[Libav-user] RTMP duration

[gga]

I am implementing network playback and currently I started with RTMP.  
The playback works fine.  However, I am missing the duration of the 
stream and thus, I cannot set the timeline appropiately.  I was 
wondering if there's a way to obtain the duration of the stream, as the 
ffmpeg server seems like it tries to set it or so it says in some of its 
messages:

frame= 3477 fps= 24 q=-1.0 size=  169512kB time=00:02:25.96 
bitrate=9513.8kbits
[flv @ 0x561b202d3b80] Failed to update header with correct duration.
[flv @ 0x561b202d3b80] Failed to update header with correct filesize.
frame= 3504 fps= 24 q=-1.0 Lsize=  169970kB time=00:02:26.12 
bitrate=9528.9kbits/s speed=   1x
video:167569kB audio:2227kB subtitle:0kB other streams:0kB global 
headers:0kB muxing overhead: 0.102230%

Ideally, I would like to obtain the duration at connection time.