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12th November 2018, 19:36 | #41 | Link | |
Pig on the wing
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For example, I just ran two test encodes; aq-mode 1, strength 1.0 gave me 6013 kbps and strength 1.8 needed 11610 kbps for the same clip with all the other settings kept the same. Running a 2-pass encode comparison at 6000 kbps, it's quite easy to predict that strength 1.0 will have less artifacts or is sharper and more detailed. It still doesn't mean it's any better at my desired base quality level
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12th November 2018, 20:50 | #42 | Link | |
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Because CRF is really not that close to constant quality. It's just a psychovisual offset from QP, and lots of changes can impact how good a given CRF value looks in practice. For example, try adding --nr 1000 to your string. It'll be a lot smaller and will look quite different. Pretty much all the psychovisual stuff changes appearance and efficiency with a given CRF value. One can think of codec parameter tuning as finding ways to make the worst parts of the video look better so that a higher CRF value can be used for the same perceptual quality. |
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12th November 2018, 23:23 | #43 | Link | |
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AQ-Mode 1 turned out a lot smaller than AQ-Mode 2. So it is highly dependant on the type of footage (grain, motion, contrast,...). So, as Ben says, its always recommended to use 2-pass when comparing. Or even 3-pass because there still is quite a difference between the resulting bitrates when using 2-pass. Maybe 3-pass is more accurate? (don't have the time to test it, sadly) So far, my (quick) tests on current project AQ-Mode 2 turned out as the 'winner'. Its HQ footage with slight (but noticeable) noise. AQ-Mode 2 preserved details better in the chroma channels and resulted in quite a bit less distortion. Keep in mind though this probably varies from type of footage... When having footage which has a lot of grain, then distortion might be a more acceptable type of artifact and result in a perceptually better image. (ill test that probably another time) Last edited by K.i.N.G; 12th November 2018 at 23:35. |
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12th November 2018, 23:33 | #44 | Link | |
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When testing to compare quality: Test using 2-pass and then when you find your desired 'target' try to match that by raising/lowering CRF until you get close enough to the desired result you got with 2pass. Last edited by K.i.N.G; 12th November 2018 at 23:37. |
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13th November 2018, 05:16 | #45 | Link | |
Pig on the wing
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13th November 2018, 13:43 | #46 | Link |
Pig on the wing
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Out of interest, would it be possible to run a 2-pass CRF encode so that the first pass uses a manually tonemapped version of the video and then the actual encode uses the real one? This would be really interesting to test at least
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13th November 2018, 17:14 | #47 | Link | |
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13th November 2018, 17:48 | #48 | Link | |
Pig on the wing
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I think I also need to compare aq-modes 1 and 3 with SDR sources in a similar way. EDIT: tested, and aq-mode 3 looks better at least in the video I checked. So it would seem to be the go-to setting for SDR but jury's very much out on aq-mode 2 and HDR.
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And if the band you're in starts playing different tunes I'll see you on the dark side of the Moon... Last edited by Boulder; 13th November 2018 at 18:52. |
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17th November 2018, 22:37 | #49 | Link | |
Angel of Night
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hdr-opt basically steals bits from the dark to the light, the inverse of mode 3, since that's half the point of HDR. It also does something to the chroma, but I can't make heads or tails of that. |
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2nd December 2018, 23:02 | #50 | Link | |
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I had a HDR video which when viewed on a non-HDR monitor through MadVR's tonemapper looked fine, but when viewed on an actual HDR monitor or TV there was obvious banding visible (in the lighter parts). Which makes sense, since a HDR -> SDR tonemapper is essentially a soft clipping curve that compresses the highlights + some color space convertions. |
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5th December 2018, 01:37 | #51 | Link |
Derek Prestegard IRL
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I've noticed that watching HDR content via MadVR does absolutely require you to enable fullscreen exclusive mode in order to get 10 bit output, else you get banding.
This is obvious in hindsight, but I missed it at the time |
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