Convert To YUVA420P8 ?

[poisondeathray]

From a RGBA source, what is the proper way to convert to YV12 with alpha (YUVA420P8)

YUVA420P8 is listed as supported , but how to convert to it ?

http://avisynth.nl/index.php/Convert
http://avisynth.nl/index.php/Avisynthplus_color_formats

I tried ConvertToYUVA420P8 , ConvertToYUVA, ConvertToYUVA420, and other combinations, but not working



Thanks

[qyot27]

It seems someone was a little overzealous adding that to the wiki. There are no ConvertToYUVA functions.

The way to do it from RGBA/RGB32 is:
Version()
ConvertToPlanarRGBA()
ConvertToYUV420()

Running ConvertToYUV420() on RGB32 drops the alpha channel. Granted, I don't know if this PlanarRGBA passthrough trick retains it either, but FFmpeg is reporting that the pix_fmt it receives from AviSynth+ in that case is yuva420p.

[poisondeathray]

Thanks qyot27 ; it works .

Info() looks correct as well for yuva420p

And ShowAlpha() shows the alpha is retained and valid too

And ffmpeg encoding that script to a yuva420p format (eg. webp) works too (valid alpha)



What are the pros/cons to having some of those steps rolled into some internal function ? Maybe it's not worth it , it's not going to be used that often.
But maybe the docs should be clarified a bit

[pinterf]

What are the pros/cons to having some of those steps rolled into some internal function ? Maybe it's not worth it , it's not going to be used that often.
But maybe the docs should be clarified a bit
Or you can use AddAlphaPlane
http://avisynth.nl/index.php/CombinePlanes#AddAlphaPlane