forge-steel/default/inc_yuyv.glsl

#ifndef INC_YUYV
#define INC_YUYV

const int YUYV_FOURCC = 1448695129;

// https://en.wikipedia.org/wiki/Y%E2%80%B2UV
const mat3x3 yuyv_to_rgb_bt709 = {
        {
            1,
            1,
            1
        },
        {
            0,
            -0.21482,
            2.12798
        },
        {
            1.28033,
            -0.38059,
            0
        }
    };

vec4 yuyvTex(sampler2D tex, vec2 vUV, int base_width) {
    float w = base_width - 1;
    int x = int(vUV.x * w);

    int xU = x - x % 2;
    int xV = x - x % 2 + 1;

    vec4 tU = texture(tex, vec2(xU / w, 1 - vUV.y));
    vec4 tV = texture(tex, vec2(xV / w, 1 - vUV.y));

    vec3 yuv = vec3(
            x % 2 == 0 ? tU.x : tV.x,
            tU.y - 0.5,
            tV.y - 0.5
        );

    return vec4(yuyv_to_rgb_bt709 * yuv, 1.0);
}

#endif