Recent experiences (COM, DirectShow)

There is always a problem with the release of dshow written in the past two days.

Igraphbuilder-> release () will die in this sentence!

In the first place, I thought it could be a reference count problem. So I looked for it carefully.

The process of searching is always progress and process. This is also because I have figured out the addition and deletion of reference count.

1. If ccomptr <ixxx> pxxx is used, when pxxx = pxxx2, 1 is added to the reference count.

2. If cocreateinterface and QueryInterface are successful, the reference count is increased by 1.

3. If ixxx * pxxx is used, the reference count remains unchanged when pxxx = pxxx2.

4. If the in-process filter is used, when pxxx = new CXXX (), the reference count is not increased, and the value is 0.

In this process, an error is also found, which solves the problem of igraphbuilder-> release,

In the process of writing the filter, make sure that each return location is in the heavy load of cbasefilter: Stop,

You must call return cbasefilter: Stop ()