From 441e384390f1cd1b1b1c159cb797429432a09493 Mon Sep 17 00:00:00 2001 From: Niklas Haas Date: Wed, 14 Feb 2018 16:10:51 +0100 Subject: vo_gpu: introduce --target-peak This solves a number of problems simultaneously: 1. When outputting HLG, this allows tuning the OOTF based on the display characteristics. 2. When outputting PQ or other HDR curves, this allows soft-limiting the output brightness using the tone mapping algorithm. 3. When outputting SDR, this allows HDR-in-SDR style output, by controlling the output brightness directly. Closes #5521 --- DOCS/man/options.rst | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'DOCS/man/options.rst') diff --git a/DOCS/man/options.rst b/DOCS/man/options.rst index e51f564490..1a5af8121a 100644 --- a/DOCS/man/options.rst +++ b/DOCS/man/options.rst @@ -5054,6 +5054,39 @@ The following video options are currently all specific to ``--vo=gpu`` and The user should independently guarantee this before using these signal formats for display. +``--target-peak=`` + Specifies the measured peak brightness of the output display, in cd/m^2 + (AKA nits). The interpretation of this brightness depends on the configured + ``--target-trc``. In all cases, it imposes a limit on the signal values + that will be sent to the display. If the source exceeds this brightness + level, a tone mapping filter will be inserted. For HLG, it has the + additional effect of parametrizing the inverse OOTF, in order to get + colorimetrically consistent results with the mastering display. For SDR, or + when using an ICC (profile (``--icc-profile``), setting this to a value + above 100 essentially causes the display to be treated as if it were an HDR + display in disguise. (See the note below) + + By default, the chosen peak defaults to an appropriate value based on the + TRC in use. For SDR curves, it defaults to 100. For HDR curves, it + defaults to 100 * the transfer function's nominal peak. + + .. note:: + + When using an SDR transfer function, this is normally not needed, and + setting it may lead to very unexpected results. The one time it *is* + useful is if you want to calibrate a HDR display using traditional + transfer functions and calibration equipment. In such cases, you can + set your HDR display to a high brightness such as 800 cd/m^2, and then + calibrate it to a standard curve like gamma2.8. Setting this value to + 800 would then instruct mpv to essentially treat it as an HDR display + with the given peak. This may be a good alternative in environments + where PQ or HLG input to the display is not possible, and makes it + possible to use HDR displays with mpv regardless of operating system + support for HDMI HDR metadata. + + In such a configuration, we highly recommend setting ``--tone-mapping`` + to ``mobius`` or even ``clip``. + ``--tone-mapping=`` Specifies the algorithm used for tone-mapping images onto the target display. This is relevant for both HDR->SDR conversion as well as gamut -- cgit v1.2.3