Multiple versions of the same video, with and without chapters

[CalicoSkies]

I've noticed that when ripping some blu-ray discs, MakeMKV shows (and will rip) two different copies of the same video, where one has chapters and the other doesn't. I'm curious why that is, and if they're the same data otherwise?

[Radiocomms237]

When you say "of the same video" are you talking about multiple playlists (.mpls titles) or a mixture of playlists and transport streams (.m2ts titles)?

Transport streams cannot contain chapters, they are mostly used as a segment (or segments) of a playlist (or multiple playlists), although they're also used for simple video content such as Special Features that don't require chapters. If you're ripping a playlist and ripping the only segment contained within that playlist, then of course the video they contain is going to be identical.

MakeMKV typically hides segments that are used in only one playlist, but there are many exceptions to that rule. For example, if the segment contains an additional track which isn't used by the playlist. And, of course, if a segment is used in multiple playlists it's usually displayed in the list too.

On the other hand, if you have multiple playlists that seem to be the same, there is normally something that is different between them, but that can sometimes be near-impossible to spot.

Sometimes playlists are duplicated except have different chapters (the alternate set of chapters may relate to a commentary or PiP track), sometimes they create a separate playlist just for the commentary track alone, sometimes there may be playlists with slightly different subtitle tracks (like English US spelling and English UK spelling) and very frequently Japanese languages seem to get a dedicated playlist (don't ask me why).

The possibilities are almost endless!

Could you provide a more specific example?

[CalicoSkies]

When you say "of the same video" are you talking about multiple playlists (.mpls titles) or a mixture of playlists and transport streams (.m2ts titles)?

Transport streams cannot contain chapters, they are mostly used as a segment (or segments) of a playlist (or multiple playlists), although they're also used for simple video content such as Special Features that don't require chapters. If you're ripping a playlist and ripping the only segment contained within that playlist, then of course the video they contain is going to be identical.

I'm not sure how to tell if they're playlists or m2ts titles, etc, as the list of items on the disc doesn't tell me.. Recently, I bought Star Trek: Strange New Worlds season 2 on 4K, and I had MakeMKV rip everything from each disc. This is an example of disc 1 - It shows 9 items (doesn't specify whether these are playlists, m2ts, etc.), some with chapters and some without; after ripping, I saw that this disc contains 4 episodes; the ones with chapters & the ones without just seem to be duplicates, with the only difference being the chapters:

[Radiocomms237]

If you highlight a title in the left pane (as you have in the picture above) and then look in the right pane, you'll see the "Source file name". If that file name has a .mlps extension then it's a playlist, or if the file name has a .m2ts extension then it's a transport stream.

Also in the right pane you'll see the "Segment map" for the highlighted playlist. The numbers listed in the segment map are the file names of the transport streams (.m2ts files) that particular playlist plays (only with all the leading zeroes removed).

So if the segment map shows only one segment of say "800", then you know that playlist plays the file 00800.m2ts.

If there's three segments listed, say it has a segment map of "31,32,33", then you know that playlist plays files 00031.m2ts, 00032.m2ts & 00033.m2ts in that order.

Now if you highlight one of the transport streams further down the page (let's choose one with an identical file size to the playlist you just looked at), you'll find one with a "Source file name" that matches the content the segment map.

Although, please note that MakeMKV often hides titles if it thinks they're duplicates of another title, typically if a playlist has only one file in its segment map, or if a file is only used in one segment map, then the file itself is usually hidden. The fact that yours aren't must mean there's something within the transport stream that isn't used in the playlist.

[CalicoSkies]

If you highlight a title in the left pane (as you have in the picture above) and then look in the right pane, you'll see the "Source file name". If that file name has a .mlps extension then it's a playlist, or if the file name has a .m2ts extension then it's a transport stream.

Also in the right pane you'll see the "Segment map" for the highlighted playlist. The numbers listed in the segment map are the file names of the transport streams (.m2ts files) that particular playlist plays (only with all the leading zeroes removed).

So if the segment map shows only one segment of say "800", then you know that playlist plays the file 00800.m2ts.

If there's three segments listed, say it has a segment map of "31,32,33", then you know that playlist plays files 00031.m2ts, 00032.m2ts & 00033.m2ts in that order.

Now if you highlight one of the transport streams further down the page (let's choose one with an identical file size to the playlist you just looked at), you'll find one with a "Source file name" that matches the content the segment map.

Although, please note that MakeMKV often hides titles if it thinks they're duplicates of another title, typically if a playlist has only one file in its segment map, or if a file is only used in one segment map, then the file itself is usually hidden. The fact that yours aren't must mean there's something within the transport stream that isn't used in the playlist.

Ah, thanks. I see now, even in the screenshot, the filename is shown in the right pane. I wasn't paying too much attention to that..