Using WMASFWriter in a DirectShow filter graph generates a video which pauses at each keyframe interval

[Andrew Dodman]

Hello all,

I am attempting to create a DirectShow source filter based on the
pushsource example from the DirectShow SDK. My source filter
essentially outputs a set of bitmaps, each of which typically lasts
around 600 milliseconds, to a video. I have set up a filter graph
which uses Async_reader with a Wave Parser for audio and my new filter
to push the video (the filter is a CSourceStream and I populate my
frames in the FillBuffer function). These are both connected to a
WMASFWriter to output a WMV.

What I am finding is that at times corresponding the keyframe interval
the video pauses for a second or two. This seems to be worse at HD
resolutions, thought that could be a red herring. What kinds of things
might be causing this? Is it related to how often I allow FillBuffer
to be called (my frame rate is 30fps, so I end up with the same bitmap
being repeated for several frames)?

Many thanks,
Andrew

[Andrew Dodman]

See http://stackoverflow.com/questions/9078739/using-wmasfwriter-generates-a-video-which-pauses-at-each-keyframe-interval.