Blu-ray subtitles on multi-file playlists

[PurpleMan]

Hello,

Some BD movies are branched across multiple m2ts files.

I was wondering if there's any way to add subtitles to these kind of titles?

I wrote a small program to split the SRT file to multiple files that match the durations of the various m2ts's (according to the playlist), and I've created a SUP file for each m2ts.

The thing is, after muxed, if a subtitle is too close to the beginning of the m2ts or the ending of it, it just won't show. For example, if there's a subtitle that spreads around two m2ts's in a way that it shows until the end of 00001.m2ts and at 00:00:00,00 of 00002.m2ts, it won't show neither at the ending of the former or the beginning of the latter.

What's the magic trick to accomplish this?

Thanks.
-PurpleMan

[rik1138]

Not sure exactly how you are muxing the m2ts files, but you can have subtitles 'overlap' m2ts boundaries like that... You can't guarantee that the subtitle in question won't flicker briefly over the 'gap', but other than that issue, it should work fine. Sub on the first m2ts ends with the same end time as the m2ts itself, and then for the second m2ts it just starts at the first frame. Make sure a single subtitle event isn't actually trying to go past the duration of the m2ts file, that'll probably create an error.

Normally, when creating subtitles for a title that has multiple m2ts files, an attempt is made to avoid subtitles overlapping the boundary just to make life easier (and to ensure no flickering of subtitles, studios don't like that much...)

But, at the very least, the sub should display at the end of the first m2ts... Possibly the muxing tool you are using thinks the sub is too close to the end (or beginning) of the file, and is just dropping it completely?

[PurpleMan]

Thanks for your reply. I know that it should work, however- try to create the following SRT file:


1
00:00:00,000 --> 00:00:05,000
Hello World


and mux it to any existing m2ts using tsMuxer in Blu-ray output mode. I guarentee it won't play using any player you wish.

[rik1138]

If this is the first piece (or only piece) of video, you should make it a second after the start of video. If a player can't display the subtitle on the frame it's supposed to, it will just skip it. I don't think any player would be able to show a subtitle that starts at the very first frame of video since it takes at least some number of microseconds to read in the subtitle and decode it into the video stream.

If this is a 2nd (or later) piece of video on a PlayList (especially a seamless PlayList), then the player can at least 'see that it's coming and get it ready', so to speak...

I've never put a subtitle on the first frame of the first piece of video in a PlayList...

It could be a tsMuxer thing too... Never know. I've only ever used Scenarist for anything that had subtitles...