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Old 14th August 2018, 06:49   #1  |  Link
skx7
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variables of x264 encodes filesizes

Hi all

I am backing up my whole DVD cartoon collection. While encoding all with same x264 settings I noticed that older cartoons (made before 1980) consistently end up with more substantial filesizes compared to more recent animation movies. What can explain this difference in encoding efficiency? Just wondering what is triggering these differences to maybe identify what can be changed to reduce the filesizes without substantial quality loss.

Thanks
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Old 14th August 2018, 06:55   #2  |  Link
kalehrl
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They probably contain more noise which is hard to compress than the more recent ones.
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Old 23rd August 2018, 21:44   #3  |  Link
Forteen88
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You might want to degrain them to save bitrate.
But don't degrain too much, since that makes the image-quality suffer.
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Old 28th August 2018, 18:44   #4  |  Link
benwaggoner
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Using x264's --nr is actually pretty good for this scenario, since it takes out exactly the noise that makes it harder to compress. Which, for anime, is pretty much the noise that wasn't in the original cels.
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Old 29th August 2018, 21:24   #5  |  Link
zub35
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Use nr has meaning only in the range of 100-300. The values are larger, not rational, compared to increasing crf.
for example, crf=20 nr=500 will be worse than crf=20.5 nr=0, with the same bitrate

In some files, it is better to strengthen psy, keeping roughly the same bitrate crf=20 vs crf=21 psy=1.2:0.2
In this case, keeping the bitrate identical, we make the codec focus more on noise and fine detail changing (not removing) it for better compression.

You can also apply them in a bundle crf=20 vs crf=21 nr=300 psy=1.2:0.2
This will help to reduce the bitrate, without significant deterioration of perception.

Last edited by zub35; 29th August 2018 at 21:46.
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Old 4th September 2018, 23:49   #6  |  Link
benwaggoner
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Quote:
Originally Posted by zub35 View Post
Use nr has meaning only in the range of 100-300. The values are larger, not rational, compared to increasing crf.
for example, crf=20 nr=500 will be worse than crf=20.5 nr=0, with the same bitrate
But crf=20 nr=500 will almost always be a lower bitrate than crf=20.5 nr=0. That nr=500 will take some of hard-to-compress coefficients, like an adaptive deadzone.
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