Qt绘制YUVI420数据并显示,不借用外部库

可以使用Qt的QImage类来绘制YUVI420数据并显示，以下是示例代码：

QImage yuv420p_to_image(unsigned char* yuv420p_data, int width, int height)
{
    QImage image(width, height, QImage::Format_RGB888);

    unsigned char* y_data = yuv420p_data;
    unsigned char* u_data = yuv420p_data + width * height;
    unsigned char* v_data = yuv420p_data + width * height * 5 / 4;

    for (int y = 0; y < height; y++)
    {
        for (int x = 0; x < width; x++)
        {
            int y_value = y_data[y * width + x];
            int u_value = u_data[(y / 2) * (width / 2) + (x / 2)];
            int v_value = v_data[(y / 2) * (width / 2) + (x / 2)];

            int r = y_value + 1.370705 * (v_value - 128);
            int g = y_value - 0.698001 * (v_value - 128) - 0.337633 * (u_value - 128);
            int b = y_value + 1.732446 * (u_value - 128);

            r = qBound(0, r, 255);
            g = qBound(0, g, 255);
            b = qBound(0, b, 255);

            image.setPixel(x, y, qRgb(r, g, b));
        }
    }

    return image;
}

这个函数将YUVI420数据转换为RGB格式的QImage对象，然后可以使用QLabel或QPixmap等Qt控件来显示这个图像。