title: Which YUV format is this? Really YUV420SP?
body: <p>Below is te RGB output of a supposed YUV420SP buffer. No conversion, I' m just displaying the YUV420SP as if it were RGB, just to see some patterns. </p>
  
  <p>The image is in a single <code>unsigned char*</code> buffer of size <code>width*height*3</code>. So if this is indeed YUV420SP, then I should have the Y as a black and white image, and then UV interleaved. I think I should see the Y as a black and white image, but why it repeats 3 times in my image? And should I see anything in the UV part? </p>
  
  <p>Of course I tried to convert this buffer to RGB. I used <a href="https://github.com/andrechen/yuv2rgb/blob/master/yuv2rgb.h#L70" rel="nofollow noreferrer">https://github.com/andrechen/yuv2rgb/blob/master/yuv2rgb.h#L70</a> but I only get a completely black image.</p>
  
  <p><a href="https://i.stack.imgur.com/eaZMc.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/eaZMc.png" alt="enter image description here"></a></p>