Files
oak-editor/app/shaders/yuv2rgb.frag
T

64 lines
1.6 KiB
GLSL

uniform sampler2D y_channel;
uniform sampler2D u_channel;
uniform sampler2D v_channel;
uniform int bits_per_pixel;
uniform bool full_range;
uniform float yuv_crv;
uniform float yuv_cgu;
uniform float yuv_cgv;
uniform float yuv_cbu;
in vec2 ove_texcoord;
out vec4 frag_color;
void main()
{
// Sample YUV planes
vec3 yuv;
yuv.r = texture(y_channel, ove_texcoord).r;
yuv.g = texture(u_channel, ove_texcoord).r;
yuv.b = texture(v_channel, ove_texcoord).r;
// Pixels will have come in aligned to 16-bit regardless of their actual bit depth, so they must
// be scaled as if they were actually 16-bit
if (bits_per_pixel == 8) {
// Convert 0.0-1.0 to -0.5-0.5
yuv.gb -= (128.0/255.0);
} else if (bits_per_pixel == 10) {
// Scale from 10-bit to 16-bit
yuv *= (65535.0/1023.0);
// Convert 0.0-1.0 to -0.5-0.5
yuv.gb -= (512.0/1023.0);
} else if (bits_per_pixel == 12) {
// Scale from 12-bit to 16-bit
yuv *= (65535.0/4095.0);
// Convert 0.0-1.0 to -0.5-0.5
yuv.gb -= (2048.0/4095.0);
}
// Convert YUV limited range from 16-235 to 0-255
yuv.r -= 0.0625; // 16/256
yuv.r *= 1.1643; // 255/219
// Use coefficients to weigh YUV into RGB
vec4 rgba;
rgba.r = yuv.r + yuv_crv * yuv.b;
rgba.g = yuv.r - yuv_cgu * yuv.g - yuv_cgv * yuv.b;
rgba.b = yuv.r + yuv_cbu * yuv.g;
// If the expected value is full range, transform to full range here
if (full_range) {
rgba.rgb /= 1.1643;
rgba.rgb += 0.0625;
}
// Currently this shader is only used for RGB textures, so just set alpha to 1
rgba.a = 1.0;
frag_color = rgba;
}