With fix in bug 149969 LO from 7.4.2 can play in loop video from PPTX.
If sample PPTX attachment 181242 [details] is resaved as PPTX, it still plays in loop in LO and MSO.
This bug is about the remaining issue:
1. Sidebar-Animation Effect-Options-Timing-Repeat Until... should be seen as checked on fileopen of original PPTX and after following savings.
2. If sample PPTX is saved as ODP and reopen, it should also play in a loop.
Confirming with Version: 184.108.40.206.alpha0+ / LibreOffice Community
Build ID: a36173359d4614a8935e2f764acadfcf736e091c
CPU threads: 8; OS: Linux 5.19; UI render: default; VCL: gtk3
Locale: en-US (en_US.UTF-8); UI: en-US
(i) Interestingly, when playing in edit mode (via the buttons in the
sidebar when one selects the image on the slide) upon initial loading
indeed the video only plays once - consistent with Timur's item 1. [BUG]
Entering presentation mode afterwards it still repeats infinitely.
(ii) Toggling the "Repeat" button to "on" replay repeats infinitely both
in edit and presentation modes. [OKAY]
(iii) Toggling the "Repeat" button again, to "off" it plays only once in
edit mode [OKAY], yet still infinitely often in presentation mode. [BUG]
(In other words, it appears presentation mode completely ignores the state
of the button?)