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This class represents a buffer object that supports the IMediaSampleinterface. It represents a buffer in memory, together with some associated properties stored as protected data members.
The constructor is passed as a pointer to the buffer with its length in bytes; other properties are normally set and accessed through implemented IMediaSampleinterface methods. These properties describe various attributes of the media sample, such as the sample's media type, start and end time, and options. The options can include whether the media sample is a sync point, a preroll sample, or discontinuous with other samples.
All member functions in this class that return HRESULTand accept a pointer as a parameter return E_POINTER when passed a null pointer.
Protected Data Members
| m_cbBuffer | Size of the buffer. |
| m_dwFlags | Sample property flags as follows: |
| Sample_Discontinuity: Set if start of a new segment. | |
| Sample_MediaTimeValid: Set if the media time is valid. | |
| Sample_Preroll: Set if sample is a preroll sample. | |
| Sample_StopValid: Set if the stop time is valid. | |
| Sample_SyncPoint: Set if sample is a synchronization point. | |
| Sample_TimeValid: Set if the time is valid. | |
| Sample_TypeChanged: Set if the type has changed. | |
| m_End | Sample end time. |
| m_lActual | Actual length of data in this sample. |
| m_MediaEnd | Media end (offset from m_MediaStart). |
| m_MediaStart | Media start position. |
| m_pAllocator | Pointer to the IMemAllocatorobject associated with this object. |
| m_pBuffer | Pointer to the complete buffer. |
| m_pMediaType | Pointer to a structure containing the media type of the sample. |
| m_pNext | Pointer to the next CMediaSampleobject in the free list. |
| m_Start | Sample start time. |
Member Functions
| CMediaSample | Constructs a CMediaSample object. |
| SetPointer | Sets the buffer pointer and length. |
Implemented IUnknown Methods
| QueryInterface | Retrieves pointers to supported interfaces. |
| AddRef | Increments the reference count. |
| Release | Decrements the reference count. |
Implemented IMediaSample Methods
| GetActualDataLength | Retrieves the data length of the sample. |
| GetMediaTime | Retrieves the media time extents of the sample. |
| GetMediaType | Retrieves the media type of the CMediaSample object. |
| GetPointer | Retrieves a read/write pointer to the memory of this buffer. |
| GetSize | Returns the size, in bytes, of the buffer data area. |
| GetTime | Sets the media time extents for this sample. |
| IsDiscontinuity | Determines if there is discontinuity in the data stream. |
| IsPreroll | Indicates a preroll property. If TRUE, this sample is for preroll only and should not be displayed. |
| IsSyncPoint | Determines if the beginning of a sample is a synchronization point. |
| SetActualDataLength | Sets the data length of the sample. |
| SetDiscontinuity | Sets the discontinuity property. |
| SetMediaTime | Sets the media time of the CMediaSample object. |
| SetMediaType | Sets the media type of the CMediaSample object. |
| SetPreroll | Sets preroll property. If TRUE, this sample is for preroll only and should not be displayed. |
| SetSyncPoint | Sets sync-point property. |
| SetTime | Sets the stream time at which this sample should start and finish. |
Implemented INonDelegatingUnknown Methods
| NonDelegatingQueryInterface | Passes out pointers to any interfaces added to the derived filter class. |