YV12 to YV24 colorspace

[naoan]

What happen to the chroma channel when you convert YV12 video to YV24 colorspace for use for Hi444p x264 profile?

And what about this scenario:
1080p video with 540p chroma and YV12 colorspace, converted to YV24 and then downscaled to 720p. What happen to the chroma?

[TheSkiller]

What happen to the chroma channel when you convert YV12 video to YV24 colorspace for use for Hi444p x264 profile?The chroma channel gets resized by a factor of two in both directions. In YV24 there is no color subsampling, which means the chroma plane is of the same resolution as the luma plane. However if you're coming from a YV12 source then it's just interpolated of course.


1080p video with 540p chroma and YV12 colorspace, converted to YV24 and then downscaled to 720p. What happen to the chroma?The chroma gets resized twice (which sounds worse than it is).

[naoan]

The chroma channel gets resized by a factor of two in both directions. In YV24 there is no color subsampling, which means the chroma plane is of the same resolution as the luma plane. However if you're coming from a YV12 source then it's just interpolated of course.


The chroma gets resized twice (which sounds worse than it is).

I see, then do you know what kernel avisynth use when you convert YV12 source to YV24?

[poisondeathray]

I see, then do you know what kernel avisynth use when you convert YV12 source to YV24?

bicubic in avisynth 2.6 , unless you specify otherwise with ConvertToYV24(chromaresample="?")

this is for converttoyv12() , but the options are applicable for YV24 as well
http://avisynth.org/mediawiki/ConvertToYV12#Options

[Gavino]

I see, then do you know what kernel avisynth use when you convert YV12 source to YV24?
This is determined by the chromaresample parameter of ConvertToYV24 (http://avisynth.org/mediawiki/ConvertToYV24) (default="bicubic").

LOL, poisondeathray - you beat me again. :D

[naoan]

Ah, thank you all. I should have read the wiki. :thanks:

[LilScrappy]

i'm with AviSynth 2.6.0 Alpha3 when i put in script ConvertToYV24 all change in avspmod but when start encoding with megui, no efect and change automaticly in YV12, how to fix ?

[poisondeathray]

i'm with AviSynth 2.6.0 Alpha3 when i put in script ConvertToYV24 all change in avspmod but when start encoding with megui, no efect and change automaticly in YV12, how to fix ?

If megui doesn't have an option in the GUI, try entering --output-csp i444 on the commandline

http://mewiki.project357.com/wiki/X264_Settings#output-csp

[sneaker_ger]

But you should have a really good reason to use a 4:4:4 colorspace. Simply converting to 4:4:4 at the end of the script (or using x264cli) does not make sense for 99% of all cases.