On Fri, 2011-06-10 at 20:18 +0200, Philipp Überbacher wrote:
> Excerpts from Ralf Mardorf's message of 2011-06-10 19:24:54 +0200:
> > On Fri, 2011-06-10 at 18:57 +0200, Renato wrote:
> > > On Fri, 10 Jun 2011 17:58:46 +0200
> > > Philipp <hollunder@lavabit.com> wrote:
> > >
> > > > Hi,
> > > > sorry for abusing this list for a mostly video editing question, but I
> > > > didn't find a proper list and knew that we have some video people on
> > > > this list.
> > > >
> > > > I'd like to fix some videos that have partially out of sync video and
> > > > audio, meaning that beginning at a certain point in the video the
> > > > audio is suddenly out of sync by a couple of seconds. There's no
> > > > constant change, the delay seems fixed once it's there.
> > > >
> > > > I wonder how to fix such a thing. The files are xvid encoded videos
> > > > and vbr mp3 audio inside avi containers. I thought it should be
> > > > reasonably easy to cut and move the audio (re-encode if unavoidable,
> > > > but I know it's in principle possible without) and put it back in a
> > > > container, but I didn't manage.
> > > >
> > > > Can someone recommend a program/workflow that would allow this?
> > > >
> > > > I tried:
> > > > - Avidemux: seems like actual editing is not what this program was
> > > > written for, couldn't figure it out, but it seems close
> > > >
> > > > - openshot: couldn't figure out how to separate video/audio
> > > >
> > > > - kino: seems to only work with DV-files, apparently takes ages to
> > > > decode the file, doesn't seem to be what I need
> > > >
> > > > - openmovieeditor: I figured it might work by dragging the file to
> > > > both a video and an audio track, but I got extremely garbled audio
> > > > output, no idea what's wrong
> > > >
> > > > - cinelerra-cv: Doesn't start. No error message, it simply shows no
> > > > window, nothing. Well, it does something with the screen, but it
> > > > shows nothing.
> > > >
> > > > - pitivi: Doesn't seem like it can play back the video. I can drag the
> > > > video to the tracks and it starts to draw a waveform, I guess no
> > > > video thumbnails because of: gst.ElementNotFoundError: pngenc
> > > > Doesn't seem to be able to play the video.
> > > >
> > > > - kdenlive: would require me to install 30 additional packages, total
> > > > about 200MB, no thanks.
> > > >
> > > > I thought it would be a simple task, really nothing fancy. Seems like
> > > > I was wrong.
> > > >
> > > > Regards,
> > > > Philipp
> > > >
> > >
> > > Hi, unfortunately can't give you a full solution, but only a hint: in
> > > mplayer with "-" and "+" you can adjust audio/video syncronization by
> > > multiples of 100ms (maybe you cand do finer, but I'm not sure).
> > >
> > > maybe you could then somehow record the output to a new file?
>
> Thanks Renato, I've played with that already and know the approximate
> offsets, but that doesn't help much. I'm not sure screen recorders
> typically can pause and resume, and even then it would be less than
> optimal anyway due to the transcoding of both audio and video.
>
> Also, to clarify, those offsets are constant but only appear beginning
> at a certain point in the file, imaginary example: after 97 Minutes the
> offset is suddenly approximately -9600ms. Hence shifting the offset of
> the whole file doesn't help.
>
> > I don't think so, assumed you can display the video without side effects
> > in a way, that you could 'record your desktop', than you only would be
> > able to record video, but AFAIK not audio.
> > An app like Cinelerra can separate the container's audio and video, but
> > using video apps on Linux can become a PITA ...
> >
> > 21.9 Improving performance
> >
> > For the moment GNU/Linux is not an excellent desktop. It is more
> > of a server. Most of what you will find on modern GNU/Linux
> > distributions are faceless, network-only programs strategically
> > designed to counteract one Microsoft server feature or another
> > and not to perform very well at user interaction. There are a
> > number of parameters on GNU/Linux, which ordinary people can
> > adjust to make it behave more like a thoroughbred in desktop
> > usage.
> > 21.9.1 Disabling swap space
> > 21.9.2 Enlarging sound buffers
> > 21.9.3 Freeing more shared memory
> > 21.9.4 Speeding up the hard drive
> > 21.9.5 Disabling cron
> > 21.9.6 Reducing USB mouse sensitivity
> > 21.9.7 Assorted X tweeks
> > 21.9.8 Speeding up the file system
> > http://cinelerra.org/docs/cinelerra_cv_manual_en.html
> >
> > ... if the app after editing should make a container again, it can
> > happen that the old man became a voice like Mickey Mouse or the
> > beautiful woman is transformed to a Conehead. After 12 hours using all
> > resources of your computer you will know if the video is ok or not. I
> > nearly have forgotten to mention, that it also can happen that audio and
> > video get out of sync during this process ;). YMMV.
> >
> > On my machine Cinelerra always 'worked' OOTB! On Philipp's it doesn't
> > run.
> >
> > Regards,
> >
> > Ralf
>
> Thanks Ralf,
> I had looked at the typical problems but they all mention error messages
> while I get none:
>
> -----
>
> $ cinelerra
> Cinelerra 2.1.5CV GIT::01dc4375a0fb65d10dd95151473d0e195239175f (C)
> 2010 Heroine Virtual Ltd.
> External ffmpeg
> Compiled on Mon Mar 28 20:17:50 UTC 2011
>
> Cinelerra is free software, covered by the GNU General Public License,
> and you are welcome to change it and/or distribute copies of it under
> certain conditions. There is absolutely no warranty for Cinelerra.
>
> -----
>
> That's it, nothing else happens in the console and no visible window
> appears, though an invisible does appear (I can tell from the reaction
> of my window manager, it tiles the invisible window but nothing is
> painted there).
>
> I thought cutting and aligning audio/video on a timeline would be a
> basic operation and possible in every NLVE...
IIRC Quentin Harley http://www.64studio.com/team is an experienced
Cinelerra user, but my memory might be wrong. I know him as very
helpful. Daniel James also is very helpful and author of a book about
Linux multimedia. I guess Robin, who is described to this list could
tell you, if they be free to give information. It might be that they are
too busy at the moment, I don't know, I don't have contact, since the 64
Studio lists are ghost towns at the moment.
AFAIK Windows currently should be a little bit better than Linux (I
don't know, it's just hearsay), regarding to video editing. Only Macs
with professional video equipment seems to be a pleasure (during my jobs
I've seen working gear a long time ago, Sony Betacam + Apple etc.) :(.
But I'm sure with some hints from someone who is experienced with Linux
video, the task you wish to do can be done with Linux. I guess for video
it's similar as for audio, an usual default install won't do it.
Did you test a live CD of a multimedia distro?
I'm sure some people, perhaps Quentin, use Linux successful without
expensive, professional gear for video editing.
Regards,
Ralf
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Received on Sat Jun 11 00:15:02 2011
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