The video on DVDs is encoded in the MPEG-2 standard. (Yes, for the pendants in the crowd, it is possible to use MPEG-1, but I'd bet my lunch money that you'll never encounter one in the wild.) Some devices have hardware acceleration for MPEG-2 playback. All modern devices have MPEG-4 hardware acceleration. Having hardware acceleration means a lot of things but, for an iPad, the most pertinent is longer battery life. Mike - You're right: one generally loses the menus and the different playback options of the original DVD by the typical process of converting the ISO file to an MP4 file. For me, that's a bonus: just let the kid watch the movie and not have to wait through all of the extra junk. But, for the same reason, I keep the original ISO file around. Should I really ever want to listen to the director's commentary of Toy Story, I can load up the ISO file and do so. A typical ISO is either 4-ish GB or 8-ish GB. A typical feature movie encoded into MP4 with HandBrake using the iPhone or iPad preset is 1-2 GB. So, it's not that much overhead to keep both around, at least not by the standards of modern hard drives. I don't think you said how many ISO files you have, but you can pick up a 5TB usb external hard drive for $120 at Best Buy which would store over 2500 feature length movies encoded into MP4. So, keeping both the ISO and the MP4 version shouldn't break the bank. Thomas On Fri, Nov 27, 2015 at 1:13 PM, Mike Miller <mbmiller+l at gmail.com> wrote: > On Fri, 27 Nov 2015, Kristopher Browne wrote: > >> Even more useful, the chips in any modern devices have dedicated MP4 >> decoders and will perform better with that on playback and battery. > > > They perform better with an MP4 file than with a DVD ISO? The ISO would > contain VOB files which are some kind of MPEG. Do you have any reference > material about that? > > > Mike > _______________________________________________ > TCLUG Mailing List - Minneapolis/St. Paul, Minnesota > tclug-list at mn-linux.org > http://mailman.mn-linux.org/mailman/listinfo/tclug-list