Libavcodec video frame rate Mpeg4

See more:

C++

video

Greetings,
I'm using FFmpegs libavcodec (c/c++) to receive video streams.
Code:

av_register_all();

     avcodec_register_all(); //-X777 not needed if av_register_all() called

     ///////////////////////////////////////////////////-[Network]
     avformat_network_init();

     ///////////////////////////////////////////////////-[Devices]
     avdevice_register_all();

//-zz open file or rtsp or udp
     if ( avformat_open_input( &ifcx, sFileInput, NULL, NULL) != 0 )
     {
       printf( "[A012] Cannot open input %s\n", sFileInput );

       return 1;
     }

Question: when the above method runs "avformat_open_input", I see, console output:

[rtsp @ 005816a0] SDP:
v=0
o=- 1389961517857208 1389961517857219 IN IP4 10.156.13.244
s=Media Presentation
e=NONE
c=IN IP4 0.0.0.0
b=AS:1500
t=0 0
a=control:*
a=range:npt=now-
a=mpeg4-iod: "data:application/mpeg4-iod;base64,AoDUAE8BAf/3AQOAbwABQFBkYXRhOmFwcGxpY2F0aW9uL21wZWc0LW9kLWF1O2
Jhc2U2NCxBUjBCR3dVZkF4Y0F5U1FBWlFRTklCRUVrK0FBRnVOZ0FCYmpZQVlCQkE9PQQNAQUABAAAAAAAAAAAAAYJAQAAAAAAAAAAAzoAAkA2
ZGF0YTphcHBsaWNhdGlvbi9tcGVnNC1iaWZzLWF1O2Jhc2U2NCx3QkFTWVFTSVVFVUZQd0E9BBICDQAAAgAAAAAAAAAABQMAAEAGCQEAAAAAAA
AAAA=="
a=isma-compliance:1,1.0,1
m=video 0 RTP/AVP 96
b=AS:1500
a=framerate:30.0

Notice that that last line I've posted reads "a=framerate:30.0 and that's what I'd like to capture. Although there are other methods in the libavcodec and libavformat that retrieves the frame rate, it is wrong (ex. 100 fps)
I need to get the above console output "a-framerate:30.0

Any ideas ? Thanks ahead !