[M4IF Technotes] mpg4ds32.ax

[Gary Hughes]

From: "Rob Koenen" <rkoenen   intertrust.com>
> Perhaps someone has an answer anyway, but this question is more
> for Microsoft tech support than for the M4IF technotes list.
> 
> > From: Yang, Wei Jian (Wei Jian) [mailto:yangwj   lucent.com]
> > Sent: Monday, October 22, 2023 2:26 AM
> > To: technotes   lists.m4if.org
> > Subject: [M4IF Technotes] mpg4ds32.ax
> > 
> > 
> > hi,all:
> > 
> >    combined with windows media player7, there is a MPEG4 codec named
> > mpg4ds32.ax. Can anyone tell me program interface exposed by 
> > this module?

It is a DirectShow filter, which as someone else already pointed
out is documented in the DirectX8 SDK, freely downloadable from
Microsoft (if you are in MSDN, you already have the SDK). The .ax
extension is a hangover from when it was called ActiveMovie under
the ActiveX umbrella.
DirectShow filters are required to export a number of well known
interfaces to allow applications to build a filter graph to process
media (e.g. connect a file reader to a demultiplexor to a codec to
a video renderer). You can play with this in the GraphEdit utility
(also in the SDK).
You could also look at the sources for something like VirtualDub
(a freeware video processing utility) for a real world example of
how to use these filters.
gary