IMediaSample2 Interface (Windows Embedded CE 6.0)

1/6/2010

This interface derives from the IMediaSample interface. It enables you to set and to retrieve sample properties such as start and stop time that are defined in AM_SAMPLE2_PROPERTIES, and sample flags defined in the AM_SAMPLE_PROPERTY_FLAGS structure.

When to Implement

Implement this interface when you implement an allocator that creates media samples. The CMediaSample class in the DirectShow class library implements this interface.

When to Use

Use this interface when you want to retrieve properties from a media sample that are available through this interface and through the IMediaSample interface or if you want to retrieve multiple sample properties in one call.

Not all media samples will support IMediaSample2, so use the IUnknown::QueryInterface method to get a pointer to the sample's IMediaSample2 interface and check for failure.

If an allocator generates samples, then either all of the media samples must support IMediaSample2 or none of them will.

Methods in Vtable Order

The following tables show the methods that appear in the Vtable beneath the standard COM methods inherited from IUnknown.

IMediaSample method	Description
GetPointer	Retrieves a read/write pointer to this buffer's memory.
GetSize	Returns the size, in bytes, of the buffer data area.
GetTime	Retrieves the stream times at which this sample should begin and finish.
SetTime	Sets the stream times at which this sample should begin and finish.
IsSyncPoint	Determines if the beginning of a sample is a synchronization point.
SetSyncPoint	Sets the synchronization point.
IsPreroll	Indicates a preroll property. If TRUE, this sample is for preroll only and should not be displayed.
SetPreroll	Sets the preroll property. If TRUE, this sample is for preroll only and should not be displayed.
GetActualDataLength	Retrieves the data length of the sample.
SetActualDataLength	Sets the data length of the sample.
GetMediaType	Retrieves the media type of the sample.
SetMediaType	Sets the media type of the sample.
IsDiscontinuity	Indicates a discontinuity property. If S_OK is returned, sample is not contiguous with previous sample.
SetDiscontinuity	Sets the discontinuity property. Set to TRUE if sample is new after a seek or dropped sample.
GetMediaTime	Retrieves the media time stamps for the sample.
SetMediaTime	Sets the media time stamps for the sample.

IMediaSample2 method	Description
GetProperties	Retrieves the properties of a media sample.
SetProperties	Sets the properties of a media sample.

Requirements

Windows Embedded CE	Windows CE 2.12 and later
Note	Microsoft DirectShow applications and DirectShow filters have different include file and Library requirements For more information, see Setting Up the Build Environment

See Also

Reference

DirectShow Interfaces