图像原始格式(YUV444 YUV422 YUV420)一探究竟

前段时间搞x264编码测试，传参的时候需要告诉编码器我的原始数据格式是什么，其中在x264.h头文件中定义了如下一堆类型。

/* Colorspace type */
#define X264_CSP_MASK           0x00ff  /* */
#define X264_CSP_NONE           0x0000  /* Invalid mode     */
#define X264_CSP_I400           0x0001  /* monochrome 4:0:0 */
#define X264_CSP_I420           0x0002  /* yuv 4:2:0 planar */
#define X264_CSP_YV12           0x0003  /* yvu 4:2:0 planar */
#define X264_CSP_NV12           0x0004  /* yuv 4:2:0, with one y plane and one packed u+v */
#define X264_CSP_NV21           0x0005  /* yuv 4:2:0, with one y plane and one packed v+u */
#define X264_CSP_I422           0x0006  /* yuv 4:2:2 planar */
#define X264_CSP_YV16           0x0007  /* yvu 4:2:2 planar */
#define X264_CSP_NV16           0x0008  /* yuv 4:2:2, with one y plane and one packed u+v */
#define X264_CSP_YUYV           0x0009  /* yuyv 4:2:2 packed */
#define X264_CSP_UYVY           0x000a  /* uyvy 4:2:2 packed */
#define X264_CSP_V210           0x000b  /* 10-bit yuv 4:2:2 packed in 32 */
#define X264_CSP_I444           0x000c  /* yuv 4:4:4 planar */
#define X264_CSP_YV24           0x000d  /* yvu 4:4:4 planar */
#define X264_CSP_BGR            0x000e  /* packed bgr 24bits */
#define X264_CSP_BGRA           0x000f  /* packed bgr 32bits */
#define X264_CSP_RGB            0x0010  /* packed rgb 24bits */
#define X264_CSP_MAX            0x0011  /* end of list */
#define X264_CSP_VFLIP          0x1000  /* the csp is vertically flipped */
#define X264_CSP_HIGH_DEPTH     0x2000  /* the csp has a depth of 16 bits per pixel component */