2016-11-17



I'm currently converting some rips of video DVDs  to  MP4  files.
It  began with a lot of trial 'n error but now I've achieved good
results.

(The quality value of 24 and VGA  resolution  is  enough  for  my
needs. YMMV.)

The most straight-forward type is this:

     cat VTS_01_[1-9].VOB | avconv -i - -s vga -q 24 -c:v libx264 \
             -c:a libmp3lame -ac 2 -async 25 foo.mp4

It works well if the first audio track is the one I want. If this
is not true, I have to remap it, e.g. like this:

     cat VTS_01_[1-9].VOB | avconv -i - -s vga -q 24 -map 0:v -map 0:a:1 \
             -c:v libx264 -c:a libmp3lame -ac 2 -async 25 foo.mp4

I haven't really understood exactly how this  mapping  works  and
which audio channel is which. Thus each time, I'm just doing some
check: encoding some seconds from within the movie, using the -ss
and -t switches.

Then I had one case in which I created two separate  files,  each
containing a part of the video. I combined them this way:

     MP4Box -cat foo-part1.mp4 -cat foo-part2.mp4 -new foo-all.mp4

In another case, there was bad or no AV-sync.  I  fixed  it  this
way:

     avconv -i foo1.mp4 -async 25 -c copy foo2.mp4




http://marmaro.de/lue/        markus schnalke <meillo@marmaro.de>