diff options
Diffstat (limited to 'video/out/gl_video_shaders.glsl')
| -rw-r--r-- | video/out/gl_video_shaders.glsl | 31 |
1 files changed, 13 insertions, 18 deletions
diff --git a/video/out/gl_video_shaders.glsl b/video/out/gl_video_shaders.glsl index 196e81e5e3..37834dc948 100644 --- a/video/out/gl_video_shaders.glsl +++ b/video/out/gl_video_shaders.glsl @@ -62,13 +62,6 @@ vec3 bt2020_compand(vec3 v) } #endif -// Constant matrix for conversion from BT.2020 to sRGB -const mat3 srgb_matrix = mat3( - 1.6604910, -0.1245505, -0.0181508, - -0.5876411, 1.1328999, -0.1005789, - -0.0728499, -0.0083494, 1.1187297 -); - #!section vertex_all #if __VERSION__ < 130 @@ -105,7 +98,9 @@ void main() { #endif #ifdef USE_OSD_CMS_MATRIX // Convert to the right target gamut first (to BT.709 for sRGB, - // and to BT.2020 for 3DLUT). + // and to BT.2020 for 3DLUT). Normal clamping here as perceptually + // accurate colorimetry is probably not worth the performance trade-off + // here. color.rgb = clamp(cms_matrix * color.rgb, 0, 1); #endif #ifdef USE_OSD_3DLUT @@ -113,7 +108,7 @@ void main() { color = vec4(texture3D(lut_3d, color.rgb).rgb, color.a); #endif #ifdef USE_OSD_SRGB - color.rgb = srgb_compand(clamp(srgb_matrix * color.rgb, 0, 1)); + color.rgb = srgb_compand(color.rgb); #endif texcoord = vertex_texcoord; @@ -452,24 +447,24 @@ void main() { // Convert to the right target gamut first (to BT.709 for sRGB, // and to BT.2020 for 3DLUT). color = cms_matrix * color; + + // Clamp to the target gamut. This clamp is needed because the gamma + // functions are not well-defined outside this range, which is related to + // the fact that they're not representable on the target device. + // TODO: Desaturate colorimetrically; this happens automatically for + // 3dlut targets but not for sRGB mode. Not sure if this is a requirement. + color = clamp(color, 0, 1); #endif #ifdef USE_3DLUT // For the 3DLUT we are arbitrarily using 2.4 as input gamma to reduce // the amount of rounding errors, so we pull up to that space first and // then pass it through the 3D texture. - // - // The value is clamped to [0,1] first because the gamma function is not - // well-defined outside it. This should not be a problem because the 3dlut - // is not defined for values outside its boundaries either way, and no - // media can possibly exceed its BT.2020 source gamut either way due to - // that being the biggest taggable color space. This is just to avoid - // numerical quirks like -1e-30 turning into NaN. - color = pow(clamp(color, 0, 1), vec3(1/2.4)); + color = pow(color, vec3(1/2.4)); color = texture3D(lut_3d, color).rgb; #endif #ifdef USE_SRGB // Adapt and compand from the linear BT2020 source to the sRGB output - color = srgb_compand(clamp(srgb_matrix * color, 0, 1)); + color = srgb_compand(color); #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 |