[FFmpeg-user] How can I join video files?

[Peter B.]

Quoting Andrey Utkin <andrey.krieger.utkin at gmail.com>:
> Using recipe mentioned above, if you have video in h264, you mustn't
> re-encode it.

Clear :)

For the sake of completeness, I'd just like to mention 2 things:

1) For codecs which are specified and supported to be wrapped in an  
MPEG-TS stream, this might be possible (such as h264), but for others  
(e.g. FFv1) it's not possible to concat it that way.


2) I agree with you that concat+remux+transcode in one step might be  
"sugarization", compared to subsequent FFmpeg calls, when you only  
have to transcode a handful of files - but with mass transcoding  
(several hundred files per day) of "heavy" stuff (like e.g. FFv1 with  
350-600 MB/Minute), intermediate steps add up runtime-wise.

For example:
At the Austrian Mediathek (=national audio/video archive), we're  
producing several hundred FFv1 encoded minute-sequences per day as  
archive format.

Now, transcoding this archive material into e.g. DVD-MPEG or  
web-videos, they need to be concatenated *and* transcoded.
Intermediately "touching" the harddisk would add a tremendous slowdown  
of this already slow transcoding process (FFv1->MPEG on 3.6Ghz CPU:  
~20-25fps).

I know it's a super-rare-extremely-special-and-not-so-everyday  
usecase, but currently I need to use mencoder for this - but would  
looooove to use FFmpeg (because I think it's better supported).

Regards,
Pb