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Old 18th October 2006, 20:43   #21  |  Link
akupenguin
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How did Smooth's INTRA8X8_LUMA end up being neither monotonic nor symmetric?
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Old 18th October 2006, 23:34   #22  |  Link
*.mp4 guy
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Quote:
Originally Posted by akupenguin View Post
How did Smooth's INTRA8X8_LUMA end up being neither monotonic nor symmetric?
Well it is predominantly monotonic (though I suppose thats an oxymoron) long story short I stole some of the frequency weighting from the JPEG matrix, which after a lot of testing turned out to work the best for what I wanted to do, anyway, the mpeg matrix isn't monotonic or symetrical either and HVS Best isn't monotonic, though it is symetrical.
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Smooth is the best I've used for CG video of any matrix. It's really awesome!
Thanks, just out of curiosity what type of cg is your source, is it like pixars stuff or is it pseudo-realistic cg?

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Old 19th October 2006, 00:32   #23  |  Link
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Yes, I see that the quant matrix recommended in the jpeg standard is also nonmonotonic and asymmetric, and has a dc value much higher than the other low freqs (like your HRM intra).

Nonmonotonic: ok, I can believe that there's a difference between even and odd frequencies regarding their tendency for blocking artifacts.
Asymmetric: the only ways this can happen, are if there's a difference in the amount of vertical vs horizontal texture in an average movie (this is true for motion, and some motion estimation algorithms exploit that), or if it's tuned for anamorphic. Of course, the best solution in either case would be to generate a matrix based on the content of the current movie, rather than depending on averages. If you can quantify the psy decisions that went into the creation of the average matrix.

Last edited by akupenguin; 19th October 2006 at 00:36.
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Old 19th October 2006, 00:53   #24  |  Link
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Originally Posted by akupenguin View Post
Yes, I see that the quant matrix recommended in the jpeg standard is also nonmonotonic and asymmetric, and has a dc value much higher than the other low freqs (like your HRM intra).

Nonmonotonic: ok, I can believe that there's a difference between even and odd frequencies regarding their tendency for blocking artifacts.
Asymmetric: the only ways this can happen, are if there's a difference in the amount of vertical vs horizontal texture in an average movie (this is true for motion, and some motion estimation algorithms exploit that), or if it's tuned for anamorphic. Of course, the best solution in either case would be to generate a matrix based on the content of the current movie, rather than depending on averages. If you can quantify the psy decisions that went into the creation of the average matrix.
Its true that relying upon pre-generated matrixes isn't optimal in some regards, but there hasn't been much success whith automated generation of matrices either, so it makes sense to use pre-generated averages to create matrices, in most cases.
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Old 19th October 2006, 14:19   #25  |  Link
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Thanks, just out of curiosity what type of cg is your source, is it like pixars stuff or is it pseudo-realistic cg?
just out of curiosity, what does cg mean at all ?
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Old 19th October 2006, 16:04   #26  |  Link
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Quote:
Originally Posted by *.mp4 guy View Post
Thanks, just out of curiosity what type of cg is your source, is it like pixars stuff or is it pseudo-realistic cg?
Pixar type stuff. Minimal texturing and lots of smooth edges and gradients. Haven't tried other stuff with it yet.
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just out of curiosity, what does cg mean at all ?
Computer generated.
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Old 19th October 2006, 23:38   #27  |  Link
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Great thread. Thanks *.mp4 guy
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Old 21st October 2006, 13:47   #28  |  Link
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Is M4G Smooth V1 similar to your M4G-V3 matrix?
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Old 21st October 2006, 15:02   #29  |  Link
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Is M4G Smooth V1 similar to your M4G-V3 matrix?
Yes, actualy its a new version with a new name, to (hopefully) keep things from getting confusing. The old version was a preliminary design I had been working on for a while, which is why it had a generic name. At this point the only thing thats likely to change are the chroma matrices, I think they may be a bit too agressive, but I have to do more testing.
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Old 29th October 2006, 14:40   #30  |  Link
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hi, Have you any suggestions for matrices to try for ~q18-20 for 720p anime? The particular source I'm playing with alternates between zero detail pure toon scenes and painted backgrounds with oodles of details. Overall complexity is low, and the final bitrate will probably end up around 1.2-1.4mbits (a 1.4gb target size), but 2mbits is also a possibility.
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Old 29th October 2006, 15:22   #31  |  Link
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At that bitrate you might be able to get away with a cqm on anime, but it is probably still not a good idea. Try adding "--deadzone-inter 6 --deadzone-intra 6" (without quotes) to the custom command line parameters section in megui instead of using a cqm, it will cause less detail to be dropped, and will probablt work better then a cqm on anime.
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Old 29th October 2006, 16:11   #32  |  Link
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Try adding "--deadzone-inter 6 --deadzone-intra 6" (without quotes) to the custom command line parameters section in megui
Would be the same replacing </CustomEncoderOptions> with <CustomEncoderOptions>--deadzone-inter 6 --deadzone-intra 6</CustomEncoderOptions> in one of the profiles?
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Old 29th October 2006, 16:52   #33  |  Link
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Yeah that should work fine.
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Old 30th October 2006, 00:22   #34  |  Link
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Old 30th October 2006, 00:51   #35  |  Link
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hmm, interesting. So are x264 cqms bad ideas in general for anime, or are your matrices simply not tuned for cartoon sources?
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Old 30th October 2006, 01:23   #36  |  Link
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I took it to mean that at those quants you won't get much from it.
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Old 30th October 2006, 03:11   #37  |  Link
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Cqms aren't usefull for anime until there won't be any visible ringing artefacts, at which point a cqm that can preserve more detail and block less will probably help. However I don't have a good idea of where the trade off occurs since I don't encode anime much. Which is why I recommended a more conservative solution by just lowering the deadzone setting, which might work better for anime at high bitrates then one of my cqms anyway, as I said I have not done much testing on the subject.

In theory it should be possible to make a matrix that looks better on anime then the flat matrix at higher bitrates, I beleive Soulhuter made one for Xvid a while ago, but its not something I've given much thought to.
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Old 30th October 2006, 11:32   #38  |  Link
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First of all thanks for the matrices and your time spent on them, well done. Second, can you suggest any of your matrices for HD Encoding at 720p 4-5Mbit. I read somewhere here that at that high resolution and bitrate, it doesn't really matter which one to use. And i can simply use flat matrix, but please clarify if i'm wrong. Thanks
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Old 30th October 2006, 14:10   #39  |  Link
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Thanks for the feedback mp4, I'm running some encodes now with modified deadzone settings thanks to your idea.
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Old 30th October 2006, 18:59   #40  |  Link
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The same general rules apply to HD as SD, the biggest difference comes from the viewing conditions, many displays can easily show the flaws in SD content, but may have trouble showing the same problems in HD content becuase of the increased resolution, which can lead people to falsely assume that HD can be overcompressed without problems. If you wan't the best results you have to find settings that look good to you on sd content, then use the same Q values and settings on hd content, this will ensure that you don't end up throwing away quality that you might miss later when higher resolution display are more readily available.

At your bitrate MRM should give you transparent results, though without knowing more about your source its really hard to say.
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