About yuv format

There are generally two categories of YUV formats: packed format and planar format. The former stores the YUV components in the same array,
Usually several adjacent pixels form a macro-pixel; the latter uses three arrays to store the three components of YUV separately, just like
is the same as a three-dimensional plane.

 

Several common yuv formats

1.YUV422 Planar

Here, the Y \ U \ V data is stored separately. For every two horizontal Y sampling points, there is a Cb and a Cr sampling point, as shown below

Definition in ffmpeg PIX_FMT_YUV422P, /// <planar YUV 4: 2: 2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)

Definition in android OMX OMX_COLOR_FormatYUV422Planar // ** YUV422Planar: Three arrays Y, U, V.

 

2. YUV420 Planar

This format is similar to YUV422 Planar, but the sampling of Cb and Cr is reduced to 2: 1 in both horizontal and vertical directions, as shown below

 

Defined in ffmpeg PIX_FMT_YUV420P /// <planar YUV 4: 2: 0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)

Defined in Android OMX OMX_COLOR_FormatYUV420Planar // // UV * YUV420Planar: Three arrays Y, U, V

 

3.YUV422 Semi-Planar ”” ”” ”” ”” ”” ”” ”” ”” Semi ”mean” half ”I understand this half plane pattern

The data volume in this format is the same as that in YUV422 Planar, but U and V are stored alternately, as shown below.

 

No definition found in ffmpeg

android OMX OMX_COLOR_FormatYUV422SemiPlanar ///// YUV422SemiPlanar: Two arrays, one is all Y, the other is U and V

 

4.YUV420 Semi-Planar

The data volume in this format is the same as that in YUV420 Planar, but U and V are stored alternately, as shown below.

Defined in ffmpeg

PIX_FMT_NV12,      ///< planar YUV 4:2:0, 12bpp, 1 plane for Y and 1 plane for the UV components, which are interleaved (first byte U and the following byte V)

Android OMX is defined in OMX_COLOR_FormatYUV420SemiPlanar // YUV420SemiPlanar: Two arrays, one is all Y, the other is U and V

 

5. YUV422 Interleaved Interleaved-Interleaved

The amount of data in this format is the same as that of YUV422 Planar, but Y, U, and V are stored alternately, as shown below. This is packed mode

ffmpeg PIX_FMT_UYVY422 //// packed YUV 4: 2: 2, 16bpp, Cb Y0 Cr Y1

android OMX_OMX_COLOR_FormatCbYCrY // CbYCrY // CbYCrY: Organized as 16bit UYVY (i.e. CbYCrY)

 

 

24bit RGB888-> 16bit RGB565 conversion

 

 24ibt RGB888 R7 R6 R5 R4 R3 R2 R1 R0 G7 G6 G5 G4 G3 G2 G1 G0 B7 B6 B5 B4 B3 B2 B1 B0

 

 16bit RGB656 R7 R6 R5 R4 R3 G7 G6 G5 G4 G3 G2 B7 B6 B5 B4 B3