why can't I open a rtp stream with vlc

[malespy]

Hi,friends:
i am a new guy here,i have a trouble in open a video rtp stream with vlc:
if i use this way to open a rtp: rtp://@IP:8090/,
the vlc will tell me:
"rtp info: A valid SDP is needed to parse this RTP stream.
main error: cannot pre fill buffer" in message box
and"SDP required:
A description in SDP format is required to receive the RTP stream. Note that rtp:// URIs cannot work with dynamic RTP payload format (96)." in error box.

and if i use this way: i first open a sdp file with vlc, then i start the rtp stream,but there is not any response of vlc.

i have heard that vlc can open a rtp stream only by opening a sdp file first,if it is true,why i can't open a rtp in the second way? And who to open a rtp correctly?

can you help me? thanks !

[Rémi Denis-Courmont]

The SDP does not match the stream.

[malespy]

thank you for your answer, but the SDP file is generated by ffmpeg automaticly ,shall i modify it by myself?

[Rémi Denis-Courmont]

Well either the SDP is wrong, or the version of live555 in your VLC installation is broken. Either way, it won't fix itself.

[zst82]

Can anyone work it out？I also face this problem.

[tabestmaker]

me too it's that i was having this problem for long time altough i cannot find any resonable explanation for that