qtdemux: edit list segment bound check is buggy

Submitted by Alicia Boya García @ntrrgc

Link to original bug (#794906)

Description

In pull mode (the only mode where complex edit lists are supported), the condition to check if a frame is outside the current edit is:

QTSAMPLE_DTS (stream, sample) >= segment->media_stop

That is wrong because it's comparing DTS with PTS (segment->media_stop). In consequence, often one or two extra frames that are out-of-segment are sent before the new GstSegment.

See the tests introduced in https://bugzilla.gnome.org/show_bug.cgi?id=794902 to see this bug in action.