[mythtv-users] Does ripping DVDs preserve all the features

Andrew Dodd atd7 at cornell.edu
Thu Jan 15 22:31:56 EST 2004

Quoting Tim Harvey <tharvey at alumni.calpoly.edu>:

> > > What is the format of the DVD menu stuff? You would think you could
> > > leave all of that alone and the DVD player would handle it like it
> does
> > > now but then re-encode the main video stream to mp4. If the player
> can
> > > play mp4 and mp2 does it care? Is some of the DVD menu stuff is
> linked
> > > to the main video file - such as scene selection? If you re-encode
> then
> > > maybe the indexing does not work? I would think you would be able to
> > > rewrite that info if you understood the format.
> > DVD streams are MPEG program streams with additional navigational data
> > added.
> > (The VOB format), which is mainly to allow easier seeking within the
> > stream.
> > 
> > Also, subtitles are multiplexed into the program stream.
> > 
> Is this to say the subtitles are in the VOB file?  I thought so, but I
> haven't been able to get any player to allow me to get to them.  I do
> know that most players can use a separate file that has all the
> subtitles with a timecode reference.  You can download many of these
> subtitle's from websites, and there is ripping software to generate them
> but of course those solutions are additional steps which are a paint.
> If the subtitles are in the VOB, I would love to get them out.  Anyone
> know any details on this?
Check out the dvdauthor package - It has subtitle multiplexers/demultiplexers.

And yes, DVD subtitles are in the VOB.

I'm surprised no Linux DVD players support DVD subtitles...

> > So if you wanted to reencode into MPEG-4, you'd need some sort of
> > container
> > format that supported subtitles, etc.
> > 
> > It's theoretically possible, but not doable at the moment.
> > 
> > If you simply rip the DVD with a decrypter, it will be treated by
> player
> > software identically to the original DVD.
> > 
> > It's also possible to strip out unnecessary features and recompress
> the
> > DVD at a
> > lower bitrate to save disk space.  You can also extract the main movie
> and
> > turn
> > it into a standalone DVD without the menus or anything.  Under
> Windows,
> > DVDShrink is excellent for "movie-only" rips and recompression.
> www.dvdshrink.org isn't responding... is it a stable program?  I've been
> looking for something to convert DVD's to Divx on a windows platform but
> there is so much crappy software out there to filter through I haven't
> found anything that's very useful.
DVDShrink isn't for recompressing DVDs to other formats.  It simply recompresses
MPEG-2 data, and reauthors the DVD as appropriate.  Its primary use is for
getting movies that were released on DVD-9 (> 4.7GB) to fit on a DVD-R, by
stripping stuff out and recompressing until it fits.

Interesting thing is that it somehow does the recompression without completely
decoding and re-encoding the file, because it is FAST.

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