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DMO_MEDIA_TYPE (Compact 2013)

  • Article

3/26/2014

This structure describes the format of the data used by a stream in a DirectX DMO. 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
    A GUID identifying the stream's major media type. This must be one of the DMO Media Types.
  • 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.

Requirements

Header

dmo.h

Library

Dmoguid.lib

See Also

Reference

DMO Structures
AM_MEDIA_TYPE
MPEG1VIDEOINFO
MPEG2VIDEOINFO
VIDEOINFOHEADER
VIDEOINFOHEADER2
WAVEFORMATEX (Waveform Audio)
DirectShow Media Types