[wellylug] Linux *.VOB to *.MPG using *.IFO ?

Klaatu klaatu at straightedgelinux.com
Thu May 21 16:31:09 NZST 2015


I have never used the IFO file; is it human-readable or is it binary
encoded that the media players use?

So aside from the IFO issue, I would start with ffmpeg. Unfortunately I
didn't bring any DVDs with me to NZ so I can't test this before sending
it to you, but something like this ought to work:

I'm assuming the chapter breaks do not conveniently fall at the start of
each VOB file, so it makes sense to concatenate all the VOB files first,
whilst also converting them to a generic mpeg file. This should not lose
quality, since we are just demuxing the VOB files into an mpeg stream
(which is what DVD players do when playing the video back to you).

ffmpeg -i "concat:foo.VOB|bar.VOB" -vcodec copy -acodec copy -f mpeg
-threads 4 foobar.mpg


Now you should have a big file called foobar.mpg

You can split these at chapter breaks with the -ss flag to tell ffmpeg
where to start, and the -t flag to tell ffmpeg how long to go for (you
do NOT give it the 'out' point, you give it DURATION. this messes me up
every time I use it.)

ffmpeg -i foobar.mpg -ss 00:00:00 -t 00:25:23 -vcodec copy -acodec copy
-threads 4 foobar_ch1.mpg

ffmpeg -i foobar.mpg -ss 00:25:23 -t 01:03:01 -vcodec copy -acodec copy
-threads 4 foobar_ch2.mpg

and so on. The first example assumes we start at 0 hours, 0 minutes, 0
seconds and play the video until 0 hours 25 minutes and 23 seconds, into
a file called foobar_ch1.mpg.

The second example assumes we pick up where we left off at 25 minutes
and 23 seconds, and play until 1 hour and 3 minutes and 1 second into a
file called foobar_ch2.mpg.

And so on.


CAVEATS:
---------

Your version of ffmpeg may differ from mine, or you may not even be
running ffmpeg. Some time ago, ffmpeg got forked into avconv, which uses
MOSTLY the same syntax and options, but just be aware that some man page
checking might be necessary.

As I said, this is off the top of my head because I don't have VOB files
to test it on. But from memory, that's the way to do it, and it should
work. Another option I could imagine trying is converting to some
lossless codec like huffYUV or FFV1 with FLAC sound, and chopping that
up. But the VOB -> mpg thing should be ok, because VOB is just muxed mpeg...


Hope that helps...?

-klaatu






On 05/21/2015 02:35 PM, Lorraine Offord &Tony Wills wrote:
> Anyone know of a linux program to split a DVD's *.VOB video files into seperate MPGS, one per chapter?  (The chapter boundaries in each *.VOB file are recorded in the DVD's *.IFO files).  This needs to be a extraction process, not a transcoding one, to maintain 100% quality.
> (No copy protection involved, these are files from a DVD camcorder).
> 
> Any pointers would be appreciated :-)
> 
> Tony.
> 
> 
> 
> 



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