List<float[]> points = new List<float[]>();
        float timeNow; // this should be Time.RealTimeSinceStartup;
        float timeFrame = 8;

        void OnButtonPressed()
        {
            if (points.Count == 0)
            {
                // jump from start to 4 seconds before NOW
                points.Add(new float[] { 0, timeNow - 0.5f * timeFrame});

                // placeholder for the next jump, we know the start, but not the end yet
                points.Add(new float[] { timeNow + 0.5f * timeFrame, float.NegativeInfinity });
            }
            else
            {
                float lastJumpStart = points[points.Count - 1][0];
                float lastJumpEndNew = timeNow - 0.5f * timeFrame;
                float lastJumpEndCurrent = points[points.Count - 1][1];
                if (lastJumpEndNew < lastJumpEndCurrent)
                {
                    points[points.Count - 1][1] = lastJumpEndNew;
                }
                else
                {
                    points[points.Count - 1][1] = lastJumpEndNew;
                    points.Add(new float[] { timeNow + 0.5f * timeFrame, float.NegativeInfinity });
                }
            }
        }

        void ProcessMarks()
        {
            for (int i = 0; i < points.Count; i++)
            {
                if (i == points.Count - 1) // last index need to modify the end of the jump to the end of the video Length
                {
                    points[i][1] = timeNow;
                }

                // just add marks directly to the Intellimark object
            }
        }