About

dwm_eotf_rs fixes washed out look in Windows' UI, applications and some SDR games, when HDR is enabled, by replacing DWM's piecewise sRGB transfer function with proper gamma curve.

It does that by reading memory of the loaded dwmcore.dll module, patching shaders that are responsible for incorrect SDR to HDR conversions and writing it back.

You do not need to disable/revert the patch (or restart DWM) when playing HDR games or videos. It only affects DWM composed SDR content!

This is an alternative implementation of the same idea that is behind dwm_eotf. dwm_eotf_rs is a major upgrade in terms of QoL, it also provides additional features, such as system tray controls, autostart and shader dumping. It's more reliable as well, as it does not require multiple retries for it to work.

Usage

Help Output

Patches DWM's shaders to use proper EOTF (gamma)

Usage: dwm_eotf_rs.exe [OPTIONS] [GAMMA] [COMMAND]

Commands:
  restore         Restores original sRGB EOTF (by restarting DWM)
  schedule        Creates a task ('dwm_eotf_rs') that runs the app on user logon
  unschedule      Removes the startup task ('dwm_eotf_rs') from Task Scheduler
  unschedule-all  Removes the startup task ('dwm_eotf_rs') from Task Scheduler for all users
  dump            Dumps DWM's original shaders as DXBC
  help            Print this message or the help of the given subcommand(s)

Arguments:
  [GAMMA]  Exponent to use during EOTF patching [default: 2.2]

Options:
  -c, --compatibility-mode     Patches DWM and exits (disables tray mode)
  -s, --skip-patching          Prevents automatic patching on app start (tray mode)
  -w, --wait-time <WAIT_TIME>  Delay (in seconds) before automatic patching on app start (tray mode) [default: 5]
  -i, --ignore-whitelist       Patch every shader that contains sRGB EOTF patterns
  -h, --help                   Print help
  -V, --version                Print version

Tray Mode

By default, the app runs in system tray, where you can toggle patch as needed as well as select a gamma value (2.0/2.2/2.4/[GAMMA]).

When it launches, it will wait a few seconds (specified by -w option) before inital patching to avoid problems in some edge cases.

Compatibility Mode

When supplied with the -c flag, dwm_eotf_rs works like a simple console app - it patches DWM and exits.

Startup

The app can register itself to run automatically when user logs in, using the Windows Task Scheduler (task named dwm_eotf_rs).

The -c schedule option combination schedules dwm_eotf_rs to autostart in Compatibility Mode. This is the intended way to use the app.

In tray mode, the context menu includes an "Autostart" checkable item that toggles the startup task on or off. If the gamma value is changed while autostart is on, the task is updated to use the new gamma.

Whitelist

By default, dwm_eotf_rs will patch only 4 shaders selected by ledoge. I think this covers most use cases, but it's possible to patch all shaders with same patterns by using --ignore-whitelist flag.

Shader Dumping

The app can dump DWM's shaders as DXBC files for research purposes.

These shaders are nested. There are 30 top-level shaders and hundreds of sub-shaders. Use --big-shaders flag to dump only former.

Library

dwm_eotf_rs depends on shader_patcher library from this repository that can be used to implement patching of other apps.

Known Issues

• Chromium-based apps (Web browsers, VS Code, etc) also use incorrect curves and will switch back and forth between original and fixed look sometimes. Setting #force-color-profile flag to hdr10 or scrgb-linear will help somewhat.

Acknowledgements

• Many thanks to ledoge for original C implementation.