Video player Shaders guide (MPC-HC, -BE, mpv)

[butterw2]

Originally Posted by butterw2

In mpc-hc and mpc-be, only 200% and 50% zoom can be easily and directly applied in windowed mode. But often the desirable scaling would be 150% or 75%...

To be more complete:
- You can go back to 100% zoom using View > Zoom > 100% or the corresponding hotkey.
- mpc-hc and mpc-be do allow to set a fixed window size or remember last window size. But random videos will have different resolutions so this isn't typically practical.
- mpc-hc has added a "zoom window +", "zoom window -" hotkey, which would allow to adjust window size manually (! the step is small though).
- in fullscreen mode, you could create a custom zoom factor with View>Pan&scan> Edit... preset, with the option to further adjust manually with numpad 9,1, 5 (PnS reset) hotkeys.

However Vlc does have the setting I was looking for (custom default windowed zoom):
Tools > Preferences > Show Settings: All (at the bottom) to access Advanced Settings.
Video > zoom Video: 150%. Restart the player.

In mpv:
> mpv.exe --no-hidpi-window-scale --window-scale=1.5 "b:\Videos\day_480p.mp4"


- mpc-hc Changes from 1.9.1 to 1.9.2: Added a 25% zoom shortcut and menu entry
I don't know what the use case for a 25% zoom is, but I would suggest having a user customizable zoom would be more useful. The default value could remain 25%.

[butterw2]

Some mobile apps have great shaders for video adjustment. Corresponding shaders may not exist or be hard to find for video players, so I'm thinking of releasing a small updated pack of essential lightweight filters. The shaders would be available for hlsl evr-cp, hlsl dx11 and mpv hook.

example: 16-235 to 0-255.hlsl from mpc-hc (1 texture, 1 arithmetic) can be used to stretch the histogram. While it's not its initial purpose, I've found the shader to be useful to boost the contrast of some lackluster internet videos (when activated the haze lifts !).

[butterw2]

To darken shadows only, I'm using the following formula (1 texture, 5 arithmetic):

#define Shadows 0.15
pixel.rgb = pixel.rgb -Shadows*(1-luma)**4

[butterw2]

with mpc-hc, you need put your custom hlsl shaders in the .\shaders (for dx9) and .\shaders11 (for dx11). The shaders need to be have the same filename (ex: bShadows.hlsl) to be applied correctly when switching between dx9 and dx11 renderers.

It's easier to develop the shaders in dx9 Evr-CP, with the debug shader compiler output available.
You can then port the shader to dx11. For this, I was able to use BingChat (I specified that the language is similar to C and gave an input/output example from mpc-hc shaders).

[toniash]

Originally Posted by butterw2

Some mobile apps have great shaders for video adjustment. Corresponding shaders may not exist or be hard to find for video players, so I'm thinking of releasing a small updated pack of essential lightweight filters. The shaders would be available for hlsl evr-cp, hlsl dx11 and mpv hook.

example: 16-235 to 0-255.hlsl from mpc-hc (1 texture, 1 arithmetic) can be used to stretch the histogram. While it's not its initial purpose, I've found the shader to be useful to boost the contrast of some lackluster internet videos (when activated the haze lifts !).

not for potplayer?

[butterw2]

My understanding is that potplayer does support hlsl pixel shaders, but I don't know the specifics as I don't use this player.
Some players require the the shaders to have a .txt extension instead of .hlsl.
Video players often come with different shader bundles (ex: mpc-hc vs mpc-be) , some shaders will simply have been renamed. If he has the required folder permissions, the user can delete these shaders and copy whatever shaders he likes to the shader folder