Differences between yuv420 (i420) and yv12, and between yuv420p and yuv420

Yuv420, i420 meaning: each pixel 12bit or expressed as iyuv, a special representation of digital cameras.
It should be noted that, although yv12 is also (), yv12 and i420 are different, and there are some differences in the storage space. Yv12: brightness (row x column) + V (row x column/4) + U (row x column/4) yuv420: brightness (row x column) + U (row x column/4) + V (row x column/4), we can see that yv12 and i420 are basically the same, that is, the order of UV is different.
From: http://baike.baidu.com/view/708133.htm
Appendix: The callback data type of haikang device is yv12, and that of Dahua device is yuv420.
The differences between yuv420p and yuv420 differ in storage formats.
Yuv420p: yyyyyyyy UUUU vvvvv
Yuv420: YUV

Differences between yuv420 (i420) and yv12, and between yuv420p and yuv420