Overriding the skipping of duplicate files / aspect ratio changes

Everything related to MakeMKV
Post Reply
NewLeeland
Posts: 2
Joined: Thu Dec 29, 2022 9:28 pm

Overriding the skipping of duplicate files / aspect ratio changes

Post by NewLeeland »

Hello,

first off, apologies if this is the wrong sub-forum, but since the question by itself does not strictly concern just DVDs, I thought that the General forum might be the more appropriate place to open this thread. Again, apologies if I am mistaken.

While making a back-up of the "Vanity Fair" (2018) DVD I noticed a curious thing. The first three episodes on disc one were saved in a 4:3 aspect ratio, while the fourth and final on that disc was saved in a 16:9 aspect ratio. The remaining episodes on the second disc were all in the 16:9 format, which was also the one given on the DVD cover. When playing the DVD itself, the 4:3 episodes were correctly shown in the 16:9 aspect ratio.

When accessing the DVD, MKV found 14 titles, among them what I assume to be the four episodes, with each of them being there in triplicate, therefore MKV skipped over those duplicate files. Is it possible that the skipped files could contain files with the correct aspect ratio? And if so, would it be possible to "force" MKV to "unskip" them?

Thanks in advance and apologies again if this question is redundant here. Any additional data/screenshots required I would of course provide.
thetoad
Posts: 233
Joined: Thu Jul 28, 2016 4:18 am

Re: Overriding the skipping of duplicate files / aspect ratio changes

Post by thetoad »

I believe this is the answer:

DVD files have aspect ratio listed in 2 places. in the VOB and in the IFO. In practice, the IFO is the one that the DVD standard says players should use. MakeMKV uses the VOB, not the IFO. Therefore, for badly authored discs (where the VOB has the wrong aspect ratio), MakeMKV will set the MKV metadata with the wrong aspect ratio.

the easiest way to fix it is to open the MKV in mkvtoolnix and edit the aspect ratio setting, setting it to the correct value.

there are many badly authored DVDs out there that has this discrepancy, most people never see it, as the players all get it from the IFO and never look at the VOB for it.

I reported this a long long time ago, I doubt it will be fixed.

viewtopic.php?f=7&t=26960&p=116763#p116763
viewtopic.php?f=7&t=25853
NewLeeland
Posts: 2
Joined: Thu Dec 29, 2022 9:28 pm

Re: Overriding the skipping of duplicate files / aspect ratio changes

Post by NewLeeland »

Thank you for your reply and the detailed explanation! I had indeed used MKV Toolnix to correct the issue. Such subpar work on part of the DVD producer is a pity, but at least there is an easy work-around. Thanks again!
Post Reply