YUV 4:1:1

In this format, each group of four pixels is represented by eight bytes, with one U and one V for every four Y values. This format represents one byte per line, with U and V values across the high-order nibble of the low-order byte in each word. The low-order nibble of each word's low-order byte is a don't care, or zero (see Figure 7).

Figure 7. YUV 4:1:1 pixel format.