Function yuyv_to_bgr

rustcv-camera/src/decode.rs:160–191

Convert YUYV (YUV 4:2:2) packed data to BGR24. 将 YUYV（YUV 4:2:2）打包数据转换为 BGR24。 Uses BT.601 standard with integer arithmetic (no floating point). 使用 BT.601 标准的整数运算（无浮点）。 Each 4-byte YUYV macro-pixel `[Y0, U, Y1, V]` produces 2 BGR pixels (6 bytes). 每 4 字节的 YUYV 宏像素 `[Y0, U, Y1, V]` 产生 2 个 BGR 像素（6 字节）。 Integer approximation of the BT.601 conversion: BT.601 转换的整数近似： ```text R = (298*(Y-16) + 409*

(src: &[u8], dst: &mut [u8], width: usize, height: usize)

/// B = (298*(Y-16) + 516*(U-128) + 128) >> 8
/// ```
pub fn yuyv_to_bgr(src: &[u8], dst: &mut [u8], width: usize, height: usize) {
    let pixel_pairs = width * height / 2;
    let src_needed = pixel_pairs * 4;
    let dst_needed = pixel_pairs * 6;

    if src.len() < src_needed || dst.len() < dst_needed {
        return;
    }

    for i in 0..pixel_pairs {
        let si = i * 4;
        let di = i * 6;

        let y0 = src[si] as i32;
        let u = src[si + 1] as i32 - 128;
        let y1 = src[si + 2] as i32;
        let v = src[si + 3] as i32 - 128;

        let c0 = y0 - 16;
        let c1 = y1 - 16;

        // Pixel 0: BGR
        dst[di] = clamp((298 * c0 + 516 * u + 128) >> 8); // B
        dst[di + 1] = clamp((298 * c0 - 100 * u - 208 * v + 128) >> 8); // G
        dst[di + 2] = clamp((298 * c0 + 409 * v + 128) >> 8); // R

        // Pixel 1: BGR
        dst[di + 3] = clamp((298 * c1 + 516 * u + 128) >> 8); // B
        dst[di + 4] = clamp((298 * c1 - 100 * u - 208 * v + 128) >> 8); // G
        dst[di + 5] = clamp((298 * c1 + 409 * v + 128) >> 8); // R
    }
}

// ─── BGRA32 → BGR24 ─────────────────────────────────────────────────────────