The problem is that the filesrc and souphttpsrc are behaving
differently regarding the calculation of the segment boundaries. The
filesrc is using a non-inclusive boundaries, while the souphttpsrc
uses inclusive. Currently the hlsdemux calculates the boundaries as
inclusive, so for this reason there is no problem with the souphttpsrc,
but there is an issue in the filesrc.

The GstSegment is non-inclusive, so the proposed solution is to use
non-inclusive boundaries in the hlsdemux in order to be consistent.
Make the change in the hlsdemux, will break the souphttpsrc, which
will expect inclusive boundaries, but the hlsdemux will offer
non-inclusive. This change makes sure that the non-inclusive
boundaries are converted to inclusive.

https://bugzilla.gnome.org/show_bug.cgi?id=748316