GetMediaType() fn 's Execution in a DShow Filter

About GetMediaType() fn :
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1. I opened the Image File in a GetMediaType() fn of a Temporal Decoder filter.
2. I added this filter to the GraphEdit as follows

Mp4 Video -> Temporal Decoder Filter ->Video Renderer
it is working fine ...
I saved this filter graph in .grf (graph) file.

If I opened the Graph(.grf ) file directly in GraphEdit, it gives error,

Because the GetMediaType() is not called in a filter. So The invalid memory is copied to my filter.

It causes the error in Graphedit while running the graph.

So instead of opening the Graph File,

Open the MP4 File in a graph edit and build the Graph manually every time as follows :


MP4 Video --> Temporal Decoder --> Video Renderer