RTSP is simply a flow channel that includes only information about the flow and lack of data. you can use it as a βtunnelβ for data streams (for example, RTP). you can use RTSP as tcp connection to support your udp stream. therefore, the necessary data cannot be lost.
Here is a simple example of server-client interaction between RTSP: Streaming video with RTSP and RTP . in this exercise there is only the basics of connection (connection), and this application is for Java, so you need to change it a little.
For more information about the RTSP connection and the sdp file, check RFC2326 - RTSP and RFC4566 - SDP
to transfer data from your Android device, see this stream: Creating RTP packets from an Android camera to send
EDIT:
found this great project example for streaming RTP: SpyDroid
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