X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=gamma_compression_effect.cpp;h=5581fca32c38c14e15fa7905460761a68d271ddb;hb=b912dbaa253ed1f091fd7201efd366c6f3154257;hp=945267ceb5225ecebd616262dd14399ad1e7a4c2;hpb=2ced784c6599cb0b21427481ee17f4c8f6afdada;p=movit

diff --git a/gamma_compression_effect.cpp b/gamma_compression_effect.cpp
index 945267c..5581fca 100644
--- a/gamma_compression_effect.cpp
+++ b/gamma_compression_effect.cpp
@@ -1,4 +1,5 @@
 #include <math.h>
+#include <string.h>
 #include <assert.h>
 
 #include "gamma_compression_effect.h"
@@ -8,6 +9,7 @@ GammaCompressionEffect::GammaCompressionEffect()
 	: destination_curve(GAMMA_LINEAR)
 {
 	register_int("destination_curve", (int *)&destination_curve);
+	memset(compression_curve, 0, sizeof(compression_curve));
 	register_1d_texture("compression_curve_tex", compression_curve, COMPRESSION_CURVE_SIZE);
 }
 
@@ -28,13 +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");