Microsoft DirectX 8.0 |
Describes the format of the data used by a stream in a Microsoft® DirectX® Media Object (DMO).
Note This structure is identical to the Microsoft® DirectShow® AM_MEDIA_TYPE structure.
Syntax
typedef struct _DMOMediaType { GUID majortype; GUID subtype; BOOL bFixedSizeSamples; BOOL bTemporalCompression; ULONG lSampleSize; GUID formattype; IUnknown *pUnk; ULONG cbFormat; [size_is(cbFormat)] BYTE * pbFormat; } DMO_MEDIA_TYPE;
Members
- majortype
- Major type GUID of the stream.
- subtype
- Subtype GUID of the stream.
- bFixedSizeSamples
- If TRUE, samples are of a fixed size. This field is informational only. For audio, it is generally set to TRUE. For video, it is usually TRUE for uncompressed video and FALSE for compressed video.
- bTemporalCompression
- If TRUE, samples are compressed using temporal (interframe) compression. (A value of TRUE indicates that not all frames are key frames.) This field is informational only.
- lSampleSize
- Size of the sample in bytes. For compressed data, the value can be zero.
- formattype
- GUID specifying the format type. The pbFormat member points to the corresponding format structure. Format types include the following:
Format Type Format Structure FORMAT_None No format type FORMAT_MPEGVideo MPEG1VIDEOINFO FORMAT_MPEG2Video MPEG2VIDEOINFO FORMAT_VideoInfo VIDEOINFOHEADER FORMAT_VideoInfo2 VIDEOINFOHEADER2 FORMAT_WaveFormatEx WAVEFORMATEX - pUnk
- Not used.
- cbFormat
- Size of the format block of the media type.
- pbFormat
- Pointer to the format structure. The structure type is specified by the formattype member. The format structure must be present, unless formattype is GUID_NULL or FORMAT_None.
Remarks
The bFixedSizeSamples, bTemporalCompression, and lSampleSize members are for compatibility with DirectShow. Other DMO clients are not required to use them.