Hello everyone!
     Now, I am writing a h264 vedio decoder based on mme, and meet some  prolems.
     Firstly,how many input channels and output channels does a   vedio decoder  filter should have.does it include 
audio channels? or I have to write a audio decoder filter for the video media file?      because a viedo media file 
include
audio and video. 
     secondly,I know the nextbuffer function(it is included in mediaoutput) is called to deal with  the video data and 
exchange buffers, but when does the nextbuffer is called? I adding some logs in the nextbuffer function,but it can not 
be called.

    Thanks very much,I am looking forword your reply!