Problem with file .sdp

[VirMarGu]

I know my question has been raised in the past, but none of the answers have helped me solve my problem.
I'm developing a video application for Android. I need a video streaming server for what I use VLC.

I have to use the RTSP network protocol. so I need a sdp file and video transmission using RTP.

I followed the following steps:
1. "Media - Stream"
2. "File" and give the "Add" button. Select the file and"open".
3. Next.
4. In the "Source" says the path where the video is located.
5. In "Destination" as I want to generate a file. "sdp", I select "File", "Add" and I put a name, such as "stream.sdp" (without quotes).
6. I give the + symbol and select a new destination.
In this case I choose RTP and "Add". Then, I complete the IP and port. For example, IP :138.4.33.108 and Port:5004
7. Then where it says "Options transcoding" , I select codecs.
8. "Next"
9. For "Generated stream output string" I get the following message:
:sout=#transcode{vcodec=h264,vb=0,scale=0,acodec=mpga,ab=128,channels=2,samplerate=44100}:duplicate{dst=file{dst=stream.mp4},dst=rtp{dst=138.4.33.108,port=5004,mux=ts,ttl=1}} :sout-keep

I see that I changed the file extension .sdp and has been .mp4 automatically.

10. Finally, I give "Stream"

The problem is that the file .sdp is not generated never and even sometimes a file .mp4 is generated. How can I do it?

Please, I need help!
Thanks!

[Rémi Denis-Courmont]

RTSP carries the SDP in the protocol during setup phase. There is no need for a separate file.

[VirMarGu]

What path I have to write after I add RTSP in "Destinations" tab? Please, an example.
I'd put the following path: /stream

In client application, I put the following URL to play this video: rtsp://138.4.33.108:5004/stream.sdp

What mistakes am I making?