ard at p850ug1.demon.co.uk
Wed Mar 14 17:32:09 CDT 2007
> > One trick I found, which I was surprised at, was that you seem to be able to
> > 'cat' several mpeg files together into one and a player will happily play the
> > entirety of the subsequent file. Weird; I mean most formats expect a single
> > header and some data, but mpeg seems to be able to cope just fine with lots of
> > header and data segments.
> But by cat-ing several mpegs together you DO end up with a single header,
> IIRC it's why the cat command exists in the first place, remember that all
> it does is concatenate multiples to a single. A side effect is that you
I'm having great difficulty understanding this.
AFAIK the cat(1) command doesn't have any knowledge of MPEG (or any
other) file format. So it does the same thing with MPEG files that it
does with all other files, namely copy the bytes to stdout.
So if you have files of the form <header><data>, and if you then cat 2 of
them together, surely the output is <header1><data1><header2><data2>. And
not <modified header><data1><data2> or something like that. In other
words catting 2 files will not produce a single header.
What am I missing?
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