Builds ffmpeg arguments for a whole-selection encode, written directly to MP4.
Used only when the requested range sits inside a single GOP (no keyframe in between),
so this always covers a short span — never the full clip — even for long selections.
Uses a fast input-level seek (-ss before -i) so ffmpeg doesn't have to decode from
the start of a long source file just to reach a cut that starts deep into it, combined
with -copyts so the source's original absolute timestamps survive that seek — the
trim filter graph below then cuts on those same absolute timestamps regardless of
exactly which keyframe the fast seek actually landed on.
Builds ffmpeg arguments for a whole-selection encode, written directly to MP4. Used only when the requested range sits inside a single GOP (no keyframe in between), so this always covers a short span — never the full clip — even for long selections.
Uses a fast input-level seek (
-ssbefore-i) so ffmpeg doesn't have to decode from the start of a long source file just to reach a cut that starts deep into it, combined with-copytsso the source's original absolute timestamps survive that seek — the trim filter graph below then cuts on those same absolute timestamps regardless of exactly which keyframe the fast seek actually landed on.