X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=gamma_compression_effect.cpp;h=5581fca32c38c14e15fa7905460761a68d271ddb;hb=9b95345e8e1dde29991638ed69def0cf187e28de;hp=0f0a2e4c73e031f930a243b9f661de1d830c7702;hpb=6dea8d2a6695a45aa6209425cdcfb4eabf704340;p=movit

diff --git a/gamma_compression_effect.cpp b/gamma_compression_effect.cpp
index 0f0a2e4..5581fca 100644
--- a/gamma_compression_effect.cpp
+++ b/gamma_compression_effect.cpp
@@ -30,13 +30,23 @@ std::string GammaCompressionEffect::output_fragment_shader()
 		invalidate_1d_texture("compression_curve_tex");
 		return read_file("gamma_compression_effect.frag");
 	}
-	if (destination_curve == GAMMA_REC_709) {  // And Rec. 601.
+	if (destination_curve == GAMMA_REC_709 ||  // And Rec. 601, and 10-bit Rec. 2020.
+	    destination_curve == GAMMA_REC_2020_12_BIT) {
+		// Rec. 2020, page 3.
+		float alpha, beta;
+		if (destination_curve == GAMMA_REC_2020_12_BIT) {
+			alpha = 1.0993f;
+			beta = 0.0181f;
+		} else {
+			alpha = 1.099f;
+			beta = 0.018f;
+		}
 		for (unsigned i = 0; i < COMPRESSION_CURVE_SIZE; ++i) {
 			float x = i / (float)(COMPRESSION_CURVE_SIZE - 1);
-			if (x < 0.018f) {
+			if (x < beta) {
 				compression_curve[i] = 4.5f * x;
 			} else {
-				compression_curve[i] = 1.099f * pow(x, 0.45f) - 0.099;
+				compression_curve[i] = alpha * pow(x, 0.45f) - (alpha - 1.0f);
 			}
 		}
 		invalidate_1d_texture("compression_curve_tex");