At this moment i see some problems with the rtsp code as used in ffmpeg.

best solution to use rtsp camera’s at the moment is the openRTSP work around:
1. create a pipe ( f.e. mkpipe /tmp/pipes/achterterrein.pipe )
2. change owner of pipe to the user you use for running zoneminder (f.e. chown nobody /tmp/pipes/achterterrein.pipe )
3. use the path to the pipe as input path for the camer, enter camera ip en port number dummy values.
4. start openRTSP to stream video to the pipe

I put my openRTSP commands in the inittab, so they are automatically restarted, check your own camera’s so your buffer is large enough:
g1:3:respawn:/usr/bin/openRTSP -t -b 40000 -v rtsp://x.x.x.x/mpeg4/media.amp > /tmp/pipes/achterterrein.pipe
g2:3:respawn:/usr/bin/openRTSP -t -b 100000 -v rtsp://x.x.x.x/live.sdp > /tmp/pipes/mpeg4.pipe
g3:3:respawn:/usr/bin/openRTSP -t -b 100000 -v rtsp://x.x.x.x/live.sdp > /tmp/pipes/lesruimte.pipe

With this work around I have al my rtsp cameras working like a charm. With openRTSP you can also add username and password  [-u <username> <password>].

camera’s working for me at the moment:
axis 2120,  http://x.x.x.x/mjpg/video.mjpg?resolution=704×576&req_fps=5&.mjpg
axis 2110, http://x.x.x.x/mjpg/video.mjpg?resolution=640×480&req_fps=5&fmt=.mjpg
axis 2100, http://x.x.x.x/mjpg/video.mjpg?resolution=640×480&.mjpg
axis 210,  rtsp://x.x.x.x/mpeg4/media.amp best via openRTSP workaround
Mobotix M1, http://x.x.x.x/cgi-bin/faststream.jpg?.mjpg
Abus T7204 & T7203, rtsp://x.x.x.x/live.sdp best via openRTSP workaround
Sony SNC-M3W, http://x.x.x.x/img/video.asf
AVTECH AVI203 h264 cam, rtsp://x.x.x.x/live/h264 best via openRTSP workaround

Hope this helps
regards,
Gert-Jan