Bug 1493898 - P1. Add preliminary BT2020 colorspace support. r=mattwoodrow

Only active with webrender and AL.

Differential Revision: https://phabricator.services.mozilla.com/D25342

--HG--
extra : moz-landing-system : lando

gfx/layers/ImageTypes.h

@@ -104,6 +104,7 @@ enum class StereoMode {
 enum class YUVColorSpace {
   BT601,
   BT709,
+  BT2020,
   // This represents the unknown format.
   UNKNOWN,
 };

gfx/thebes/gfxUtils.cpp

@@ -1095,6 +1095,10 @@ const float kBT709NarrowYCbCrToRGB_RowMajor[16] = {
     1.16438f,  0.00000f, 1.79274f, -0.97295f, 1.16438f, -0.21325f,
     -0.53291f, 0.30148f, 1.16438f, 2.11240f,  0.00000f, -1.13340f,
     0.00000f,  0.00000f, 0.00000f, 1.00000f};
+const float kBT2020NarrowYCbCrToRGB_RowMajor[16] = {
+    1.16438f,  0.00000f, 1.67867f, -0.91569f, 1.16438f, -0.18733f,
+    -0.65042f, 0.34746f, 1.16438f, 2.14177f,  0.00000f, -1.14815f,
+    0.00000f,  0.00000f, 0.00000f, 1.00000f};
 
 /* static */ const float* gfxUtils::YuvToRgbMatrix4x3RowMajor(
     YUVColorSpace aYUVColorSpace) {
@@ -1103,6 +1107,7 @@ const float kBT709NarrowYCbCrToRGB_RowMajor[16] = {
 
   static const float rec601[12] = X(kBT601NarrowYCbCrToRGB_RowMajor);
   static const float rec709[12] = X(kBT709NarrowYCbCrToRGB_RowMajor);
+  static const float rec2020[12] = X(kBT2020NarrowYCbCrToRGB_RowMajor);
 
 #undef X
 
@@ -1111,6 +1116,8 @@ const float kBT709NarrowYCbCrToRGB_RowMajor[16] = {
       return rec601;
     case YUVColorSpace::BT709:
       return rec709;
+    case YUVColorSpace::BT2020:
+      return rec2020;
     default:  // YUVColorSpace::UNKNOWN
       MOZ_ASSERT(false, "unknown aYUVColorSpace");
       return rec601;
@@ -1124,6 +1131,7 @@ const float kBT709NarrowYCbCrToRGB_RowMajor[16] = {
 
   static const float rec601[9] = X(kBT601NarrowYCbCrToRGB_RowMajor);
   static const float rec709[9] = X(kBT709NarrowYCbCrToRGB_RowMajor);
+  static const float rec2020[9] = X(kBT2020NarrowYCbCrToRGB_RowMajor);
 
 #undef X
 
@@ -1132,6 +1140,8 @@ const float kBT709NarrowYCbCrToRGB_RowMajor[16] = {
       return rec601;
     case YUVColorSpace::BT709:
       return rec709;
+    case YUVColorSpace::BT2020:
+      return rec2020;
     default:  // YUVColorSpace::UNKNOWN
       MOZ_ASSERT(false, "unknown aYUVColorSpace");
       return rec601;
@@ -1148,6 +1158,7 @@ const float kBT709NarrowYCbCrToRGB_RowMajor[16] = {
 
   static const float rec601[16] = X(kBT601NarrowYCbCrToRGB_RowMajor);
   static const float rec709[16] = X(kBT709NarrowYCbCrToRGB_RowMajor);
+  static const float rec2020[16] = X(kBT2020NarrowYCbCrToRGB_RowMajor);
 
 #undef X
 
@@ -1156,6 +1167,8 @@ const float kBT709NarrowYCbCrToRGB_RowMajor[16] = {
       return rec601;
     case YUVColorSpace::BT709:
       return rec709;
+    case YUVColorSpace::BT2020:
+      return rec2020;
     default:  // YUVColorSpace::UNKNOWN
       MOZ_ASSERT(false, "unknown aYUVColorSpace");
       return rec601;

gfx/webrender_bindings/WebRenderTypes.h

@@ -878,6 +878,8 @@ static inline wr::WrYuvColorSpace ToWrYuvColorSpace(
       return wr::WrYuvColorSpace::Rec601;
     case YUVColorSpace::BT709:
       return wr::WrYuvColorSpace::Rec709;
+    case YUVColorSpace::BT2020:
+      return wr::WrYuvColorSpace::Rec2020;
     default:
       MOZ_ASSERT_UNREACHABLE("Tried to convert invalid YUVColorSpace.");
   }

gfx/wr/webrender/res/brush_yuv_image.glsl

@@ -13,6 +13,7 @@
 
 #define YUV_COLOR_SPACE_REC601 0
 #define YUV_COLOR_SPACE_REC709 1
+#define YUV_COLOR_SPACE_REC2020 2
 
 #define YUV_FORMAT_NV12 0
 #define YUV_FORMAT_PLANAR 1
@@ -59,7 +60,7 @@ const mat3 YuvColorMatrixRec601 = mat3(
 );
 
 // From Rec709:
-// [R]   [1.1643835616438356,  4.2781193979771426e-17, 1.7927410714285714]   [Y -  16]
+// [R]   [1.1643835616438356,  0.0,                    1.7927410714285714]   [Y -  16]
 // [G] = [1.1643835616438358, -0.21324861427372963,   -0.532909328559444 ] x [U - 128]
 // [B]   [1.1643835616438356,  2.1124017857142854,     0.0               ]   [V - 128]
 //
@@ -72,6 +73,20 @@ const mat3 YuvColorMatrixRec709 = mat3(
     1.79274, -0.53291,  0.0
 );
 
+// From Re2020:
+// [R]   [1.16438356164384,  0.0,                    1.678674107142860 ]   [Y -  16]
+// [G] = [1.16438356164384, -0.187326104219343,     -0.650424318505057 ] x [U - 128]
+// [B]   [1.16438356164384,  2.14177232142857,       0.0               ]   [V - 128]
+//
+// For the range [0,1] instead of [0,255]:
+//
+// The matrix is stored in column-major.
+const mat3 YuvColorMatrixRec2020 = mat3(
+    1.16438356164384 ,  1.164383561643840,  1.16438356164384,
+    0.0              , -0.187326104219343,  2.14177232142857,
+    1.67867410714286 , -0.650424318505057,  0.0
+);
+
 void write_uv_rect(
     int resource_id,
     vec2 f,
@@ -124,8 +139,10 @@ void brush_vs(
 
     if (prim.color_space == YUV_COLOR_SPACE_REC601) {
       vYuvColorMatrix = YuvColorMatrixRec601;
-    } else {
+    } else if (prim.color_space == YUV_COLOR_SPACE_REC709) {
       vYuvColorMatrix = YuvColorMatrixRec709;
+    } else {
+      vYuvColorMatrix = YuvColorMatrixRec2020;
     }
     vFormat = prim.yuv_format;
 

gfx/wr/webrender_api/src/display_item.rs

@@ -805,6 +805,7 @@ pub struct YuvImageDisplayItem {
 pub enum YuvColorSpace {
     Rec601 = 0,
     Rec709 = 1,
+    Rec2020 = 2,
 }
 
 #[derive(Clone, Copy, Debug, Deserialize, Eq, Hash, PartialEq, Serialize)]