Find motion intervals above threshold

You are processing data from a single security camera. You are given: - A threshold value `T` (a real number). - A vector (array) of time-stamped motion readings. Each reading is a pair `[time, motion_level]`, where: - `time` is a strictly increasing integer timestamp (in seconds), - `motion_level` is a real number. Whenever `motion_level > T`, we consider the camera to be "active". Consecutive active readings form a continuous active interval from the time of the first active reading to the time of the last active reading in that group. Assume: - The input vector is sorted by `time` in strictly increasing order. - If two active readings are adjacent in the array (with no inactive reading between them), they belong to the same active interval, even if there is a time gap between their timestamps. - If a reading is inactive (`motion_level <= T`), it does not belong to any active interval. Return a list of active time intervals `[start_time, end_time]` covering all maximal contiguous segments of readings where `motion_level > T`. Example: - Input: - `readings = [[1, 0.4], [5, 0.2], [11, 0.9], [15, 0.9], [17, 0.8], [25, 0.5], [27, 0.8], [36, 0.9]]` - `T = 0.8` - Output: - `[[11, 17], [27, 36]]` Explanation: - Readings at times 11, 15, 17 have `motion_level > 0.8`, so they form one interval `[11, 17]`. - Readings at times 27 and 36 have `motion_level > 0.8`, forming interval `[27, 36]`. - All other readings have `motion_level <= 0.8` and are ignored. Implement a function that takes the readings and threshold and returns the list of such intervals.