Washed-Out Colors After Compressing?

Zarxrax · Post by **Zarxrax** » Mon Feb 04, 2008 6:47 am

Actually, no need to do all that complicated stuff, since it's adjustable in the gui under the advanced tab :p
That setting is the slider thing. It defaults to 0 but you apparently slid it over to 3. I honestly can't see much difference in the screenshot you posted, seems negligible to me. That setting MAY have something to do with it though. I've never played around with that setting much, myself.

Kero777 · Post by **Kero777** » Mon Feb 04, 2008 4:28 pm

I can't thank you enough for typing all that out for me! I went through the process of changing it to 1:1. Unfortunately, no difference in the picture.

I may adjust the saturation very slightly with Avisynth and see if that helps. I changed the slider to 3 in the first place because I read the it could help with blocking and that 3 may be good for anime in some cases. Both versions seems to be exactly the same besides a very, very slight difference in size. Hm..

Qyot27 · Post by **Qyot27** » Mon Feb 04, 2008 7:31 pm

Kero777 wrote:I can't thank you enough for typing all that out for me! I went through the process of changing it to 1:1. Unfortunately, no difference in the picture. I may adjust the saturation very slightly with Avisynth and see if that helps. I changed the slider to 3 in the first place because I read the it could help with blocking and that 3 may be good for anime in some cases. Both versions seems to be exactly the same besides a very, very slight difference in size. Hm..

Well, the thing about the deblocking filter is that the times it really makes a difference (and when higher values might be desirable) is when the bitrate is low enough for it to actually matter - what it does is smooth the edges of macroblocks so that the image can be compressed easier; however, this sort of necessitates that the bitrate be low enough for said smoothing to be effective. Anime tends to be flatter than live action, which is why it can get that benefit more readily at lower bitrates and possibly not be too affected quality-wise, along with being able to take advantage of other H.264 features. With a high bitrate though, the deblocker isn't as important.

Personally, I don't use the deblocker on my archival-quality encodes, and for distro stuff I never put it over 1:1. Of course, I also use --crf 18 for my distro encodes.

What are you using to decode the streams, by any chance? Maybe it's an issue in the decoder instead of in the encode itself. Granted, the issue on this thread deals with comparing the output of CoreAVC to libavcodec rather than the final encode to the original, but I wouldn't be surprised if it could still be pegged to a decoding issue.

Kero777 · Post by **Kero777** » Thu Feb 07, 2008 8:55 pm

Qyot27 wrote:
Kero777 wrote:I can't thank you enough for typing all that out for me! I went through the process of changing it to 1:1. Unfortunately, no difference in the picture. I may adjust the saturation very slightly with Avisynth and see if that helps. I changed the slider to 3 in the first place because I read the it could help with blocking and that 3 may be good for anime in some cases. Both versions seems to be exactly the same besides a very, very slight difference in size. Hm..
Well, the thing about the deblocking filter is that the times it really makes a difference (and when higher values might be desirable) is when the bitrate is low enough for it to actually matter - what it does is smooth the edges of macroblocks so that the image can be compressed easier; however, this sort of necessitates that the bitrate be low enough for said smoothing to be effective. Anime tends to be flatter than live action, which is why it can get that benefit more readily at lower bitrates and possibly not be too affected quality-wise, along with being able to take advantage of other H.264 features. With a high bitrate though, the deblocker isn't as important.

Personally, I don't use the deblocker on my archival-quality encodes, and for distro stuff I never put it over 1:1. Of course, I also use --crf 18 for my distro encodes.

What are you using to decode the streams, by any chance? Maybe it's an issue in the decoder instead of in the encode itself. Granted, the issue on this thread deals with comparing the output of CoreAVC to libavcodec rather than the final encode to the original, but I wouldn't be surprised if it could still be pegged to a decoding issue.

Sorry about the slow reply, I've been really busy the last few days. I am using libavcodec to decode x264 streams. Not too long ago I didn't have Ffdshow (I hate installing things like that, especially codecs, they always make my system go buggy) and just used VLC to view it. Seems the same either way though. :-\

Kero777 · Post by **Kero777** » Tue Feb 12, 2008 1:13 am

I attempted some things tonight... and came across some discoveries.

This is really urking me... and frustrating me.

I realized that maybe "Washed out" isn't the best way to describe it after all. It's more like... the footage is getting brighter and therefore making it SEEM like the colors are being washed out. OR it almost seems like it switches color-spaces or something. I notice a pretty big difference between my Lagarith and HuffYUV exports... the Lagarith is nice, but the HuffYUV export from Vegas is noticeably "lighter". However, I do not seem to get any difference in the final compression: Lagarith gets brighter and HuffYUV stays the same, EXCEPT when I open up VirtualDubMod and compare the HuffYUV and Lagarith from Vegas... it's the opposite: Lagarith is lighter and HuffYUV is correct. I have NO idea what's going on with that. Both are lossless so I shouldn't see any difference between the two anyway. Regardless, my compressed version seems to be the same whether I use Huffy or Lagarith. Here are my settings with HuffYUV just in case anyone thinks I could have anything set wrong and it's rendering in a different colorspace:

I tried getting removegrain for the temporalrepair() as suggested earlier in this thread, but AviSynth doesn't detect it properly (I cannot put in values for some reason). I also tried increasing the saturation a little, and the results weren't what I am looking for unfortunately. (I still appreciate your suggestions very much, thank you!)

I'm so confused.

Anyone have any more suggestions?

Kero777 · Post by **Kero777** » Tue Feb 12, 2008 11:57 am

Sorry for the double posting. I was too tired last night to get another example pic. Below is an example picture of Chobits. This is a screencap of the last episode, which has a spoiler so you might not want to click if you plan on watching Chobits and haven't before!

I used this part as an example because I think it shows up the most. Look at Chi's very dark, nearly black eyes how they turn into a medium brown and the buildings behind her get significantly brighter. Her hair gets brighter as well making it appear almost platinum blond. Here is the pic:

Picture Example 1

It might not seem like a huge difference, you actually might not even notice a difference at first, but it really is a nuisance, especially when it makes dark gloomy scenes not seem as gloomy!

This happens in both the XviD and MP4 compressing. However, it does not change when I compress it to MPEG-2 (if anything, it gets darker)... but that's not a good format for online distribution anyway since those types of files are on the large size.

BasharOfTheAges · Post by **BasharOfTheAges** » Tue Feb 12, 2008 12:43 pm

The difference is very minimal and only really visible if you're looking to see it.
I suppose you can just darken the video a tiny bit in the avisynth script so your encoding would compensate for that.

Niotex · Post by **Niotex** » Sat Feb 16, 2008 2:10 pm

I've come across the same issue and it apparently has to do with the chroma resolution of yv12. Anyway this is what I've done to remedy "most" of the problems its causing for my own upcoming video. Its pretty ghetto but it works remarkably well. Mind you this has been tweaked to my own video so I cant guarantee the same results for other sources.

Code: Select all

directshowsource("Video.avi")
converttoyv12()
tweak(sat=1.2)
tweak(bright=-5.0)
tweak(cont=1.1)
Lanczos4Resize(848,416)
gradfun2db

The "Grabfun2db" is a debander that cleans up the footage a reasonable amount. And is actually included in the AmvAPP 3.0 Beta. So you should be able to use that straight up. If your still using the old version and just updated the Gui then get the filter here.

Niotex · Post by **Niotex** » Sat Feb 16, 2008 2:12 pm

Errr I forgot to mention that this is the AVS script I use right before heading into the Gui. So this is a mere compensation for the RGB to YV12 conversion.