VLC rtp streaming confusion

[eurfyl]

I have setup VLC on two separate PCs. One PC has a webcam connected and the VLC is setup to sends the webcam video stream to the VLC client on the other PC. I selected the stream to be RTP but when I use Wireshark/ethereal the stream packets doesn’t appear as RTP. It shows as UDP only. AND why doesn’t it work if I select UDP protocol to stream, instead of RTP? Is it because RTP is a streaming protocol and UDP isn’t? Why don’t I see RTSP setup procedures and SDP etc etc between the two peers. I thought you needed RTSP setup before streaming in RTP so how does this stream server direct show work at all. That’s a few question but can you clear up a little of the above as I’m missing the whole picture on how this works!!

Many thanks…

[compcent]

hello,

i have the same problems to understand that.
Could i stream with vlc in "real" rtp pakets. Its interesting because
i can look up paketloss and jitter of rtp streams with wireshark.

So, does anyone know how to create a real rtp stream like darwin does?

thx

[AlessandroC82]

Try to check this link

http://thud.ethereal.com/lists/ethereal ... 00167.html

I have the same problem: it seems to be given from the version of RTP in VLC.
Ethereal isn't able to read RTP version 0 or 1.

In the VLC documantation I read that the RTP version used is the number 2....so, what do you think?

According to me there is an other problem...but actually I don't know wich

[AlessandroC82]

I use ethereal from a few time so maybe I'm wrong...but,

I stream a movie in localhost and than I analyze the traffic with ethereal:
the total size of the package is 1370 bytes -> 20 bytes of IP header, 1328 bytes of data and the remain is at the begin of the package (Ethernet II header)

I wrote a sniffer with python: if I make a print of the data size, I obtain 1328!!!

Checking with ethereal this 1328 bytes you'll see that is an RTP package version 2 and you'll be able to see the sequence number increasing and the SSRC that remain always the same.

Acually, the unique idea that come up to me is :
when VLC send an RTP package,it encapsulates this package in an other UDP ...it's strange but give sense...

What do you think? Am I totally drunk?

[Rémi Denis-Courmont]

Wireshark does not agressively detects RTP packets. It would probably yield too many false positives. You need to hint it: right-click on the UDP packet, Decode As... and RTP. Voilà.