On Thu, Jun 19, 2014 at 09:06:22AM +0100, akhiezer wrote:
> 
> A few possibly useful handles:
> --
> * Do the problems exist if you run vlc as root?
> 
root@ac4tv /home/ken #vlc
VLC is not supposed to be run as root. Sorry.
If you need to use real-time priorities and/or privileged TCP ports
you can use vlc-wrapper (make sure it is Set-UID root and
cannot be run by non-trusted users first).

> * Do the problems basically not exist if you use xine for the various 
> tests/tasks?

Correct - provided that /dev/sr0 has a DVD symlink and is writable
by my a group my user is in - I seem to have lost or broken the
workaround I used to use for that [ I do not play DVDs very often ]
> 
> * Have you looked at how other folks build vlc (I kindof guess yes): e.g.:
>     ==
>     http://www.slackware.com/~alien/slackbuilds/vlc/build/vlc.SlackBuild
>     http://www.slackware.com/~alien/slackbuilds/vlc/build/
>     ==

 I haven't looked at those, for the moment - I use BLFS-based
instructions.  I might take a look later, because I've just decided
that I _do_ want to keep vlc : it is a better way of looking at my
work-in-progress movie edits than parole, i.e. scrolling works
reliably, and it is more capable than xine.  Thanks anyway.

 After two days of intermittent banging my head against a keyboard /
googling / cursing, I have now got a process of preparing the
individual clips with ffmpeg to a position where it might be usable.
I do start to wonder if the time might have been better used looking
at python-based video editors (I tried avidemux last week, but the
audio is b0rken for me with alsa, and the python deps for other
editors looked horrendous - details appear to be in gentoo).

 I have now cut a 42.5s .mov clip to exactly 42s, and created a 42s
x264 mp4 video with fade from/to black at the ends (the audio is a
little longer, and ffmpeg cannot fade it), separated the audio to a
wav file and used sox to fade that in/out, and then combined them.

 The obvious combination would be to convert the audio to aac in an
mp4 file, but when I do that the audio becomes 128ms longer than the
video.  I expect to use parhaps 10 clips to make the complete video,
so by the end the sound would be out of sync.

 What I have done for now is to keep the audio as .wav, and called
it a .mkv file because it clearly isn't mp4.  Xine only plays the
video from this.  The benefit of this is that the although even the
video has now grown by 67ms, the audio has only grown by 69ms so the
relative loss of sync is 2ms for this clip.

 Still need to do similar things to at least one other clip (but
I think I now understand the process, and on a good day I can
remember how the ffmpeg options fit together), and prepare at least a
title image, then I will find out if I can successfully convert it
all to mp4 and upload it to youtube : for the moment, I am sort-of
expecting that to fail, in which case I will be in mega-sulk mode in
a few days :-(

ĸen
-- 
Nanny Ogg usually went to bed early. After all, she was an old lady.
Sometimes she went to bed as early as 6 a.m.
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