Hi,
I've read carefully the announce :
What's new in Avidemux 2.6.0:
September 11th, 2012
Deal with time and not assume constant framerate. You can now edit your .ts and keep a/v sync
But it seems that Avidemux 2.6.8 doesn't keep embedded subtitles (that's incidentally how french digital TV (TNT) works) while working on TS files (see in french https://linuxfr.org/users/mac_is_mac/journaux/comment-recuperer-les-sous-titres-d-un-enregistrement-de-la-tnt-mini-tuto and specially https://linuxfr.org/nodes/101851/comments/1532478).
Thanks
Correct me, but as far as I am aware embedded subtitles are ignored at all regardless of the input format until now.
Correct: Subtitles are dropped/disregarded when copying/editing with avidemux.
You need to extract somehow subtitles before editing. Save these to ssa format and edit these separate in subtitle editor. And join these afterwards in avidemux. I've still not found a workable solution for doing so.