When trying to use librtmp as a server I am having trouble getting the initial handshake to succeed. The problem can be seen with the rtmpsrv sample. For example, using ffmpeg as the client with something such as:   ffmpeg  -f lavfi -i testsrc  -f flv rtmp://127.0.0.1/live/instance fails to connect. The rtmpsrv fails with:   $ rtmpsrv   RTMP Server v2.4   (c) 2010 Andrej Stepanchuk, Howard Chu; license: GPL   Streaming on rtmp://0.0.0.0:1935   WARNING: SHandShake: Client not genuine Adobe!   ERROR: Handshake failed   Closing connection... done! Is there something else that is required to satisfy that "genuine Adobe"? ---- ffmpeg version 4.3.6-0+deb11u1 Copyright (c) 2000-2023 the FFmpeg developers built with gcc 10 (Debian 10.2.1-6)