Static (not live stream) MPD with multiple periods: Result video size contains all periods but duration is only first period

[zamroni111]

Static (not live stream) MPD with multiple periods: Result video byte size contains all Periods but duration is only first period

Test case pluto.tv (free from usa, use vpn if needed)
https://pluto.tv/on-demand/movies/5a9da843fb6f2f17481afa96

Each Period.Represetation has unique initialization file.
The init file defines duration of the Period.Represetation.

Pluto.tv use multiple periods for static mpd because they insert ads periods.

N_m3u8DL-RE should do this:
a. merge media segments of each distinct Period.Represetation into a temporary mp4/mkv.
hence, this will respect the distinct init file of Period.Represetation.
result file contains correct duration according to the init file.
b. mux result of step (a) into Period's mkv/mp4.
c. concat all Periods' mp4/mkv files of step (b) into final video file result.

Currently N_m3u8DL-RE results error because N_m3u8DL-RE merges all media segments (of same contenttype) from all periods into a file.
this method ignores the unique init file of Period.Represetation of 2nd and subsequent Periods.