[FFmpeg-user] cannot normalize MP4 from RTMP live recorded stream

[Madovsky]

Hi,

I just recorded some rtmp mp4 live stream from flash media server
and concatenate on the fly the stream with server side function that append
recorded stream to the current one.
once done I can read the stream correctly from flash player
but from other players (like VLC or ffplay) it's absolute crap. size is 
not respected and quality is awful,
more, the concatenate file is not shown.
so I tried to encode with ffmpeg but it says that "concatenated mp4 
files is not supported correctly, patch welcome"
the metadata is not caught by ffmpeg and the quality is still awful, 
even if I use -vcodec copy. sound is OK
the command line I tried is

ffmpeg -i test.mp4 -async 1 -vsync 1 -apad -vpad -acodec libfdk_aac 
-vcodec copy -crf 23 -y output.mp4

I can provide the video sample

thanks

Franck