Windows Media Video 9 Screen Decoder
The Windows Media Video 9 Screen decoder decodes streams that were encoded by the Windows Media Video 9 Screen Encoder.
Class Identifier
The class identifier (CLSID) for the Windows Media Video 9 Screen decoder is represented by the constant CLSID_CMSSCDecMediaObject. You can create an instance of the decoder by calling CoCreateInstance.
Input Types
The four-character code (FOURCC) for Windows Media Video Screen Version 9 encoded content is "MSS2".
The following input types are supported by the Version 9 Screen decoder.
- MEDIASUBTYPE_MSS2
Output Types
The following output types are supported by the Version 9 Screen decoder when it is being used as a DirectX Media Object (DMO).
- MEDIASUBTYPE_RGB24
- MEDIASUBTYPE_RGB32
- MEDIASUBTYPE_ARGB32
- MEDIASUBTYPE_RGB565
- MEDIASUBTYPE_RGB555
- MEDIASUBTYPE_RGB8
The following output types are supported by the Version 9 Screen decoder when it is being used as a Media Foundation Transform (MFT).
- MFVideoFormat_RGB24
- MFVideoFormat_RGB32
- MFVideoFormat_ARGB32
- MFVideoFormat_RGB565
- MFVideoFormat_RGB555
- MFVideoFormat_RGB8
Remarks
A screen decoder object exposes the IMediaObject interface so that the object can be used as a DirectX Media Object (DMO), and it exposes the IMFTransform interface so that the object can be used as a Media Foundation Transform (MFT).
A screen decoder behaves as a DMO or an MFT depending on which interfaces you obtain and which version of Windows is running. The following table shows the conditions under which a screen decoder behaves as a DMO or an MFT.
| Operating system | Decoder behavior |
|---|---|
| Windows XP | A Windows Media Screen decoder always behaves as a DMO. |
| Windows Vista and Windows 7 | By default, a Windows Media Screen decoder behaves as a DMO. If you obtain an IMFTransform interface on a screen decoder, it behaves as an MFT. |
You can use the same CLSID (CLSID_CMSSCDecMediaObject) to create the Version 7 Screen decoder and the Version 9 Screen decoder. The FOURCC for Windows Media Video Screen Version 7 encoded content is "MSS1". The Version 7 Screen decoder supports the MEDIASUBTYPE_MSS1 input type.
Requirements
Client |
Windows XP, Windows Vista, or Windows 7 |
Header |
Wmcodecdsp.h |
DLL |
Wmvsdecd.dll |
See Also
Using the Windows Media Video 9 Screen Codec
Windows Media Video 9 Screen Encoder
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Build date: 4/7/2010