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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include shared
#define YUV_FORMAT_NV12 0
#define YUV_FORMAT_PLANAR 1
#define YUV_FORMAT_INTERLEAVED 2
#ifdef WR_VERTEX_SHADER
#ifdef WR_FEATURE_TEXTURE_RECT
#define TEX_SIZE(sampler) vec2(1.0)
#else
#define TEX_SIZE(sampler) vec2(textureSize(sampler, 0).xy)
#endif
#define YUV_COLOR_SPACE_REC601 0
#define YUV_COLOR_SPACE_REC709 1
#define YUV_COLOR_SPACE_REC2020 2
#define YUV_COLOR_SPACE_IDENTITY 3
// The constants added to the Y, U and V components are applied in the fragment shader.
// From Rec601:
// [R] [1.1643835616438356, 0.0, 1.5960267857142858 ] [Y - 16]
// [G] = [1.1643835616438358, -0.3917622900949137, -0.8129676472377708 ] x [U - 128]
// [B] [1.1643835616438356, 2.017232142857143, 8.862867620416422e-17] [V - 128]
//
// For the range [0,1] instead of [0,255].
//
// The matrix is stored in column-major.
const mat3 YuvColorMatrixRec601 = mat3(
1.16438, 1.16438, 1.16438,
0.0, -0.39176, 2.01723,
1.59603, -0.81297, 0.0
);
// From Rec709:
// [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]
//
// For the range [0,1] instead of [0,255]:
//
// The matrix is stored in column-major.
const mat3 YuvColorMatrixRec709 = mat3(
1.16438, 1.16438, 1.16438,
0.0 , -0.21325, 2.11240,
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
);
// The matrix is stored in column-major.
// Identity is stored as GBR
const mat3 IdentityColorMatrix = mat3(
0.0 , 1.0, 0.0,
0.0 , 0.0, 1.0,
1.0 , 0.0, 0.0
);
mat3 get_yuv_color_matrix(int color_space) {
if (color_space == YUV_COLOR_SPACE_REC601) {
return YuvColorMatrixRec601;
} else if (color_space == YUV_COLOR_SPACE_REC709) {
return YuvColorMatrixRec709;
} else if (color_space == YUV_COLOR_SPACE_IDENTITY) {
return IdentityColorMatrix;
} else {
return YuvColorMatrixRec2020;
}
}
vec3 get_yuv_offset_vector(int color_space) {
// Float conversion to work around a macOS Intel shader compiler bug
if (float(color_space) == float(YUV_COLOR_SPACE_IDENTITY)) {
return vec3(0.0, 0.0, 0.0);
} else {
return vec3(0.06275, 0.50196, 0.50196);
}
}
void write_uv_rect(
vec2 uv0,
vec2 uv1,
vec2 f,
vec2 texture_size,
out vec2 uv,
out vec4 uv_bounds
) {
uv = mix(uv0, uv1, f);
uv_bounds = vec4(uv0 + vec2(0.5), uv1 - vec2(0.5));
#ifndef WR_FEATURE_TEXTURE_RECT
uv /= texture_size;
uv_bounds /= texture_size.xyxy;
#endif
}
#endif
#ifdef WR_FRAGMENT_SHADER
vec4 sample_yuv(
int format,
mat3 yuv_color_matrix,
vec3 yuv_offset_vector,
float coefficient,
vec3 yuv_layers,
vec2 in_uv_y,
vec2 in_uv_u,
vec2 in_uv_v,
vec4 uv_bounds_y,
vec4 uv_bounds_u,
vec4 uv_bounds_v
) {
vec3 yuv_value;
switch (format) {
case YUV_FORMAT_PLANAR:
{
// The yuv_planar format should have this third texture coordinate.
vec2 uv_y = clamp(in_uv_y, uv_bounds_y.xy, uv_bounds_y.zw);
vec2 uv_u = clamp(in_uv_u, uv_bounds_u.xy, uv_bounds_u.zw);
vec2 uv_v = clamp(in_uv_v, uv_bounds_v.xy, uv_bounds_v.zw);
yuv_value.x = TEX_SAMPLE(sColor0, vec3(uv_y, yuv_layers.x)).r;
yuv_value.y = TEX_SAMPLE(sColor1, vec3(uv_u, yuv_layers.y)).r;
yuv_value.z = TEX_SAMPLE(sColor2, vec3(uv_v, yuv_layers.z)).r;
}
break;
case YUV_FORMAT_NV12:
{
vec2 uv_y = clamp(in_uv_y, uv_bounds_y.xy, uv_bounds_y.zw);
vec2 uv_uv = clamp(in_uv_u, uv_bounds_u.xy, uv_bounds_u.zw);
yuv_value.x = TEX_SAMPLE(sColor0, vec3(uv_y, yuv_layers.x)).r;
yuv_value.yz = TEX_SAMPLE(sColor1, vec3(uv_uv, yuv_layers.y)).rg;
}
break;
case YUV_FORMAT_INTERLEAVED:
{
// "The Y, Cb and Cr color channels within the 422 data are mapped into
// the existing green, blue and red color channels."
// https://www.khronos.org/registry/OpenGL/extensions/APPLE/APPLE_rgb_422.txt
vec2 uv_y = clamp(in_uv_y, uv_bounds_y.xy, uv_bounds_y.zw);
yuv_value = TEX_SAMPLE(sColor0, vec3(uv_y, yuv_layers.x)).gbr;
}
break;
default:
yuv_value = vec3(0.0);
break;
}
// See the YuvColorMatrix definition for an explanation of where the constants come from.
vec3 rgb = yuv_color_matrix * (yuv_value * coefficient - yuv_offset_vector);
vec4 color = vec4(rgb, 1.0);
return color;
}
#endif
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