This topic documents a feature of Visual Filters and Transitions, which is deprecated as of Windows Internet Explorer 9 and obsolete as of Internet Explorer 10.
Determines whether a temporary buffer is needed when calling a sample for surface read/write methods.
Returns TRUE to indicate that you need to allocate a sample buffer for surface read/write methods when using the IDXARGBReadWritePtr interface.
If the native pixel format of your transform is PMARGB32, you will call methods such as IDXARGBReadWritePtr::PackPremultAndMove to write sample data. If the format of the output surface does not match, a temporary buffer is required by the output methods. The CDXBaseNTo1::NeedDestPMBuff method tests for this condition and informs you if a buffer will need to be allocated or not.