The WIA_IPA_BUFFER_SIZE property contains the size of the buffer, in bytes, that is used during a data transfer. The WIA minidriver creates and maintains this property.

Property Type: VT_I4

Valid Values: WIA_PROP_NONE

Access Rights: Read-only


The WIA_IPA_BUFFER_SIZE property is identical to the WIA_IPA_MIN_BUFFER_SIZE property.

An application can read WIA_IPA_BUFFER_SIZE to determine the driver-specified buffer size for data transfers. The WIA service also reads this property to allocate memory for the minidriver during the data transfer.

Note   The value that the WIA_IPA_BUFFER_SIZE property contains is the minimum amount of data that an application can request at any given time. The larger the buffer size, the larger the requests to the device will be. This larger buffer size can make the device seem slow and unresponsive, can slow the overall computer performance, and can consume excessive resources. Buffer sizes that are too small can slow performance of the data transfer by requiring many smaller requests. Choose a reasonable buffer size by considering the typical size of a data request to your device, the number of requests, and the size of those requests.



Optional for Windows Vista drivers for all transfer-enabled items. If you implement this property, applications that are designed for Windows Server 2003, Windows XP, and previous versions of Windows can estimate the transfer buffer size and, therefore, the transfer rate will be optimal.


Wiadef.h (include Wiadef.h)

See also




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