[FFmpeg-user] How can I join video files?
tsinghal18 at gmail.com
Mon Feb 20 17:43:42 CET 2012
Well, I am still in learning stage, but I faced same use case,
The problem is, if the segments are in GB scale and are of different
format, concatenating them by converting into mpg raw video format, is
highly costly business,
According to me command line can look like this -
ffmpeg -i "merge: seg1,seg2,seg3" <transcoding_options> output
"merge" would be a new option introduced
At the back end: We can try to analyze each segment specified in the input
option, and process everything.
step 1: start transcoding seg1 as per <transcoding_option>, and as it get
step2: just start transcoding seg2 and those frames are to be added to
stream being obtained from step1
and go on...
I don't know how that logic will look like, just thought to share what I
On Sun, Feb 19, 2012 at 1:04 AM, Andrey Utkin <
andrey.krieger.utkin at gmail.com> wrote:
> 2012/2/17 Peter B. <pb at das-werkstatt.com>:
> > 2) I agree with you that concat+remux+transcode in one step might be
> > "sugarization", compared to subsequent FFmpeg calls, when you only have
> > 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
> > 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:
> > I know it's a super-rare-extremely-special-and-not-so-everyday usecase,
> > currently I need to use mencoder for this - but would looooove to use
> > (because I think it's better supported).
> Merging video in one pass, when full transcoding is acceptable, is
> possible using API (i mean requires specific application ATM).
> I guess this task can raise timing (and a/v sync) issues when
> transcoding variable-framerate files, like FLV.
> Well, it is often easy to implement app that works on exact type of
> files, and hard to think up how all-purposed app should work. (E.g. i
> have made an app that merges certain FLV h264 videos just by remuxing,
> a lot later i've realized that it's not guaranteed to work).
> But video merging is feature of high demand, i agree ffmpeg should
> have such tool.
> But i think it's easier to make it separate utility. I just wonder how
> can we denote our intention to merge video, how should ffmpeg command
> line look like?
> If you provide samples of your files, you have a chance to get
> supported with such tool from early days, if volunteers appear to put
> efforts on it.
> Andrey Utkin
> ffmpeg-user mailing list
> ffmpeg-user at ffmpeg.org
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