Override the CBaseOutput::DecideAllocator Member Function (Windows Embedded CE 6.0)
1/6/2010
The base classes implement CBaseOutputPin::DecideAllocator to let the output pin automatically use the downstream pin's allocator. One of the most common alterations in the derived class is to force the use of an object's own allocator (or one from an upstream filter).
In the DirectShow model, a source filter pushes media samples onto the next filter and requires its own allocator.
For example, if you write a transform-inplace filter and insert it between a source filter and a decompressor filter, the transform filter must present the source filter's allocator to the decompressor. Therefore, you must override the CBaseOutputPin::DecideAllocator member function.