AM_MEDIA_TYPE (Windows CE 5.0)
This structure describes a media sample type.
typedef struct _MediaType{GUID majortype;GUID subtype;BOOL bFixedSizeSamples;BOOL bTemporalCompression;ULONG lSampleSize;GUID formattype;IUnknown* pUnk;ULONG cbFormat;/* [size_is] */ BYTE __RPC_FAR* pbFormat;} AM_MEDIA_TYPE;
Members
majortype
Major type of the media sample.subtype
Subtype of the media sample.bFixedSizeSamples
If TRUE, samples are of a fixed size.bTemporalCompression
If TRUE, samples are compressed.lSampleSize
Size of the sample in bytes.formattype
Registered (GUID) format type.pUnk
Pointer to the IUnknown interface.cbFormat
Size of the format section of the media type.pbFormat
Pointer to the format section of the media type. The layout of this is determined by the format type GUID.Format types include the following.
Format type Structure pointed to FORMAT_MPEGVideo MPEG1VIDEOINFO FORMAT_VideoInfo VIDEOINFOHEADER FORMAT_WaveFormatEx WAVEFORMATEX FORMAT_MPEG2Video MPEG2VIDEOINFO FORMAT_VideoInfo2 VIDEOINFOHEADER2
Remarks
Media Types
In any function that receives an AM_MEDIA_TYPE parameter, always validate the values of cbFormat and formattype before dereferencing the pbFormat member.
The following code is incorrect:
if (pmt->formattype == FORMAT_VideoInfo)
{
VIDEOINFOHEADER *pVIH = (VIDEOINFOHEADER*)pmt->pbFormat;
// **** Wrong! ****
}
The following code is correct:
if ((pmt->formattype == FORMAT_VideoInfo) &&
(pmt->cbFormat > sizeof(VIDEOINFOHEADER) &&
(pbFormat != NULL))
{
VIDEOINFOHEADER *pVIH = (VIDEOINFOHEADER*)pmt->pbFormat;
// Now you can use pVIH.
}
Requirements
DirectShow applications and DirectShow filters have different include file and link library requirements. See Setting Up the Build Environment for more information.
Pocket PC: Windows Mobile 5.0 and later
Smartphone: Windows Mobile 5.0 and later
OS Versions: Windows CE 2.12 and later. Version 2.12 requires DXPAK 1.0 or later.
Header: Dshow.h.
See Also
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