rtmpdump and "no frame" error

[blousefet]

Hi everyone,

I managed to write a perl script to launch rtmpdump perfectly...
It works as a charm and allows me to schedule download for some livestreams.
Typical command would be :
/usr/local/bin/rtmpdump -r rtmpe://rtmpstreamwebsite.com -a typicalApp -f flashVer -W swfUrl --live -C AMFconnectparams -y playpath -o flvfile

Most of the time (say 90%), my downloaded streams are playable through vlc and when not through mplayer which seems more tolerant with errors.
However, sometimes the stream wont be playable at all without a clue of what's wrong in it...
vlc/mplayer/ffmpeg tells me "no frame".

Typical output in that case :
[h264 @ ???] no frame!
Last message repeated 38 times

Sometimes its playable even though but I would get this :
[flv @ ???] Stream discovered after head already parsed
Truncating packet of size 13574511 to 12471295

Now, i test the file by running an ffmpeg -i command which will tell me instantly if the stream will not be playable.

I then launch GetFlv (that I purchased) to download the same stream. The resulting flv is playable with no problem.
I know that rtmpdump dumps the stream as it downloads it ... (or am I wrong ?).
So what's the problem ? is there something I need to do to avoid these streams not to be unplayable ? How can I manage to play corrupted downloaded streams ?

Thanks for help