docs: public static void nv21ToGray(byte[] dataNV, GrayF32 output) {
  
  		//CONCURRENT_BELOW BoofConcurrency.loopFor(0, output.height, y -> {
  		for( int y = 0; y < output.height; y++ ) {
  			int indexIn = y*output.width;
  			int indexOut = output.startIndex + y*output.stride;
  
  			for( int x = 0; x < output.width; x++ ) {
  				output.data[ indexOut++ ] = dataNV[ indexIn++ ] & 0xFF;
  			}
  		}
  		//CONCURRENT_ABOVE });
  	}