diff options
Diffstat (limited to 'video/out/gl_video_shaders.glsl')
| -rw-r--r-- | video/out/gl_video_shaders.glsl | 48 |
1 files changed, 43 insertions, 5 deletions
diff --git a/video/out/gl_video_shaders.glsl b/video/out/gl_video_shaders.glsl index a6ecc2eeeb..196e81e5e3 100644 --- a/video/out/gl_video_shaders.glsl +++ b/video/out/gl_video_shaders.glsl @@ -45,7 +45,7 @@ #if __VERSION__ >= 130 vec3 srgb_compand(vec3 v) { - return mix(v * 12.92, 1.055 * pow(v, vec3(1.0/2.4)) - vec3(0.055), + return mix(v * 12.92, 1.055 * pow(v, vec3(1.0/2.4)) - 0.055, lessThanEqual(vec3(0.0031308), v)); } @@ -54,6 +54,12 @@ vec3 bt2020_expand(vec3 v) return mix(v / 4.5, pow((v + vec3(0.0993))/1.0993, vec3(1/0.45)), lessThanEqual(vec3(0.08145), v)); } + +vec3 bt2020_compand(vec3 v) +{ + return mix(v * 4.5, 1.0993 * pow(v, vec3(0.45)) - vec3(0.0993), + lessThanEqual(vec3(0.0181), v)); +} #endif // Constant matrix for conversion from BT.2020 to sRGB @@ -393,13 +399,30 @@ void main() { #ifdef USE_COLORMATRIX // Conversion from Y'CbCr or other spaces to RGB color = mat3(colormatrix) * color + colormatrix[3]; - color = clamp(color, 0, 1); #endif #ifdef USE_CONV_GAMMA // Post-colormatrix converted gamma correction (eg. for MP_IMGFLAG_XYZ) color = pow(color, vec3(conv_gamma)); #endif -#ifdef USE_LINEAR_LIGHT +#ifdef USE_CONST_LUMA + // Conversion from C'rcY'cC'bc to R'Y'cB' via the BT.2020 CL system: + // C'bc = (B'-Y'c) / 1.9404 | C'bc <= 0 + // = (B'-Y'c) / 1.5816 | C'bc > 0 + // + // C'rc = (R'-Y'c) / 1.7184 | C'rc <= 0 + // = (R'-Y'c) / 0.9936 | C'rc > 0 + // + // as per the BT.2020 specification, table 4. This is a non-linear + // transformation because (constant) luminance receives non-equal + // contributions from the three different channels. + color.br = color.br * mix(vec2(1.5816, 0.9936), vec2(1.9404, 1.7184), + lessThanEqual(color.br, vec2(0))) + color.gg; +#endif +#ifdef USE_COLORMATRIX + // Clamp down here to avoid clipping CbCr details before CONST_LUMA + // has a chance to convert them. + color = clamp(color, 0, 1); +#endif // If we are scaling in linear light (SRGB or 3DLUT option enabled), we // expand our source colors before scaling. This shader currently just // assumes everything uses the BT.2020 12-bit gamma function, since the @@ -407,13 +430,18 @@ void main() { // below the rounding error threshold for both 8-bit and even 10-bit // content. It only makes a difference for 12-bit sources, so it should be // fine to use here. -#ifdef USE_APPROX_GAMMA +#ifdef USE_LINEAR_LIGHT_APPROX // We differentiate between approximate BT.2020 (gamma 1.95) ... color = pow(color, vec3(1.95)); -#else +#endif +#ifdef USE_LINEAR_LIGHT_BT2020 // ... and actual BT.2020 (two-part function) color = bt2020_expand(color); #endif +#ifdef USE_CONST_LUMA + // Calculate the green channel from the expanded RYcB + // The BT.2020 specification says Yc = 0.2627*R + 0.6780*G + 0.0593*B + color.g = (color.g - 0.2627*color.r - 0.0593*color.b)/0.6780; #endif // Image upscaling happens roughly here #ifdef USE_GAMMA_POW @@ -443,6 +471,16 @@ void main() { // Adapt and compand from the linear BT2020 source to the sRGB output color = srgb_compand(clamp(srgb_matrix * color, 0, 1)); #endif + // If none of these options took care of companding again, we have to do + // it manually here for the previously-expanded channels. This again + // comes in two flavours, one for the approximate gamma system and one + // for the actual gamma system. +#ifdef USE_CONST_LUMA_INV_APPROX + color = pow(color, vec3(1/1.95)); +#endif +#ifdef USE_CONST_LUMA_INV_BT2020 + color = bt2020_compand(color); +#endif #ifdef USE_DITHER vec2 dither_pos = gl_FragCoord.xy / dither_size; #ifdef USE_TEMPORAL_DITHER |