[pinterf]

Originally Posted by jpsdr

I've looked on post #2484, but don't find an answer.

If i have a planar YUV mode with alpha channel, and i'm doing the following :

vu = env->Invoke("UtoY8",v).AsClip();
vv = env->Invoke("VtoY8",v).AsClip();
v = env->Invoke("ConvertToY8",v).AsClip();

Where is my alpha channel ?
Is it still on v ?
If still on Y, is doing the following, putting everything back :

AVSValue ytouvargs[3] = {vu,vv,v};
v=env->Invoke("YtoUV",AVSValue(ytouvargs,3)).AsClip();

If not, what should i do when handling this case ?

UtoY8, VtoY8 and ConvertToY8 functions create greyscale image.

Then there became too much color formats after having Planar RGB and A channel.
Instead of making AtoY8, RtoY8, GtoY8, BtoY8, there is a PlaneToY(plane_string) in Avisynth+ that creates a greyscale clip from the relevant channel.

E.g. PlaneToY("A), PlaneToY("R")
PlaneToY accepts any plane identifier (Y,U,V,A,R,G,B)

PlaneToY("U") is equivalent to UToY8
PlaneToY("V") is equivalent to VToY8
PlaneToY("Y") is equivalent to ConvertToY (ConvertToY8)

All the above functions keep the current bitdepth, the Y8 ending is just because UToY and VToY was already existing functions.

Regarding the back conversion, YtoUV only has U,V and an optional Y clip parameter. To answer on your question, it seems, there is no function for putting A channel back to a YUVA clip.

I always wanted to make a general way mixing together arbitrary planes, something like ShufflePlanes in VapourSynth.

Albeit there is MergeRGB and MergeARGB for packed and planar RGB, it seems that making the same for YUV is missing.
On more reason for implementing a general MergePlanes or something like that. Now I'm considering that.