Question about the MakeMKV FAQ

[israfelli]

The FAQ says:

"Unlike DVD, on Blu-ray, each subtitle item has an attribute that specified whether particular subtitle appearance should be forced."

Well, Handbrake searches for forced subtitles in DVDs as well. So obviously DVDs can have forced subs as well as BluRays. What's the difference...what do they mean by "unlike DVD"?

Thanks,
Dave

[Icanseestars]

Forced subs on DVD's can be messy over the years I've seen it does various ways, the point I think is that Blu-ray's are more strict on how forced subs are done.

[Romansh]

Forced subs on DVD's can be messy over the years I've seen it does various ways, the point I think is that Blu-ray's are more strict on how forced subs are done.

Perhaps they're more often authored the same way, but on both Blu-ray and DVD, I've seen the following 3 cases:

- a full subtitle track where some of the items are flagged as forced (e.g. on Blu-ray: Avatar, Alien)

- a separate subtitle track containing the forced subtitles, where all items are flagged as forced (e.g. on Blu-ray: Star Wars, Mission Impossible - Ghost Protocol)

- a separate subtitle track containing the forced subtitles, where none of them items are flagged as forced (e.g. on Blu-ray: Jurassic Park trilogy)

I can't think of any DVD examples right now.

As for adding a checkbox and forced-only extraction for DVD subtitles in MakeMKV, it should be simple enough. Forced DVD subtitles have a "forced start display" command (0x00) instead of the regular "start display" command (0x01). I'm assuming MakeMKV already has some sort of DVD subtitle parser, since it sets the stop time (usually signaled by a "stop display" command and the associated date/timestamp) at the MKV container level, IIRC.