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4/8/2010

This structure contains the allocator's count, size, alignment, and prefix properties.

Syntax 

typedef struct _AllocatorProperties {
  long 
cBuffers;
  long 
cbBuffer;
  long 
cbAlign;
  long 
cbPrefix;
} ALLOCATOR_PROPERTIES;

Members

cBuffers

Count of buffers at this allocator.

cbBuffer

Size of each buffer in bytes, excluding any prefix.

cbAlign

Alignment of the buffer; buffer start will be aligned on a multiple of this value.

cbPrefix

Each buffer is preceded by a prefix of this many bytes.

Remarks

The CMediaSample::GetPointermember function points to the beginning of the buffer, not including the prefix bytes designated by cbPrefix.

The alignment is applied to the prefix data, if any. If a nonzero prefix is used, the beginning of the prefix is aligned according to cbAlign.

Since the buffer pointer returned by IMediaSample::GetPointerpoints to the area immediately following the prefix, the cbPrefixaddress (the value returned by IMediaSample::GetPointerminus cbPrefix) should be aligned on an address that is a multiple of cbAlignbytes.

Requirements

Header dshow.h
Windows Embedded CE Windows CE 2.12 and later
Windows Mobile Pocket PC for Windows Mobile Version 5.0 and later, Smartphone for Windows Mobile Version 5.0 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,
Version 2.12 requires DXPAK 1.0 or later

See Also