[FFmpeg-user] Make FFMPEG ignore 0 kb frames

[Marco]

I've been recording some flv streams using RTMPDump and one of the problems 
I've encountered is that with live streams it tends to start the timestamp
of the next instance of a stream right after the previous one. 

So for instance if the first instance of a stream went from 0 to 30 minutes
the next instance of the stream's video would start at 30:01.

So I'm trying to convert the files in FFMPEG and the problem I'm 
encountering is that if I just convert the files as is it takes forever 
and I end up with a video that has all the blank time before the video starts. 

Now I can tell FFMPEG to simply start at the point where the video starts but
that would mean that for every video I convert I would have to figure that 
out. 

What I'm hoping is that there would be someway for me to tell FFMPEG to simply
skip any frames that have 0 kb of video which would hopefully in turn cut out
the blank parts of the video.

If anyone could point me in the right direction of doing something like this 
or has some other suggestions as to a way to rectify my problem I would 
appreciate it.