4GB limit, chunk download, what to use to demux and remux?

[dinkypumpkin]

dinkypumpkin wrote:
> I've used Avidemux to concatenate the trimmed and re-muxed chunks.
> mencoder worked as well, though I had to re-encode the audio. I tried
> concatenating with ffmpeg and mp4box, but I couldn't get the right
> incantations. The splices are a bit rough, but I'm not too bothered

I was being a bit obtuse there.  It is possible to use ffmpeg with 
mp4box, but the only way I found to do it is to de-mux the elementary 
streams with mp4box, concatenate them with ffmpeg, then re-mux the 
concatenated streams with mp4box.  Avidemux was much easier.