Improve metering

[natural-harmonia-gropius]

What I did?

• Convert linear values to perceptual luminance (PQ)
• Downscaling image to fixed size (512x288)
• Spatial filtering for image of metering (fast gaussian blur, default to 2 iterations)
• Get metered values (max)
• Temporal filtering for metered values (harmonic mean, default to 1/3 fps samples)

What does Dolby do?

视界·本色｜杜比视界全新 L1 元数据介绍

• Spatial filtering (downscaling, fixed resolution(?), 基于最大空间频率的滤波算法(?))
• Highlight processing (5 levels analysis tuning, from most to least highlight, default to balance, blurring(?)).
• Get values (in PQ, max: weighted maxRGB, avg: improved(?), min: minY)
• Working space (BT.2020)
• Three-segment spline curve.

What I want

• Reduce flickering
• Better black and white clipping, tm(w_in) == w_out, tm(b_in) == b_out
• Mid-grey adaptation, tm(m_in) == m_out

[pbiancardi]

Is this in the code already or we have to update?

[natural-harmonia-gropius]

Is this in the code already or we have to update?

update https://github.com/natural-harmonia-gropius/hdr-toys/commit/6de021848bdb9da87a6f9cc451d05c8f3155454e

Sample in https://github.com/natural-harmonia-gropius/hdr-toys/issues/20 is much better now.

[pbiancardi]

Yes this looks very promising thank you.

[pbiancardi]

The flickering seems much better but I have always had the issue where hdr toys looks much more washed out than spline, almost like a gamma or levels issue?

[Vern2]

I am having an issue where brightness is sometimes changing in the middle of a scene. These brightness changes are significant.

For example, there are times when the brightness will change when someone new walks into a scene or someone in the scene moves from sunlight into a shadow. I do have the latest changes in dynamic.gsl.

Another one I just came across involves a dark haired lady in a side on shot. When she turns to face the camera, the image gets darker for about a second or so then returns to its original brightness. It also seems to more common in low APL scenes. Other than that, it's looking really really good.

[movieperson]

Here is a capture of the HEVC frames of the 5 second sequence from Mamma Mia that clearly shows the brightness fluctuation mentioned in my previous post.

mm.zip

my settings:

vo=gpu-next gpu-api=d3d11 gpu-context=d3d11

[bt.2100-pq] profile-cond=get("video-params/primaries") == "bt.2020" and get("video-params/gamma") == "pq" profile-restore=copy target-trc=pq target-prim=bt.2020 glsl-shader=~~/shaders/hdr-toys/utils/clip_both.glsl glsl-shader=~~/shaders/hdr-toys/transfer-function/pq_to_l.glsl glsl-shader=~~/shaders/hdr-toys/transfer-function/l_to_linear.glsl glsl-shader=~~/shaders/hdr-toys/utils/chroma_correction.glsl glsl-shader=~~/shaders/hdr-toys/tone-mapping/dynamic.glsl glsl-shader=~~/shaders/hdr-toys/gamut-mapping/matrix.glsl glsl-shader=~~/shaders/hdr-toys/transfer-function/linear_to_bt1886.glsl

set glsl-shader-opts L_sdr=500

glsl-shader-opts sigma=.10

Using latest code and hdr-toys-helper.lua

Please let me know if you need more info.

BTW, I watched "Puss in Boots The Last Wish" and "Mario Bros" on my JVC RS3100 (110 nits on screen) last night and the results were amazing!!!

Just tried the 06/28 build, issue is still present.

[wlb123git]

作者你好，我发现画面场景黑暗部分跳变过快，则动态映射会造成画面亮度明显变化 在madvr的sdr映射上也同样能观察到画面闪烁，这是一个小片段，扫灰的时候，左边手指这亮度变化明显

使用的是tone-mapping/dynamic.glsl，更换成bt2390或其他则不会 The Exorcist (3).zip

hello toys' developer! I found is there's some dark scenes changes fast, the daynamic tone mapping will make the brightness fluctuating too. When use madvr to sdr tone mapping, this clip would also show up fluctuation.

I used dynamic.glsl, but if use others shaders this wouldn't show up.

[natural-harmonia-gropius]

刷子的金属反光亮度跳动很厉害，对这种片源换bt2390画面总体没什么太大问题的话，应该是最好的解决办法

[geextahslex]

Wouldn't it be possible to implement a lookahead function like it is used in music programs? He could lookahead 30s-60s so he would already know which scene is coming next and be prepared instead of making noticeable adjustments on the fly. This would solve this issue for good

[natural-harmonia-gropius]

I can only observe the present and record a limited past, not the future.