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20th October 2009, 20:25 | #21 | Link | |||
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I'm not at all against research into better techniques--H.264 has many flaws and can surely be beaten--but there's no need to be overly defensive and try to pretend that problems don't exist. Finally, you claim SIF1 to be "free", but if so, where is the source? It doesn't seem to have come with the download.
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20th October 2009, 20:29 | #22 | Link | |
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I do not think that somebody will encode a football match in 1280x720x50 and with bitrate in one megabit. In addition through the Internet it to transfer it will not turn out. I think that it is encoded in VBR a mode and in two passes. And such file cannot be transferred in live on a network. Or I am not right? |
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20th October 2009, 21:48 | #23 | Link |
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Anyways, it's test time!
I don't at all expect SIF to get anywhere close to x264--it is certainly in early development while x264 is quite mature. But we can at least throw some tests at it. I've picked two random frames from it for comparison. For comparison's sake, I've included "x264_hpel": a build of x264 that doesn't use qpel. As a result I had to disable a few other features that I couldn't easily adapt to avoid qpel (direct auto, bime), but it should be mostly fine. Obviously the purpose of this is to serve as a more fair comparison to SIF, which lacks qpel. Source: LosslessKoishi.mkv Bitrate: 2000kbps Output files Frame 86: x264: x264 hpel: sif1: xvid: Frame 558: x264: x264 hpel: sif: xvid: Summary: 1) SIF isn't too bad--better than Xvid, but it primarily gets to its position by blurring everything. It seems like the "psy optimizations" in SIF are likely the standard CSF masking bullcrap which says that you should basically lowpass everything beyond the first couple frequency coefficients. I advise the developer of SIF to drop this immediately, as it looks terrible. It's definitely a good start though. 2) I told you that hpel makes things sharper, not blurrier, than qpel
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20th October 2009, 22:07 | #25 | Link | |||||
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For an example, i took a small example with anime Also has compressed it with two different bitrates. The first example is compressed with bitrate lower than usually twice. http://mysif.ru/Avi/Shangri-La1.avi The second example is compressed with bitrate lower than usually three times. http://mysif.ru/Avi/Shangri-La1.avi In the first case of a ring practically is not present In the second it suddenly appears and becomes very strong. It because at compression with normal bitrate the codec uses one set of functions. And at very low bitrate it is necessary it will be switched to long filters, as causes a ring. Actually it also uses Atak_Snajpera for misleading people. In a reality on those bitrate which are really used for compression of a ring is not present. Quote:
I am going to use absolutely other algorithm for interpolation Quote:
2-D non-separable adaptive interpolation filter directional AIF For an example Quote:
The codec? The source code of the decoder is available a long time, but you apparently at all did not read it: Easy-to-understand description of SIF оr it: http://mysif.ru/Patent.htm Otherwise would not ask questions concerning a ringing |
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20th October 2009, 22:10 | #26 | Link | |||
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Do I need to say it more simply? Machine translation is useless. It does not produce understandable output.
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20th October 2009, 22:14 | #27 | Link | ||
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Windows 7 Image Updater - SkyLake\KabyLake\CoffeLake\Ryzen Threadripper Last edited by Atak_Snajpera; 20th October 2009 at 22:20. |
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20th October 2009, 22:35 | #28 | Link | ||
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Here a direct reference: http://mysif.ru/Files/Sif1DecoderSource.zip |
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20th October 2009, 23:13 | #32 | Link | |
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This way your format would be directly supported by dozens of OpenSource video encoding and playback tools...
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20th October 2009, 23:17 | #33 | Link | |
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Also, let's just say the ffmpeg coding standards would require a rather significant rewrite of the SIF1 code . |
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21st October 2009, 19:15 | #34 | Link | ||
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SIF in itself as the algorithm, smoothes the image. But the psychovisual model, on the contrary, adds details in the compressed image. Quote:
But it too is not so good. SIF is very sensitive to quality of interpolation. The choice of correct algorithm of interpolation gives a considerable increase to quality for SIF. |
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22nd October 2009, 20:15 | #36 | Link | ||
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It is result of compression algorithm work. But it is really similar to noise. The psychovisual model has no relation to it. The psychovisual model does other things, and really improves quality of the image. Quote:
And only then when the codec platform will be improvement to the right degree I will be make the new SIF compression engine. |
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22nd October 2009, 20:38 | #37 | Link | ||
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Unique important conditions for me it: Quote:
If these conditions do not contradict to GPL licence there are no obstacles. In addition, any person can make the codec which compatible with SIF1 and release it under any licence. |
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22nd October 2009, 20:54 | #38 | Link | |
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But regardless, such a condition is not GPL-compatible. Or for that matter, compatible with any free license. |
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22nd October 2009, 21:38 | #39 | Link | |
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Otherwise nobody will protect me if Microsoft release a codec which will be based on SIF technologies. |
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22nd October 2009, 21:50 | #40 | Link |
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If you release your code under LPGL, then neither Microsoft nor any other company is allowed to incorporate your code into any proprietary product!
They'd be allowed to compile a library from your code and link their own (proprietary) applications against that library though. But if they did modify/improve your code, they'd have to make those changed public under LGPL again. So with the LGPL you should be on the safe side.
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