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| author | Niklas Haas <git@nand.wakku.to> | 2015-01-14 00:45:31 +0100 |
|---|---|---|
| committer | Niklas Haas <git@nand.wakku.to> | 2015-01-16 02:17:19 +0100 |
| commit | 61f5a80f1070202a5b993591770653184328f629 (patch) | |
| tree | ea5e8c7ab9f7163474fe9e3276d6a382d7435c81 /DOCS | |
| parent | 4e419b2b7b76bedacd9b16e895fbd33798afb5eb (diff) | |
| download | mpv-61f5a80f1070202a5b993591770653184328f629.tar.bz2 mpv-61f5a80f1070202a5b993591770653184328f629.tar.xz | |
vo_opengl: get rid of approx-gamma and make it the default as per BT.1886
After finding out more about how video mastering is done in the real
world it dawned upon me why the "hack" we figured out in #534 looks so
much better.
Since mastering studios have historically been using only CRTs, the
practice adopted for backwards compatibility was to simulate CRT
responses even on modern digital monitors, a practice so ubiquitous that
the ITU-R formalized it in R-Rec BT.1886 to be precisely gamma 2.40.
As such, we finally have enough proof to get rid of the option
altogether and just always do that.
The value 1.961 is a rounded version of my experimentally obtained
approximation of the BT.709 curve, which resulted in a value of around
1.9610336. This is the closest average match to the source brightness
while preserving the nonlinear response of the BT.1886 ideal monitor.
For playback in dark environments, it's expected that the gamma shift
should be reproduced by a user controlled setting, up to a maximum of
1.224 (2.4/1.961) for a pitch black environment.
More information:
https://developer.apple.com/library/mac/technotes/tn2257/_index.html
Diffstat (limited to 'DOCS')
| -rw-r--r-- | DOCS/man/vo.rst | 10 |
1 files changed, 0 insertions, 10 deletions
diff --git a/DOCS/man/vo.rst b/DOCS/man/vo.rst index 92b88dc523..bbca84ecdb 100644 --- a/DOCS/man/vo.rst +++ b/DOCS/man/vo.rst @@ -568,16 +568,6 @@ Available video output drivers are: 3 absolute colorimetric - ``approx-gamma`` - Approximate the actual gamma function as a pure power curve of - 1.95. A number of video editing programs and studios apparently use this - for mastering instead of the true curve. Most notably, anything in the - Apple ecosystem uses this approximation - including all programs - compatible with it. It's a sound idea to try enabling this flag first - when watching videos and shows to see if things look better that way. - - This only affects the output when using either ``icc-profile`` or ``srgb``. - ``3dlut-size=<r>x<g>x<b>`` Size of the 3D LUT generated from the ICC profile in each dimension. Default is 128x256x64. |