m2ts files with no AV streams

[x0pht]

I've just noticed that on some bluray discs, there're m2ts files without any audio/video streams. The sizes of the files vary from 20-30ish KB to several MB's. Some show up with a length, some don't.

There's no problem with playback, but I'm just curious what those files are for.

e.g.

General
ID : 0 (0x0)
Complete name : Z:\BDMV\STREAM\00360.m2ts
Format : BDAV
Format/Info : Blu-ray Video
File size : 3.51 MiB
Duration : 1s 530ms
Overall bit rate : 16.8 Mbps
Maximum Overall bit rate : 48.0 Mbps


General
ID : 0 (0x0)
Complete name : Z:\BDMV\STREAM\00352.m2ts
Format : BDAV
Format/Info : Blu-ray Video
File size : 462 KiB
Maximum Overall bit rate : 48.0 Mbps

[nevcairiel]

If i had to guess, it probably contains still images for the menu, or things like that.
Try analyzing them with ffprobe (from ffmpeg) instead of MediaInfo, maybe it'll show you something.

[x0pht]

probably, though I've always thought still images are stored in m2ts as video streams as well. I'll try ffprobe some time later when I have time, I just did a quick search on google, all i could find is ffprobe source files, i'll try to find a compiled executable when i get a chance.

Thanks for the suggestion, nevcairiel.

[rik1138]

Could be the Menu IGs if it's and HDMV disc... The IG is just a bunch of graphics (not still images, but the actual pop-up graphics) that are stored in m2ts format and loaded along with the video of the menu background/feature (which is a separate m2ts). That's the only non A/V Clip I can think of off hand... A text subtitle stream is also a possibility, but probably isn't very common.