"DirectShow Development Guide" study notes

This book should be studied eight years ago, this is a wasting time tragedy. I hope you study well and take notes .

The first chapter of the DirectShow Development Guide covers the following key points:

(1) DirectShow composition

I would like to point out two points: one is the filter manager, that is, the filter Graph Manager, which is a filter container, responsible for creating, destroying all filters, followed by the filter is divided into three categories, Source filter,transform filter, Render Filter. This can be determined based on whether they both have an input pin or an output pin.

(2) The concept and use of COM components

Any interface inherits from IUnkown, which is the main three functions: Queryinterfaces, Addref,release.

Chapter II Filter Principle:

(1) Filter Registration

(2) Filter Media type Am_media_type:

Divided into three parts: Major type (main type), Subtype (auxiliary description type), formattype (Format detail description type).

(3) Filter Connection:

First step: Filter Graph Manager on the output pin up ' Ipinbase::connect (ipin* precivepin,const am_media_type* PMT).

Second step: If the output pin accepts the connection, the input ipin is called on Ipin::receiveconnect.

Step three: If the input pin also accepts this connection, the connection succeeds.

(4)

"DirectShow Development Guide" study notes