[Live-devel] RTP Unicast of ADTS AAC file

[Ross Finlayson]

>I have written a simple program to stream an ADTS AAC file that I
>extracted from an MPEG-4 file using mp4create -extract.  I based my test
>program off of ADTSAudioFileServerMediaSubsession and
>ADTSAudioFileSource.  When I open the stream with VLC on my remote pc,
>it connects but does not decode any audio.  One of the things that I am
>unsure of is the payloadFormatCode to use, I guessed 14 (mpa).  What
>else am I missing here?

You're missing the fact that the static payload type 14 is used for 
MPEG-1 or 2 audio *only*.  AAC audio must use a dynamic payload type 
(with the actual RTP media type designated by a "a=rtpmap:" line in 
the SDP description.

If you had actually used "ADTSAudioFileServerMediaSubsession" instead 
of just 'basing' your code on this, you probably would not have had 
this problem :-)

And yes, if you want VLC to play your stream, you're going to have to 
give VLC a SDP description.  The easiest way to do this is to use 
RTSP.  Don't fight this - our code lets you easily add a built-in 
RTSP server to your streaming server application, so you should just 
do this.
-- 

Ross Finlayson
Live Networks, Inc.
http://www.live555.com/