yuv420，yuv420p，yuv420sp，nv12，nv21，I420，YV12概念区别

yuv420有yuv420p和yuv420sp两种。如果不加特别说明，yuv420指的就是yuv420p。而yuv420p又可分为I420与YV12，yuv420sp也可分为NV12和NV21.它们的区别是uv的排列顺序。