Microsoft Media Foundation官方文档翻译（19）《Video FOURCCs》

官方英文文档链接：https://docs.microsoft.com/en-us/windows/desktop/medfound/video-fourccs

基于05/31/2018

中间跳过了一些，先把media foundation相关的弄完再视频编码知识

许多视频格式都有对应的 FOURCC 码。FOURCC 码是通过四个 ASCII 字符创建的32位无符号整数。例如 YUY2 的FOURCC 码是 'YUY2'。

已经有了各种 C/C++ 宏，用于在代码中声明 FOURCC 码。例如，Mmsystem.h 中定义的 MAKEFOURCC 宏，Aviriff.h 中的 FCC 宏等等。你也可以通过反转字符顺序来直接定义一个 FOURCC 码。因此，以下的语句是等价的：

syntaxCopy

DWORD fccYUY2 = MAKEFOURCC('Y','U','Y','2');
DWORD fccYUY2 = FCC('YUY2');
DWORD fccYUY2 = '2YUY';  // Declares the FOURCC 'YUY2'.

(上面的例子中，必须反转字节顺序，因为 Windows 使用 little-endian 结构。 'Y' = 0x59, 'U' = 0x55, and '2' = 0x32, so '2YUY' is 0x32595559.)

一些 DirectX Video Acceleration 2.0 APIs 使用 D3DFORMAT 值来描述视频格式。FOURCC 码也可以像下面这样使用：

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D3DFORMAT fmt = (D3DFORMAT)MAKEFOURCC('Y','U','Y','2');
D3DFORMAT fmt = (D3DFORMAT)FCC('YUY2');
D3DFORMAT fmt = D3DFORMAT('2YUY'); // Coerce to D3DFORMAT type.

FOURCC Constants

下面名列出了一些常用的 FOURCC 码

FOURCC value	Description
'H264'	H.264 video.
'I420'	YUV video stored in planar 4:2:0 format.
'IYUV'	YUV video stored in planar 4:2:0 format.
'M4S2'	MPEG-4 part 2 video.
'MP4S'	Microsoft MPEG 4 codec version 3. This codec is no longer supported.
'MP4V'	MPEG-4 part 2 video.
'MPG1'	MPEG-1 video.
'MSS1'	Content encoded with the Windows Media Video 7 screen codec.
'MSS2'	Content encoded with the Windows Media Video 9 screen codec.
'UYVY'	YUV video stored in packed 4:2:2 format. Similar to YUY2 but with different ordering of data.
'WMV1'	Content encoded with the Windows Media Video 7 codec.
'WMV2'	Content encoded with the Windows Media Video 8 codec.
'WMV3'	Content encoded with the Windows Media Video 9 codec.
'WMVA'	Content encoded with the older, obsolete version of the Windows Media Video 9 Advanced Profile codec.
'WMVP'	Content encoded with the Windows Media Video 9.1 Image codec.
'WVC1'	SMPTE 421M ("VC-1"). Content encoded with Windows Media Video 9 Advanced Profile.
'WVP2'	Content encoded with the Windows Media Video 9.1 Image v2 codec.
'YUY2'	YUV video stored in packed 4:2:2 format.
'YV12'	YUV video stored in planar 4:2:0 or 4:1:1 format. Identical to I420/IYUV except that the U and V planes are switched.
'YVU9'	YUV video stored in planar 16:1:1 format.
'YVYU'	YUV video stored in packed 4:2:2 format. Similar to YUY2 but with different ordering of data.