Harmy's STAR WARS Despecialized Edition HD - V2.7 - MKV (Released) — Page 188

I don't know if this is intentional or not, but after watching some of the WP I think it looks like there's been an incorrect colorspace conversion somewhere along the way, or something similar.

It's mostly visible in reds, which a lot of the time looks orange.

To convert the colorspace back to get the reds more correct while watching, I made a script like this:

DirectShowSource("Despecialized Edition v2.0 Final Workprint.mkv")
ConvertToRGB()
crop( 0, 89, 0, -89)
ConvertToYV12()

Cropped it to avoid that brightness change in the black bars. ;)

Anyway, here's some comparisons before this script and after:

It's easiest to see if you save the images and switch between them.

And here are the strongest reds from Leia's scene beside each other:

Hope this will help if it was unintentional.

If you'd wanna change only the reds, you'd have to use selective color in AE, choose reds and lower the yellow slider a bit, and maybe up the magenta slider slightly.

Harmy, I sent you a mail with detailed instructions on how to render to UtVideo Codec from Premiere. It's a lossless codec with a good compression ratio. I was able to reduce file size of the lossless avi you posted earlier by 75%! Choose the YUV420 variant and render a short sequence. I think there should be no color space issues present this way.  

You sure aren't alone Harmy, it is this difficult for everyone it seems.

Me and DJ got the exact same problem and had to offset this using a script when rendering our projects.

If you can't find a way to fix it, I'll help you when the time comes to make a script for your final encode.

Like:

1. Render an uncompressed avi.

2. Use a script to encode it for blu-ray/mkv which fixes the colorspace.

Or maybe there's some way to offset it in AE?

Could i get the workprint?

You are welcome Harmy :-)

Rendering at 8 bit is fine since the finale encode has to be 8 bit anyway, at least if it should be playable on hardware players.

The color space stuff is complicated for me as well. The thing is that there will always be a conversion to YUV420 somewhere. It either happens when rendering in Premiere or in the encoding process. 

Can you upload a sample of the scene you posted screenshots of? Render it with UtVideo RGB. Output colorspace should be BT.709 or Rec.709 if that's available.

BTW, I'm always using the Lagarith codec for lossless compression... brings your Mos Eisley shot down to 50% of its uncompressed size. Haven't heard of the UtVideo Codec before - I'll give it a shot.

Harmy said:

On a brighter note, here's the fixed pandown and stardestroyer flyover shot, including a reconstructed frame, which was missing in the SE (one before last in the shot) and highlights fixed in the next shot:

http://uloz.to/x5Dj8pb/pandown-new-mp4

I've got a teeny-tiny thing (I hate being a prefectionist :p):

Now that the whole frame is moving after the pan down, you see a tiny slice of black on the edges where Tatooine leaves the frame. If your version of After Effects has the an effect called "RepeTile" that's very easy to fix, as with that one you can basically "smear" the edge pixels of a layer further to the sides. This would take care of that.

Not that it's THAT prominent... just noticed. Apart from that it's perfect now!

Thanks for the sample Harmy, I'll do some tests later or tomorrow.

Well, RGB => YUV420 is a lossy conversion (rounding errors etc.). It does however consider the fact that the human eye is much more sensitive to brightness than it is to color and thereby achieves a much better compressibility. So I think it's a combination of both. But even if that much color information is thrown away, you should not see much of a difference. The color shift that we see here should not happen I think.

Also, you have to remember that your source is not RGB anyway. Most of it originates from Bluray, HDTV or DVD, which already use YUV420.

Ok guys, I got something. As I suspected from the beginning it seems to be a problem with BT601 vs. BT709 colorspace. The former is usually used for SD, while the latter is used for HD.

I uploaded an encode, please check if the colors, blacks and whites are correct.

https://rapidshare.com/files/671478413/Leia-RGB-sample_colorfix.mkv

Harmy said:

Have you read my previous post?

Actually, you posted that while I was typing mine. :)

Anyway, for a lossless codec you could try Huffyuv, it's the one me and DJ are using.

And even if any render would change colors when encoding it to blu-ray later, you could always offset it with a script.

I think it's worth solving, since even though the orangey reds make some scenes look slightly more natural, it's just too visible in the strongest reds that they're off. (At least to me, on a calibrated monitor)

There's also a small thing I noticed in the WP when checking that scene with Leia and R2. When this shot starts, the picture has a cooler tint and suddenly it turns warmer:

You are very welcome Harmy :-)

I used your UtVideo RGB sample and loaded it in avisynth using FFVideoSource. The video has to be indexed first of course. This is the avisynth script:

LoadPlugin("C:\Program Files\MeGUI\tools\ffms\ffms2.dll")

FFVideoSource("E:\star wars\Leia-RGB-sample.avi", threads=1)

ConvertToYV12(matrix="rec709")

The only magic is to add matrix="rec709", which makes sure the output uses HD color space BT709 with limited TV range, meaning 16-235.

The x264 commandline had the following options checked as well, but I think it works correctly if you leave them out:

--colorprim "bt709" --transfer "bt709" --colormatrix "bt709"

These are the options to use for HD releases. For the DVD one should first resize in RGB and then convert to REC601 using the colormatrix plugin for avisynth. The reason is that most players/decoders will assume the colorspace based on the video resolution. So it must be set accordingly, otherwise the decoder assumes the wrong one and you get color shifts during playback.

Unfortunately UtVideo codec does not allow to specify rec709 when rendering to YUV420. Maybe there's an option in Premiere for that?

Harmy said:

@You Too: That's weird, I'll give it a look - it definitely has the same settings throughout; the change must already be on the BD.

Checked the BD and the color doesn't change there.