[Delta] PsiMedia testing

[Justin Karneges]

PsiMedia is considered ready for testing.  This does not mean it is RC 
quality, but I'm at the point where I'm interested in feedback before 
proceeding much further.

Please try the demo app:

  svn checkout https://delta.affinix.com/svn/trunk/psimedia
  cd psimedia
  qmake
  make

There is no configure script yet.  Paths to GStreamer and related dependencies 
are hardcoded in gstprovider/gstprovider.pri, which you may need to adjust.  
You need gstreamer 0.10, gst-plugins-base, gst-plugins-good, gst-plugins-bad, 
gst-ffmpeg, and whatever they depend on in turn.

After building, the demo app should be available in the 'demo' subdirectory.

How to use the demo app:

First, configure devices and modes.  Go to "File -> Configure Audio/Video" to 
do this.  Unless you have multiple devices of the same type, the defaults 
should be good.  If you don't have input devices, you can use a file instead.  
You can leave the modes as-is, but you may enjoy toying with them later.

The demo app offers sending and receiving as distinct operations.  You can 
just send or just receive, or do both at once.

How to send:
- In the Send box, press 'Start'.  This won't cause any sending just yet; it 
merely prepares the process.  If you have video input, you should see it 
previewing.  The 'Codec config' field will be given a value.  Copy and paste 
this one-line config string and give it to whoever will be receiving.
- Fill out IP address, audio base port, and video base port of where to send 
to, and press Transmit to begin actually sending.

How to receive:
- In the Receive box, fill out the audio and video base ports to listen on, 
plus the codec config string (obtained from the sender), and press 'Start'.

The reason the ports are called "base ports" rather than simply "ports" is 
because two ports are used for each base port specified.  For example, if an 
audio base port is specified as 60000, then both UDP ports 60000 and 60001 
are used for audio.

Testing is as easy as having the demo transmit over loopback to itself, but 
much more interesting would be transmitting over a network.

Open issues:
 - Looping files may not work.
 - Recording doesn't work.
 - RTCP is not used yet (traffic over baseport + 1).

-Justin