[FFmpeg-user] How can I join video files?
pb at das-werkstatt.com
Fri Feb 17 15:58:59 CET 2012
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.
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.
At the Austrian Mediathek (=national audio/video archive), we're
producing several hundred FFv1 encoded minute-sequences per day as
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:
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).
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