Microsoft DirectShow 9.0


This topic applies only to Windows XP Service Pack 1 or later.

The SetBackingFileCount method sets the maximum and minimum number of backing files.


  HRESULT SetBackingFileCount(
  DWORD  dwMin,
  DWORD  dwMax



[in]  Specifies the backing file minimum. The valid range is from 4 to 100.


[in]  Specifies the backing file maximum. The valid range is from 6 to 102, and the value must be at least 2 greater than dwMin.

Return Values

Returns an HRESULT. Possible values include those in the following table.

Value Description
E_UNEXPECTED The StreamBufferConfig object was not initialized.
S_OK The method succeeded.


If the reader lags behind the writer by more than dwMin files, the writer starts to send STREAMBUFFER_EC_CONTENT_BECOMING_STALE events. If the reader lags behind the writer by more than dwMax files, the writer begins to overwrite files and sends an STREAMBUFFER_EC_STALE_FILE_DELETED event.

Before calling this method, call IStreamBufferInitialize::SetHKEY to specify a registry key where the information will be stored.


Header: Include Sbe.h.

See Also