[Live-devel] Port to Pocket PC 2003 and GSM encoding

[Ross Finlayson]

>Is the xxxSink the receiver and xxxSource sender?

See <http://www.live.com/liveMedia/faq.html#control-flow>

>Then I am confused that there is a class
>GSMAudioRTPSink, does it mean it is just a virtual
>class?

No, it's a real (not virtual) class.  It's used to send - within outgoing 
RTP packets - GSM audio data that *already exists*.

As I noted earlier, there are no classes within the "LIVE.COM Streaming 
Media" code that encode PCM audio data into GSM, or decode GSM audio data 
into PCM.

>Do you mean that they are all wrapper classes which is
>just for simplifying constructing RTP packet?

Yes.  All of the "*RTPSink" classes take data that *has already been 
encoded*, and packs them into outgoing RTP packets.

>And if no Codec is supplied, any one you suggest to
>use? Which codecs are actually the compatible ones you
>have tested work with your RTP stack?

I don't have any specific recommendation for GSM codecs, but if you find 
one, you should be able to use it with the LIVE.COM code (by writing a new 
class - e.g., based on "DeviceSource" - that encapsulates it).

>And how about the Demos under the testProgs directory,
>are they really runnable?

Yes, because they use audio and/or video files  (e.g., ".mp3", ".mpg") that 
already exist.  They do not do any actual encoding or decoding.


	Ross Finlayson
	LIVE.COM
	<http://www.live.com/>