[FFmpeg-user] Extracting forced subtitles from a DVD.

[Michael Mueck]

Thanks for responding Nicolas.

> On 2022.0428, at 14:01, Nicolas George <george at nsup.org> wrote:
> 
> Michael Mueck via ffmpeg-user (12022-04-28):
>> I have decrypted and ripped all of my DVDs into individual VIDEO_TS
>> structures for just the main movie or an individual TV episode. Each
>> move or TV episode consists of a VIDEO_TS folder containing the
>> original uncompressed
>> 	VIDEO_TS.IFO,  VTS_01_0.IFO  and  VTS_01_[1->N].VOB  files.
> 
> This is already wrong. The VOB files do not map directly to the video
> parts of the contents. If you do that, you will get also all the menu
> crap in your resulting file.

The ripping software that I used dealt with that i.e. all the VOB files are categorically only for the main movie (or a given episode) and there are no menus at all. Notice that all my VOB files reference the same stream and the 1->N part is just the sequentially numbered sequence of 1GB files.

> Also, the subtitles palette is not in the VOB files.

Agreed, but for now I'm focusing on just getting the forced subtitles working right.

> You can generate a concat script to access the DVD hierarchy correctly
> using the dvd2concat script in the tools directory.
> 
> It is entirely possible that doing so would fix your issue.

do I still need to do this given the above response? (I'll look into dvd2concat after sending this email).

> Also, do not re-encode the subtitles, use -c copy, it will be more
> reliable.

I'm not sure how I latched onto the dvdsub codec, but I did just now try "copy" and I get the same good result when using an MKV as the input. However I get a curiously different result when using the VOB input with the "copy" subtitle codec - instead of an empty subtitle track I now get full-time English subtitles but the subtitle track is for stream 7 instead of stream 6! Stream 6 was the regular English subtitle track (that contained embedded forced subtitles) and Stream 7 is the English SDH subtitle track. That's weird!

Slightly off-topic: Is it really true that ffmpeg can't handle a standard DVD file structure (especially if everything is decrypted)?

> 
> Regards,
> 
> -- 
>  Nicolas George