Experimental feature: Black crush mitigation #525
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Pepper SDK and NaCl in general is EOL for Chrome, although still supported for Chrome Apps. This means that the Pepper Gamepad API was never updated with rumble support so in order to add rumble support, rumble messages from Gamestream have to be forwarded to JavaScript and handled with gamepad.vibrationActuator.playEffect(). Side note, Chrome limits the duration of playEffect to 5 seconds and requesting more than that causes the vibration request to be rejected.
Moonlight's fullscreen requests generally conflict with what ChromeOS is trying to do automatically for the app, especially when using tablet mode. Just remove it for now and let the OS handle fullscreen.
Otherwise, Esc breaks out of fullscreen instead of being sent to the streaming app.
Adding fullscreen class to the #listener seems to fix the game stream getting stuck in a black screen. I suspect that #main-content isn't recomputing its layout when #listener is resized.
Shader is compiling successfully, but the required data not yet hooked up.
A lot of plumbing is set up but Chrome seems sensitive to certain OGL calls hanging the NaCl module. I don't understand what's happening but this is version at least draws the video stream again, even if it's messed up.
Finally back to a no-op equivalent state.
XYZ space doesn't automatically adjust chromaticity when luminance changes meaning colors can shift when Y is changed.
Rumble events may be received for controllers that are no longer present or attached so they should be dropped instead of being forwarded to JS for handling.
- Black crush now runs in gamma space and does far less work to achieve roughly the same thing. Unfortunately, there is visual corruption still to be figured out. - Fixed UI button not reflecting the mitigation state.
Video compression can introduce false colors since all compressors are lossy, and when that happens, the false colors can be emphasized by the black crush mitigation. To fix this, the shader explicitly neutralizes pixels below a threshold (currently 4/255) before applying any compensation curves.
Turns out, the supplied texture can contain negative RGB values. I'm assuming that compression artifacts are causing the invalid channel values so now I make sure to clamp input RGB to [0,1] range before computing lookup coordinates for the gamma ramp. Also simplified the gamma index to be based on max RGB value instead of luminance. Just seeing if this produces more visually pleasing results.
- Move gamepad index check to the JS side to simplify the code - Handle gamepads that don't support haptics
Getting weird artifacting with black crush enabled on high contrast areas, probably need to tune the curve behavior to better hide compression artifacts. For now, the shader fully skips the curve look up if the mitigation is disabled.
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Experimental feature: Black crush mitigation
The OLED display on my Lenovo Chomebook Duet 5 suffers from black crush so this experimental feature adds a custom gamma curve to boost dark values and alleviate the worst of the black crush.
Since this is forked from my master branch, there's a bunch of identical changes as my other pull request. I'm not even sure this "feature" is desirable so I'm leaving the PR in draft mode.
@moonlight-stream