[h323plus] enabling DirectShow video input

Simon Horne s.horne at packetizer.com
Thu Oct 28 01:06:08 EDT 2010


The factory loader system was changed recently.
I added this patch for DirectShow2 to load


-----Original Message-----
From: h323plus-bounces at lists.packetizer.com
[mailto:h323plus-bounces at lists.packetizer.com] On Behalf Of Alessandro
Sent: Thursday, October 28, 2010 12:16 PM
To: h323plus at lists.packetizer.com
Subject: Re: [h323plus] enabling DirectShow video input

From: "Simon Horne" <s.horne at packetizer.com>
Date: Wednesday 27 October 2010 21:11

> There are 2 directshow implementations. The original directshow
> (P_DIRECTSHOW) was dependent on DirectSound being present (which 
> sometimes it is not) and the second directshow2 (P_DIRECTSHOW2) did 
> not. DirectShow2 files should be in the distro but may or may not be 
> loaded in the project (vidinput_directx2.h\.cxx)  Check to see in the 
> ptbuildopts.h what has been enabled.

Thanks for your quick reply Simon.

In my case both DirectShow and DirectSound are present and correctly found
in the Windows SDK 7.1 and they are both enabled and compiled without

However, the static initialization code that registers the DirectShow
service is never executed and, apparently, not even loaded in memory, which
suggests that it was stripped by the linker, but I can not see why (since I
can not spot any difference between DirectShow and FakeVideo and the latter
is registered).

> It appears directshow is not loading because the dependency is not 
> present. Try DirectShow2.
> The current PTLIB SVN and H323plus CVS now use DirectShow2 by default.

I will download a more recent snapshot of both libs and try them with


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