Code:ConvertToYUY2(matrix="rec709")#keeps the luma in the TV range
Code:Colormatrix(mode="rec.709->rec.601",clamp=0) Convertoyuy2()
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Anonymous344Guest
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