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14th March 2017, 11:52 | #4981 | Link | |
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Inviato dal mio GT-N7100 utilizzando Tapatalk |
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14th March 2017, 12:31 | #4983 | Link | ||
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https://github.com/stax76/software-list https://www.youtube.com/@stax76/playlists Last edited by stax76; 14th March 2017 at 12:40. |
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14th March 2017, 19:42 | #4988 | Link |
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If you run CRF, the new build will generate larger files. There's no point in trying to compare the visual quality of 2 encodes that have different bit rates. So, you would have to experiment to figure out a higher CRF value that produces the same file size as before. If you went through that trouble, you could then make a valid comparison.
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14th March 2017, 21:07 | #4989 | Link | |
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I've made some tests with the new lambda table, and the results are great, there are more details with the the last build. Greats works !!!!
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14th March 2017, 23:54 | #4991 | Link |
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As you can read, this lambda2 file is for 8-bit encoding only. I believe it is now already default in a current build (v2.3+22)? commit db5e22b
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15th March 2017, 06:49 | #4994 | Link | |
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Noticeable improvements generally speaking but there seems to be more noise, especially in dark scenes. Will check and compare screenshots later. X265 last posted version, Staxrip, preset fast, two pass, Abr 4000, no Sao no deblock, no strong is, aq motion, no slow first pass. I assume new lambda table is default? Inviato dal mio GT-N7100 utilizzando Tapatalk Last edited by need4speed; 15th March 2017 at 06:51. |
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15th March 2017, 07:08 | #4995 | Link |
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Trade secret.
No, seriously... part theoretical, part experimental. We calculated a better theoretical curve, and then we experimented with variations on this curve until we were satisfied that we found the optimal curve. [The values in the lambda table are an exponential function... forming a straight line if you plot them exponentially]. This is not the optimal curve with respect to objective quality metrics like SSIM and PSNR... it's the optimal curve with respect to subjective visual quality. Psy-rd, psy-rdoq, AQ and cu-tree may all need to be slightly tuned now, and we're looking at this. The starting few seconds of ABR rate control (--bitrate) will also need to be recalibrated. |
15th March 2017, 19:43 | #4996 | Link |
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Just to confirm if you have multi build, lambda 2 table is used if input and output depth both are at 8 bit.
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15th March 2017, 19:43 | #4997 | Link |
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So what's the story with rdoq-level 1 vs 2? I've been toying around with it and it seems that 1 is "sharper" but it might not be as true to the source compared with 2.
I also noticed rdoq-level 2 is used in the higher presets. |
15th March 2017, 21:14 | #4998 | Link |
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It only depends on output depth. If input depth is greater than output depth, x265 truncates the samples to the internal depth (the output depth). It will dither the last bit if you add --dither. So if you have 10 bit content but you want an 8 bit encode, x265 will use 8 bits for all calculations, and it will use the 8 bit lambda table.
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16th March 2017, 11:18 | #4999 | Link |
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did you ever made tests how high the 10->8bit conversion overhead is for an almost perceptual banding free result, especially on high f-stop captured skyboxes internally and where the point of f-stop slope is it makes virtually no difference anymore in overall perception ? and at which QP this merges currently depending on the overall Preset Setup in x265 or does it explicitly need AQ enabled, and how this shifts between Generations ? Or do you know some papers this was discussed about in General @ HEVC at conferences primarily maybe by Ateme, Dolby, Technicolor, Sony, Samsung ?
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all my compares are riddles so please try to decipher them yourselves :) It is about Time Join the Revolution NOW before it is to Late ! http://forum.doom9.org/showthread.php?t=168004 Last edited by CruNcher; 16th March 2017 at 12:10. |
16th March 2017, 18:27 | #5000 | Link | |
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