Standarts...

>  And , the other question is ,what exectly
>is the difference between "MP4A-LATM" and "mpeg4-generic".

They're different RTP payload formats.  The former is described in 
RFC 3016 (and implemented by us in the "MPEG4LATMAudioRTPSink" and 
"MPEG4LATMAudioRTPSource" classes); the latter is described in RFC 
3640 (and implemented by us in the "MPEG4GenericRTPSink" and 
"MPEG4GenericRTPSource" classes)